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linux/fs/btrfs/inode.c
Christoph Hellwig cbfce4c7fb btrfs: optimize the logical to physical mapping for zoned writes 
The current code to store the final logical to physical mapping for a
zone append write in the extent tree is rather inefficient.  It first has
to split the ordered extent so that there is one ordered extent per bio,
so that it can look up the ordered extent on I/O completion in
btrfs_record_physical_zoned and store the physical LBA returned by the
block driver in the ordered extent.

btrfs_rewrite_logical_zoned then has to do a lookup in the chunk tree to
see what physical address the logical address for this bio / ordered
extent is mapped to, and then rewrite it in the extent tree.

To optimize this process, we can store the physical address assigned in
the chunk tree to the original logical address and a pointer to
btrfs_ordered_sum structure the in the btrfs_bio structure, and then use
this information to rewrite the logical address in the btrfs_ordered_sum
structure directly at I/O completion time in btrfs_record_physical_zoned.
btrfs_rewrite_logical_zoned then simply updates the logical address in
the extent tree and the ordered_extent itself.

The code in btrfs_rewrite_logical_zoned now runs for all data I/O
completions in zoned file systems, which is fine as there is no remapping
to do for non-append writes to conventional zones or for relocation, and
the overhead for quickly breaking out of the loop is very low.

Because zoned file systems now need the ordered_sums structure to
record the actual write location returned by zone append, allocate dummy
structures without the csum array for them when the I/O doesn't use
checksums, and free them when completing the ordered_extent.

Note that the btrfs_bio doesn't grow as the new field are places into
a union that is so far not used for data writes and has plenty of space
left in it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19 13:59:32 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <crypto/hash.h>
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/blk-cgroup.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/writeback.h>
#include <linux/compat.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/btrfs.h>
#include <linux/blkdev.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include <linux/magic.h>
#include <linux/iversion.h>
#include <linux/swap.h>
#include <linux/migrate.h>
#include <linux/sched/mm.h>
#include <linux/iomap.h>
#include <asm/unaligned.h>
#include <linux/fsverity.h>
#include "misc.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "ordered-data.h"
#include "xattr.h"
#include "tree-log.h"
#include "bio.h"
#include "compression.h"
#include "locking.h"
#include "free-space-cache.h"
#include "props.h"
#include "qgroup.h"
#include "delalloc-space.h"
#include "block-group.h"
#include "space-info.h"
#include "zoned.h"
#include "subpage.h"
#include "inode-item.h"
#include "fs.h"
#include "accessors.h"
#include "extent-tree.h"
#include "root-tree.h"
#include "defrag.h"
#include "dir-item.h"
#include "file-item.h"
#include "uuid-tree.h"
#include "ioctl.h"
#include "file.h"
#include "acl.h"
#include "relocation.h"
#include "verity.h"
#include "super.h"
#include "orphan.h"
#include "backref.h"
struct btrfs_iget_args {
u64 ino;
struct btrfs_root *root;
};
struct btrfs_dio_data {
ssize_t submitted;
struct extent_changeset *data_reserved;
struct btrfs_ordered_extent *ordered;
bool data_space_reserved;
bool nocow_done;
};
struct btrfs_dio_private {
/* Range of I/O */
u64 file_offset;
u32 bytes;
/* This must be last */
struct btrfs_bio bbio;
};
static struct bio_set btrfs_dio_bioset;
struct btrfs_rename_ctx {
/* Output field. Stores the index number of the old directory entry. */
u64 index;
};
/*
* Used by data_reloc_print_warning_inode() to pass needed info for filename
* resolution and output of error message.
*/
struct data_reloc_warn {
struct btrfs_path path;
struct btrfs_fs_info *fs_info;
u64 extent_item_size;
u64 logical;
int mirror_num;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
static const struct address_space_operations btrfs_aops;
static const struct file_operations btrfs_dir_file_operations;
static struct kmem_cache *btrfs_inode_cachep;
static int btrfs_setsize(struct inode *inode, struct iattr *attr);
static int btrfs_truncate(struct btrfs_inode *inode, bool skip_writeback);
static noinline int cow_file_range(struct btrfs_inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock,
u64 *done_offset);
static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
u64 len, u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type);
static int data_reloc_print_warning_inode(u64 inum, u64 offset, u64 num_bytes,
u64 root, void *warn_ctx)
{
struct data_reloc_warn *warn = warn_ctx;
struct btrfs_fs_info *fs_info = warn->fs_info;
struct extent_buffer *eb;
struct btrfs_inode_item *inode_item;
struct inode_fs_paths *ipath = NULL;
struct btrfs_root *local_root;
struct btrfs_key key;
unsigned int nofs_flag;
u32 nlink;
int ret;
local_root = btrfs_get_fs_root(fs_info, root, true);
if (IS_ERR(local_root)) {
ret = PTR_ERR(local_root);
goto err;
}
/* This makes the path point to (inum INODE_ITEM ioff). */
key.objectid = inum;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, local_root, &key, &warn->path, 0, 0);
if (ret) {
btrfs_put_root(local_root);
btrfs_release_path(&warn->path);
goto err;
}
eb = warn->path.nodes[0];
inode_item = btrfs_item_ptr(eb, warn->path.slots[0], struct btrfs_inode_item);
nlink = btrfs_inode_nlink(eb, inode_item);
btrfs_release_path(&warn->path);
nofs_flag = memalloc_nofs_save();
ipath = init_ipath(4096, local_root, &warn->path);
memalloc_nofs_restore(nofs_flag);
if (IS_ERR(ipath)) {
btrfs_put_root(local_root);
ret = PTR_ERR(ipath);
ipath = NULL;
/*
* -ENOMEM, not a critical error, just output an generic error
* without filename.
*/
btrfs_warn(fs_info,
"checksum error at logical %llu mirror %u root %llu, inode %llu offset %llu",
warn->logical, warn->mirror_num, root, inum, offset);
return ret;
}
ret = paths_from_inode(inum, ipath);
if (ret < 0)
goto err;
/*
* We deliberately ignore the bit ipath might have been too small to
* hold all of the paths here
*/
for (int i = 0; i < ipath->fspath->elem_cnt; i++) {
btrfs_warn(fs_info,
"checksum error at logical %llu mirror %u root %llu inode %llu offset %llu length %u links %u (path: %s)",
warn->logical, warn->mirror_num, root, inum, offset,
fs_info->sectorsize, nlink,
(char *)(unsigned long)ipath->fspath->val[i]);
}
btrfs_put_root(local_root);
free_ipath(ipath);
return 0;
err:
btrfs_warn(fs_info,
"checksum error at logical %llu mirror %u root %llu inode %llu offset %llu, path resolving failed with ret=%d",
warn->logical, warn->mirror_num, root, inum, offset, ret);
free_ipath(ipath);
return ret;
}
/*
* Do extra user-friendly error output (e.g. lookup all the affected files).
*
* Return true if we succeeded doing the backref lookup.
* Return false if such lookup failed, and has to fallback to the old error message.
*/
static void print_data_reloc_error(const struct btrfs_inode *inode, u64 file_off,
const u8 *csum, const u8 *csum_expected,
int mirror_num)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_path path = { 0 };
struct btrfs_key found_key = { 0 };
struct extent_buffer *eb;
struct btrfs_extent_item *ei;
const u32 csum_size = fs_info->csum_size;
u64 logical;
u64 flags;
u32 item_size;
int ret;
mutex_lock(&fs_info->reloc_mutex);
logical = btrfs_get_reloc_bg_bytenr(fs_info);
mutex_unlock(&fs_info->reloc_mutex);
if (logical == U64_MAX) {
btrfs_warn_rl(fs_info, "has data reloc tree but no running relocation");
btrfs_warn_rl(fs_info,
"csum failed root %lld ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
inode->root->root_key.objectid, btrfs_ino(inode), file_off,
CSUM_FMT_VALUE(csum_size, csum),
CSUM_FMT_VALUE(csum_size, csum_expected),
mirror_num);
return;
}
logical += file_off;
btrfs_warn_rl(fs_info,
"csum failed root %lld ino %llu off %llu logical %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
inode->root->root_key.objectid,
btrfs_ino(inode), file_off, logical,
CSUM_FMT_VALUE(csum_size, csum),
CSUM_FMT_VALUE(csum_size, csum_expected),
mirror_num);
ret = extent_from_logical(fs_info, logical, &path, &found_key, &flags);
if (ret < 0) {
btrfs_err_rl(fs_info, "failed to lookup extent item for logical %llu: %d",
logical, ret);
return;
}
eb = path.nodes[0];
ei = btrfs_item_ptr(eb, path.slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size(eb, path.slots[0]);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
unsigned long ptr = 0;
u64 ref_root;
u8 ref_level;
while (true) {
ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
item_size, &ref_root,
&ref_level);
if (ret < 0) {
btrfs_warn_rl(fs_info,
"failed to resolve tree backref for logical %llu: %d",
logical, ret);
break;
}
if (ret > 0)
break;
btrfs_warn_rl(fs_info,
"csum error at logical %llu mirror %u: metadata %s (level %d) in tree %llu",
logical, mirror_num,
(ref_level ? "node" : "leaf"),
ref_level, ref_root);
}
btrfs_release_path(&path);
} else {
struct btrfs_backref_walk_ctx ctx = { 0 };
struct data_reloc_warn reloc_warn = { 0 };
btrfs_release_path(&path);
ctx.bytenr = found_key.objectid;
ctx.extent_item_pos = logical - found_key.objectid;
ctx.fs_info = fs_info;
reloc_warn.logical = logical;
reloc_warn.extent_item_size = found_key.offset;
reloc_warn.mirror_num = mirror_num;
reloc_warn.fs_info = fs_info;
iterate_extent_inodes(&ctx, true,
data_reloc_print_warning_inode, &reloc_warn);
}
}
static void __cold btrfs_print_data_csum_error(struct btrfs_inode *inode,
u64 logical_start, u8 *csum, u8 *csum_expected, int mirror_num)
{
struct btrfs_root *root = inode->root;
const u32 csum_size = root->fs_info->csum_size;
/* For data reloc tree, it's better to do a backref lookup instead. */
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
return print_data_reloc_error(inode, logical_start, csum,
csum_expected, mirror_num);
/* Output without objectid, which is more meaningful */
if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID) {
btrfs_warn_rl(root->fs_info,
"csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
root->root_key.objectid, btrfs_ino(inode),
logical_start,
CSUM_FMT_VALUE(csum_size, csum),
CSUM_FMT_VALUE(csum_size, csum_expected),
mirror_num);
} else {
btrfs_warn_rl(root->fs_info,
"csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
root->root_key.objectid, btrfs_ino(inode),
logical_start,
CSUM_FMT_VALUE(csum_size, csum),
CSUM_FMT_VALUE(csum_size, csum_expected),
mirror_num);
}
}
/*
* btrfs_inode_lock - lock inode i_rwsem based on arguments passed
*
* ilock_flags can have the following bit set:
*
* BTRFS_ILOCK_SHARED - acquire a shared lock on the inode
* BTRFS_ILOCK_TRY - try to acquire the lock, if fails on first attempt
* return -EAGAIN
* BTRFS_ILOCK_MMAP - acquire a write lock on the i_mmap_lock
*/
int btrfs_inode_lock(struct btrfs_inode *inode, unsigned int ilock_flags)
{
if (ilock_flags & BTRFS_ILOCK_SHARED) {
if (ilock_flags & BTRFS_ILOCK_TRY) {
if (!inode_trylock_shared(&inode->vfs_inode))
return -EAGAIN;
else
return 0;
}
inode_lock_shared(&inode->vfs_inode);
} else {
if (ilock_flags & BTRFS_ILOCK_TRY) {
if (!inode_trylock(&inode->vfs_inode))
return -EAGAIN;
else
return 0;
}
inode_lock(&inode->vfs_inode);
}
if (ilock_flags & BTRFS_ILOCK_MMAP)
down_write(&inode->i_mmap_lock);
return 0;
}
/*
* btrfs_inode_unlock - unock inode i_rwsem
*
* ilock_flags should contain the same bits set as passed to btrfs_inode_lock()
* to decide whether the lock acquired is shared or exclusive.
*/
void btrfs_inode_unlock(struct btrfs_inode *inode, unsigned int ilock_flags)
{
if (ilock_flags & BTRFS_ILOCK_MMAP)
up_write(&inode->i_mmap_lock);
if (ilock_flags & BTRFS_ILOCK_SHARED)
inode_unlock_shared(&inode->vfs_inode);
else
inode_unlock(&inode->vfs_inode);
}
/*
* Cleanup all submitted ordered extents in specified range to handle errors
* from the btrfs_run_delalloc_range() callback.
*
* NOTE: caller must ensure that when an error happens, it can not call
* extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
* and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
* to be released, which we want to happen only when finishing the ordered
* extent (btrfs_finish_ordered_io()).
*/
static inline void btrfs_cleanup_ordered_extents(struct btrfs_inode *inode,
struct page *locked_page,
u64 offset, u64 bytes)
{
unsigned long index = offset >> PAGE_SHIFT;
unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
u64 page_start = 0, page_end = 0;
struct page *page;
if (locked_page) {
page_start = page_offset(locked_page);
page_end = page_start + PAGE_SIZE - 1;
}
while (index <= end_index) {
/*
* For locked page, we will call end_extent_writepage() on it
* in run_delalloc_range() for the error handling. That
* end_extent_writepage() function will call
* btrfs_mark_ordered_io_finished() to clear page Ordered and
* run the ordered extent accounting.
*
* Here we can't just clear the Ordered bit, or
* btrfs_mark_ordered_io_finished() would skip the accounting
* for the page range, and the ordered extent will never finish.
*/
if (locked_page && index == (page_start >> PAGE_SHIFT)) {
index++;
continue;
}
page = find_get_page(inode->vfs_inode.i_mapping, index);
index++;
if (!page)
continue;
/*
* Here we just clear all Ordered bits for every page in the
* range, then btrfs_mark_ordered_io_finished() will handle
* the ordered extent accounting for the range.
*/
btrfs_page_clamp_clear_ordered(inode->root->fs_info, page,
offset, bytes);
put_page(page);
}
if (locked_page) {
/* The locked page covers the full range, nothing needs to be done */
if (bytes + offset <= page_start + PAGE_SIZE)
return;
/*
* In case this page belongs to the delalloc range being
* instantiated then skip it, since the first page of a range is
* going to be properly cleaned up by the caller of
* run_delalloc_range
*/
if (page_start >= offset && page_end <= (offset + bytes - 1)) {
bytes = offset + bytes - page_offset(locked_page) - PAGE_SIZE;
offset = page_offset(locked_page) + PAGE_SIZE;
}
}
return btrfs_mark_ordered_io_finished(inode, NULL, offset, bytes, false);
}
static int btrfs_dirty_inode(struct btrfs_inode *inode);
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
struct btrfs_new_inode_args *args)
{
int err;
if (args->default_acl) {
err = __btrfs_set_acl(trans, args->inode, args->default_acl,
ACL_TYPE_DEFAULT);
if (err)
return err;
}
if (args->acl) {
err = __btrfs_set_acl(trans, args->inode, args->acl, ACL_TYPE_ACCESS);
if (err)
return err;
}
if (!args->default_acl && !args->acl)
cache_no_acl(args->inode);
return btrfs_xattr_security_init(trans, args->inode, args->dir,
&args->dentry->d_name);
}
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
* no overlapping inline items exist in the btree
*/
static int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_path *path,
struct btrfs_inode *inode, bool extent_inserted,
size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages,
bool update_i_size)
{
struct btrfs_root *root = inode->root;
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int ret;
size_t cur_size = size;
u64 i_size;
ASSERT((compressed_size > 0 && compressed_pages) ||
(compressed_size == 0 && !compressed_pages));
if (compressed_size && compressed_pages)
cur_size = compressed_size;
if (!extent_inserted) {
struct btrfs_key key;
size_t datasize;
key.objectid = btrfs_ino(inode);
key.offset = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(cur_size);
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (ret)
goto fail;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, size);
ptr = btrfs_file_extent_inline_start(ei);
if (compress_type != BTRFS_COMPRESS_NONE) {
struct page *cpage;
int i = 0;
while (compressed_size > 0) {
cpage = compressed_pages[i];
cur_size = min_t(unsigned long, compressed_size,
PAGE_SIZE);
kaddr = kmap_local_page(cpage);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_local(kaddr);
i++;
ptr += cur_size;
compressed_size -= cur_size;
}
btrfs_set_file_extent_compression(leaf, ei,
compress_type);
} else {
page = find_get_page(inode->vfs_inode.i_mapping, 0);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_local_page(page);
write_extent_buffer(leaf, kaddr, ptr, size);
kunmap_local(kaddr);
put_page(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* We align size to sectorsize for inline extents just for simplicity
* sake.
*/
ret = btrfs_inode_set_file_extent_range(inode, 0,
ALIGN(size, root->fs_info->sectorsize));
if (ret)
goto fail;
/*
* We're an inline extent, so nobody can extend the file past i_size
* without locking a page we already have locked.
*
* We must do any i_size and inode updates before we unlock the pages.
* Otherwise we could end up racing with unlink.
*/
i_size = i_size_read(&inode->vfs_inode);
if (update_i_size && size > i_size) {
i_size_write(&inode->vfs_inode, size);
i_size = size;
}
inode->disk_i_size = i_size;
fail:
return ret;
}
/*
* conditionally insert an inline extent into the file. This
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
size_t compressed_size,
int compress_type,
struct page **compressed_pages,
bool update_i_size)
{
struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
u64 data_len = (compressed_size ?: size);
int ret;
struct btrfs_path *path;
/*
* We can create an inline extent if it ends at or beyond the current
* i_size, is no larger than a sector (decompressed), and the (possibly
* compressed) data fits in a leaf and the configured maximum inline
* size.
*/
if (size < i_size_read(&inode->vfs_inode) ||
size > fs_info->sectorsize ||
data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
data_len > fs_info->max_inline)
return 1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &inode->block_rsv;
drop_args.path = path;
drop_args.start = 0;
drop_args.end = fs_info->sectorsize;
drop_args.drop_cache = true;
drop_args.replace_extent = true;
drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(data_len);
ret = btrfs_drop_extents(trans, root, inode, &drop_args);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = insert_inline_extent(trans, path, inode, drop_args.extent_inserted,
size, compressed_size, compress_type,
compressed_pages, update_i_size);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
btrfs_update_inode_bytes(inode, size, drop_args.bytes_found);
ret = btrfs_update_inode(trans, root, inode);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
btrfs_set_inode_full_sync(inode);
out:
/*
* Don't forget to free the reserved space, as for inlined extent
* it won't count as data extent, free them directly here.
* And at reserve time, it's always aligned to page size, so
* just free one page here.
*/
btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
btrfs_free_path(path);
btrfs_end_transaction(trans);
return ret;
}
struct async_extent {
u64 start;
u64 ram_size;
u64 compressed_size;
struct page **pages;
unsigned long nr_pages;
int compress_type;
struct list_head list;
};
struct async_chunk {
struct btrfs_inode *inode;
struct page *locked_page;
u64 start;
u64 end;
blk_opf_t write_flags;
struct list_head extents;
struct cgroup_subsys_state *blkcg_css;
struct btrfs_work work;
struct async_cow *async_cow;
};
struct async_cow {
atomic_t num_chunks;
struct async_chunk chunks[];
};
static noinline int add_async_extent(struct async_chunk *cow,
u64 start, u64 ram_size,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
int compress_type)
{
struct async_extent *async_extent;
async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
BUG_ON(!async_extent); /* -ENOMEM */
async_extent->start = start;
async_extent->ram_size = ram_size;
async_extent->compressed_size = compressed_size;
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
/*
* Check if the inode needs to be submitted to compression, based on mount
* options, defragmentation, properties or heuristics.
*/
static inline int inode_need_compress(struct btrfs_inode *inode, u64 start,
u64 end)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
if (!btrfs_inode_can_compress(inode)) {
WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
btrfs_ino(inode));
return 0;
}
/*
* Special check for subpage.
*
* We lock the full page then run each delalloc range in the page, thus
* for the following case, we will hit some subpage specific corner case:
*
* 0 32K 64K
* | |///////| |///////|
* \- A \- B
*
* In above case, both range A and range B will try to unlock the full
* page [0, 64K), causing the one finished later will have page
* unlocked already, triggering various page lock requirement BUG_ON()s.
*
* So here we add an artificial limit that subpage compression can only
* if the range is fully page aligned.
*
* In theory we only need to ensure the first page is fully covered, but
* the tailing partial page will be locked until the full compression
* finishes, delaying the write of other range.
*
* TODO: Make btrfs_run_delalloc_range() to lock all delalloc range
* first to prevent any submitted async extent to unlock the full page.
* By this, we can ensure for subpage case that only the last async_cow
* will unlock the full page.
*/
if (fs_info->sectorsize < PAGE_SIZE) {
if (!PAGE_ALIGNED(start) ||
!PAGE_ALIGNED(end + 1))
return 0;
}
/* force compress */
if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
return 1;
/* defrag ioctl */
if (inode->defrag_compress)
return 1;
/* bad compression ratios */
if (inode->flags & BTRFS_INODE_NOCOMPRESS)
return 0;
if (btrfs_test_opt(fs_info, COMPRESS) ||
inode->flags & BTRFS_INODE_COMPRESS ||
inode->prop_compress)
return btrfs_compress_heuristic(&inode->vfs_inode, start, end);
return 0;
}
static inline void inode_should_defrag(struct btrfs_inode *inode,
u64 start, u64 end, u64 num_bytes, u32 small_write)
{
/* If this is a small write inside eof, kick off a defrag */
if (num_bytes < small_write &&
(start > 0 || end + 1 < inode->disk_i_size))
btrfs_add_inode_defrag(NULL, inode, small_write);
}
/*
* we create compressed extents in two phases. The first
* phase compresses a range of pages that have already been
* locked (both pages and state bits are locked).
*
* This is done inside an ordered work queue, and the compression
* is spread across many cpus. The actual IO submission is step
* two, and the ordered work queue takes care of making sure that
* happens in the same order things were put onto the queue by
* writepages and friends.
*
* If this code finds it can't get good compression, it puts an
* entry onto the work queue to write the uncompressed bytes. This
* makes sure that both compressed inodes and uncompressed inodes
* are written in the same order that the flusher thread sent them
* down.
*/
static noinline int compress_file_range(struct async_chunk *async_chunk)
{
struct btrfs_inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
u64 blocksize = fs_info->sectorsize;
u64 start = async_chunk->start;
u64 end = async_chunk->end;
u64 actual_end;
u64 i_size;
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
int i;
int will_compress;
int compress_type = fs_info->compress_type;
int compressed_extents = 0;
int redirty = 0;
inode_should_defrag(inode, start, end, end - start + 1, SZ_16K);
/*
* We need to save i_size before now because it could change in between
* us evaluating the size and assigning it. This is because we lock and
* unlock the page in truncate and fallocate, and then modify the i_size
* later on.
*
* The barriers are to emulate READ_ONCE, remove that once i_size_read
* does that for us.
*/
barrier();
i_size = i_size_read(&inode->vfs_inode);
barrier();
actual_end = min_t(u64, i_size, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
nr_pages = min_t(unsigned long, nr_pages, BTRFS_MAX_COMPRESSED_PAGES);
/*
* we don't want to send crud past the end of i_size through
* compression, that's just a waste of CPU time. So, if the
* end of the file is before the start of our current
* requested range of bytes, we bail out to the uncompressed
* cleanup code that can deal with all of this.
*
* It isn't really the fastest way to fix things, but this is a
* very uncommon corner.
*/
if (actual_end <= start)
goto cleanup_and_bail_uncompressed;
total_compressed = actual_end - start;
/*
* Skip compression for a small file range(<=blocksize) that
* isn't an inline extent, since it doesn't save disk space at all.
*/
if (total_compressed <= blocksize &&
(start > 0 || end + 1 < inode->disk_i_size))
goto cleanup_and_bail_uncompressed;
/*
* For subpage case, we require full page alignment for the sector
* aligned range.
* Thus we must also check against @actual_end, not just @end.
*/
if (blocksize < PAGE_SIZE) {
if (!PAGE_ALIGNED(start) ||
!PAGE_ALIGNED(round_up(actual_end, blocksize)))
goto cleanup_and_bail_uncompressed;
}
total_compressed = min_t(unsigned long, total_compressed,
BTRFS_MAX_UNCOMPRESSED);
total_in = 0;
ret = 0;
/*
* we do compression for mount -o compress and when the
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (inode_need_compress(inode, start, end)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
nr_pages = 0;
goto cont;
}
if (inode->defrag_compress)
compress_type = inode->defrag_compress;
else if (inode->prop_compress)
compress_type = inode->prop_compress;
/*
* we need to call clear_page_dirty_for_io on each
* page in the range. Otherwise applications with the file
* mmap'd can wander in and change the page contents while
* we are compressing them.
*
* If the compression fails for any reason, we set the pages
* dirty again later on.
*
* Note that the remaining part is redirtied, the start pointer
* has moved, the end is the original one.
*/
if (!redirty) {
extent_range_clear_dirty_for_io(&inode->vfs_inode, start, end);
redirty = 1;
}
/* Compression level is applied here and only here */
ret = btrfs_compress_pages(
compress_type | (fs_info->compress_level << 4),
inode->vfs_inode.i_mapping, start,
pages,
&nr_pages,
&total_in,
&total_compressed);
if (!ret) {
unsigned long offset = offset_in_page(total_compressed);
struct page *page = pages[nr_pages - 1];
/* zero the tail end of the last page, we might be
* sending it down to disk
*/
if (offset)
memzero_page(page, offset, PAGE_SIZE - offset);
will_compress = 1;
}
}
cont:
/*
* Check cow_file_range() for why we don't even try to create inline
* extent for subpage case.
*/
if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
/* lets try to make an inline extent */
if (ret || total_in < actual_end) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(inode, actual_end,
0, BTRFS_COMPRESS_NONE,
NULL, false);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(inode, actual_end,
total_compressed,
compress_type, pages,
false);
}
if (ret <= 0) {
unsigned long clear_flags = EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_error_op;
page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
/*
* inline extent creation worked or returned error,
* we don't need to create any more async work items.
* Unlock and free up our temp pages.
*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be done _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end,
NULL,
clear_flags,
PAGE_UNLOCK |
PAGE_START_WRITEBACK |
page_error_op |
PAGE_END_WRITEBACK);
/*
* Ensure we only free the compressed pages if we have
* them allocated, as we can still reach here with
* inode_need_compress() == false.
*/
if (pages) {
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
}
return 0;
}
}
if (will_compress) {
/*
* we aren't doing an inline extent round the compressed size
* up to a block size boundary so the allocator does sane
* things
*/
total_compressed = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk,
* compression must free at least one sector size
*/
total_in = round_up(total_in, fs_info->sectorsize);
if (total_compressed + blocksize <= total_in) {
compressed_extents++;
/*
* The async work queues will take care of doing actual
* allocation on disk for these compressed pages, and
* will submit them to the elevator.
*/
add_async_extent(async_chunk, start, total_in,
total_compressed, pages, nr_pages,
compress_type);
if (start + total_in < end) {
start += total_in;
pages = NULL;
cond_resched();
goto again;
}
return compressed_extents;
}
}
if (pages) {
/*
* the compression code ran but failed to make things smaller,
* free any pages it allocated and our page pointer array
*/
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
!(inode->prop_compress)) {
inode->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
cleanup_and_bail_uncompressed:
/*
* No compression, but we still need to write the pages in the file
* we've been given so far. redirty the locked page if it corresponds
* to our extent and set things up for the async work queue to run
* cow_file_range to do the normal delalloc dance.
*/
if (async_chunk->locked_page &&
(page_offset(async_chunk->locked_page) >= start &&
page_offset(async_chunk->locked_page)) <= end) {
__set_page_dirty_nobuffers(async_chunk->locked_page);
/* unlocked later on in the async handlers */
}
if (redirty)
extent_range_redirty_for_io(&inode->vfs_inode, start, end);
add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
BTRFS_COMPRESS_NONE);
compressed_extents++;
return compressed_extents;
}
static void free_async_extent_pages(struct async_extent *async_extent)
{
int i;
if (!async_extent->pages)
return;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
put_page(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
}
static int submit_uncompressed_range(struct btrfs_inode *inode,
struct async_extent *async_extent,
struct page *locked_page)
{
u64 start = async_extent->start;
u64 end = async_extent->start + async_extent->ram_size - 1;
unsigned long nr_written = 0;
int page_started = 0;
int ret;
/*
* Call cow_file_range() to run the delalloc range directly, since we
* won't go to NOCOW or async path again.
*
* Also we call cow_file_range() with @unlock_page == 0, so that we
* can directly submit them without interruption.
*/
ret = cow_file_range(inode, locked_page, start, end, &page_started,
&nr_written, 0, NULL);
/* Inline extent inserted, page gets unlocked and everything is done */
if (page_started)
return 0;
if (ret < 0) {
btrfs_cleanup_ordered_extents(inode, locked_page, start, end - start + 1);
if (locked_page) {
const u64 page_start = page_offset(locked_page);
const u64 page_end = page_start + PAGE_SIZE - 1;
btrfs_page_set_error(inode->root->fs_info, locked_page,
page_start, PAGE_SIZE);
set_page_writeback(locked_page);
end_page_writeback(locked_page);
end_extent_writepage(locked_page, ret, page_start, page_end);
unlock_page(locked_page);
}
return ret;
}
/* All pages will be unlocked, including @locked_page */
return extent_write_locked_range(&inode->vfs_inode, start, end);
}
static int submit_one_async_extent(struct btrfs_inode *inode,
struct async_chunk *async_chunk,
struct async_extent *async_extent,
u64 *alloc_hint)
{
struct extent_io_tree *io_tree = &inode->io_tree;
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key ins;
struct page *locked_page = NULL;
struct extent_map *em;
int ret = 0;
u64 start = async_extent->start;
u64 end = async_extent->start + async_extent->ram_size - 1;
if (async_chunk->blkcg_css)
kthread_associate_blkcg(async_chunk->blkcg_css);
/*
* If async_chunk->locked_page is in the async_extent range, we need to
* handle it.
*/
if (async_chunk->locked_page) {
u64 locked_page_start = page_offset(async_chunk->locked_page);
u64 locked_page_end = locked_page_start + PAGE_SIZE - 1;
if (!(start >= locked_page_end || end <= locked_page_start))
locked_page = async_chunk->locked_page;
}
lock_extent(io_tree, start, end, NULL);
/* We have fall back to uncompressed write */
if (!async_extent->pages) {
ret = submit_uncompressed_range(inode, async_extent, locked_page);
goto done;
}
ret = btrfs_reserve_extent(root, async_extent->ram_size,
async_extent->compressed_size,
async_extent->compressed_size,
0, *alloc_hint, &ins, 1, 1);
if (ret) {
free_async_extent_pages(async_extent);
/*
* Here we used to try again by going back to non-compressed
* path for ENOSPC. But we can't reserve space even for
* compressed size, how could it work for uncompressed size
* which requires larger size? So here we directly go error
* path.
*/
goto out_free;
}
/* Here we're doing allocation and writeback of the compressed pages */
em = create_io_em(inode, start,
async_extent->ram_size, /* len */
start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
async_extent->ram_size, /* ram_bytes */
async_extent->compress_type,
BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_free_reserve;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, /* file_offset */
async_extent->ram_size, /* num_bytes */
async_extent->ram_size, /* ram_bytes */
ins.objectid, /* disk_bytenr */
ins.offset, /* disk_num_bytes */
0, /* offset */
1 << BTRFS_ORDERED_COMPRESSED,
async_extent->compress_type);
if (ret) {
btrfs_drop_extent_map_range(inode, start, end, false);
goto out_free_reserve;
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/* Clear dirty, set writeback and unlock the pages. */
extent_clear_unlock_delalloc(inode, start, end,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
PAGE_UNLOCK | PAGE_START_WRITEBACK);
btrfs_submit_compressed_write(inode, start, /* file_offset */
async_extent->ram_size, /* num_bytes */
ins.objectid, /* disk_bytenr */
ins.offset, /* compressed_len */
async_extent->pages, /* compressed_pages */
async_extent->nr_pages,
async_chunk->write_flags, true);
*alloc_hint = ins.objectid + ins.offset;
done:
if (async_chunk->blkcg_css)
kthread_associate_blkcg(NULL);
kfree(async_extent);
return ret;
out_free_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_free:
extent_clear_unlock_delalloc(inode, start, end,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
PAGE_UNLOCK | PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK | PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
goto done;
}
/*
* Phase two of compressed writeback. This is the ordered portion of the code,
* which only gets called in the order the work was queued. We walk all the
* async extents created by compress_file_range and send them down to the disk.
*/
static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
{
struct btrfs_inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct async_extent *async_extent;
u64 alloc_hint = 0;
int ret = 0;
while (!list_empty(&async_chunk->extents)) {
u64 extent_start;
u64 ram_size;
async_extent = list_entry(async_chunk->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
extent_start = async_extent->start;
ram_size = async_extent->ram_size;
ret = submit_one_async_extent(inode, async_chunk, async_extent,
&alloc_hint);
btrfs_debug(fs_info,
"async extent submission failed root=%lld inode=%llu start=%llu len=%llu ret=%d",
inode->root->root_key.objectid,
btrfs_ino(inode), extent_start, ram_size, ret);
}
}
static u64 get_extent_allocation_hint(struct btrfs_inode *inode, u64 start,
u64 num_bytes)
{
struct extent_map_tree *em_tree = &inode->extent_tree;
struct extent_map *em;
u64 alloc_hint = 0;
read_lock(&em_tree->lock);
em = search_extent_mapping(em_tree, start, num_bytes);
if (em) {
/*
* if block start isn't an actual block number then find the
* first block in this inode and use that as a hint. If that
* block is also bogus then just don't worry about it.
*/
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
if (em)
free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
}
}
read_unlock(&em_tree->lock);
return alloc_hint;
}
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
* allocate extents on disk for the range, and create ordered data structs
* in ram to track those extents.
*
* locked_page is the page that writepage had locked already. We use
* it to make sure we don't do extra locks or unlocks.
*
* *page_started is set to one if we unlock locked_page and do everything
* required to start IO on it. It may be clean and already done with
* IO when we return.
*
* When unlock == 1, we unlock the pages in successfully allocated regions.
* When unlock == 0, we leave them locked for writing them out.
*
* However, we unlock all the pages except @locked_page in case of failure.
*
* In summary, page locking state will be as follow:
*
* - page_started == 1 (return value)
* - All the pages are unlocked. IO is started.
* - Note that this can happen only on success
* - unlock == 1
* - All the pages except @locked_page are unlocked in any case
* - unlock == 0
* - On success, all the pages are locked for writing out them
* - On failure, all the pages except @locked_page are unlocked
*
* When a failure happens in the second or later iteration of the
* while-loop, the ordered extents created in previous iterations are kept
* intact. So, the caller must clean them up by calling
* btrfs_cleanup_ordered_extents(). See btrfs_run_delalloc_range() for
* example.
*/
static noinline int cow_file_range(struct btrfs_inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock,
u64 *done_offset)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 alloc_hint = 0;
u64 orig_start = start;
u64 num_bytes;
unsigned long ram_size;
u64 cur_alloc_size = 0;
u64 min_alloc_size;
u64 blocksize = fs_info->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
unsigned clear_bits;
unsigned long page_ops;
bool extent_reserved = false;
int ret = 0;
if (btrfs_is_free_space_inode(inode)) {
ret = -EINVAL;
goto out_unlock;
}
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
inode_should_defrag(inode, start, end, num_bytes, SZ_64K);
/*
* Due to the page size limit, for subpage we can only trigger the
* writeback for the dirty sectors of page, that means data writeback
* is doing more writeback than what we want.
*
* This is especially unexpected for some call sites like fallocate,
* where we only increase i_size after everything is done.
* This means we can trigger inline extent even if we didn't want to.
* So here we skip inline extent creation completely.
*/
if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
u64 actual_end = min_t(u64, i_size_read(&inode->vfs_inode),
end + 1);
/* lets try to make an inline extent */
ret = cow_file_range_inline(inode, actual_end, 0,
BTRFS_COMPRESS_NONE, NULL, false);
if (ret == 0) {
/*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be run _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end,
locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_START_WRITEBACK | PAGE_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_SIZE) / PAGE_SIZE;
*page_started = 1;
/*
* locked_page is locked by the caller of
* writepage_delalloc(), not locked by
* __process_pages_contig().
*
* We can't let __process_pages_contig() to unlock it,
* as it doesn't have any subpage::writers recorded.
*
* Here we manually unlock the page, since the caller
* can't use page_started to determine if it's an
* inline extent or a compressed extent.
*/
unlock_page(locked_page);
goto out;
} else if (ret < 0) {
goto out_unlock;
}
}
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
/*
* Relocation relies on the relocated extents to have exactly the same
* size as the original extents. Normally writeback for relocation data
* extents follows a NOCOW path because relocation preallocates the
* extents. However, due to an operation such as scrub turning a block
* group to RO mode, it may fallback to COW mode, so we must make sure
* an extent allocated during COW has exactly the requested size and can
* not be split into smaller extents, otherwise relocation breaks and
* fails during the stage where it updates the bytenr of file extent
* items.
*/
if (btrfs_is_data_reloc_root(root))
min_alloc_size = num_bytes;
else
min_alloc_size = fs_info->sectorsize;
while (num_bytes > 0) {
cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
min_alloc_size, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
cur_alloc_size = ins.offset;
extent_reserved = true;
ram_size = ins.offset;
em = create_io_em(inode, start, ins.offset, /* len */
start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
ram_size, /* ram_bytes */
BTRFS_COMPRESS_NONE, /* compress_type */
BTRFS_ORDERED_REGULAR /* type */);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_reserve;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, ram_size, ram_size,
ins.objectid, cur_alloc_size, 0,
1 << BTRFS_ORDERED_REGULAR,
BTRFS_COMPRESS_NONE);
if (ret)
goto out_drop_extent_cache;
if (btrfs_is_data_reloc_root(root)) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
/*
* Only drop cache here, and process as normal.
*
* We must not allow extent_clear_unlock_delalloc()
* at out_unlock label to free meta of this ordered
* extent, as its meta should be freed by
* btrfs_finish_ordered_io().
*
* So we must continue until @start is increased to
* skip current ordered extent.
*/
if (ret)
btrfs_drop_extent_map_range(inode, start,
start + ram_size - 1,
false);
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/*
* We're not doing compressed IO, don't unlock the first page
* (which the caller expects to stay locked), don't clear any
* dirty bits and don't set any writeback bits
*
* Do set the Ordered (Private2) bit so we know this page was
* properly setup for writepage.
*/
page_ops = unlock ? PAGE_UNLOCK : 0;
page_ops |= PAGE_SET_ORDERED;
extent_clear_unlock_delalloc(inode, start, start + ram_size - 1,
locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
page_ops);
if (num_bytes < cur_alloc_size)
num_bytes = 0;
else
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
extent_reserved = false;
/*
* btrfs_reloc_clone_csums() error, since start is increased
* extent_clear_unlock_delalloc() at out_unlock label won't
* free metadata of current ordered extent, we're OK to exit.
*/
if (ret)
goto out_unlock;
}
out:
return ret;
out_drop_extent_cache:
btrfs_drop_extent_map_range(inode, start, start + ram_size - 1, false);
out_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_unlock:
/*
* If done_offset is non-NULL and ret == -EAGAIN, we expect the
* caller to write out the successfully allocated region and retry.
*/
if (done_offset && ret == -EAGAIN) {
if (orig_start < start)
*done_offset = start - 1;
else
*done_offset = start;
return ret;
} else if (ret == -EAGAIN) {
/* Convert to -ENOSPC since the caller cannot retry. */
ret = -ENOSPC;
}
/*
* Now, we have three regions to clean up:
*
* |-------(1)----|---(2)---|-------------(3)----------|
* `- orig_start `- start `- start + cur_alloc_size `- end
*
* We process each region below.
*/
clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK | PAGE_END_WRITEBACK;
/*
* For the range (1). We have already instantiated the ordered extents
* for this region. They are cleaned up by
* btrfs_cleanup_ordered_extents() in e.g,
* btrfs_run_delalloc_range(). EXTENT_LOCKED | EXTENT_DELALLOC are
* already cleared in the above loop. And, EXTENT_DELALLOC_NEW |
* EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV are handled by the cleanup
* function.
*
* However, in case of unlock == 0, we still need to unlock the pages
* (except @locked_page) to ensure all the pages are unlocked.
*/
if (!unlock && orig_start < start) {
if (!locked_page)
mapping_set_error(inode->vfs_inode.i_mapping, ret);
extent_clear_unlock_delalloc(inode, orig_start, start - 1,
locked_page, 0, page_ops);
}
/*
* For the range (2). If we reserved an extent for our delalloc range
* (or a subrange) and failed to create the respective ordered extent,
* then it means that when we reserved the extent we decremented the
* extent's size from the data space_info's bytes_may_use counter and
* incremented the space_info's bytes_reserved counter by the same
* amount. We must make sure extent_clear_unlock_delalloc() does not try
* to decrement again the data space_info's bytes_may_use counter,
* therefore we do not pass it the flag EXTENT_CLEAR_DATA_RESV.
*/
if (extent_reserved) {
extent_clear_unlock_delalloc(inode, start,
start + cur_alloc_size - 1,
locked_page,
clear_bits,
page_ops);
start += cur_alloc_size;
if (start >= end)
return ret;
}
/*
* For the range (3). We never touched the region. In addition to the
* clear_bits above, we add EXTENT_CLEAR_DATA_RESV to release the data
* space_info's bytes_may_use counter, reserved in
* btrfs_check_data_free_space().
*/
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits | EXTENT_CLEAR_DATA_RESV,
page_ops);
return ret;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
int compressed_extents;
async_chunk = container_of(work, struct async_chunk, work);
compressed_extents = compress_file_range(async_chunk);
if (compressed_extents == 0) {
btrfs_add_delayed_iput(async_chunk->inode);
async_chunk->inode = NULL;
}
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_chunk *async_chunk = container_of(work, struct async_chunk,
work);
struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
unsigned long nr_pages;
nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
PAGE_SHIFT;
/*
* ->inode could be NULL if async_chunk_start has failed to compress,
* in which case we don't have anything to submit, yet we need to
* always adjust ->async_delalloc_pages as its paired with the init
* happening in cow_file_range_async
*/
if (async_chunk->inode)
submit_compressed_extents(async_chunk);
/* atomic_sub_return implies a barrier */
if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
5 * SZ_1M)
cond_wake_up_nomb(&fs_info->async_submit_wait);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
struct async_cow *async_cow;
async_chunk = container_of(work, struct async_chunk, work);
if (async_chunk->inode)
btrfs_add_delayed_iput(async_chunk->inode);
if (async_chunk->blkcg_css)
css_put(async_chunk->blkcg_css);
async_cow = async_chunk->async_cow;
if (atomic_dec_and_test(&async_cow->num_chunks))
kvfree(async_cow);
}
static int cow_file_range_async(struct btrfs_inode *inode,
struct writeback_control *wbc,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc);
struct async_cow *ctx;
struct async_chunk *async_chunk;
unsigned long nr_pages;
u64 cur_end;
u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
int i;
bool should_compress;
unsigned nofs_flag;
const blk_opf_t write_flags = wbc_to_write_flags(wbc);
unlock_extent(&inode->io_tree, start, end, NULL);
if (inode->flags & BTRFS_INODE_NOCOMPRESS &&
!btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
num_chunks = 1;
should_compress = false;
} else {
should_compress = true;
}
nofs_flag = memalloc_nofs_save();
ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!ctx) {
unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_ops = PAGE_UNLOCK | PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK | PAGE_SET_ERROR;
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits, page_ops);
return -ENOMEM;
}
async_chunk = ctx->chunks;
atomic_set(&ctx->num_chunks, num_chunks);
for (i = 0; i < num_chunks; i++) {
if (should_compress)
cur_end = min(end, start + SZ_512K - 1);
else
cur_end = end;
/*
* igrab is called higher up in the call chain, take only the
* lightweight reference for the callback lifetime
*/
ihold(&inode->vfs_inode);
async_chunk[i].async_cow = ctx;
async_chunk[i].inode = inode;
async_chunk[i].start = start;
async_chunk[i].end = cur_end;
async_chunk[i].write_flags = write_flags;
INIT_LIST_HEAD(&async_chunk[i].extents);
/*
* The locked_page comes all the way from writepage and its
* the original page we were actually given. As we spread
* this large delalloc region across multiple async_chunk
* structs, only the first struct needs a pointer to locked_page
*
* This way we don't need racey decisions about who is supposed
* to unlock it.
*/
if (locked_page) {
/*
* Depending on the compressibility, the pages might or
* might not go through async. We want all of them to
* be accounted against wbc once. Let's do it here
* before the paths diverge. wbc accounting is used
* only for foreign writeback detection and doesn't
* need full accuracy. Just account the whole thing
* against the first page.
*/
wbc_account_cgroup_owner(wbc, locked_page,
cur_end - start);
async_chunk[i].locked_page = locked_page;
locked_page = NULL;
} else {
async_chunk[i].locked_page = NULL;
}
if (blkcg_css != blkcg_root_css) {
css_get(blkcg_css);
async_chunk[i].blkcg_css = blkcg_css;
async_chunk[i].write_flags |= REQ_BTRFS_CGROUP_PUNT;
} else {
async_chunk[i].blkcg_css = NULL;
}
btrfs_init_work(&async_chunk[i].work, async_cow_start,
async_cow_submit, async_cow_free);
nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
atomic_add(nr_pages, &fs_info->async_delalloc_pages);
btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int run_delalloc_zoned(struct btrfs_inode *inode,
struct page *locked_page, u64 start,
u64 end, int *page_started,
unsigned long *nr_written)
{
u64 done_offset = end;
int ret;
bool locked_page_done = false;
while (start <= end) {
ret = cow_file_range(inode, locked_page, start, end, page_started,
nr_written, 0, &done_offset);
if (ret && ret != -EAGAIN)
return ret;
if (*page_started) {
ASSERT(ret == 0);
return 0;
}
if (ret == 0)
done_offset = end;
if (done_offset == start) {
wait_on_bit_io(&inode->root->fs_info->flags,
BTRFS_FS_NEED_ZONE_FINISH,
TASK_UNINTERRUPTIBLE);
continue;
}
if (!locked_page_done) {
__set_page_dirty_nobuffers(locked_page);
account_page_redirty(locked_page);
}
locked_page_done = true;
extent_write_locked_range(&inode->vfs_inode, start, done_offset);
start = done_offset + 1;
}
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
u64 bytenr, u64 num_bytes, bool nowait)
{
struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bytenr);
struct btrfs_ordered_sum *sums;
int ret;
LIST_HEAD(list);
ret = btrfs_lookup_csums_list(csum_root, bytenr, bytenr + num_bytes - 1,
&list, 0, nowait);
if (ret == 0 && list_empty(&list))
return 0;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
if (ret < 0)
return ret;
return 1;
}
static int fallback_to_cow(struct btrfs_inode *inode, struct page *locked_page,
const u64 start, const u64 end,
int *page_started, unsigned long *nr_written)
{
const bool is_space_ino = btrfs_is_free_space_inode(inode);
const bool is_reloc_ino = btrfs_is_data_reloc_root(inode->root);
const u64 range_bytes = end + 1 - start;
struct extent_io_tree *io_tree = &inode->io_tree;
u64 range_start = start;
u64 count;
/*
* If EXTENT_NORESERVE is set it means that when the buffered write was
* made we had not enough available data space and therefore we did not
* reserve data space for it, since we though we could do NOCOW for the
* respective file range (either there is prealloc extent or the inode
* has the NOCOW bit set).
*
* However when we need to fallback to COW mode (because for example the
* block group for the corresponding extent was turned to RO mode by a
* scrub or relocation) we need to do the following:
*
* 1) We increment the bytes_may_use counter of the data space info.
* If COW succeeds, it allocates a new data extent and after doing
* that it decrements the space info's bytes_may_use counter and
* increments its bytes_reserved counter by the same amount (we do
* this at btrfs_add_reserved_bytes()). So we need to increment the
* bytes_may_use counter to compensate (when space is reserved at
* buffered write time, the bytes_may_use counter is incremented);
*
* 2) We clear the EXTENT_NORESERVE bit from the range. We do this so
* that if the COW path fails for any reason, it decrements (through
* extent_clear_unlock_delalloc()) the bytes_may_use counter of the
* data space info, which we incremented in the step above.
*
* If we need to fallback to cow and the inode corresponds to a free
* space cache inode or an inode of the data relocation tree, we must
* also increment bytes_may_use of the data space_info for the same
* reason. Space caches and relocated data extents always get a prealloc
* extent for them, however scrub or balance may have set the block
* group that contains that extent to RO mode and therefore force COW
* when starting writeback.
*/
count = count_range_bits(io_tree, &range_start, end, range_bytes,
EXTENT_NORESERVE, 0, NULL);
if (count > 0 || is_space_ino || is_reloc_ino) {
u64 bytes = count;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_space_info *sinfo = fs_info->data_sinfo;
if (is_space_ino || is_reloc_ino)
bytes = range_bytes;
spin_lock(&sinfo->lock);
btrfs_space_info_update_bytes_may_use(fs_info, sinfo, bytes);
spin_unlock(&sinfo->lock);
if (count > 0)
clear_extent_bit(io_tree, start, end, EXTENT_NORESERVE,
NULL);
}
return cow_file_range(inode, locked_page, start, end, page_started,
nr_written, 1, NULL);
}
struct can_nocow_file_extent_args {
/* Input fields. */
/* Start file offset of the range we want to NOCOW. */
u64 start;
/* End file offset (inclusive) of the range we want to NOCOW. */
u64 end;
bool writeback_path;
bool strict;
/*
* Free the path passed to can_nocow_file_extent() once it's not needed
* anymore.
*/
bool free_path;
/* Output fields. Only set when can_nocow_file_extent() returns 1. */
u64 disk_bytenr;
u64 disk_num_bytes;
u64 extent_offset;
/* Number of bytes that can be written to in NOCOW mode. */
u64 num_bytes;
};
/*
* Check if we can NOCOW the file extent that the path points to.
* This function may return with the path released, so the caller should check
* if path->nodes[0] is NULL or not if it needs to use the path afterwards.
*
* Returns: < 0 on error
* 0 if we can not NOCOW
* 1 if we can NOCOW
*/
static int can_nocow_file_extent(struct btrfs_path *path,
struct btrfs_key *key,
struct btrfs_inode *inode,
struct can_nocow_file_extent_args *args)
{
const bool is_freespace_inode = btrfs_is_free_space_inode(inode);
struct extent_buffer *leaf = path->nodes[0];
struct btrfs_root *root = inode->root;
struct btrfs_file_extent_item *fi;
u64 extent_end;
u8 extent_type;
int can_nocow = 0;
int ret = 0;
bool nowait = path->nowait;
fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type == BTRFS_FILE_EXTENT_INLINE)
goto out;
/* Can't access these fields unless we know it's not an inline extent. */
args->disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
args->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
args->extent_offset = btrfs_file_extent_offset(leaf, fi);
if (!(inode->flags & BTRFS_INODE_NODATACOW) &&
extent_type == BTRFS_FILE_EXTENT_REG)
goto out;
/*
* If the extent was created before the generation where the last snapshot
* for its subvolume was created, then this implies the extent is shared,
* hence we must COW.
*/
if (!args->strict &&
btrfs_file_extent_generation(leaf, fi) <=
btrfs_root_last_snapshot(&root->root_item))
goto out;
/* An explicit hole, must COW. */
if (args->disk_bytenr == 0)
goto out;
/* Compressed/encrypted/encoded extents must be COWed. */
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out;
extent_end = btrfs_file_extent_end(path);
/*
* The following checks can be expensive, as they need to take other
* locks and do btree or rbtree searches, so release the path to avoid
* blocking other tasks for too long.
*/
btrfs_release_path(path);
ret = btrfs_cross_ref_exist(root, btrfs_ino(inode),
key->offset - args->extent_offset,
args->disk_bytenr, args->strict, path);
WARN_ON_ONCE(ret > 0 && is_freespace_inode);
if (ret != 0)
goto out;
if (args->free_path) {
/*
* We don't need the path anymore, plus through the
* csum_exist_in_range() call below we will end up allocating
* another path. So free the path to avoid unnecessary extra
* memory usage.
*/
btrfs_free_path(path);
path = NULL;
}
/* If there are pending snapshots for this root, we must COW. */
if (args->writeback_path && !is_freespace_inode &&
atomic_read(&root->snapshot_force_cow))
goto out;
args->disk_bytenr += args->extent_offset;
args->disk_bytenr += args->start - key->offset;
args->num_bytes = min(args->end + 1, extent_end) - args->start;
/*
* Force COW if csums exist in the range. This ensures that csums for a
* given extent are either valid or do not exist.
*/
ret = csum_exist_in_range(root->fs_info, args->disk_bytenr, args->num_bytes,
nowait);
WARN_ON_ONCE(ret > 0 && is_freespace_inode);
if (ret != 0)
goto out;
can_nocow = 1;
out:
if (args->free_path && path)
btrfs_free_path(path);
return ret < 0 ? ret : can_nocow;
}
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
*
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
struct page *locked_page,
const u64 start, const u64 end,
int *page_started,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_root *root = inode->root;
struct btrfs_path *path;
u64 cow_start = (u64)-1;
u64 cur_offset = start;
int ret;
bool check_prev = true;
u64 ino = btrfs_ino(inode);
struct btrfs_block_group *bg;
bool nocow = false;
struct can_nocow_file_extent_args nocow_args = { 0 };
path = btrfs_alloc_path();
if (!path) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK);
return -ENOMEM;
}
nocow_args.end = end;
nocow_args.writeback_path = true;
while (1) {
struct btrfs_key found_key;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
u64 extent_end;
u64 ram_bytes;
u64 nocow_end;
int extent_type;
nocow = false;
ret = btrfs_lookup_file_extent(NULL, root, path, ino,
cur_offset, 0);
if (ret < 0)
goto error;
/*
* If there is no extent for our range when doing the initial
* search, then go back to the previous slot as it will be the
* one containing the search offset
*/
if (ret > 0 && path->slots[0] > 0 && check_prev) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0] - 1);
if (found_key.objectid == ino &&
found_key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
check_prev = false;
next_slot:
/* Go to next leaf if we have exhausted the current one */
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* Didn't find anything for our INO */
if (found_key.objectid > ino)
break;
/*
* Keep searching until we find an EXTENT_ITEM or there are no
* more extents for this inode
*/
if (WARN_ON_ONCE(found_key.objectid < ino) ||
found_key.type < BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
goto next_slot;
}
/* Found key is not EXTENT_DATA_KEY or starts after req range */
if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
/*
* If the found extent starts after requested offset, then
* adjust extent_end to be right before this extent begins
*/
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
/*
* Found extent which begins before our range and potentially
* intersect it
*/
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
/* If this is triggered then we have a memory corruption. */
ASSERT(extent_type < BTRFS_NR_FILE_EXTENT_TYPES);
if (WARN_ON(extent_type >= BTRFS_NR_FILE_EXTENT_TYPES)) {
ret = -EUCLEAN;
goto error;
}
ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
extent_end = btrfs_file_extent_end(path);
/*
* If the extent we got ends before our current offset, skip to
* the next extent.
*/
if (extent_end <= cur_offset) {
path->slots[0]++;
goto next_slot;
}
nocow_args.start = cur_offset;
ret = can_nocow_file_extent(path, &found_key, inode, &nocow_args);
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
} else if (ret == 0) {
goto out_check;
}
ret = 0;
bg = btrfs_inc_nocow_writers(fs_info, nocow_args.disk_bytenr);
if (bg)
nocow = true;
out_check:
/*
* If nocow is false then record the beginning of the range
* that needs to be COWed
*/
if (!nocow) {
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
if (cur_offset > end)
break;
if (!path->nodes[0])
continue;
path->slots[0]++;
goto next_slot;
}
/*
* COW range from cow_start to found_key.offset - 1. As the key
* will contain the beginning of the first extent that can be
* NOCOW, following one which needs to be COW'ed
*/
if (cow_start != (u64)-1) {
ret = fallback_to_cow(inode, locked_page,
cow_start, found_key.offset - 1,
page_started, nr_written);
if (ret)
goto error;
cow_start = (u64)-1;
}
nocow_end = cur_offset + nocow_args.num_bytes - 1;
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 orig_start = found_key.offset - nocow_args.extent_offset;
struct extent_map *em;
em = create_io_em(inode, cur_offset, nocow_args.num_bytes,
orig_start,
nocow_args.disk_bytenr, /* block_start */
nocow_args.num_bytes, /* block_len */
nocow_args.disk_num_bytes, /* orig_block_len */
ram_bytes, BTRFS_COMPRESS_NONE,
BTRFS_ORDERED_PREALLOC);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto error;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode,
cur_offset, nocow_args.num_bytes,
nocow_args.num_bytes,
nocow_args.disk_bytenr,
nocow_args.num_bytes, 0,
1 << BTRFS_ORDERED_PREALLOC,
BTRFS_COMPRESS_NONE);
if (ret) {
btrfs_drop_extent_map_range(inode, cur_offset,
nocow_end, false);
goto error;
}
} else {
ret = btrfs_add_ordered_extent(inode, cur_offset,
nocow_args.num_bytes,
nocow_args.num_bytes,
nocow_args.disk_bytenr,
nocow_args.num_bytes,
0,
1 << BTRFS_ORDERED_NOCOW,
BTRFS_COMPRESS_NONE);
if (ret)
goto error;
}
if (nocow) {
btrfs_dec_nocow_writers(bg);
nocow = false;
}
if (btrfs_is_data_reloc_root(root))
/*
* Error handled later, as we must prevent
* extent_clear_unlock_delalloc() in error handler
* from freeing metadata of created ordered extent.
*/
ret = btrfs_reloc_clone_csums(inode, cur_offset,
nocow_args.num_bytes);
extent_clear_unlock_delalloc(inode, cur_offset, nocow_end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC |
EXTENT_CLEAR_DATA_RESV,
PAGE_UNLOCK | PAGE_SET_ORDERED);
cur_offset = extent_end;
/*
* btrfs_reloc_clone_csums() error, now we're OK to call error
* handler, as metadata for created ordered extent will only
* be freed by btrfs_finish_ordered_io().
*/
if (ret)
goto error;
if (cur_offset > end)
break;
}
btrfs_release_path(path);
if (cur_offset <= end && cow_start == (u64)-1)
cow_start = cur_offset;
if (cow_start != (u64)-1) {
cur_offset = end;
ret = fallback_to_cow(inode, locked_page, cow_start, end,
page_started, nr_written);
if (ret)
goto error;
}
error:
if (nocow)
btrfs_dec_nocow_writers(bg);
if (ret && cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_START_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return ret;
}
static bool should_nocow(struct btrfs_inode *inode, u64 start, u64 end)
{
if (inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)) {
if (inode->defrag_bytes &&
test_range_bit(&inode->io_tree, start, end, EXTENT_DEFRAG,
0, NULL))
return false;
return true;
}
return false;
}
/*
* Function to process delayed allocation (create CoW) for ranges which are
* being touched for the first time.
*/
int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started, unsigned long *nr_written,
struct writeback_control *wbc)
{
int ret;
const bool zoned = btrfs_is_zoned(inode->root->fs_info);
/*
* The range must cover part of the @locked_page, or the returned
* @page_started can confuse the caller.
*/
ASSERT(!(end <= page_offset(locked_page) ||
start >= page_offset(locked_page) + PAGE_SIZE));
if (should_nocow(inode, start, end)) {
/*
* Normally on a zoned device we're only doing COW writes, but
* in case of relocation on a zoned filesystem we have taken
* precaution, that we're only writing sequentially. It's safe
* to use run_delalloc_nocow() here, like for regular
* preallocated inodes.
*/
ASSERT(!zoned || btrfs_is_data_reloc_root(inode->root));
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, nr_written);
} else if (!btrfs_inode_can_compress(inode) ||
!inode_need_compress(inode, start, end)) {
if (zoned)
ret = run_delalloc_zoned(inode, locked_page, start, end,
page_started, nr_written);
else
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1, NULL);
} else {
set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &inode->runtime_flags);
ret = cow_file_range_async(inode, wbc, locked_page, start, end,
page_started, nr_written);
}
ASSERT(ret <= 0);
if (ret)
btrfs_cleanup_ordered_extents(inode, locked_page, start,
end - start + 1);
return ret;
}
void btrfs_split_delalloc_extent(struct btrfs_inode *inode,
struct extent_state *orig, u64 split)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
u64 size;
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
size = orig->end - orig->start + 1;
if (size > fs_info->max_extent_size) {
u32 num_extents;
u64 new_size;
/*
* See the explanation in btrfs_merge_delalloc_extent, the same
* applies here, just in reverse.
*/
new_size = orig->end - split + 1;
num_extents = count_max_extents(fs_info, new_size);
new_size = split - orig->start;
num_extents += count_max_extents(fs_info, new_size);
if (count_max_extents(fs_info, size) >= num_extents)
return;
}
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, 1);
spin_unlock(&inode->lock);
}
/*
* Handle merged delayed allocation extents so we can keep track of new extents
* that are just merged onto old extents, such as when we are doing sequential
* writes, so we can properly account for the metadata space we'll need.
*/
void btrfs_merge_delalloc_extent(struct btrfs_inode *inode, struct extent_state *new,
struct extent_state *other)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
u64 new_size, old_size;
u32 num_extents;
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= fs_info->max_extent_size) {
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, -1);
spin_unlock(&inode->lock);
return;
}
/*
* We have to add up either side to figure out how many extents were
* accounted for before we merged into one big extent. If the number of
* extents we accounted for is <= the amount we need for the new range
* then we can return, otherwise drop. Think of it like this
*
* [ 4k][MAX_SIZE]
*
* So we've grown the extent by a MAX_SIZE extent, this would mean we
* need 2 outstanding extents, on one side we have 1 and the other side
* we have 1 so they are == and we can return. But in this case
*
* [MAX_SIZE+4k][MAX_SIZE+4k]
*
* Each range on their own accounts for 2 extents, but merged together
* they are only 3 extents worth of accounting, so we need to drop in
* this case.
*/
old_size = other->end - other->start + 1;
num_extents = count_max_extents(fs_info, old_size);
old_size = new->end - new->start + 1;
num_extents += count_max_extents(fs_info, old_size);
if (count_max_extents(fs_info, new_size) >= num_extents)
return;
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, -1);
spin_unlock(&inode->lock);
}
static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
spin_lock(&root->delalloc_lock);
if (list_empty(&inode->delalloc_inodes)) {
list_add_tail(&inode->delalloc_inodes, &root->delalloc_inodes);
set_bit(BTRFS_INODE_IN_DELALLOC_LIST, &inode->runtime_flags);
root->nr_delalloc_inodes++;
if (root->nr_delalloc_inodes == 1) {
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(!list_empty(&root->delalloc_root));
list_add_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
void __btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!list_empty(&inode->delalloc_inodes)) {
list_del_init(&inode->delalloc_inodes);
clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags);
root->nr_delalloc_inodes--;
if (!root->nr_delalloc_inodes) {
ASSERT(list_empty(&root->delalloc_inodes));
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(list_empty(&root->delalloc_root));
list_del_init(&root->delalloc_root);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
}
static void btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
spin_lock(&root->delalloc_lock);
__btrfs_del_delalloc_inode(root, inode);
spin_unlock(&root->delalloc_lock);
}
/*
* Properly track delayed allocation bytes in the inode and to maintain the
* list of inodes that have pending delalloc work to be done.
*/
void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *state,
u32 bits)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
if ((bits & EXTENT_DEFRAG) && !(bits & EXTENT_DELALLOC))
WARN_ON(1);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if (!(state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = inode->root;
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(fs_info, len);
bool do_list = !btrfs_is_free_space_inode(inode);
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, num_extents);
spin_unlock(&inode->lock);
/* For sanity tests */
if (btrfs_is_testing(fs_info))
return;
percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
fs_info->delalloc_batch);
spin_lock(&inode->lock);
inode->delalloc_bytes += len;
if (bits & EXTENT_DEFRAG)
inode->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
spin_unlock(&inode->lock);
}
if (!(state->state & EXTENT_DELALLOC_NEW) &&
(bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&inode->lock);
inode->new_delalloc_bytes += state->end + 1 - state->start;
spin_unlock(&inode->lock);
}
}
/*
* Once a range is no longer delalloc this function ensures that proper
* accounting happens.
*/
void btrfs_clear_delalloc_extent(struct btrfs_inode *inode,
struct extent_state *state, u32 bits)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(fs_info, len);
if ((state->state & EXTENT_DEFRAG) && (bits & EXTENT_DEFRAG)) {
spin_lock(&inode->lock);
inode->defrag_bytes -= len;
spin_unlock(&inode->lock);
}
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if ((state->state & EXTENT_DELALLOC) && (bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = inode->root;
bool do_list = !btrfs_is_free_space_inode(inode);
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, -num_extents);
spin_unlock(&inode->lock);
/*
* We don't reserve metadata space for space cache inodes so we
* don't need to call delalloc_release_metadata if there is an
* error.
*/
if (bits & EXTENT_CLEAR_META_RESV &&
root != fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, len, false);
/* For sanity tests. */
if (btrfs_is_testing(fs_info))
return;
if (!btrfs_is_data_reloc_root(root) &&
do_list && !(state->state & EXTENT_NORESERVE) &&
(bits & EXTENT_CLEAR_DATA_RESV))
btrfs_free_reserved_data_space_noquota(fs_info, len);
percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
fs_info->delalloc_batch);
spin_lock(&inode->lock);
inode->delalloc_bytes -= len;
if (do_list && inode->delalloc_bytes == 0 &&
test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags))
btrfs_del_delalloc_inode(root, inode);
spin_unlock(&inode->lock);
}
if ((state->state & EXTENT_DELALLOC_NEW) &&
(bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&inode->lock);
ASSERT(inode->new_delalloc_bytes >= len);
inode->new_delalloc_bytes -= len;
if (bits & EXTENT_ADD_INODE_BYTES)
inode_add_bytes(&inode->vfs_inode, len);
spin_unlock(&inode->lock);
}
}
/*
* Split off the first pre bytes from the extent_map at [start, start + len]
*
* This function is intended to be used only for extract_ordered_extent().
*/
static int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre)
{
struct extent_map_tree *em_tree = &inode->extent_tree;
struct extent_map *em;
struct extent_map *split_pre = NULL;
struct extent_map *split_mid = NULL;
int ret = 0;
unsigned long flags;
ASSERT(pre != 0);
ASSERT(pre < len);
split_pre = alloc_extent_map();
if (!split_pre)
return -ENOMEM;
split_mid = alloc_extent_map();
if (!split_mid) {
ret = -ENOMEM;
goto out_free_pre;
}
lock_extent(&inode->io_tree, start, start + len - 1, NULL);
write_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (!em) {
ret = -EIO;
goto out_unlock;
}
ASSERT(em->len == len);
ASSERT(!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags));
ASSERT(em->block_start < EXTENT_MAP_LAST_BYTE);
ASSERT(test_bit(EXTENT_FLAG_PINNED, &em->flags));
ASSERT(!test_bit(EXTENT_FLAG_LOGGING, &em->flags));
ASSERT(!list_empty(&em->list));
flags = em->flags;
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
/* First, replace the em with a new extent_map starting from * em->start */
split_pre->start = em->start;
split_pre->len = pre;
split_pre->orig_start = split_pre->start;
split_pre->block_start = em->block_start;
split_pre->block_len = split_pre->len;
split_pre->orig_block_len = split_pre->block_len;
split_pre->ram_bytes = split_pre->len;
split_pre->flags = flags;
split_pre->compress_type = em->compress_type;
split_pre->generation = em->generation;
replace_extent_mapping(em_tree, em, split_pre, 1);
/*
* Now we only have an extent_map at:
* [em->start, em->start + pre]
*/
/* Insert the middle extent_map. */
split_mid->start = em->start + pre;
split_mid->len = em->len - pre;
split_mid->orig_start = split_mid->start;
split_mid->block_start = em->block_start + pre;
split_mid->block_len = split_mid->len;
split_mid->orig_block_len = split_mid->block_len;
split_mid->ram_bytes = split_mid->len;
split_mid->flags = flags;
split_mid->compress_type = em->compress_type;
split_mid->generation = em->generation;
add_extent_mapping(em_tree, split_mid, 1);
/* Once for us */
free_extent_map(em);
/* Once for the tree */
free_extent_map(em);
out_unlock:
write_unlock(&em_tree->lock);
unlock_extent(&inode->io_tree, start, start + len - 1, NULL);
free_extent_map(split_mid);
out_free_pre:
free_extent_map(split_pre);
return ret;
}
int btrfs_extract_ordered_extent(struct btrfs_bio *bbio,
struct btrfs_ordered_extent *ordered)
{
u64 start = (u64)bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
u64 len = bbio->bio.bi_iter.bi_size;
struct btrfs_inode *inode = bbio->inode;
u64 ordered_len = ordered->num_bytes;
int ret = 0;
/* Must always be called for the beginning of an ordered extent. */
if (WARN_ON_ONCE(start != ordered->disk_bytenr))
return -EINVAL;
/* No need to split if the ordered extent covers the entire bio. */
if (ordered->disk_num_bytes == len)
return 0;
ret = btrfs_split_ordered_extent(ordered, len);
if (ret)
return ret;
/*
* Don't split the extent_map for NOCOW extents, as we're writing into
* a pre-existing one.
*/
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
return 0;
return split_extent_map(inode, bbio->file_offset, ordered_len, len);
}
/*
* given a list of ordered sums record them in the inode. This happens
* at IO completion time based on sums calculated at bio submission time.
*/
static int add_pending_csums(struct btrfs_trans_handle *trans,
struct list_head *list)
{
struct btrfs_ordered_sum *sum;
struct btrfs_root *csum_root = NULL;
int ret;
list_for_each_entry(sum, list, list) {
trans->adding_csums = true;
if (!csum_root)
csum_root = btrfs_csum_root(trans->fs_info,
sum->logical);
ret = btrfs_csum_file_blocks(trans, csum_root, sum);
trans->adding_csums = false;
if (ret)
return ret;
}
return 0;
}
static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
const u64 start,
const u64 len,
struct extent_state **cached_state)
{
u64 search_start = start;
const u64 end = start + len - 1;
while (search_start < end) {
const u64 search_len = end - search_start + 1;
struct extent_map *em;
u64 em_len;
int ret = 0;
em = btrfs_get_extent(inode, NULL, 0, search_start, search_len);
if (IS_ERR(em))
return PTR_ERR(em);
if (em->block_start != EXTENT_MAP_HOLE)
goto next;
em_len = em->len;
if (em->start < search_start)
em_len -= search_start - em->start;
if (em_len > search_len)
em_len = search_len;
ret = set_extent_bit(&inode->io_tree, search_start,
search_start + em_len - 1,
EXTENT_DELALLOC_NEW, cached_state);
next:
search_start = extent_map_end(em);
free_extent_map(em);
if (ret)
return ret;
}
return 0;
}
int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
unsigned int extra_bits,
struct extent_state **cached_state)
{
WARN_ON(PAGE_ALIGNED(end));
if (start >= i_size_read(&inode->vfs_inode) &&
!(inode->flags & BTRFS_INODE_PREALLOC)) {
/*
* There can't be any extents following eof in this case so just
* set the delalloc new bit for the range directly.
*/
extra_bits |= EXTENT_DELALLOC_NEW;
} else {
int ret;
ret = btrfs_find_new_delalloc_bytes(inode, start,
end + 1 - start,
cached_state);
if (ret)
return ret;
}
return set_extent_bit(&inode->io_tree, start, end,
EXTENT_DELALLOC | extra_bits, cached_state);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct btrfs_inode *inode;
struct btrfs_work work;
};
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
struct page *page;
struct btrfs_inode *inode;
u64 page_start;
u64 page_end;
int ret = 0;
bool free_delalloc_space = true;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
inode = fixup->inode;
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_SIZE - 1;
/*
* This is similar to page_mkwrite, we need to reserve the space before
* we take the page lock.
*/
ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
PAGE_SIZE);
again:
lock_page(page);
/*
* Before we queued this fixup, we took a reference on the page.
* page->mapping may go NULL, but it shouldn't be moved to a different
* address space.
*/
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
/*
* Unfortunately this is a little tricky, either
*
* 1) We got here and our page had already been dealt with and
* we reserved our space, thus ret == 0, so we need to just
* drop our space reservation and bail. This can happen the
* first time we come into the fixup worker, or could happen
* while waiting for the ordered extent.
* 2) Our page was already dealt with, but we happened to get an
* ENOSPC above from the btrfs_delalloc_reserve_space. In
* this case we obviously don't have anything to release, but
* because the page was already dealt with we don't want to
* mark the page with an error, so make sure we're resetting
* ret to 0. This is why we have this check _before_ the ret
* check, because we do not want to have a surprise ENOSPC
* when the page was already properly dealt with.
*/
if (!ret) {
btrfs_delalloc_release_extents(inode, PAGE_SIZE);
btrfs_delalloc_release_space(inode, data_reserved,
page_start, PAGE_SIZE,
true);
}
ret = 0;
goto out_page;
}
/*
* We can't mess with the page state unless it is locked, so now that
* it is locked bail if we failed to make our space reservation.
*/
if (ret)
goto out_page;
lock_extent(&inode->io_tree, page_start, page_end, &cached_state);
/* already ordered? We're done */
if (PageOrdered(page))
goto out_reserved;
ordered = btrfs_lookup_ordered_range(inode, page_start, PAGE_SIZE);
if (ordered) {
unlock_extent(&inode->io_tree, page_start, page_end,
&cached_state);
unlock_page(page);
btrfs_start_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
goto again;
}
ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
&cached_state);
if (ret)
goto out_reserved;
/*
* Everything went as planned, we're now the owner of a dirty page with
* delayed allocation bits set and space reserved for our COW
* destination.
*
* The page was dirty when we started, nothing should have cleaned it.
*/
BUG_ON(!PageDirty(page));
free_delalloc_space = false;
out_reserved:
btrfs_delalloc_release_extents(inode, PAGE_SIZE);
if (free_delalloc_space)
btrfs_delalloc_release_space(inode, data_reserved, page_start,
PAGE_SIZE, true);
unlock_extent(&inode->io_tree, page_start, page_end, &cached_state);
out_page:
if (ret) {
/*
* We hit ENOSPC or other errors. Update the mapping and page
* to reflect the errors and clean the page.
*/
mapping_set_error(page->mapping, ret);
end_extent_writepage(page, ret, page_start, page_end);
clear_page_dirty_for_io(page);
SetPageError(page);
}
btrfs_page_clear_checked(inode->root->fs_info, page, page_start, PAGE_SIZE);
unlock_page(page);
put_page(page);
kfree(fixup);
extent_changeset_free(data_reserved);
/*
* As a precaution, do a delayed iput in case it would be the last iput
* that could need flushing space. Recursing back to fixup worker would
* deadlock.
*/
btrfs_add_delayed_iput(inode);
}
/*
* There are a few paths in the higher layers of the kernel that directly
* set the page dirty bit without asking the filesystem if it is a
* good idea. This causes problems because we want to make sure COW
* properly happens and the data=ordered rules are followed.
*
* In our case any range that doesn't have the ORDERED bit set
* hasn't been properly setup for IO. We kick off an async process
* to fix it up. The async helper will wait for ordered extents, set
* the delalloc bit and make it safe to write the page.
*/
int btrfs_writepage_cow_fixup(struct page *page)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_writepage_fixup *fixup;
/* This page has ordered extent covering it already */
if (PageOrdered(page))
return 0;
/*
* PageChecked is set below when we create a fixup worker for this page,
* don't try to create another one if we're already PageChecked()
*
* The extent_io writepage code will redirty the page if we send back
* EAGAIN.
*/
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
/*
* We are already holding a reference to this inode from
* write_cache_pages. We need to hold it because the space reservation
* takes place outside of the page lock, and we can't trust
* page->mapping outside of the page lock.
*/
ihold(inode);
btrfs_page_set_checked(fs_info, page, page_offset(page), PAGE_SIZE);
get_page(page);
btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
fixup->page = page;
fixup->inode = BTRFS_I(inode);
btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
return -EAGAIN;
}
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, u64 file_pos,
struct btrfs_file_extent_item *stack_fi,
const bool update_inode_bytes,
u64 qgroup_reserved)
{
struct btrfs_root *root = inode->root;
const u64 sectorsize = root->fs_info->sectorsize;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key ins;
u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi);
u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi);
u64 offset = btrfs_stack_file_extent_offset(stack_fi);
u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
struct btrfs_drop_extents_args drop_args = { 0 };
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* we may be replacing one extent in the tree with another.
* The new extent is pinned in the extent map, and we don't want
* to drop it from the cache until it is completely in the btree.
*
* So, tell btrfs_drop_extents to leave this extent in the cache.
* the caller is expected to unpin it and allow it to be merged
* with the others.
*/
drop_args.path = path;
drop_args.start = file_pos;
drop_args.end = file_pos + num_bytes;
drop_args.replace_extent = true;
drop_args.extent_item_size = sizeof(*stack_fi);
ret = btrfs_drop_extents(trans, root, inode, &drop_args);
if (ret)
goto out;
if (!drop_args.extent_inserted) {
ins.objectid = btrfs_ino(inode);
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*stack_fi));
if (ret)
goto out;
}
leaf = path->nodes[0];
btrfs_set_stack_file_extent_generation(stack_fi, trans->transid);
write_extent_buffer(leaf, stack_fi,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(struct btrfs_file_extent_item));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* If we dropped an inline extent here, we know the range where it is
* was not marked with the EXTENT_DELALLOC_NEW bit, so we update the
* number of bytes only for that range containing the inline extent.
* The remaining of the range will be processed when clearning the
* EXTENT_DELALLOC_BIT bit through the ordered extent completion.
*/
if (file_pos == 0 && !IS_ALIGNED(drop_args.bytes_found, sectorsize)) {
u64 inline_size = round_down(drop_args.bytes_found, sectorsize);
inline_size = drop_args.bytes_found - inline_size;
btrfs_update_inode_bytes(inode, sectorsize, inline_size);
drop_args.bytes_found -= inline_size;
num_bytes -= sectorsize;
}
if (update_inode_bytes)
btrfs_update_inode_bytes(inode, num_bytes, drop_args.bytes_found);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_inode_set_file_extent_range(inode, file_pos, ram_bytes);
if (ret)
goto out;
ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode),
file_pos - offset,
qgroup_reserved, &ins);
out:
btrfs_free_path(path);
return ret;
}
static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
u64 start, u64 len)
{
struct btrfs_block_group *cache;
cache = btrfs_lookup_block_group(fs_info, start);
ASSERT(cache);
spin_lock(&cache->lock);
cache->delalloc_bytes -= len;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
}
static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_ordered_extent *oe)
{
struct btrfs_file_extent_item stack_fi;
bool update_inode_bytes;
u64 num_bytes = oe->num_bytes;
u64 ram_bytes = oe->ram_bytes;
memset(&stack_fi, 0, sizeof(stack_fi));
btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG);
btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr);
btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi,
oe->disk_num_bytes);
btrfs_set_stack_file_extent_offset(&stack_fi, oe->offset);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags)) {
num_bytes = oe->truncated_len;
ram_bytes = num_bytes;
}
btrfs_set_stack_file_extent_num_bytes(&stack_fi, num_bytes);
btrfs_set_stack_file_extent_ram_bytes(&stack_fi, ram_bytes);
btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type);
/* Encryption and other encoding is reserved and all 0 */
/*
* For delalloc, when completing an ordered extent we update the inode's
* bytes when clearing the range in the inode's io tree, so pass false
* as the argument 'update_inode_bytes' to insert_reserved_file_extent(),
* except if the ordered extent was truncated.
*/
update_inode_bytes = test_bit(BTRFS_ORDERED_DIRECT, &oe->flags) ||
test_bit(BTRFS_ORDERED_ENCODED, &oe->flags) ||
test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags);
return insert_reserved_file_extent(trans, BTRFS_I(oe->inode),
oe->file_offset, &stack_fi,
update_inode_bytes, oe->qgroup_rsv);
}
/*
* As ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
*/
int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
{
struct btrfs_inode *inode = BTRFS_I(ordered_extent->inode);
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans = NULL;
struct extent_io_tree *io_tree = &inode->io_tree;
struct extent_state *cached_state = NULL;
u64 start, end;
int compress_type = 0;
int ret = 0;
u64 logical_len = ordered_extent->num_bytes;
bool freespace_inode;
bool truncated = false;
bool clear_reserved_extent = true;
unsigned int clear_bits = EXTENT_DEFRAG;
start = ordered_extent->file_offset;
end = start + ordered_extent->num_bytes - 1;
if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_ENCODED, &ordered_extent->flags))
clear_bits |= EXTENT_DELALLOC_NEW;
freespace_inode = btrfs_is_free_space_inode(inode);
if (!freespace_inode)
btrfs_lockdep_acquire(fs_info, btrfs_ordered_extent);
if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
ret = -EIO;
goto out;
}
if (btrfs_is_zoned(fs_info)) {
btrfs_rewrite_logical_zoned(ordered_extent);
btrfs_zone_finish_endio(fs_info, ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
}
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
truncated = true;
logical_len = ordered_extent->truncated_len;
/* Truncated the entire extent, don't bother adding */
if (!logical_len)
goto out;
}
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
btrfs_inode_safe_disk_i_size_write(inode, 0);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &inode->block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
clear_bits |= EXTENT_LOCKED;
lock_extent(io_tree, start, end, &cached_state);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &inode->block_rsv;
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compress_type = ordered_extent->compress_type;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
BUG_ON(compress_type);
ret = btrfs_mark_extent_written(trans, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
logical_len);
btrfs_zoned_release_data_reloc_bg(fs_info, ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
} else {
BUG_ON(root == fs_info->tree_root);
ret = insert_ordered_extent_file_extent(trans, ordered_extent);
if (!ret) {
clear_reserved_extent = false;
btrfs_release_delalloc_bytes(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
}
}
unpin_extent_cache(&inode->extent_tree, ordered_extent->file_offset,
ordered_extent->num_bytes, trans->transid);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = add_pending_csums(trans, &ordered_extent->list);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
/*
* If this is a new delalloc range, clear its new delalloc flag to
* update the inode's number of bytes. This needs to be done first
* before updating the inode item.
*/
if ((clear_bits & EXTENT_DELALLOC_NEW) &&
!test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags))
clear_extent_bit(&inode->io_tree, start, end,
EXTENT_DELALLOC_NEW | EXTENT_ADD_INODE_BYTES,
&cached_state);
btrfs_inode_safe_disk_i_size_write(inode, 0);
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) { /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = 0;
out:
clear_extent_bit(&inode->io_tree, start, end, clear_bits,
&cached_state);
if (trans)
btrfs_end_transaction(trans);
if (ret || truncated) {
u64 unwritten_start = start;
/*
* If we failed to finish this ordered extent for any reason we
* need to make sure BTRFS_ORDERED_IOERR is set on the ordered
* extent, and mark the inode with the error if it wasn't
* already set. Any error during writeback would have already
* set the mapping error, so we need to set it if we're the ones
* marking this ordered extent as failed.
*/
if (ret && !test_and_set_bit(BTRFS_ORDERED_IOERR,
&ordered_extent->flags))
mapping_set_error(ordered_extent->inode->i_mapping, -EIO);
if (truncated)
unwritten_start += logical_len;
clear_extent_uptodate(io_tree, unwritten_start, end, NULL);
/* Drop extent maps for the part of the extent we didn't write. */
btrfs_drop_extent_map_range(inode, unwritten_start, end, false);
/*
* If the ordered extent had an IOERR or something else went
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
*
* If we made it past insert_reserved_file_extent before we
* errored out then we don't need to do this as the accounting
* has already been done.
*/
if ((ret || !logical_len) &&
clear_reserved_extent &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
/*
* Discard the range before returning it back to the
* free space pool
*/
if (ret && btrfs_test_opt(fs_info, DISCARD_SYNC))
btrfs_discard_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes,
NULL);
btrfs_free_reserved_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes, 1);
}
}
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
*/
btrfs_remove_ordered_extent(inode, ordered_extent);
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return ret;
}
void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
struct page *page, u64 start,
u64 end, bool uptodate)
{
trace_btrfs_writepage_end_io_hook(inode, start, end, uptodate);
btrfs_mark_ordered_io_finished(inode, page, start, end + 1 - start, uptodate);
}
/*
* Verify the checksum for a single sector without any extra action that depend
* on the type of I/O.
*/
int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
u32 pgoff, u8 *csum, const u8 * const csum_expected)
{
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
char *kaddr;
ASSERT(pgoff + fs_info->sectorsize <= PAGE_SIZE);
shash->tfm = fs_info->csum_shash;
kaddr = kmap_local_page(page) + pgoff;
crypto_shash_digest(shash, kaddr, fs_info->sectorsize, csum);
kunmap_local(kaddr);
if (memcmp(csum, csum_expected, fs_info->csum_size))
return -EIO;
return 0;
}
/*
* Verify the checksum of a single data sector.
*
* @bbio: btrfs_io_bio which contains the csum
* @dev: device the sector is on
* @bio_offset: offset to the beginning of the bio (in bytes)
* @bv: bio_vec to check
*
* Check if the checksum on a data block is valid. When a checksum mismatch is
* detected, report the error and fill the corrupted range with zero.
*
* Return %true if the sector is ok or had no checksum to start with, else %false.
*/
bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,
u32 bio_offset, struct bio_vec *bv)
{
struct btrfs_inode *inode = bbio->inode;
struct btrfs_fs_info *fs_info = inode->root->fs_info;
u64 file_offset = bbio->file_offset + bio_offset;
u64 end = file_offset + bv->bv_len - 1;
u8 *csum_expected;
u8 csum[BTRFS_CSUM_SIZE];
ASSERT(bv->bv_len == fs_info->sectorsize);
if (!bbio->csum)
return true;
if (btrfs_is_data_reloc_root(inode->root) &&
test_range_bit(&inode->io_tree, file_offset, end, EXTENT_NODATASUM,
1, NULL)) {
/* Skip the range without csum for data reloc inode */
clear_extent_bits(&inode->io_tree, file_offset, end,
EXTENT_NODATASUM);
return true;
}
csum_expected = bbio->csum + (bio_offset >> fs_info->sectorsize_bits) *
fs_info->csum_size;
if (btrfs_check_sector_csum(fs_info, bv->bv_page, bv->bv_offset, csum,
csum_expected))
goto zeroit;
return true;
zeroit:
btrfs_print_data_csum_error(inode, file_offset, csum, csum_expected,
bbio->mirror_num);
if (dev)
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS);
memzero_bvec(bv);
return false;
}
/*
* btrfs_add_delayed_iput - perform a delayed iput on @inode
*
* @inode: The inode we want to perform iput on
*
* This function uses the generic vfs_inode::i_count to track whether we should
* just decrement it (in case it's > 1) or if this is the last iput then link
* the inode to the delayed iput machinery. Delayed iputs are processed at
* transaction commit time/superblock commit/cleaner kthread.
*/
void btrfs_add_delayed_iput(struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
if (atomic_add_unless(&inode->vfs_inode.i_count, -1, 1))
return;
atomic_inc(&fs_info->nr_delayed_iputs);
spin_lock(&fs_info->delayed_iput_lock);
ASSERT(list_empty(&inode->delayed_iput));
list_add_tail(&inode->delayed_iput, &fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
wake_up_process(fs_info->cleaner_kthread);
}
static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
list_del_init(&inode->delayed_iput);
spin_unlock(&fs_info->delayed_iput_lock);
iput(&inode->vfs_inode);
if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
wake_up(&fs_info->delayed_iputs_wait);
spin_lock(&fs_info->delayed_iput_lock);
}
static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
if (!list_empty(&inode->delayed_iput)) {
spin_lock(&fs_info->delayed_iput_lock);
if (!list_empty(&inode->delayed_iput))
run_delayed_iput_locked(fs_info, inode);
spin_unlock(&fs_info->delayed_iput_lock);
}
}
void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
{
spin_lock(&fs_info->delayed_iput_lock);
while (!list_empty(&fs_info->delayed_iputs)) {
struct btrfs_inode *inode;
inode = list_first_entry(&fs_info->delayed_iputs,
struct btrfs_inode, delayed_iput);
run_delayed_iput_locked(fs_info, inode);
cond_resched_lock(&fs_info->delayed_iput_lock);
}
spin_unlock(&fs_info->delayed_iput_lock);
}
/*
* Wait for flushing all delayed iputs
*
* @fs_info: the filesystem
*
* This will wait on any delayed iputs that are currently running with KILLABLE
* set. Once they are all done running we will return, unless we are killed in
* which case we return EINTR. This helps in user operations like fallocate etc
* that might get blocked on the iputs.
*
* Return EINTR if we were killed, 0 if nothing's pending
*/
int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info)
{
int ret = wait_event_killable(fs_info->delayed_iputs_wait,
atomic_read(&fs_info->nr_delayed_iputs) == 0);
if (ret)
return -EINTR;
return 0;
}
/*
* This creates an orphan entry for the given inode in case something goes wrong
* in the middle of an unlink.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
int ret;
ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode));
if (ret && ret != -EEXIST) {
btrfs_abort_transaction(trans, ret);
return ret;
}
return 0;
}
/*
* We have done the delete so we can go ahead and remove the orphan item for
* this particular inode.
*/
static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode));
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
int btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
u64 last_objectid = 0;
int ret = 0, nr_unlink = 0;
if (test_and_set_bit(BTRFS_ROOT_ORPHAN_CLEANUP, &root->state))
return 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->reada = READA_BACK;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didn't
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* make sure the item matches what we want */
if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
break;
if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
/* release the path since we're done with it */
btrfs_release_path(path);
/*
* this is where we are basically btrfs_lookup, without the
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
if (found_key.offset == last_objectid) {
btrfs_err(fs_info,
"Error removing orphan entry, stopping orphan cleanup");
ret = -EINVAL;
goto out;
}
last_objectid = found_key.offset;
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
inode = btrfs_iget(fs_info->sb, last_objectid, root);
ret = PTR_ERR_OR_ZERO(inode);
if (ret && ret != -ENOENT)
goto out;
if (ret == -ENOENT && root == fs_info->tree_root) {
struct btrfs_root *dead_root;
int is_dead_root = 0;
/*
* This is an orphan in the tree root. Currently these
* could come from 2 sources:
* a) a root (snapshot/subvolume) deletion in progress
* b) a free space cache inode
* We need to distinguish those two, as the orphan item
* for a root must not get deleted before the deletion
* of the snapshot/subvolume's tree completes.
*
* btrfs_find_orphan_roots() ran before us, which has
* found all deleted roots and loaded them into
* fs_info->fs_roots_radix. So here we can find if an
* orphan item corresponds to a deleted root by looking
* up the root from that radix tree.
*/
spin_lock(&fs_info->fs_roots_radix_lock);
dead_root = radix_tree_lookup(&fs_info->fs_roots_radix,
(unsigned long)found_key.objectid);
if (dead_root && btrfs_root_refs(&dead_root->root_item) == 0)
is_dead_root = 1;
spin_unlock(&fs_info->fs_roots_radix_lock);
if (is_dead_root) {
/* prevent this orphan from being found again */
key.offset = found_key.objectid - 1;
continue;
}
}
/*
* If we have an inode with links, there are a couple of
* possibilities:
*
* 1. We were halfway through creating fsverity metadata for the
* file. In that case, the orphan item represents incomplete
* fsverity metadata which must be cleaned up with
* btrfs_drop_verity_items and deleting the orphan item.
* 2. Old kernels (before v3.12) used to create an
* orphan item for truncate indicating that there were possibly
* extent items past i_size that needed to be deleted. In v3.12,
* truncate was changed to update i_size in sync with the extent
* items, but the (useless) orphan item was still created. Since
* v4.18, we don't create the orphan item for truncate at all.
*
* So, this item could mean that we need to do a truncate, but
* only if this filesystem was last used on a pre-v3.12 kernel
* and was not cleanly unmounted. The odds of that are quite
* slim, and it's a pain to do the truncate now, so just delete
* the orphan item.
*
* It's also possible that this orphan item was supposed to be
* deleted but wasn't. The inode number may have been reused,
* but either way, we can delete the orphan item.
*/
if (ret == -ENOENT || inode->i_nlink) {
if (!ret) {
ret = btrfs_drop_verity_items(BTRFS_I(inode));
iput(inode);
if (ret)
goto out;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
iput(inode);
goto out;
}
btrfs_debug(fs_info, "auto deleting %Lu",
found_key.objectid);
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
btrfs_end_transaction(trans);
if (ret) {
iput(inode);
goto out;
}
continue;
}
nr_unlink++;
/* this will do delete_inode and everything for us */
iput(inode);
}
/* release the path since we're done with it */
btrfs_release_path(path);
if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
trans = btrfs_join_transaction(root);
if (!IS_ERR(trans))
btrfs_end_transaction(trans);
}
if (nr_unlink)
btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
out:
if (ret)
btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
btrfs_free_path(path);
return ret;
}
/*
* very simple check to peek ahead in the leaf looking for xattrs. If we
* don't find any xattrs, we know there can't be any acls.
*
* slot is the slot the inode is in, objectid is the objectid of the inode
*/
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
int slot, u64 objectid,
int *first_xattr_slot)
{
u32 nritems = btrfs_header_nritems(leaf);
struct btrfs_key found_key;
static u64 xattr_access = 0;
static u64 xattr_default = 0;
int scanned = 0;
if (!xattr_access) {
xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
strlen(XATTR_NAME_POSIX_ACL_ACCESS));
xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
}
slot++;
*first_xattr_slot = -1;
while (slot < nritems) {
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* we found a different objectid, there must not be acls */
if (found_key.objectid != objectid)
return 0;
/* we found an xattr, assume we've got an acl */
if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
if (found_key.offset == xattr_access ||
found_key.offset == xattr_default)
return 1;
}
/*
* we found a key greater than an xattr key, there can't
* be any acls later on
*/
if (found_key.type > BTRFS_XATTR_ITEM_KEY)
return 0;
slot++;
scanned++;
/*
* it goes inode, inode backrefs, xattrs, extents,
* so if there are a ton of hard links to an inode there can
* be a lot of backrefs. Don't waste time searching too hard,
* this is just an optimization
*/
if (scanned >= 8)
break;
}
/* we hit the end of the leaf before we found an xattr or
* something larger than an xattr. We have to assume the inode
* has acls
*/
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
return 1;
}
/*
* read an inode from the btree into the in-memory inode
*/
static int btrfs_read_locked_inode(struct inode *inode,
struct btrfs_path *in_path)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_path *path = in_path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
unsigned long ptr;
int maybe_acls;
u32 rdev;
int ret;
bool filled = false;
int first_xattr_slot;
ret = btrfs_fill_inode(inode, &rdev);
if (!ret)
filled = true;
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret) {
if (path != in_path)
btrfs_free_path(path);
return ret;
}
leaf = path->nodes[0];
if (filled)
goto cache_index;
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
round_up(i_size_read(inode), fs_info->sectorsize));
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
BTRFS_I(inode)->i_otime.tv_sec =
btrfs_timespec_sec(leaf, &inode_item->otime);
BTRFS_I(inode)->i_otime.tv_nsec =
btrfs_timespec_nsec(leaf, &inode_item->otime);
inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
inode_set_iversion_queried(inode,
btrfs_inode_sequence(leaf, inode_item));
inode->i_generation = BTRFS_I(inode)->generation;
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
BTRFS_I(inode)->index_cnt = (u64)-1;
btrfs_inode_split_flags(btrfs_inode_flags(leaf, inode_item),
&BTRFS_I(inode)->flags, &BTRFS_I(inode)->ro_flags);
cache_index:
/*
* If we were modified in the current generation and evicted from memory
* and then re-read we need to do a full sync since we don't have any
* idea about which extents were modified before we were evicted from
* cache.
*
* This is required for both inode re-read from disk and delayed inode
* in delayed_nodes_tree.
*/
if (BTRFS_I(inode)->last_trans == fs_info->generation)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
/*
* We don't persist the id of the transaction where an unlink operation
* against the inode was last made. So here we assume the inode might
* have been evicted, and therefore the exact value of last_unlink_trans
* lost, and set it to last_trans to avoid metadata inconsistencies
* between the inode and its parent if the inode is fsync'ed and the log
* replayed. For example, in the scenario:
*
* touch mydir/foo
* ln mydir/foo mydir/bar
* sync
* unlink mydir/bar
* echo 2 > /proc/sys/vm/drop_caches # evicts inode
* xfs_io -c fsync mydir/foo
* <power failure>
* mount fs, triggers fsync log replay
*
* We must make sure that when we fsync our inode foo we also log its
* parent inode, otherwise after log replay the parent still has the
* dentry with the "bar" name but our inode foo has a link count of 1
* and doesn't have an inode ref with the name "bar" anymore.
*
* Setting last_unlink_trans to last_trans is a pessimistic approach,
* but it guarantees correctness at the expense of occasional full
* transaction commits on fsync if our inode is a directory, or if our
* inode is not a directory, logging its parent unnecessarily.
*/
BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
/*
* Same logic as for last_unlink_trans. We don't persist the generation
* of the last transaction where this inode was used for a reflink
* operation, so after eviction and reloading the inode we must be
* pessimistic and assume the last transaction that modified the inode.
*/
BTRFS_I(inode)->last_reflink_trans = BTRFS_I(inode)->last_trans;
path->slots[0]++;
if (inode->i_nlink != 1 ||
path->slots[0] >= btrfs_header_nritems(leaf))
goto cache_acl;
btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
if (location.objectid != btrfs_ino(BTRFS_I(inode)))
goto cache_acl;
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
if (location.type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
} else if (location.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
extref);
}
cache_acl:
/*
* try to precache a NULL acl entry for files that don't have
* any xattrs or acls
*/
maybe_acls = acls_after_inode_item(leaf, path->slots[0],
btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
if (first_xattr_slot != -1) {
path->slots[0] = first_xattr_slot;
ret = btrfs_load_inode_props(inode, path);
if (ret)
btrfs_err(fs_info,
"error loading props for ino %llu (root %llu): %d",
btrfs_ino(BTRFS_I(inode)),
root->root_key.objectid, ret);
}
if (path != in_path)
btrfs_free_path(path);
if (!maybe_acls)
cache_no_acl(inode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_aops;
break;
default:
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
}
btrfs_sync_inode_flags_to_i_flags(inode);
return 0;
}
/*
* given a leaf and an inode, copy the inode fields into the leaf
*/
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
struct btrfs_map_token token;
u64 flags;
btrfs_init_map_token(&token, leaf);
btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
btrfs_set_token_inode_size(&token, item, BTRFS_I(inode)->disk_i_size);
btrfs_set_token_inode_mode(&token, item, inode->i_mode);
btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
btrfs_set_token_timespec_sec(&token, &item->atime,
inode->i_atime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->atime,
inode->i_atime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->mtime,
inode->i_mtime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->mtime,
inode->i_mtime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->ctime,
inode->i_ctime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->ctime,
inode->i_ctime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->otime,
BTRFS_I(inode)->i_otime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->otime,
BTRFS_I(inode)->i_otime.tv_nsec);
btrfs_set_token_inode_nbytes(&token, item, inode_get_bytes(inode));
btrfs_set_token_inode_generation(&token, item,
BTRFS_I(inode)->generation);
btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
btrfs_set_token_inode_transid(&token, item, trans->transid);
btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
BTRFS_I(inode)->ro_flags);
btrfs_set_token_inode_flags(&token, item, flags);
btrfs_set_token_inode_block_group(&token, item, 0);
}
/*
* copy everything in the in-memory inode into the btree.
*/
static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_lookup_inode(trans, root, path, &inode->location, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, leaf, inode_item, &inode->vfs_inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_free_path(path);
return ret;
}
/*
* copy everything in the in-memory inode into the btree.
*/
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
/*
* If the inode is a free space inode, we can deadlock during commit
* if we put it into the delayed code.
*
* The data relocation inode should also be directly updated
* without delay
*/
if (!btrfs_is_free_space_inode(inode)
&& !btrfs_is_data_reloc_root(root)
&& !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
btrfs_update_root_times(trans, root);
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
return ret;
}
return btrfs_update_inode_item(trans, root, inode);
}
int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode)
{
int ret;
ret = btrfs_update_inode(trans, root, inode);
if (ret == -ENOSPC)
return btrfs_update_inode_item(trans, root, inode);
return ret;
}
/*
* unlink helper that gets used here in inode.c and in the tree logging
* recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory
*/
static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
const struct fscrypt_str *name,
struct btrfs_rename_ctx *rename_ctx)
{
struct btrfs_root *root = dir->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
int ret = 0;
struct btrfs_dir_item *di;
u64 index;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, -1);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto err;
}
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(path);
/*
* If we don't have dir index, we have to get it by looking up
* the inode ref, since we get the inode ref, remove it directly,
* it is unnecessary to do delayed deletion.
*
* But if we have dir index, needn't search inode ref to get it.
* Since the inode ref is close to the inode item, it is better
* that we delay to delete it, and just do this deletion when
* we update the inode item.
*/
if (inode->dir_index) {
ret = btrfs_delayed_delete_inode_ref(inode);
if (!ret) {
index = inode->dir_index;
goto skip_backref;
}
}
ret = btrfs_del_inode_ref(trans, root, name, ino, dir_ino, &index);
if (ret) {
btrfs_info(fs_info,
"failed to delete reference to %.*s, inode %llu parent %llu",
name->len, name->name, ino, dir_ino);
btrfs_abort_transaction(trans, ret);
goto err;
}
skip_backref:
if (rename_ctx)
rename_ctx->index = index;
ret = btrfs_delete_delayed_dir_index(trans, dir, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto err;
}
/*
* If we are in a rename context, we don't need to update anything in the
* log. That will be done later during the rename by btrfs_log_new_name().
* Besides that, doing it here would only cause extra unnecessary btree
* operations on the log tree, increasing latency for applications.
*/
if (!rename_ctx) {
btrfs_del_inode_ref_in_log(trans, root, name, inode, dir_ino);
btrfs_del_dir_entries_in_log(trans, root, name, dir, index);
}
/*
* If we have a pending delayed iput we could end up with the final iput
* being run in btrfs-cleaner context. If we have enough of these built
* up we can end up burning a lot of time in btrfs-cleaner without any
* way to throttle the unlinks. Since we're currently holding a ref on
* the inode we can run the delayed iput here without any issues as the
* final iput won't be done until after we drop the ref we're currently
* holding.
*/
btrfs_run_delayed_iput(fs_info, inode);
err:
btrfs_free_path(path);
if (ret)
goto out;
btrfs_i_size_write(dir, dir->vfs_inode.i_size - name->len * 2);
inode_inc_iversion(&inode->vfs_inode);
inode_inc_iversion(&dir->vfs_inode);
inode->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
dir->vfs_inode.i_mtime = inode->vfs_inode.i_ctime;
dir->vfs_inode.i_ctime = inode->vfs_inode.i_ctime;
ret = btrfs_update_inode(trans, root, dir);
out:
return ret;
}
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
const struct fscrypt_str *name)
{
int ret;
ret = __btrfs_unlink_inode(trans, dir, inode, name, NULL);
if (!ret) {
drop_nlink(&inode->vfs_inode);
ret = btrfs_update_inode(trans, inode->root, inode);
}
return ret;
}
/*
* helper to start transaction for unlink and rmdir.
*
* unlink and rmdir are special in btrfs, they do not always free space, so
* if we cannot make our reservations the normal way try and see if there is
* plenty of slack room in the global reserve to migrate, otherwise we cannot
* allow the unlink to occur.
*/
static struct btrfs_trans_handle *__unlink_start_trans(struct btrfs_inode *dir)
{
struct btrfs_root *root = dir->root;
return btrfs_start_transaction_fallback_global_rsv(root,
BTRFS_UNLINK_METADATA_UNITS);
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_trans_handle *trans;
struct inode *inode = d_inode(dentry);
int ret;
struct fscrypt_name fname;
ret = fscrypt_setup_filename(dir, &dentry->d_name, 1, &fname);
if (ret)
return ret;
/* This needs to handle no-key deletions later on */
trans = __unlink_start_trans(BTRFS_I(dir));
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto fscrypt_free;
}
btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
false);
ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
&fname.disk_name);
if (ret)
goto end_trans;
if (inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret)
goto end_trans;
}
end_trans:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(BTRFS_I(dir)->root->fs_info);
fscrypt_free:
fscrypt_free_filename(&fname);
return ret;
}
static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = dir->root;
struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
int ret;
u64 objectid;
u64 dir_ino = btrfs_ino(dir);
struct fscrypt_name fname;
ret = fscrypt_setup_filename(&dir->vfs_inode, &dentry->d_name, 1, &fname);
if (ret)
return ret;
/* This needs to handle no-key deletions later on */
if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
objectid = inode->root->root_key.objectid;
} else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
objectid = inode->location.objectid;
} else {
WARN_ON(1);
fscrypt_free_filename(&fname);
return -EINVAL;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
&fname.disk_name, -1);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto out;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_release_path(path);
/*
* This is a placeholder inode for a subvolume we didn't have a
* reference to at the time of the snapshot creation. In the meantime
* we could have renamed the real subvol link into our snapshot, so
* depending on btrfs_del_root_ref to return -ENOENT here is incorrect.
* Instead simply lookup the dir_index_item for this entry so we can
* remove it. Otherwise we know we have a ref to the root and we can
* call btrfs_del_root_ref, and it _shouldn't_ fail.
*/
if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
di = btrfs_search_dir_index_item(root, path, dir_ino, &fname.disk_name);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
btrfs_abort_transaction(trans, ret);
goto out;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
index = key.offset;
btrfs_release_path(path);
} else {
ret = btrfs_del_root_ref(trans, objectid,
root->root_key.objectid, dir_ino,
&index, &fname.disk_name);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
}
ret = btrfs_delete_delayed_dir_index(trans, dir, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_i_size_write(dir, dir->vfs_inode.i_size - fname.disk_name.len * 2);
inode_inc_iversion(&dir->vfs_inode);
dir->vfs_inode.i_mtime = current_time(&dir->vfs_inode);
dir->vfs_inode.i_ctime = dir->vfs_inode.i_mtime;
ret = btrfs_update_inode_fallback(trans, root, dir);
if (ret)
btrfs_abort_transaction(trans, ret);
out:
btrfs_free_path(path);
fscrypt_free_filename(&fname);
return ret;
}
/*
* Helper to check if the subvolume references other subvolumes or if it's
* default.
*/
static noinline int may_destroy_subvol(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct fscrypt_str name = FSTR_INIT("default", 7);
u64 dir_id;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* Make sure this root isn't set as the default subvol */
dir_id = btrfs_super_root_dir(fs_info->super_copy);
di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
dir_id, &name, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
if (key.objectid == root->root_key.objectid) {
ret = -EPERM;
btrfs_err(fs_info,
"deleting default subvolume %llu is not allowed",
key.objectid);
goto out;
}
btrfs_release_path(path);
}
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
ret = 0;
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid == root->root_key.objectid &&
key.type == BTRFS_ROOT_REF_KEY)
ret = -ENOTEMPTY;
}
out:
btrfs_free_path(path);
return ret;
}
/* Delete all dentries for inodes belonging to the root */
static void btrfs_prune_dentries(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct rb_node *node;
struct rb_node *prev;
struct btrfs_inode *entry;
struct inode *inode;
u64 objectid = 0;
if (!BTRFS_FS_ERROR(fs_info))
WARN_ON(btrfs_root_refs(&root->root_item) != 0);
spin_lock(&root->inode_lock);
again:
node = root->inode_tree.rb_node;
prev = NULL;
while (node) {
prev = node;
entry = rb_entry(node, struct btrfs_inode, rb_node);
if (objectid < btrfs_ino(entry))
node = node->rb_left;
else if (objectid > btrfs_ino(entry))
node = node->rb_right;
else
break;
}
if (!node) {
while (prev) {
entry = rb_entry(prev, struct btrfs_inode, rb_node);
if (objectid <= btrfs_ino(entry)) {
node = prev;
break;
}
prev = rb_next(prev);
}
}
while (node) {
entry = rb_entry(node, struct btrfs_inode, rb_node);
objectid = btrfs_ino(entry) + 1;
inode = igrab(&entry->vfs_inode);
if (inode) {
spin_unlock(&root->inode_lock);
if (atomic_read(&inode->i_count) > 1)
d_prune_aliases(inode);
/*
* btrfs_drop_inode will have it removed from the inode
* cache when its usage count hits zero.
*/
iput(inode);
cond_resched();
spin_lock(&root->inode_lock);
goto again;
}
if (cond_resched_lock(&root->inode_lock))
goto again;
node = rb_next(node);
}
spin_unlock(&root->inode_lock);
}
int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
struct btrfs_root *root = dir->root;
struct inode *inode = d_inode(dentry);
struct btrfs_root *dest = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct btrfs_block_rsv block_rsv;
u64 root_flags;
int ret;
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
* again is not run concurrently.
*/
spin_lock(&dest->root_item_lock);
if (dest->send_in_progress) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
return -EPERM;
}
if (atomic_read(&dest->nr_swapfiles)) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu with active swapfile",
root->root_key.objectid);
return -EPERM;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
down_write(&fs_info->subvol_sem);
ret = may_destroy_subvol(dest);
if (ret)
goto out_up_write;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
* One for dir inode,
* two for dir entries,
* two for root ref/backref.
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (ret)
goto out_up_write;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_release;
}
trans->block_rsv = &block_rsv;
trans->bytes_reserved = block_rsv.size;
btrfs_record_snapshot_destroy(trans, dir);
ret = btrfs_unlink_subvol(trans, dir, dentry);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
ret = btrfs_record_root_in_trans(trans, dest);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
memset(&dest->root_item.drop_progress, 0,
sizeof(dest->root_item.drop_progress));
btrfs_set_root_drop_level(&dest->root_item, 0);
btrfs_set_root_refs(&dest->root_item, 0);
if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
ret = btrfs_insert_orphan_item(trans,
fs_info->tree_root,
dest->root_key.objectid);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
}
ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid,
BTRFS_UUID_KEY_SUBVOL,
dest->root_key.objectid);
if (ret && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
ret = btrfs_uuid_tree_remove(trans,
dest->root_item.received_uuid,
BTRFS_UUID_KEY_RECEIVED_SUBVOL,
dest->root_key.objectid);
if (ret && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
}
free_anon_bdev(dest->anon_dev);
dest->anon_dev = 0;
out_end_trans:
trans->block_rsv = NULL;
trans->bytes_reserved = 0;
ret = btrfs_end_transaction(trans);
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(root, &block_rsv);
out_up_write:
up_write(&fs_info->subvol_sem);
if (ret) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
} else {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
}
return ret;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
int err = 0;
struct btrfs_trans_handle *trans;
u64 last_unlink_trans;
struct fscrypt_name fname;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID) {
if (unlikely(btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))) {
btrfs_err(fs_info,
"extent tree v2 doesn't support snapshot deletion yet");
return -EOPNOTSUPP;
}
return btrfs_delete_subvolume(BTRFS_I(dir), dentry);
}
err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &fname);
if (err)
return err;
/* This needs to handle no-key deletions later on */
trans = __unlink_start_trans(BTRFS_I(dir));
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_notrans;
}
if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
err = btrfs_unlink_subvol(trans, BTRFS_I(dir), dentry);
goto out;
}
err = btrfs_orphan_add(trans, BTRFS_I(inode));
if (err)
goto out;
last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
/* now the directory is empty */
err = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
&fname.disk_name);
if (!err) {
btrfs_i_size_write(BTRFS_I(inode), 0);
/*
* Propagate the last_unlink_trans value of the deleted dir to
* its parent directory. This is to prevent an unrecoverable
* log tree in the case we do something like this:
* 1) create dir foo
* 2) create snapshot under dir foo
* 3) delete the snapshot
* 4) rmdir foo
* 5) mkdir foo
* 6) fsync foo or some file inside foo
*/
if (last_unlink_trans >= trans->transid)
BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
}
out:
btrfs_end_transaction(trans);
out_notrans:
btrfs_btree_balance_dirty(fs_info);
fscrypt_free_filename(&fname);
return err;
}
/*
* btrfs_truncate_block - read, zero a chunk and write a block
* @inode - inode that we're zeroing
* @from - the offset to start zeroing
* @len - the length to zero, 0 to zero the entire range respective to the
* offset
* @front - zero up to the offset instead of from the offset on
*
* This will find the block for the "from" offset and cow the block and zero the
* part we want to zero. This is used with truncate and hole punching.
*/
int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
int front)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct address_space *mapping = inode->vfs_inode.i_mapping;
struct extent_io_tree *io_tree = &inode->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
bool only_release_metadata = false;
u32 blocksize = fs_info->sectorsize;
pgoff_t index = from >> PAGE_SHIFT;
unsigned offset = from & (blocksize - 1);
struct page *page;
gfp_t mask = btrfs_alloc_write_mask(mapping);
size_t write_bytes = blocksize;
int ret = 0;
u64 block_start;
u64 block_end;
if (IS_ALIGNED(offset, blocksize) &&
(!len || IS_ALIGNED(len, blocksize)))
goto out;
block_start = round_down(from, blocksize);
block_end = block_start + blocksize - 1;
ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,
blocksize, false);
if (ret < 0) {
if (btrfs_check_nocow_lock(inode, block_start, &write_bytes, false) > 0) {
/* For nocow case, no need to reserve data space */
only_release_metadata = true;
} else {
goto out;
}
}
ret = btrfs_delalloc_reserve_metadata(inode, blocksize, blocksize, false);
if (ret < 0) {
if (!only_release_metadata)
btrfs_free_reserved_data_space(inode, data_reserved,
block_start, blocksize);
goto out;
}
again:
page = find_or_create_page(mapping, index, mask);
if (!page) {
btrfs_delalloc_release_space(inode, data_reserved, block_start,
blocksize, true);
btrfs_delalloc_release_extents(inode, blocksize);
ret = -ENOMEM;
goto out;
}
ret = set_page_extent_mapped(page);
if (ret < 0)
goto out_unlock;
if (!PageUptodate(page)) {
ret = btrfs_read_folio(NULL, page_folio(page));
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
put_page(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto out_unlock;
}
}
wait_on_page_writeback(page);
lock_extent(io_tree, block_start, block_end, &cached_state);
ordered = btrfs_lookup_ordered_extent(inode, block_start);
if (ordered) {
unlock_extent(io_tree, block_start, block_end, &cached_state);
unlock_page(page);
put_page(page);
btrfs_start_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
goto again;
}
clear_extent_bit(&inode->io_tree, block_start, block_end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
&cached_state);
ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
&cached_state);
if (ret) {
unlock_extent(io_tree, block_start, block_end, &cached_state);
goto out_unlock;
}
if (offset != blocksize) {
if (!len)
len = blocksize - offset;
if (front)
memzero_page(page, (block_start - page_offset(page)),
offset);
else
memzero_page(page, (block_start - page_offset(page)) + offset,
len);
}
btrfs_page_clear_checked(fs_info, page, block_start,
block_end + 1 - block_start);
btrfs_page_set_dirty(fs_info, page, block_start, block_end + 1 - block_start);
unlock_extent(io_tree, block_start, block_end, &cached_state);
if (only_release_metadata)
set_extent_bit(&inode->io_tree, block_start, block_end,
EXTENT_NORESERVE, NULL);
out_unlock:
if (ret) {
if (only_release_metadata)
btrfs_delalloc_release_metadata(inode, blocksize, true);
else
btrfs_delalloc_release_space(inode, data_reserved,
block_start, blocksize, true);
}
btrfs_delalloc_release_extents(inode, blocksize);
unlock_page(page);
put_page(page);
out:
if (only_release_metadata)
btrfs_check_nocow_unlock(inode);
extent_changeset_free(data_reserved);
return ret;
}
static int maybe_insert_hole(struct btrfs_root *root, struct btrfs_inode *inode,
u64 offset, u64 len)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
struct btrfs_drop_extents_args drop_args = { 0 };
int ret;
/*
* If NO_HOLES is enabled, we don't need to do anything.
* Later, up in the call chain, either btrfs_set_inode_last_sub_trans()
* or btrfs_update_inode() will be called, which guarantee that the next
* fsync will know this inode was changed and needs to be logged.
*/
if (btrfs_fs_incompat(fs_info, NO_HOLES))
return 0;
/*
* 1 - for the one we're dropping
* 1 - for the one we're adding
* 1 - for updating the inode.
*/
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans))
return PTR_ERR(trans);
drop_args.start = offset;
drop_args.end = offset + len;
drop_args.drop_cache = true;
ret = btrfs_drop_extents(trans, root, inode, &drop_args);
if (ret) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
return ret;
}
ret = btrfs_insert_hole_extent(trans, root, btrfs_ino(inode), offset, len);
if (ret) {
btrfs_abort_transaction(trans, ret);
} else {
btrfs_update_inode_bytes(inode, 0, drop_args.bytes_found);
btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans);
return ret;
}
/*
* This function puts in dummy file extents for the area we're creating a hole
* for. So if we are truncating this file to a larger size we need to insert
* these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
* the range between oldsize and size
*/
int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *io_tree = &inode->io_tree;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
u64 block_end = ALIGN(size, fs_info->sectorsize);
u64 last_byte;
u64 cur_offset;
u64 hole_size;
int err = 0;
/*
* If our size started in the middle of a block we need to zero out the
* rest of the block before we expand the i_size, otherwise we could
* expose stale data.
*/
err = btrfs_truncate_block(inode, oldsize, 0, 0);
if (err)
return err;
if (size <= hole_start)
return 0;
btrfs_lock_and_flush_ordered_range(inode, hole_start, block_end - 1,
&cached_state);
cur_offset = hole_start;
while (1) {
em = btrfs_get_extent(inode, NULL, 0, cur_offset,
block_end - cur_offset);
if (IS_ERR(em)) {
err = PTR_ERR(em);
em = NULL;
break;
}
last_byte = min(extent_map_end(em), block_end);
last_byte = ALIGN(last_byte, fs_info->sectorsize);
hole_size = last_byte - cur_offset;
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
struct extent_map *hole_em;
err = maybe_insert_hole(root, inode, cur_offset,
hole_size);
if (err)
break;
err = btrfs_inode_set_file_extent_range(inode,
cur_offset, hole_size);
if (err)
break;
hole_em = alloc_extent_map();
if (!hole_em) {
btrfs_drop_extent_map_range(inode, cur_offset,
cur_offset + hole_size - 1,
false);
btrfs_set_inode_full_sync(inode);
goto next;
}
hole_em->start = cur_offset;
hole_em->len = hole_size;
hole_em->orig_start = cur_offset;
hole_em->block_start = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->orig_block_len = 0;
hole_em->ram_bytes = hole_size;
hole_em->compress_type = BTRFS_COMPRESS_NONE;
hole_em->generation = fs_info->generation;
err = btrfs_replace_extent_map_range(inode, hole_em, true);
free_extent_map(hole_em);
} else {
err = btrfs_inode_set_file_extent_range(inode,
cur_offset, hole_size);
if (err)
break;
}
next:
free_extent_map(em);
em = NULL;
cur_offset = last_byte;
if (cur_offset >= block_end)
break;
}
free_extent_map(em);
unlock_extent(io_tree, hole_start, block_end - 1, &cached_state);
return err;
}
static int btrfs_setsize(struct inode *inode, struct iattr *attr)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
loff_t oldsize = i_size_read(inode);
loff_t newsize = attr->ia_size;
int mask = attr->ia_valid;
int ret;
/*
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
* special case where we need to update the times despite not having
* these flags set. For all other operations the VFS set these flags
* explicitly if it wants a timestamp update.
*/
if (newsize != oldsize) {
inode_inc_iversion(inode);
if (!(mask & (ATTR_CTIME | ATTR_MTIME))) {
inode->i_mtime = current_time(inode);
inode->i_ctime = inode->i_mtime;
}
}
if (newsize > oldsize) {
/*
* Don't do an expanding truncate while snapshotting is ongoing.
* This is to ensure the snapshot captures a fully consistent
* state of this file - if the snapshot captures this expanding
* truncation, it must capture all writes that happened before
* this truncation.
*/
btrfs_drew_write_lock(&root->snapshot_lock);
ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, newsize);
if (ret) {
btrfs_drew_write_unlock(&root->snapshot_lock);
return ret;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_drew_write_unlock(&root->snapshot_lock);
return PTR_ERR(trans);
}
i_size_write(inode, newsize);
btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
pagecache_isize_extended(inode, oldsize, newsize);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
btrfs_drew_write_unlock(&root->snapshot_lock);
btrfs_end_transaction(trans);
} else {
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if (btrfs_is_zoned(fs_info)) {
ret = btrfs_wait_ordered_range(inode,
ALIGN(newsize, fs_info->sectorsize),
(u64)-1);
if (ret)
return ret;
}
/*
* We're truncating a file that used to have good data down to
* zero. Make sure any new writes to the file get on disk
* on close.
*/
if (newsize == 0)
set_bit(BTRFS_INODE_FLUSH_ON_CLOSE,
&BTRFS_I(inode)->runtime_flags);
truncate_setsize(inode, newsize);
inode_dio_wait(inode);
ret = btrfs_truncate(BTRFS_I(inode), newsize == oldsize);
if (ret && inode->i_nlink) {
int err;
/*
* Truncate failed, so fix up the in-memory size. We
* adjusted disk_i_size down as we removed extents, so
* wait for disk_i_size to be stable and then update the
* in-memory size to match.
*/
err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (err)
return err;
i_size_write(inode, BTRFS_I(inode)->disk_i_size);
}
}
return ret;
}
static int btrfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct btrfs_root *root = BTRFS_I(inode)->root;
int err;
if (btrfs_root_readonly(root))
return -EROFS;
err = setattr_prepare(idmap, dentry, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
err = btrfs_setsize(inode, attr);
if (err)
return err;
}
if (attr->ia_valid) {
setattr_copy(idmap, inode, attr);
inode_inc_iversion(inode);
err = btrfs_dirty_inode(BTRFS_I(inode));
if (!err && attr->ia_valid & ATTR_MODE)
err = posix_acl_chmod(idmap, dentry, inode->i_mode);
}
return err;
}
/*
* While truncating the inode pages during eviction, we get the VFS
* calling btrfs_invalidate_folio() against each folio of the inode. This
* is slow because the calls to btrfs_invalidate_folio() result in a
* huge amount of calls to lock_extent() and clear_extent_bit(),
* which keep merging and splitting extent_state structures over and over,
* wasting lots of time.
*
* Therefore if the inode is being evicted, let btrfs_invalidate_folio()
* skip all those expensive operations on a per folio basis and do only
* the ordered io finishing, while we release here the extent_map and
* extent_state structures, without the excessive merging and splitting.
*/
static void evict_inode_truncate_pages(struct inode *inode)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct rb_node *node;
ASSERT(inode->i_state & I_FREEING);
truncate_inode_pages_final(&inode->i_data);
btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (u64)-1, false);
/*
* Keep looping until we have no more ranges in the io tree.
* We can have ongoing bios started by readahead that have
* their endio callback (extent_io.c:end_bio_extent_readpage)
* still in progress (unlocked the pages in the bio but did not yet
* unlocked the ranges in the io tree). Therefore this means some
* ranges can still be locked and eviction started because before
* submitting those bios, which are executed by a separate task (work
* queue kthread), inode references (inode->i_count) were not taken
* (which would be dropped in the end io callback of each bio).
* Therefore here we effectively end up waiting for those bios and
* anyone else holding locked ranges without having bumped the inode's
* reference count - if we don't do it, when they access the inode's
* io_tree to unlock a range it may be too late, leading to an
* use-after-free issue.
*/
spin_lock(&io_tree->lock);
while (!RB_EMPTY_ROOT(&io_tree->state)) {
struct extent_state *state;
struct extent_state *cached_state = NULL;
u64 start;
u64 end;
unsigned state_flags;
node = rb_first(&io_tree->state);
state = rb_entry(node, struct extent_state, rb_node);
start = state->start;
end = state->end;
state_flags = state->state;
spin_unlock(&io_tree->lock);
lock_extent(io_tree, start, end, &cached_state);
/*
* If still has DELALLOC flag, the extent didn't reach disk,
* and its reserved space won't be freed by delayed_ref.
* So we need to free its reserved space here.
* (Refer to comment in btrfs_invalidate_folio, case 2)
*
* Note, end is the bytenr of last byte, so we need + 1 here.
*/
if (state_flags & EXTENT_DELALLOC)
btrfs_qgroup_free_data(BTRFS_I(inode), NULL, start,
end - start + 1);
clear_extent_bit(io_tree, start, end,
EXTENT_CLEAR_ALL_BITS | EXTENT_DO_ACCOUNTING,
&cached_state);
cond_resched();
spin_lock(&io_tree->lock);
}
spin_unlock(&io_tree->lock);
}
static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
struct btrfs_block_rsv *rsv)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
u64 delayed_refs_extra = btrfs_calc_delayed_ref_bytes(fs_info, 1);
int ret;
/*
* Eviction should be taking place at some place safe because of our
* delayed iputs. However the normal flushing code will run delayed
* iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock.
*
* We reserve the delayed_refs_extra here again because we can't use
* btrfs_start_transaction(root, 0) for the same deadlocky reason as
* above. We reserve our extra bit here because we generate a ton of
* delayed refs activity by truncating.
*
* BTRFS_RESERVE_FLUSH_EVICT will steal from the global_rsv if it can,
* if we fail to make this reservation we can re-try without the
* delayed_refs_extra so we can make some forward progress.
*/
ret = btrfs_block_rsv_refill(fs_info, rsv, rsv->size + delayed_refs_extra,
BTRFS_RESERVE_FLUSH_EVICT);
if (ret) {
ret = btrfs_block_rsv_refill(fs_info, rsv, rsv->size,
BTRFS_RESERVE_FLUSH_EVICT);
if (ret) {
btrfs_warn(fs_info,
"could not allocate space for delete; will truncate on mount");
return ERR_PTR(-ENOSPC);
}
delayed_refs_extra = 0;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return trans;
if (delayed_refs_extra) {
trans->block_rsv = &fs_info->trans_block_rsv;
trans->bytes_reserved = delayed_refs_extra;
btrfs_block_rsv_migrate(rsv, trans->block_rsv,
delayed_refs_extra, true);
}
return trans;
}
void btrfs_evict_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv = NULL;
int ret;
trace_btrfs_inode_evict(inode);
if (!root) {
fsverity_cleanup_inode(inode);
clear_inode(inode);
return;
}
evict_inode_truncate_pages(inode);
if (inode->i_nlink &&
((btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
btrfs_is_free_space_inode(BTRFS_I(inode))))
goto out;
if (is_bad_inode(inode))
goto out;
if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
goto out;
if (inode->i_nlink > 0) {
BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
goto out;
}
/*
* This makes sure the inode item in tree is uptodate and the space for
* the inode update is released.
*/
ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
if (ret)
goto out;
/*
* This drops any pending insert or delete operations we have for this
* inode. We could have a delayed dir index deletion queued up, but
* we're removing the inode completely so that'll be taken care of in
* the truncate.
*/
btrfs_kill_delayed_inode_items(BTRFS_I(inode));
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
goto out;
rsv->size = btrfs_calc_metadata_size(fs_info, 1);
rsv->failfast = true;
btrfs_i_size_write(BTRFS_I(inode), 0);
while (1) {
struct btrfs_truncate_control control = {
.inode = BTRFS_I(inode),
.ino = btrfs_ino(BTRFS_I(inode)),
.new_size = 0,
.min_type = 0,
};
trans = evict_refill_and_join(root, rsv);
if (IS_ERR(trans))
goto out;
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, &control);
trans->block_rsv = &fs_info->trans_block_rsv;
btrfs_end_transaction(trans);
/*
* We have not added new delayed items for our inode after we
* have flushed its delayed items, so no need to throttle on
* delayed items. However we have modified extent buffers.
*/
btrfs_btree_balance_dirty_nodelay(fs_info);
if (ret && ret != -ENOSPC && ret != -EAGAIN)
goto out;
else if (!ret)
break;
}
/*
* Errors here aren't a big deal, it just means we leave orphan items in
* the tree. They will be cleaned up on the next mount. If the inode
* number gets reused, cleanup deletes the orphan item without doing
* anything, and unlink reuses the existing orphan item.
*
* If it turns out that we are dropping too many of these, we might want
* to add a mechanism for retrying these after a commit.
*/
trans = evict_refill_and_join(root, rsv);
if (!IS_ERR(trans)) {
trans->block_rsv = rsv;
btrfs_orphan_del(trans, BTRFS_I(inode));
trans->block_rsv = &fs_info->trans_block_rsv;
btrfs_end_transaction(trans);
}
out:
btrfs_free_block_rsv(fs_info, rsv);
/*
* If we didn't successfully delete, the orphan item will still be in
* the tree and we'll retry on the next mount. Again, we might also want
* to retry these periodically in the future.
*/
btrfs_remove_delayed_node(BTRFS_I(inode));
fsverity_cleanup_inode(inode);
clear_inode(inode);
}
/*
* Return the key found in the dir entry in the location pointer, fill @type
* with BTRFS_FT_*, and return 0.
*
* If no dir entries were found, returns -ENOENT.
* If found a corrupted location in dir entry, returns -EUCLEAN.
*/
static int btrfs_inode_by_name(struct btrfs_inode *dir, struct dentry *dentry,
struct btrfs_key *location, u8 *type)
{
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = dir->root;
int ret = 0;
struct fscrypt_name fname;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = fscrypt_setup_filename(&dir->vfs_inode, &dentry->d_name, 1, &fname);
if (ret < 0)
goto out;
/*
* fscrypt_setup_filename() should never return a positive value, but
* gcc on sparc/parisc thinks it can, so assert that doesn't happen.
*/
ASSERT(ret == 0);
/* This needs to handle no-key deletions later on */
di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir),
&fname.disk_name, 0);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto out;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
if (location->type != BTRFS_INODE_ITEM_KEY &&
location->type != BTRFS_ROOT_ITEM_KEY) {
ret = -EUCLEAN;
btrfs_warn(root->fs_info,
"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
__func__, fname.disk_name.name, btrfs_ino(dir),
location->objectid, location->type, location->offset);
}
if (!ret)
*type = btrfs_dir_ftype(path->nodes[0], di);
out:
fscrypt_free_filename(&fname);
btrfs_free_path(path);
return ret;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
struct btrfs_inode *dir,
struct dentry *dentry,
struct btrfs_key *location,
struct btrfs_root **sub_root)
{
struct btrfs_path *path;
struct btrfs_root *new_root;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
int err = 0;
struct fscrypt_name fname;
ret = fscrypt_setup_filename(&dir->vfs_inode, &dentry->d_name, 0, &fname);
if (ret)
return ret;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
err = -ENOENT;
key.objectid = dir->root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = location->objectid;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret) {
if (ret < 0)
err = ret;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
btrfs_root_ref_name_len(leaf, ref) != fname.disk_name.len)
goto out;
ret = memcmp_extent_buffer(leaf, fname.disk_name.name,
(unsigned long)(ref + 1), fname.disk_name.len);
if (ret)
goto out;
btrfs_release_path(path);
new_root = btrfs_get_fs_root(fs_info, location->objectid, true);
if (IS_ERR(new_root)) {
err = PTR_ERR(new_root);
goto out;
}
*sub_root = new_root;
location->objectid = btrfs_root_dirid(&new_root->root_item);
location->type = BTRFS_INODE_ITEM_KEY;
location->offset = 0;
err = 0;
out:
btrfs_free_path(path);
fscrypt_free_filename(&fname);
return err;
}
static void inode_tree_add(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
struct btrfs_inode *entry;
struct rb_node **p;
struct rb_node *parent;
struct rb_node *new = &inode->rb_node;
u64 ino = btrfs_ino(inode);
if (inode_unhashed(&inode->vfs_inode))
return;
parent = NULL;
spin_lock(&root->inode_lock);
p = &root->inode_tree.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_inode, rb_node);
if (ino < btrfs_ino(entry))
p = &parent->rb_left;
else if (ino > btrfs_ino(entry))
p = &parent->rb_right;
else {
WARN_ON(!(entry->vfs_inode.i_state &
(I_WILL_FREE | I_FREEING)));
rb_replace_node(parent, new, &root->inode_tree);
RB_CLEAR_NODE(parent);
spin_unlock(&root->inode_lock);
return;
}
}
rb_link_node(new, parent, p);
rb_insert_color(new, &root->inode_tree);
spin_unlock(&root->inode_lock);
}
static void inode_tree_del(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
int empty = 0;
spin_lock(&root->inode_lock);
if (!RB_EMPTY_NODE(&inode->rb_node)) {
rb_erase(&inode->rb_node, &root->inode_tree);
RB_CLEAR_NODE(&inode->rb_node);
empty = RB_EMPTY_ROOT(&root->inode_tree);
}
spin_unlock(&root->inode_lock);
if (empty && btrfs_root_refs(&root->root_item) == 0) {
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
spin_unlock(&root->inode_lock);
if (empty)
btrfs_add_dead_root(root);
}
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->ino;
BTRFS_I(inode)->location.objectid = args->ino;
BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
BTRFS_I(inode)->location.offset = 0;
BTRFS_I(inode)->root = btrfs_grab_root(args->root);
BUG_ON(args->root && !BTRFS_I(inode)->root);
if (args->root && args->root == args->root->fs_info->tree_root &&
args->ino != BTRFS_BTREE_INODE_OBJECTID)
set_bit(BTRFS_INODE_FREE_SPACE_INODE,
&BTRFS_I(inode)->runtime_flags);
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return args->ino == BTRFS_I(inode)->location.objectid &&
args->root == BTRFS_I(inode)->root;
}
static struct inode *btrfs_iget_locked(struct super_block *s, u64 ino,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
unsigned long hashval = btrfs_inode_hash(ino, root);
args.ino = ino;
args.root = root;
inode = iget5_locked(s, hashval, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
/*
* Get an inode object given its inode number and corresponding root.
* Path can be preallocated to prevent recursing back to iget through
* allocator. NULL is also valid but may require an additional allocation
* later.
*/
struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
struct btrfs_root *root, struct btrfs_path *path)
{
struct inode *inode;
inode = btrfs_iget_locked(s, ino, root);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
int ret;
ret = btrfs_read_locked_inode(inode, path);
if (!ret) {
inode_tree_add(BTRFS_I(inode));
unlock_new_inode(inode);
} else {
iget_failed(inode);
/*
* ret > 0 can come from btrfs_search_slot called by
* btrfs_read_locked_inode, this means the inode item
* was not found.
*/
if (ret > 0)
ret = -ENOENT;
inode = ERR_PTR(ret);
}
}
return inode;
}
struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root)
{
return btrfs_iget_path(s, ino, root, NULL);
}
static struct inode *new_simple_dir(struct super_block *s,
struct btrfs_key *key,
struct btrfs_root *root)
{
struct inode *inode = new_inode(s);
if (!inode)
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = btrfs_grab_root(root);
memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
/*
* We only need lookup, the rest is read-only and there's no inode
* associated with the dentry
*/
inode->i_op = &simple_dir_inode_operations;
inode->i_opflags &= ~IOP_XATTR;
inode->i_fop = &simple_dir_operations;
inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
inode->i_mtime = current_time(inode);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
return inode;
}
static_assert(BTRFS_FT_UNKNOWN == FT_UNKNOWN);
static_assert(BTRFS_FT_REG_FILE == FT_REG_FILE);
static_assert(BTRFS_FT_DIR == FT_DIR);
static_assert(BTRFS_FT_CHRDEV == FT_CHRDEV);
static_assert(BTRFS_FT_BLKDEV == FT_BLKDEV);
static_assert(BTRFS_FT_FIFO == FT_FIFO);
static_assert(BTRFS_FT_SOCK == FT_SOCK);
static_assert(BTRFS_FT_SYMLINK == FT_SYMLINK);
static inline u8 btrfs_inode_type(struct inode *inode)
{
return fs_umode_to_ftype(inode->i_mode);
}
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
u8 di_type = 0;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(BTRFS_I(dir), dentry, &location, &di_type);
if (ret < 0)
return ERR_PTR(ret);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, location.objectid, root);
if (IS_ERR(inode))
return inode;
/* Do extra check against inode mode with di_type */
if (btrfs_inode_type(inode) != di_type) {
btrfs_crit(fs_info,
"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
inode->i_mode, btrfs_inode_type(inode),
di_type);
iput(inode);
return ERR_PTR(-EUCLEAN);
}
return inode;
}
ret = fixup_tree_root_location(fs_info, BTRFS_I(dir), dentry,
&location, &sub_root);
if (ret < 0) {
if (ret != -ENOENT)
inode = ERR_PTR(ret);
else
inode = new_simple_dir(dir->i_sb, &location, root);
} else {
inode = btrfs_iget(dir->i_sb, location.objectid, sub_root);
btrfs_put_root(sub_root);
if (IS_ERR(inode))
return inode;
down_read(&fs_info->cleanup_work_sem);
if (!sb_rdonly(inode->i_sb))
ret = btrfs_orphan_cleanup(sub_root);
up_read(&fs_info->cleanup_work_sem);
if (ret) {
iput(inode);
inode = ERR_PTR(ret);
}
}
return inode;
}
static int btrfs_dentry_delete(const struct dentry *dentry)
{
struct btrfs_root *root;
struct inode *inode = d_inode(dentry);
if (!inode && !IS_ROOT(dentry))
inode = d_inode(dentry->d_parent);
if (inode) {
root = BTRFS_I(inode)->root;
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return 1;
}
return 0;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = btrfs_lookup_dentry(dir, dentry);
if (inode == ERR_PTR(-ENOENT))
inode = NULL;
return d_splice_alias(inode, dentry);
}
/*
* All this infrastructure exists because dir_emit can fault, and we are holding
* the tree lock when doing readdir. For now just allocate a buffer and copy
* our information into that, and then dir_emit from the buffer. This is
* similar to what NFS does, only we don't keep the buffer around in pagecache
* because I'm afraid I'll mess that up. Long term we need to make filldir do
* copy_to_user_inatomic so we don't have to worry about page faulting under the
* tree lock.
*/
static int btrfs_opendir(struct inode *inode, struct file *file)
{
struct btrfs_file_private *private;
private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
if (!private)
return -ENOMEM;
private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!private->filldir_buf) {
kfree(private);
return -ENOMEM;
}
file->private_data = private;
return 0;
}
struct dir_entry {
u64 ino;
u64 offset;
unsigned type;
int name_len;
};
static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
{
while (entries--) {
struct dir_entry *entry = addr;
char *name = (char *)(entry + 1);
ctx->pos = get_unaligned(&entry->offset);
if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
get_unaligned(&entry->ino),
get_unaligned(&entry->type)))
return 1;
addr += sizeof(struct dir_entry) +
get_unaligned(&entry->name_len);
ctx->pos++;
}
return 0;
}
static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_private *private = file->private_data;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
void *addr;
struct list_head ins_list;
struct list_head del_list;
int ret;
char *name_ptr;
int name_len;
int entries = 0;
int total_len = 0;
bool put = false;
struct btrfs_key location;
if (!dir_emit_dots(file, ctx))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
addr = private->filldir_buf;
path->reada = READA_FORWARD;
INIT_LIST_HEAD(&ins_list);
INIT_LIST_HEAD(&del_list);
put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
again:
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = ctx->pos;
key.objectid = btrfs_ino(BTRFS_I(inode));
btrfs_for_each_slot(root, &key, &found_key, path, ret) {
struct dir_entry *entry;
struct extent_buffer *leaf = path->nodes[0];
u8 ftype;
if (found_key.objectid != key.objectid)
break;
if (found_key.type != BTRFS_DIR_INDEX_KEY)
break;
if (found_key.offset < ctx->pos)
continue;
if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
continue;
di = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
name_len = btrfs_dir_name_len(leaf, di);
if ((total_len + sizeof(struct dir_entry) + name_len) >=
PAGE_SIZE) {
btrfs_release_path(path);
ret = btrfs_filldir(private->filldir_buf, entries, ctx);
if (ret)
goto nopos;
addr = private->filldir_buf;
entries = 0;
total_len = 0;
goto again;
}
ftype = btrfs_dir_flags_to_ftype(btrfs_dir_flags(leaf, di));
entry = addr;
name_ptr = (char *)(entry + 1);
read_extent_buffer(leaf, name_ptr,
(unsigned long)(di + 1), name_len);
put_unaligned(name_len, &entry->name_len);
put_unaligned(fs_ftype_to_dtype(ftype), &entry->type);
btrfs_dir_item_key_to_cpu(leaf, di, &location);
put_unaligned(location.objectid, &entry->ino);
put_unaligned(found_key.offset, &entry->offset);
entries++;
addr += sizeof(struct dir_entry) + name_len;
total_len += sizeof(struct dir_entry) + name_len;
}
/* Catch error encountered during iteration */
if (ret < 0)
goto err;
btrfs_release_path(path);
ret = btrfs_filldir(private->filldir_buf, entries, ctx);
if (ret)
goto nopos;
ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
if (ret)
goto nopos;
/*
* Stop new entries from being returned after we return the last
* entry.
*
* New directory entries are assigned a strictly increasing
* offset. This means that new entries created during readdir
* are *guaranteed* to be seen in the future by that readdir.
* This has broken buggy programs which operate on names as
* they're returned by readdir. Until we re-use freed offsets
* we have this hack to stop new entries from being returned
* under the assumption that they'll never reach this huge
* offset.
*
* This is being careful not to overflow 32bit loff_t unless the
* last entry requires it because doing so has broken 32bit apps
* in the past.
*/
if (ctx->pos >= INT_MAX)
ctx->pos = LLONG_MAX;
else
ctx->pos = INT_MAX;
nopos:
ret = 0;
err:
if (put)
btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
btrfs_free_path(path);
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
static int btrfs_dirty_inode(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
int ret;
if (test_bit(BTRFS_INODE_DUMMY, &inode->runtime_flags))
return 0;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
if (ret && (ret == -ENOSPC || ret == -EDQUOT)) {
/* whoops, lets try again with the full transaction */
btrfs_end_transaction(trans);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans);
if (inode->delayed_node)
btrfs_balance_delayed_items(fs_info);
return ret;
}
/*
* This is a copy of file_update_time. We need this so we can return error on
* ENOSPC for updating the inode in the case of file write and mmap writes.
*/
static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
int flags)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
bool dirty = flags & ~S_VERSION;
if (btrfs_root_readonly(root))
return -EROFS;
if (flags & S_VERSION)
dirty |= inode_maybe_inc_iversion(inode, dirty);
if (flags & S_CTIME)
inode->i_ctime = *now;
if (flags & S_MTIME)
inode->i_mtime = *now;
if (flags & S_ATIME)
inode->i_atime = *now;
return dirty ? btrfs_dirty_inode(BTRFS_I(inode)) : 0;
}
/*
* find the highest existing sequence number in a directory
* and then set the in-memory index_cnt variable to reflect
* free sequence numbers
*/
static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
struct btrfs_key key, found_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/* FIXME: we should be able to handle this */
if (ret == 0)
goto out;
ret = 0;
if (path->slots[0] == 0) {
inode->index_cnt = BTRFS_DIR_START_INDEX;
goto out;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != btrfs_ino(inode) ||
found_key.type != BTRFS_DIR_INDEX_KEY) {
inode->index_cnt = BTRFS_DIR_START_INDEX;
goto out;
}
inode->index_cnt = found_key.offset + 1;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to find a free sequence number in a given directory. This current
* code is very simple, later versions will do smarter things in the btree
*/
int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
{
int ret = 0;
if (dir->index_cnt == (u64)-1) {
ret = btrfs_inode_delayed_dir_index_count(dir);
if (ret) {
ret = btrfs_set_inode_index_count(dir);
if (ret)
return ret;
}
}
*index = dir->index_cnt;
dir->index_cnt++;
return ret;
}
static int btrfs_insert_inode_locked(struct inode *inode)
{
struct btrfs_iget_args args;
args.ino = BTRFS_I(inode)->location.objectid;
args.root = BTRFS_I(inode)->root;
return insert_inode_locked4(inode,
btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
btrfs_find_actor, &args);
}
int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
unsigned int *trans_num_items)
{
struct inode *dir = args->dir;
struct inode *inode = args->inode;
int ret;
if (!args->orphan) {
ret = fscrypt_setup_filename(dir, &args->dentry->d_name, 0,
&args->fname);
if (ret)
return ret;
}
ret = posix_acl_create(dir, &inode->i_mode, &args->default_acl, &args->acl);
if (ret) {
fscrypt_free_filename(&args->fname);
return ret;
}
/* 1 to add inode item */
*trans_num_items = 1;
/* 1 to add compression property */
if (BTRFS_I(dir)->prop_compress)
(*trans_num_items)++;
/* 1 to add default ACL xattr */
if (args->default_acl)
(*trans_num_items)++;
/* 1 to add access ACL xattr */
if (args->acl)
(*trans_num_items)++;
#ifdef CONFIG_SECURITY
/* 1 to add LSM xattr */
if (dir->i_security)
(*trans_num_items)++;
#endif
if (args->orphan) {
/* 1 to add orphan item */
(*trans_num_items)++;
} else {
/*
* 1 to add dir item
* 1 to add dir index
* 1 to update parent inode item
*
* No need for 1 unit for the inode ref item because it is
* inserted in a batch together with the inode item at
* btrfs_create_new_inode().
*/
*trans_num_items += 3;
}
return 0;
}
void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args)
{
posix_acl_release(args->acl);
posix_acl_release(args->default_acl);
fscrypt_free_filename(&args->fname);
}
/*
* Inherit flags from the parent inode.
*
* Currently only the compression flags and the cow flags are inherited.
*/
static void btrfs_inherit_iflags(struct btrfs_inode *inode, struct btrfs_inode *dir)
{
unsigned int flags;
flags = dir->flags;
if (flags & BTRFS_INODE_NOCOMPRESS) {
inode->flags &= ~BTRFS_INODE_COMPRESS;
inode->flags |= BTRFS_INODE_NOCOMPRESS;
} else if (flags & BTRFS_INODE_COMPRESS) {
inode->flags &= ~BTRFS_INODE_NOCOMPRESS;
inode->flags |= BTRFS_INODE_COMPRESS;
}
if (flags & BTRFS_INODE_NODATACOW) {
inode->flags |= BTRFS_INODE_NODATACOW;
if (S_ISREG(inode->vfs_inode.i_mode))
inode->flags |= BTRFS_INODE_NODATASUM;
}
btrfs_sync_inode_flags_to_i_flags(&inode->vfs_inode);
}
int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_new_inode_args *args)
{
struct inode *dir = args->dir;
struct inode *inode = args->inode;
const struct fscrypt_str *name = args->orphan ? NULL : &args->fname.disk_name;
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_root *root;
struct btrfs_inode_item *inode_item;
struct btrfs_key *location;
struct btrfs_path *path;
u64 objectid;
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
struct btrfs_item_batch batch;
unsigned long ptr;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (!args->subvol)
BTRFS_I(inode)->root = btrfs_grab_root(BTRFS_I(dir)->root);
root = BTRFS_I(inode)->root;
ret = btrfs_get_free_objectid(root, &objectid);
if (ret)
goto out;
inode->i_ino = objectid;
if (args->orphan) {
/*
* O_TMPFILE, set link count to 0, so that after this point, we
* fill in an inode item with the correct link count.
*/
set_nlink(inode, 0);
} else {
trace_btrfs_inode_request(dir);
ret = btrfs_set_inode_index(BTRFS_I(dir), &BTRFS_I(inode)->dir_index);
if (ret)
goto out;
}
/* index_cnt is ignored for everything but a dir. */
BTRFS_I(inode)->index_cnt = BTRFS_DIR_START_INDEX;
BTRFS_I(inode)->generation = trans->transid;
inode->i_generation = BTRFS_I(inode)->generation;
/*
* Subvolumes don't inherit flags from their parent directory.
* Originally this was probably by accident, but we probably can't
* change it now without compatibility issues.
*/
if (!args->subvol)
btrfs_inherit_iflags(BTRFS_I(inode), BTRFS_I(dir));
if (S_ISREG(inode->i_mode)) {
if (btrfs_test_opt(fs_info, NODATASUM))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
if (btrfs_test_opt(fs_info, NODATACOW))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM;
}
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
location->type = BTRFS_INODE_ITEM_KEY;
ret = btrfs_insert_inode_locked(inode);
if (ret < 0) {
if (!args->orphan)
BTRFS_I(dir)->index_cnt--;
goto out;
}
/*
* We could have gotten an inode number from somebody who was fsynced
* and then removed in this same transaction, so let's just set full
* sync since it will be a full sync anyway and this will blow away the
* old info in the log.
*/
btrfs_set_inode_full_sync(BTRFS_I(inode));
key[0].objectid = objectid;
key[0].type = BTRFS_INODE_ITEM_KEY;
key[0].offset = 0;
sizes[0] = sizeof(struct btrfs_inode_item);
if (!args->orphan) {
/*
* Start new inodes with an inode_ref. This is slightly more
* efficient for small numbers of hard links since they will
* be packed into one item. Extended refs will kick in if we
* add more hard links than can fit in the ref item.
*/
key[1].objectid = objectid;
key[1].type = BTRFS_INODE_REF_KEY;
if (args->subvol) {
key[1].offset = objectid;
sizes[1] = 2 + sizeof(*ref);
} else {
key[1].offset = btrfs_ino(BTRFS_I(dir));
sizes[1] = name->len + sizeof(*ref);
}
}
batch.keys = &key[0];
batch.data_sizes = &sizes[0];
batch.total_data_size = sizes[0] + (args->orphan ? 0 : sizes[1]);
batch.nr = args->orphan ? 1 : 2;
ret = btrfs_insert_empty_items(trans, root, path, &batch);
if (ret != 0) {
btrfs_abort_transaction(trans, ret);
goto discard;
}
inode->i_mtime = current_time(inode);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
/*
* We're going to fill the inode item now, so at this point the inode
* must be fully initialized.
*/
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
if (!args->orphan) {
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_inode_ref);
ptr = (unsigned long)(ref + 1);
if (args->subvol) {
btrfs_set_inode_ref_name_len(path->nodes[0], ref, 2);
btrfs_set_inode_ref_index(path->nodes[0], ref, 0);
write_extent_buffer(path->nodes[0], "..", ptr, 2);
} else {
btrfs_set_inode_ref_name_len(path->nodes[0], ref,
name->len);
btrfs_set_inode_ref_index(path->nodes[0], ref,
BTRFS_I(inode)->dir_index);
write_extent_buffer(path->nodes[0], name->name, ptr,
name->len);
}
}
btrfs_mark_buffer_dirty(path->nodes[0]);
/*
* We don't need the path anymore, plus inheriting properties, adding
* ACLs, security xattrs, orphan item or adding the link, will result in
* allocating yet another path. So just free our path.
*/
btrfs_free_path(path);
path = NULL;
if (args->subvol) {
struct inode *parent;
/*
* Subvolumes inherit properties from their parent subvolume,
* not the directory they were created in.
*/
parent = btrfs_iget(fs_info->sb, BTRFS_FIRST_FREE_OBJECTID,
BTRFS_I(dir)->root);
if (IS_ERR(parent)) {
ret = PTR_ERR(parent);
} else {
ret = btrfs_inode_inherit_props(trans, inode, parent);
iput(parent);
}
} else {
ret = btrfs_inode_inherit_props(trans, inode, dir);
}
if (ret) {
btrfs_err(fs_info,
"error inheriting props for ino %llu (root %llu): %d",
btrfs_ino(BTRFS_I(inode)), root->root_key.objectid,
ret);
}
/*
* Subvolumes don't inherit ACLs or get passed to the LSM. This is
* probably a bug.
*/
if (!args->subvol) {
ret = btrfs_init_inode_security(trans, args);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto discard;
}
}
inode_tree_add(BTRFS_I(inode));
trace_btrfs_inode_new(inode);
btrfs_set_inode_last_trans(trans, BTRFS_I(inode));
btrfs_update_root_times(trans, root);
if (args->orphan) {
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
} else {
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
0, BTRFS_I(inode)->dir_index);
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto discard;
}
return 0;
discard:
/*
* discard_new_inode() calls iput(), but the caller owns the reference
* to the inode.
*/
ihold(inode);
discard_new_inode(inode);
out:
btrfs_free_path(path);
return ret;
}
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
* if 'add_backref' is true, also insert a backref from the
* inode to the parent directory.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
const struct fscrypt_str *name, int add_backref, u64 index)
{
int ret = 0;
struct btrfs_key key;
struct btrfs_root *root = parent_inode->root;
u64 ino = btrfs_ino(inode);
u64 parent_ino = btrfs_ino(parent_inode);
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
memcpy(&key, &inode->root->root_key, sizeof(key));
} else {
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
}
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_add_root_ref(trans, key.objectid,
root->root_key.objectid, parent_ino,
index, name);
} else if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root, name,
ino, parent_ino, index);
}
/* Nothing to clean up yet */
if (ret)
return ret;
ret = btrfs_insert_dir_item(trans, name, parent_inode, &key,
btrfs_inode_type(&inode->vfs_inode), index);
if (ret == -EEXIST || ret == -EOVERFLOW)
goto fail_dir_item;
else if (ret) {
btrfs_abort_transaction(trans, ret);
return ret;
}
btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
name->len * 2);
inode_inc_iversion(&parent_inode->vfs_inode);
/*
* If we are replaying a log tree, we do not want to update the mtime
* and ctime of the parent directory with the current time, since the
* log replay procedure is responsible for setting them to their correct
* values (the ones it had when the fsync was done).
*/
if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
struct timespec64 now = current_time(&parent_inode->vfs_inode);
parent_inode->vfs_inode.i_mtime = now;
parent_inode->vfs_inode.i_ctime = now;
}
ret = btrfs_update_inode(trans, root, parent_inode);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
fail_dir_item:
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
u64 local_index;
int err;
err = btrfs_del_root_ref(trans, key.objectid,
root->root_key.objectid, parent_ino,
&local_index, name);
if (err)
btrfs_abort_transaction(trans, err);
} else if (add_backref) {
u64 local_index;
int err;
err = btrfs_del_inode_ref(trans, root, name, ino, parent_ino,
&local_index);
if (err)
btrfs_abort_transaction(trans, err);
}
/* Return the original error code */
return ret;
}
static int btrfs_create_common(struct inode *dir, struct dentry *dentry,
struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_new_inode_args new_inode_args = {
.dir = dir,
.dentry = dentry,
.inode = inode,
};
unsigned int trans_num_items;
struct btrfs_trans_handle *trans;
int err;
err = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
if (err)
goto out_inode;
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_new_inode_args;
}
err = btrfs_create_new_inode(trans, &new_inode_args);
if (!err)
d_instantiate_new(dentry, inode);
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
out_new_inode_args:
btrfs_new_inode_args_destroy(&new_inode_args);
out_inode:
if (err)
iput(inode);
return err;
}
static int btrfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct inode *inode;
inode = new_inode(dir->i_sb);
if (!inode)
return -ENOMEM;
inode_init_owner(idmap, inode, dir, mode);
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
return btrfs_create_common(dir, dentry, inode);
}
static int btrfs_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
struct inode *inode;
inode = new_inode(dir->i_sb);
if (!inode)
return -ENOMEM;
inode_init_owner(idmap, inode, dir, mode);
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
return btrfs_create_common(dir, dentry, inode);
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans = NULL;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(old_dentry);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct fscrypt_name fname;
u64 index;
int err;
int drop_inode = 0;
/* do not allow sys_link's with other subvols of the same device */
if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
return -EXDEV;
if (inode->i_nlink >= BTRFS_LINK_MAX)
return -EMLINK;
err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &fname);
if (err)
goto fail;
err = btrfs_set_inode_index(BTRFS_I(dir), &index);
if (err)
goto fail;
/*
* 2 items for inode and inode ref
* 2 items for dir items
* 1 item for parent inode
* 1 item for orphan item deletion if O_TMPFILE
*/
trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
trans = NULL;
goto fail;
}
/* There are several dir indexes for this inode, clear the cache. */
BTRFS_I(inode)->dir_index = 0ULL;
inc_nlink(inode);
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
ihold(inode);
set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
&fname.disk_name, 1, index);
if (err) {
drop_inode = 1;
} else {
struct dentry *parent = dentry->d_parent;
err = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (err)
goto fail;
if (inode->i_nlink == 1) {
/*
* If new hard link count is 1, it's a file created
* with open(2) O_TMPFILE flag.
*/
err = btrfs_orphan_del(trans, BTRFS_I(inode));
if (err)
goto fail;
}
d_instantiate(dentry, inode);
btrfs_log_new_name(trans, old_dentry, NULL, 0, parent);
}
fail:
fscrypt_free_filename(&fname);
if (trans)
btrfs_end_transaction(trans);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static int btrfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct inode *inode;
inode = new_inode(dir->i_sb);
if (!inode)
return -ENOMEM;
inode_init_owner(idmap, inode, dir, S_IFDIR | mode);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
return btrfs_create_common(dir, dentry, inode);
}
static noinline int uncompress_inline(struct btrfs_path *path,
struct page *page,
struct btrfs_file_extent_item *item)
{
int ret;
struct extent_buffer *leaf = path->nodes[0];
char *tmp;
size_t max_size;
unsigned long inline_size;
unsigned long ptr;
int compress_type;
compress_type = btrfs_file_extent_compression(leaf, item);
max_size = btrfs_file_extent_ram_bytes(leaf, item);
inline_size = btrfs_file_extent_inline_item_len(leaf, path->slots[0]);
tmp = kmalloc(inline_size, GFP_NOFS);
if (!tmp)
return -ENOMEM;
ptr = btrfs_file_extent_inline_start(item);
read_extent_buffer(leaf, tmp, ptr, inline_size);
max_size = min_t(unsigned long, PAGE_SIZE, max_size);
ret = btrfs_decompress(compress_type, tmp, page, 0, inline_size, max_size);
/*
* decompression code contains a memset to fill in any space between the end
* of the uncompressed data and the end of max_size in case the decompressed
* data ends up shorter than ram_bytes. That doesn't cover the hole between
* the end of an inline extent and the beginning of the next block, so we
* cover that region here.
*/
if (max_size < PAGE_SIZE)
memzero_page(page, max_size, PAGE_SIZE - max_size);
kfree(tmp);
return ret;
}
static int read_inline_extent(struct btrfs_inode *inode, struct btrfs_path *path,
struct page *page)
{
struct btrfs_file_extent_item *fi;
void *kaddr;
size_t copy_size;
if (!page || PageUptodate(page))
return 0;
ASSERT(page_offset(page) == 0);
fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_compression(path->nodes[0], fi) != BTRFS_COMPRESS_NONE)
return uncompress_inline(path, page, fi);
copy_size = min_t(u64, PAGE_SIZE,
btrfs_file_extent_ram_bytes(path->nodes[0], fi));
kaddr = kmap_local_page(page);
read_extent_buffer(path->nodes[0], kaddr,
btrfs_file_extent_inline_start(fi), copy_size);
kunmap_local(kaddr);
if (copy_size < PAGE_SIZE)
memzero_page(page, copy_size, PAGE_SIZE - copy_size);
return 0;
}
/*
* Lookup the first extent overlapping a range in a file.
*
* @inode: file to search in
* @page: page to read extent data into if the extent is inline
* @pg_offset: offset into @page to copy to
* @start: file offset
* @len: length of range starting at @start
*
* Return the first &struct extent_map which overlaps the given range, reading
* it from the B-tree and caching it if necessary. Note that there may be more
* extents which overlap the given range after the returned extent_map.
*
* If @page is not NULL and the extent is inline, this also reads the extent
* data directly into the page and marks the extent up to date in the io_tree.
*
* Return: ERR_PTR on error, non-NULL extent_map on success.
*/
struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
struct page *page, size_t pg_offset,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
int ret = 0;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = btrfs_ino(inode);
int extent_type = -1;
struct btrfs_path *path = NULL;
struct btrfs_root *root = inode->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &inode->extent_tree;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
read_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
free_extent_map(em);
else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
}
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto out;
}
em->start = EXTENT_MAP_HOLE;
em->orig_start = EXTENT_MAP_HOLE;
em->len = (u64)-1;
em->block_len = (u64)-1;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/* Chances are we'll be called again, so go ahead and do readahead */
path->reada = READA_FORWARD;
/*
* The same explanation in load_free_space_cache applies here as well,
* we only read when we're loading the free space cache, and at that
* point the commit_root has everything we need.
*/
if (btrfs_is_free_space_inode(inode)) {
path->search_commit_root = 1;
path->skip_locking = 1;
}
ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
if (ret < 0) {
goto out;
} else if (ret > 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
ret = 0;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY) {
/*
* If we backup past the first extent we want to move forward
* and see if there is an extent in front of us, otherwise we'll
* say there is a hole for our whole search range which can
* cause problems.
*/
extent_end = start;
goto next;
}
extent_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
extent_end = btrfs_file_extent_end(path);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
/* Only regular file could have regular/prealloc extent */
if (!S_ISREG(inode->vfs_inode.i_mode)) {
ret = -EUCLEAN;
btrfs_crit(fs_info,
"regular/prealloc extent found for non-regular inode %llu",
btrfs_ino(inode));
goto out;
}
trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
extent_start);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
path->slots[0],
extent_start);
}
next:
if (start >= extent_end) {
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
goto not_found;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY)
goto not_found;
if (start + len <= found_key.offset)
goto not_found;
if (start > found_key.offset)
goto next;
/* New extent overlaps with existing one */
em->start = start;
em->orig_start = start;
em->len = found_key.offset - start;
em->block_start = EXTENT_MAP_HOLE;
goto insert;
}
btrfs_extent_item_to_extent_map(inode, path, item, em);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
goto insert;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
/*
* Inline extent can only exist at file offset 0. This is
* ensured by tree-checker and inline extent creation path.
* Thus all members representing file offsets should be zero.
*/
ASSERT(pg_offset == 0);
ASSERT(extent_start == 0);
ASSERT(em->start == 0);
/*
* btrfs_extent_item_to_extent_map() should have properly
* initialized em members already.
*
* Other members are not utilized for inline extents.
*/
ASSERT(em->block_start == EXTENT_MAP_INLINE);
ASSERT(em->len == fs_info->sectorsize);
ret = read_inline_extent(inode, path, page);
if (ret < 0)
goto out;
goto insert;
}
not_found:
em->start = start;
em->orig_start = start;
em->len = len;
em->block_start = EXTENT_MAP_HOLE;
insert:
ret = 0;
btrfs_release_path(path);
if (em->start > start || extent_map_end(em) <= start) {
btrfs_err(fs_info,
"bad extent! em: [%llu %llu] passed [%llu %llu]",
em->start, em->len, start, len);
ret = -EIO;
goto out;
}
write_lock(&em_tree->lock);
ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
write_unlock(&em_tree->lock);
out:
btrfs_free_path(path);
trace_btrfs_get_extent(root, inode, em);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
return em;
}
static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
struct btrfs_dio_data *dio_data,
const u64 start,
const u64 len,
const u64 orig_start,
const u64 block_start,
const u64 block_len,
const u64 orig_block_len,
const u64 ram_bytes,
const int type)
{
struct extent_map *em = NULL;
struct btrfs_ordered_extent *ordered;
if (type != BTRFS_ORDERED_NOCOW) {
em = create_io_em(inode, start, len, orig_start, block_start,
block_len, orig_block_len, ram_bytes,
BTRFS_COMPRESS_NONE, /* compress_type */
type);
if (IS_ERR(em))
goto out;
}
ordered = btrfs_alloc_ordered_extent(inode, start, len, len,
block_start, block_len, 0,
(1 << type) |
(1 << BTRFS_ORDERED_DIRECT),
BTRFS_COMPRESS_NONE);
if (IS_ERR(ordered)) {
if (em) {
free_extent_map(em);
btrfs_drop_extent_map_range(inode, start,
start + len - 1, false);
}
em = ERR_CAST(ordered);
} else {
ASSERT(!dio_data->ordered);
dio_data->ordered = ordered;
}
out:
return em;
}
static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
struct btrfs_dio_data *dio_data,
u64 start, u64 len)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_map *em;
struct btrfs_key ins;
u64 alloc_hint;
int ret;
alloc_hint = get_extent_allocation_hint(inode, start, len);
ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
0, alloc_hint, &ins, 1, 1);
if (ret)
return ERR_PTR(ret);
em = btrfs_create_dio_extent(inode, dio_data, start, ins.offset, start,
ins.objectid, ins.offset, ins.offset,
ins.offset, BTRFS_ORDERED_REGULAR);
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(em))
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset,
1);
return em;
}
static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr)
{
struct btrfs_block_group *block_group;
bool readonly = false;
block_group = btrfs_lookup_block_group(fs_info, bytenr);
if (!block_group || block_group->ro)
readonly = true;
if (block_group)
btrfs_put_block_group(block_group);
return readonly;
}
/*
* Check if we can do nocow write into the range [@offset, @offset + @len)
*
* @offset: File offset
* @len: The length to write, will be updated to the nocow writeable
* range
* @orig_start: (optional) Return the original file offset of the file extent
* @orig_len: (optional) Return the original on-disk length of the file extent
* @ram_bytes: (optional) Return the ram_bytes of the file extent
* @strict: if true, omit optimizations that might force us into unnecessary
* cow. e.g., don't trust generation number.
*
* Return:
* >0 and update @len if we can do nocow write
* 0 if we can't do nocow write
* <0 if error happened
*
* NOTE: This only checks the file extents, caller is responsible to wait for
* any ordered extents.
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
u64 *ram_bytes, bool nowait, bool strict)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct can_nocow_file_extent_args nocow_args = { 0 };
struct btrfs_path *path;
int ret;
struct extent_buffer *leaf;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
int found_type;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->nowait = nowait;
ret = btrfs_lookup_file_extent(NULL, root, path,
btrfs_ino(BTRFS_I(inode)), offset, 0);
if (ret < 0)
goto out;
if (ret == 1) {
if (path->slots[0] == 0) {
/* can't find the item, must cow */
ret = 0;
goto out;
}
path->slots[0]--;
}
ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
/* not our file or wrong item type, must cow */
goto out;
}
if (key.offset > offset) {
/* Wrong offset, must cow */
goto out;
}
if (btrfs_file_extent_end(path) <= offset)
goto out;
fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, fi);
if (ram_bytes)
*ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
nocow_args.start = offset;
nocow_args.end = offset + *len - 1;
nocow_args.strict = strict;
nocow_args.free_path = true;
ret = can_nocow_file_extent(path, &key, BTRFS_I(inode), &nocow_args);
/* can_nocow_file_extent() has freed the path. */
path = NULL;
if (ret != 1) {
/* Treat errors as not being able to NOCOW. */
ret = 0;
goto out;
}
ret = 0;
if (btrfs_extent_readonly(fs_info, nocow_args.disk_bytenr))
goto out;
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 range_end;
range_end = round_up(offset + nocow_args.num_bytes,
root->fs_info->sectorsize) - 1;
ret = test_range_bit(io_tree, offset, range_end,
EXTENT_DELALLOC, 0, NULL);
if (ret) {
ret = -EAGAIN;
goto out;
}
}
if (orig_start)
*orig_start = key.offset - nocow_args.extent_offset;
if (orig_block_len)
*orig_block_len = nocow_args.disk_num_bytes;
*len = nocow_args.num_bytes;
ret = 1;
out:
btrfs_free_path(path);
return ret;
}
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
struct extent_state **cached_state,
unsigned int iomap_flags)
{
const bool writing = (iomap_flags & IOMAP_WRITE);
const bool nowait = (iomap_flags & IOMAP_NOWAIT);
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
int ret = 0;
while (1) {
if (nowait) {
if (!try_lock_extent(io_tree, lockstart, lockend,
cached_state))
return -EAGAIN;
} else {
lock_extent(io_tree, lockstart, lockend, cached_state);
}
/*
* We're concerned with the entire range that we're going to be
* doing DIO to, so we need to make sure there's no ordered
* extents in this range.
*/
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
lockend - lockstart + 1);
/*
* We need to make sure there are no buffered pages in this
* range either, we could have raced between the invalidate in
* generic_file_direct_write and locking the extent. The
* invalidate needs to happen so that reads after a write do not
* get stale data.
*/
if (!ordered &&
(!writing || !filemap_range_has_page(inode->i_mapping,
lockstart, lockend)))
break;
unlock_extent(io_tree, lockstart, lockend, cached_state);
if (ordered) {
if (nowait) {
btrfs_put_ordered_extent(ordered);
ret = -EAGAIN;
break;
}
/*
* If we are doing a DIO read and the ordered extent we
* found is for a buffered write, we can not wait for it
* to complete and retry, because if we do so we can
* deadlock with concurrent buffered writes on page
* locks. This happens only if our DIO read covers more
* than one extent map, if at this point has already
* created an ordered extent for a previous extent map
* and locked its range in the inode's io tree, and a
* concurrent write against that previous extent map's
* range and this range started (we unlock the ranges
* in the io tree only when the bios complete and
* buffered writes always lock pages before attempting
* to lock range in the io tree).
*/
if (writing ||
test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
btrfs_start_ordered_extent(ordered);
else
ret = nowait ? -EAGAIN : -ENOTBLK;
btrfs_put_ordered_extent(ordered);
} else {
/*
* We could trigger writeback for this range (and wait
* for it to complete) and then invalidate the pages for
* this range (through invalidate_inode_pages2_range()),
* but that can lead us to a deadlock with a concurrent
* call to readahead (a buffered read or a defrag call
* triggered a readahead) on a page lock due to an
* ordered dio extent we created before but did not have
* yet a corresponding bio submitted (whence it can not
* complete), which makes readahead wait for that
* ordered extent to complete while holding a lock on
* that page.
*/
ret = nowait ? -EAGAIN : -ENOTBLK;
}
if (ret)
break;
cond_resched();
}
return ret;
}
/* The callers of this must take lock_extent() */
static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
u64 len, u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type)
{
struct extent_map *em;
int ret;
ASSERT(type == BTRFS_ORDERED_PREALLOC ||
type == BTRFS_ORDERED_COMPRESSED ||
type == BTRFS_ORDERED_NOCOW ||
type == BTRFS_ORDERED_REGULAR);
em = alloc_extent_map();
if (!em)
return ERR_PTR(-ENOMEM);
em->start = start;
em->orig_start = orig_start;
em->len = len;
em->block_len = block_len;
em->block_start = block_start;
em->orig_block_len = orig_block_len;
em->ram_bytes = ram_bytes;
em->generation = -1;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
if (type == BTRFS_ORDERED_PREALLOC) {
set_bit(EXTENT_FLAG_FILLING, &em->flags);
} else if (type == BTRFS_ORDERED_COMPRESSED) {
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->compress_type = compress_type;
}
ret = btrfs_replace_extent_map_range(inode, em, true);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
/* em got 2 refs now, callers needs to do free_extent_map once. */
return em;
}
static int btrfs_get_blocks_direct_write(struct extent_map **map,
struct inode *inode,
struct btrfs_dio_data *dio_data,
u64 start, u64 *lenp,
unsigned int iomap_flags)
{
const bool nowait = (iomap_flags & IOMAP_NOWAIT);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em = *map;
int type;
u64 block_start, orig_start, orig_block_len, ram_bytes;
struct btrfs_block_group *bg;
bool can_nocow = false;
bool space_reserved = false;
u64 len = *lenp;
u64 prev_len;
int ret = 0;
/*
* We don't allocate a new extent in the following cases
*
* 1) The inode is marked as NODATACOW. In this case we'll just use the
* existing extent.
* 2) The extent is marked as PREALLOC. We're good to go here and can
* just use the extent.
*
*/
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
em->block_start != EXTENT_MAP_HOLE)) {
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
type = BTRFS_ORDERED_PREALLOC;
else
type = BTRFS_ORDERED_NOCOW;
len = min(len, em->len - (start - em->start));
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
&orig_block_len, &ram_bytes, false, false) == 1) {
bg = btrfs_inc_nocow_writers(fs_info, block_start);
if (bg)
can_nocow = true;
}
}
prev_len = len;
if (can_nocow) {
struct extent_map *em2;
/* We can NOCOW, so only need to reserve metadata space. */
ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len,
nowait);
if (ret < 0) {
/* Our caller expects us to free the input extent map. */
free_extent_map(em);
*map = NULL;
btrfs_dec_nocow_writers(bg);
if (nowait && (ret == -ENOSPC || ret == -EDQUOT))
ret = -EAGAIN;
goto out;
}
space_reserved = true;
em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, len,
orig_start, block_start,
len, orig_block_len,
ram_bytes, type);
btrfs_dec_nocow_writers(bg);
if (type == BTRFS_ORDERED_PREALLOC) {
free_extent_map(em);
*map = em2;
em = em2;
}
if (IS_ERR(em2)) {
ret = PTR_ERR(em2);
goto out;
}
dio_data->nocow_done = true;
} else {
/* Our caller expects us to free the input extent map. */
free_extent_map(em);
*map = NULL;
if (nowait) {
ret = -EAGAIN;
goto out;
}
/*
* If we could not allocate data space before locking the file
* range and we can't do a NOCOW write, then we have to fail.
*/
if (!dio_data->data_space_reserved) {
ret = -ENOSPC;
goto out;
}
/*
* We have to COW and we have already reserved data space before,
* so now we reserve only metadata.
*/
ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len,
false);
if (ret < 0)
goto out;
space_reserved = true;
em = btrfs_new_extent_direct(BTRFS_I(inode), dio_data, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
*map = em;
len = min(len, em->len - (start - em->start));
if (len < prev_len)
btrfs_delalloc_release_metadata(BTRFS_I(inode),
prev_len - len, true);
}
/*
* We have created our ordered extent, so we can now release our reservation
* for an outstanding extent.
*/
btrfs_delalloc_release_extents(BTRFS_I(inode), prev_len);
/*
* Need to update the i_size under the extent lock so buffered
* readers will get the updated i_size when we unlock.
*/
if (start + len > i_size_read(inode))
i_size_write(inode, start + len);
out:
if (ret && space_reserved) {
btrfs_delalloc_release_extents(BTRFS_I(inode), len);
btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true);
}
*lenp = len;
return ret;
}
static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
loff_t length, unsigned int flags, struct iomap *iomap,
struct iomap *srcmap)
{
struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em;
struct extent_state *cached_state = NULL;
struct btrfs_dio_data *dio_data = iter->private;
u64 lockstart, lockend;
const bool write = !!(flags & IOMAP_WRITE);
int ret = 0;
u64 len = length;
const u64 data_alloc_len = length;
bool unlock_extents = false;
/*
* We could potentially fault if we have a buffer > PAGE_SIZE, and if
* we're NOWAIT we may submit a bio for a partial range and return
* EIOCBQUEUED, which would result in an errant short read.
*
* The best way to handle this would be to allow for partial completions
* of iocb's, so we could submit the partial bio, return and fault in
* the rest of the pages, and then submit the io for the rest of the
* range. However we don't have that currently, so simply return
* -EAGAIN at this point so that the normal path is used.
*/
if (!write && (flags & IOMAP_NOWAIT) && length > PAGE_SIZE)
return -EAGAIN;
/*
* Cap the size of reads to that usually seen in buffered I/O as we need
* to allocate a contiguous array for the checksums.
*/
if (!write)
len = min_t(u64, len, fs_info->sectorsize * BTRFS_MAX_BIO_SECTORS);
lockstart = start;
lockend = start + len - 1;
/*
* iomap_dio_rw() only does filemap_write_and_wait_range(), which isn't
* enough if we've written compressed pages to this area, so we need to
* flush the dirty pages again to make absolutely sure that any
* outstanding dirty pages are on disk - the first flush only starts
* compression on the data, while keeping the pages locked, so by the
* time the second flush returns we know bios for the compressed pages
* were submitted and finished, and the pages no longer under writeback.
*
* If we have a NOWAIT request and we have any pages in the range that
* are locked, likely due to compression still in progress, we don't want
* to block on page locks. We also don't want to block on pages marked as
* dirty or under writeback (same as for the non-compression case).
* iomap_dio_rw() did the same check, but after that and before we got
* here, mmap'ed writes may have happened or buffered reads started
* (readpage() and readahead(), which lock pages), as we haven't locked
* the file range yet.
*/
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags)) {
if (flags & IOMAP_NOWAIT) {
if (filemap_range_needs_writeback(inode->i_mapping,
lockstart, lockend))
return -EAGAIN;
} else {
ret = filemap_fdatawrite_range(inode->i_mapping, start,
start + length - 1);
if (ret)
return ret;
}
}
memset(dio_data, 0, sizeof(*dio_data));
/*
* We always try to allocate data space and must do it before locking
* the file range, to avoid deadlocks with concurrent writes to the same
* range if the range has several extents and the writes don't expand the
* current i_size (the inode lock is taken in shared mode). If we fail to
* allocate data space here we continue and later, after locking the
* file range, we fail with ENOSPC only if we figure out we can not do a
* NOCOW write.
*/
if (write && !(flags & IOMAP_NOWAIT)) {
ret = btrfs_check_data_free_space(BTRFS_I(inode),
&dio_data->data_reserved,
start, data_alloc_len, false);
if (!ret)
dio_data->data_space_reserved = true;
else if (ret && !(BTRFS_I(inode)->flags &
(BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
goto err;
}
/*
* If this errors out it's because we couldn't invalidate pagecache for
* this range and we need to fallback to buffered IO, or we are doing a
* NOWAIT read/write and we need to block.
*/
ret = lock_extent_direct(inode, lockstart, lockend, &cached_state, flags);
if (ret < 0)
goto err;
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
/*
* Ok for INLINE and COMPRESSED extents we need to fallback on buffered
* io. INLINE is special, and we could probably kludge it in here, but
* it's still buffered so for safety lets just fall back to the generic
* buffered path.
*
* For COMPRESSED we _have_ to read the entire extent in so we can
* decompress it, so there will be buffering required no matter what we
* do, so go ahead and fallback to buffered.
*
* We return -ENOTBLK because that's what makes DIO go ahead and go back
* to buffered IO. Don't blame me, this is the price we pay for using
* the generic code.
*/
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
em->block_start == EXTENT_MAP_INLINE) {
free_extent_map(em);
/*
* If we are in a NOWAIT context, return -EAGAIN in order to
* fallback to buffered IO. This is not only because we can
* block with buffered IO (no support for NOWAIT semantics at
* the moment) but also to avoid returning short reads to user
* space - this happens if we were able to read some data from
* previous non-compressed extents and then when we fallback to
* buffered IO, at btrfs_file_read_iter() by calling
* filemap_read(), we fail to fault in pages for the read buffer,
* in which case filemap_read() returns a short read (the number
* of bytes previously read is > 0, so it does not return -EFAULT).
*/
ret = (flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOTBLK;
goto unlock_err;
}
len = min(len, em->len - (start - em->start));
/*
* If we have a NOWAIT request and the range contains multiple extents
* (or a mix of extents and holes), then we return -EAGAIN to make the
* caller fallback to a context where it can do a blocking (without
* NOWAIT) request. This way we avoid doing partial IO and returning
* success to the caller, which is not optimal for writes and for reads
* it can result in unexpected behaviour for an application.
*
* When doing a read, because we use IOMAP_DIO_PARTIAL when calling
* iomap_dio_rw(), we can end up returning less data then what the caller
* asked for, resulting in an unexpected, and incorrect, short read.
* That is, the caller asked to read N bytes and we return less than that,
* which is wrong unless we are crossing EOF. This happens if we get a
* page fault error when trying to fault in pages for the buffer that is
* associated to the struct iov_iter passed to iomap_dio_rw(), and we
* have previously submitted bios for other extents in the range, in
* which case iomap_dio_rw() may return us EIOCBQUEUED if not all of
* those bios have completed by the time we get the page fault error,
* which we return back to our caller - we should only return EIOCBQUEUED
* after we have submitted bios for all the extents in the range.
*/
if ((flags & IOMAP_NOWAIT) && len < length) {
free_extent_map(em);
ret = -EAGAIN;
goto unlock_err;
}
if (write) {
ret = btrfs_get_blocks_direct_write(&em, inode, dio_data,
start, &len, flags);
if (ret < 0)
goto unlock_err;
unlock_extents = true;
/* Recalc len in case the new em is smaller than requested */
len = min(len, em->len - (start - em->start));
if (dio_data->data_space_reserved) {
u64 release_offset;
u64 release_len = 0;
if (dio_data->nocow_done) {
release_offset = start;
release_len = data_alloc_len;
} else if (len < data_alloc_len) {
release_offset = start + len;
release_len = data_alloc_len - len;
}
if (release_len > 0)
btrfs_free_reserved_data_space(BTRFS_I(inode),
dio_data->data_reserved,
release_offset,
release_len);
}
} else {
/*
* We need to unlock only the end area that we aren't using.
* The rest is going to be unlocked by the endio routine.
*/
lockstart = start + len;
if (lockstart < lockend)
unlock_extents = true;
}
if (unlock_extents)
unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
&cached_state);
else
free_extent_state(cached_state);
/*
* Translate extent map information to iomap.
* We trim the extents (and move the addr) even though iomap code does
* that, since we have locked only the parts we are performing I/O in.
*/
if ((em->block_start == EXTENT_MAP_HOLE) ||
(test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && !write)) {
iomap->addr = IOMAP_NULL_ADDR;
iomap->type = IOMAP_HOLE;
} else {
iomap->addr = em->block_start + (start - em->start);
iomap->type = IOMAP_MAPPED;
}
iomap->offset = start;
iomap->bdev = fs_info->fs_devices->latest_dev->bdev;
iomap->length = len;
free_extent_map(em);
return 0;
unlock_err:
unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
&cached_state);
err:
if (dio_data->data_space_reserved) {
btrfs_free_reserved_data_space(BTRFS_I(inode),
dio_data->data_reserved,
start, data_alloc_len);
extent_changeset_free(dio_data->data_reserved);
}
return ret;
}
static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,
ssize_t written, unsigned int flags, struct iomap *iomap)
{
struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap);
struct btrfs_dio_data *dio_data = iter->private;
size_t submitted = dio_data->submitted;
const bool write = !!(flags & IOMAP_WRITE);
int ret = 0;
if (!write && (iomap->type == IOMAP_HOLE)) {
/* If reading from a hole, unlock and return */
unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1,
NULL);
return 0;
}
if (submitted < length) {
pos += submitted;
length -= submitted;
if (write)
btrfs_mark_ordered_io_finished(BTRFS_I(inode), NULL,
pos, length, false);
else
unlock_extent(&BTRFS_I(inode)->io_tree, pos,
pos + length - 1, NULL);
ret = -ENOTBLK;
}
if (write) {
btrfs_put_ordered_extent(dio_data->ordered);
dio_data->ordered = NULL;
}
if (write)
extent_changeset_free(dio_data->data_reserved);
return ret;
}
static void btrfs_dio_end_io(struct btrfs_bio *bbio)
{
struct btrfs_dio_private *dip =
container_of(bbio, struct btrfs_dio_private, bbio);
struct btrfs_inode *inode = bbio->inode;
struct bio *bio = &bbio->bio;
if (bio->bi_status) {
btrfs_warn(inode->root->fs_info,
"direct IO failed ino %llu op 0x%0x offset %#llx len %u err no %d",
btrfs_ino(inode), bio->bi_opf,
dip->file_offset, dip->bytes, bio->bi_status);
}
if (btrfs_op(bio) == BTRFS_MAP_WRITE)
btrfs_mark_ordered_io_finished(inode, NULL, dip->file_offset,
dip->bytes, !bio->bi_status);
else
unlock_extent(&inode->io_tree, dip->file_offset,
dip->file_offset + dip->bytes - 1, NULL);
bbio->bio.bi_private = bbio->private;
iomap_dio_bio_end_io(bio);
}
static void btrfs_dio_submit_io(const struct iomap_iter *iter, struct bio *bio,
loff_t file_offset)
{
struct btrfs_bio *bbio = btrfs_bio(bio);
struct btrfs_dio_private *dip =
container_of(bbio, struct btrfs_dio_private, bbio);
struct btrfs_dio_data *dio_data = iter->private;
btrfs_bio_init(bbio, BTRFS_I(iter->inode)->root->fs_info,
btrfs_dio_end_io, bio->bi_private);
bbio->inode = BTRFS_I(iter->inode);
bbio->file_offset = file_offset;
dip->file_offset = file_offset;
dip->bytes = bio->bi_iter.bi_size;
dio_data->submitted += bio->bi_iter.bi_size;
/*
* Check if we are doing a partial write. If we are, we need to split
* the ordered extent to match the submitted bio. Hang on to the
* remaining unfinishable ordered_extent in dio_data so that it can be
* cancelled in iomap_end to avoid a deadlock wherein faulting the
* remaining pages is blocked on the outstanding ordered extent.
*/
if (iter->flags & IOMAP_WRITE) {
int ret;
ret = btrfs_extract_ordered_extent(bbio, dio_data->ordered);
if (ret) {
btrfs_bio_end_io(bbio, errno_to_blk_status(ret));
return;
}
}
btrfs_submit_bio(bbio, 0);
}
static const struct iomap_ops btrfs_dio_iomap_ops = {
.iomap_begin = btrfs_dio_iomap_begin,
.iomap_end = btrfs_dio_iomap_end,
};
static const struct iomap_dio_ops btrfs_dio_ops = {
.submit_io = btrfs_dio_submit_io,
.bio_set = &btrfs_dio_bioset,
};
ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_before)
{
struct btrfs_dio_data data = { 0 };
return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
IOMAP_DIO_PARTIAL, &data, done_before);
}
struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
size_t done_before)
{
struct btrfs_dio_data data = { 0 };
return __iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
IOMAP_DIO_PARTIAL, &data, done_before);
}
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
int ret;
ret = fiemap_prep(inode, fieinfo, start, &len, 0);
if (ret)
return ret;
/*
* fiemap_prep() called filemap_write_and_wait() for the whole possible
* file range (0 to LLONG_MAX), but that is not enough if we have
* compression enabled. The first filemap_fdatawrite_range() only kicks
* in the compression of data (in an async thread) and will return
* before the compression is done and writeback is started. A second
* filemap_fdatawrite_range() is needed to wait for the compression to
* complete and writeback to start. We also need to wait for ordered
* extents to complete, because our fiemap implementation uses mainly
* file extent items to list the extents, searching for extent maps
* only for file ranges with holes or prealloc extents to figure out
* if we have delalloc in those ranges.
*/
if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC) {
ret = btrfs_wait_ordered_range(inode, 0, LLONG_MAX);
if (ret)
return ret;
}
return extent_fiemap(BTRFS_I(inode), fieinfo, start, len);
}
static int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return extent_writepages(mapping, wbc);
}
static void btrfs_readahead(struct readahead_control *rac)
{
extent_readahead(rac);
}
/*
* For release_folio() and invalidate_folio() we have a race window where
* folio_end_writeback() is called but the subpage spinlock is not yet released.
* If we continue to release/invalidate the page, we could cause use-after-free
* for subpage spinlock. So this function is to spin and wait for subpage
* spinlock.
*/
static void wait_subpage_spinlock(struct page *page)
{
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
struct btrfs_subpage *subpage;
if (!btrfs_is_subpage(fs_info, page))
return;
ASSERT(PagePrivate(page) && page->private);
subpage = (struct btrfs_subpage *)page->private;
/*
* This may look insane as we just acquire the spinlock and release it,
* without doing anything. But we just want to make sure no one is
* still holding the subpage spinlock.
* And since the page is not dirty nor writeback, and we have page
* locked, the only possible way to hold a spinlock is from the endio
* function to clear page writeback.
*
* Here we just acquire the spinlock so that all existing callers
* should exit and we're safe to release/invalidate the page.
*/
spin_lock_irq(&subpage->lock);
spin_unlock_irq(&subpage->lock);
}
static bool __btrfs_release_folio(struct folio *folio, gfp_t gfp_flags)
{
int ret = try_release_extent_mapping(&folio->page, gfp_flags);
if (ret == 1) {
wait_subpage_spinlock(&folio->page);
clear_page_extent_mapped(&folio->page);
}
return ret;
}
static bool btrfs_release_folio(struct folio *folio, gfp_t gfp_flags)
{
if (folio_test_writeback(folio) || folio_test_dirty(folio))
return false;
return __btrfs_release_folio(folio, gfp_flags);
}
#ifdef CONFIG_MIGRATION
static int btrfs_migrate_folio(struct address_space *mapping,
struct folio *dst, struct folio *src,
enum migrate_mode mode)
{
int ret = filemap_migrate_folio(mapping, dst, src, mode);
if (ret != MIGRATEPAGE_SUCCESS)
return ret;
if (folio_test_ordered(src)) {
folio_clear_ordered(src);
folio_set_ordered(dst);
}
return MIGRATEPAGE_SUCCESS;
}
#else
#define btrfs_migrate_folio NULL
#endif
static void btrfs_invalidate_folio(struct folio *folio, size_t offset,
size_t length)
{
struct btrfs_inode *inode = BTRFS_I(folio->mapping->host);
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct extent_io_tree *tree = &inode->io_tree;
struct extent_state *cached_state = NULL;
u64 page_start = folio_pos(folio);
u64 page_end = page_start + folio_size(folio) - 1;
u64 cur;
int inode_evicting = inode->vfs_inode.i_state & I_FREEING;
/*
* We have folio locked so no new ordered extent can be created on this
* page, nor bio can be submitted for this folio.
*
* But already submitted bio can still be finished on this folio.
* Furthermore, endio function won't skip folio which has Ordered
* (Private2) already cleared, so it's possible for endio and
* invalidate_folio to do the same ordered extent accounting twice
* on one folio.
*
* So here we wait for any submitted bios to finish, so that we won't
* do double ordered extent accounting on the same folio.
*/
folio_wait_writeback(folio);
wait_subpage_spinlock(&folio->page);
/*
* For subpage case, we have call sites like
* btrfs_punch_hole_lock_range() which passes range not aligned to
* sectorsize.
* If the range doesn't cover the full folio, we don't need to and
* shouldn't clear page extent mapped, as folio->private can still
* record subpage dirty bits for other part of the range.
*
* For cases that invalidate the full folio even the range doesn't
* cover the full folio, like invalidating the last folio, we're
* still safe to wait for ordered extent to finish.
*/
if (!(offset == 0 && length == folio_size(folio))) {
btrfs_release_folio(folio, GFP_NOFS);
return;
}
if (!inode_evicting)
lock_extent(tree, page_start, page_end, &cached_state);
cur = page_start;
while (cur < page_end) {
struct btrfs_ordered_extent *ordered;
u64 range_end;
u32 range_len;
u32 extra_flags = 0;
ordered = btrfs_lookup_first_ordered_range(inode, cur,
page_end + 1 - cur);
if (!ordered) {
range_end = page_end;
/*
* No ordered extent covering this range, we are safe
* to delete all extent states in the range.
*/
extra_flags = EXTENT_CLEAR_ALL_BITS;
goto next;
}
if (ordered->file_offset > cur) {
/*
* There is a range between [cur, oe->file_offset) not
* covered by any ordered extent.
* We are safe to delete all extent states, and handle
* the ordered extent in the next iteration.
*/
range_end = ordered->file_offset - 1;
extra_flags = EXTENT_CLEAR_ALL_BITS;
goto next;
}
range_end = min(ordered->file_offset + ordered->num_bytes - 1,
page_end);
ASSERT(range_end + 1 - cur < U32_MAX);
range_len = range_end + 1 - cur;
if (!btrfs_page_test_ordered(fs_info, &folio->page, cur, range_len)) {
/*
* If Ordered (Private2) is cleared, it means endio has
* already been executed for the range.
* We can't delete the extent states as
* btrfs_finish_ordered_io() may still use some of them.
*/
goto next;
}
btrfs_page_clear_ordered(fs_info, &folio->page, cur, range_len);
/*
* IO on this page will never be started, so we need to account
* for any ordered extents now. Don't clear EXTENT_DELALLOC_NEW
* here, must leave that up for the ordered extent completion.
*
* This will also unlock the range for incoming
* btrfs_finish_ordered_io().
*/
if (!inode_evicting)
clear_extent_bit(tree, cur, range_end,
EXTENT_DELALLOC |
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, &cached_state);
spin_lock_irq(&inode->ordered_tree.lock);
set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
ordered->truncated_len = min(ordered->truncated_len,
cur - ordered->file_offset);
spin_unlock_irq(&inode->ordered_tree.lock);
/*
* If the ordered extent has finished, we're safe to delete all
* the extent states of the range, otherwise
* btrfs_finish_ordered_io() will get executed by endio for
* other pages, so we can't delete extent states.
*/
if (btrfs_dec_test_ordered_pending(inode, &ordered,
cur, range_end + 1 - cur)) {
btrfs_finish_ordered_io(ordered);
/*
* The ordered extent has finished, now we're again
* safe to delete all extent states of the range.
*/
extra_flags = EXTENT_CLEAR_ALL_BITS;
}
next:
if (ordered)
btrfs_put_ordered_extent(ordered);
/*
* Qgroup reserved space handler
* Sector(s) here will be either:
*
* 1) Already written to disk or bio already finished
* Then its QGROUP_RESERVED bit in io_tree is already cleared.
* Qgroup will be handled by its qgroup_record then.
* btrfs_qgroup_free_data() call will do nothing here.
*
* 2) Not written to disk yet
* Then btrfs_qgroup_free_data() call will clear the
* QGROUP_RESERVED bit of its io_tree, and free the qgroup
* reserved data space.
* Since the IO will never happen for this page.
*/
btrfs_qgroup_free_data(inode, NULL, cur, range_end + 1 - cur);
if (!inode_evicting) {
clear_extent_bit(tree, cur, range_end, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_UPTODATE |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG |
extra_flags, &cached_state);
}
cur = range_end + 1;
}
/*
* We have iterated through all ordered extents of the page, the page
* should not have Ordered (Private2) anymore, or the above iteration
* did something wrong.
*/
ASSERT(!folio_test_ordered(folio));
btrfs_page_clear_checked(fs_info, &folio->page, folio_pos(folio), folio_size(folio));
if (!inode_evicting)
__btrfs_release_folio(folio, GFP_NOFS);
clear_page_extent_mapped(&folio->page);
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* truncate_setsize() writes the inode size before removing pages, once we have
* the page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
unsigned long zero_start;
loff_t size;
vm_fault_t ret;
int ret2;
int reserved = 0;
u64 reserved_space;
u64 page_start;
u64 page_end;
u64 end;
reserved_space = PAGE_SIZE;
sb_start_pagefault(inode->i_sb);
page_start = page_offset(page);
page_end = page_start + PAGE_SIZE - 1;
end = page_end;
/*
* Reserving delalloc space after obtaining the page lock can lead to
* deadlock. For example, if a dirty page is locked by this function
* and the call to btrfs_delalloc_reserve_space() ends up triggering
* dirty page write out, then the btrfs_writepages() function could
* end up waiting indefinitely to get a lock on the page currently
* being processed by btrfs_page_mkwrite() function.
*/
ret2 = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
page_start, reserved_space);
if (!ret2) {
ret2 = file_update_time(vmf->vma->vm_file);
reserved = 1;
}
if (ret2) {
ret = vmf_error(ret2);
if (reserved)
goto out;
goto out_noreserve;
}
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
again:
down_read(&BTRFS_I(inode)->i_mmap_lock);
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
wait_on_page_writeback(page);
lock_extent(io_tree, page_start, page_end, &cached_state);
ret2 = set_page_extent_mapped(page);
if (ret2 < 0) {
ret = vmf_error(ret2);
unlock_extent(io_tree, page_start, page_end, &cached_state);
goto out_unlock;
}
/*
* we can't set the delalloc bits if there are pending ordered
* extents. Drop our locks and wait for them to finish
*/
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
PAGE_SIZE);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, &cached_state);
unlock_page(page);
up_read(&BTRFS_I(inode)->i_mmap_lock);
btrfs_start_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
goto again;
}
if (page->index == ((size - 1) >> PAGE_SHIFT)) {
reserved_space = round_up(size - page_start,
fs_info->sectorsize);
if (reserved_space < PAGE_SIZE) {
end = page_start + reserved_space - 1;
btrfs_delalloc_release_space(BTRFS_I(inode),
data_reserved, page_start,
PAGE_SIZE - reserved_space, true);
}
}
/*
* page_mkwrite gets called when the page is firstly dirtied after it's
* faulted in, but write(2) could also dirty a page and set delalloc
* bits, thus in this case for space account reason, we still need to
* clear any delalloc bits within this page range since we have to
* reserve data&meta space before lock_page() (see above comments).
*/
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, &cached_state);
ret2 = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, end, 0,
&cached_state);
if (ret2) {
unlock_extent(io_tree, page_start, page_end, &cached_state);
ret = VM_FAULT_SIGBUS;
goto out_unlock;
}
/* page is wholly or partially inside EOF */
if (page_start + PAGE_SIZE > size)
zero_start = offset_in_page(size);
else
zero_start = PAGE_SIZE;
if (zero_start != PAGE_SIZE)
memzero_page(page, zero_start, PAGE_SIZE - zero_start);
btrfs_page_clear_checked(fs_info, page, page_start, PAGE_SIZE);
btrfs_page_set_dirty(fs_info, page, page_start, end + 1 - page_start);
btrfs_page_set_uptodate(fs_info, page, page_start, end + 1 - page_start);
btrfs_set_inode_last_sub_trans(BTRFS_I(inode));
unlock_extent(io_tree, page_start, page_end, &cached_state);
up_read(&BTRFS_I(inode)->i_mmap_lock);
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
return VM_FAULT_LOCKED;
out_unlock:
unlock_page(page);
up_read(&BTRFS_I(inode)->i_mmap_lock);
out:
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start,
reserved_space, (ret != 0));
out_noreserve:
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
return ret;
}
static int btrfs_truncate(struct btrfs_inode *inode, bool skip_writeback)
{
struct btrfs_truncate_control control = {
.inode = inode,
.ino = btrfs_ino(inode),
.min_type = BTRFS_EXTENT_DATA_KEY,
.clear_extent_range = true,
};
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_rsv *rsv;
int ret;
struct btrfs_trans_handle *trans;
u64 mask = fs_info->sectorsize - 1;
u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
if (!skip_writeback) {
ret = btrfs_wait_ordered_range(&inode->vfs_inode,
inode->vfs_inode.i_size & (~mask),
(u64)-1);
if (ret)
return ret;
}
/*
* Yes ladies and gentlemen, this is indeed ugly. We have a couple of
* things going on here:
*
* 1) We need to reserve space to update our inode.
*
* 2) We need to have something to cache all the space that is going to
* be free'd up by the truncate operation, but also have some slack
* space reserved in case it uses space during the truncate (thank you
* very much snapshotting).
*
* And we need these to be separate. The fact is we can use a lot of
* space doing the truncate, and we have no earthly idea how much space
* we will use, so we need the truncate reservation to be separate so it
* doesn't end up using space reserved for updating the inode. We also
* need to be able to stop the transaction and start a new one, which
* means we need to be able to update the inode several times, and we
* have no idea of knowing how many times that will be, so we can't just
* reserve 1 item for the entirety of the operation, so that has to be
* done separately as well.
*
* So that leaves us with
*
* 1) rsv - for the truncate reservation, which we will steal from the
* transaction reservation.
* 2) fs_info->trans_block_rsv - this will have 1 items worth left for
* updating the inode.
*/
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
return -ENOMEM;
rsv->size = min_size;
rsv->failfast = true;
/*
* 1 for the truncate slack space
* 1 for updating the inode.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
/* Migrate the slack space for the truncate to our reserve */
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
min_size, false);
BUG_ON(ret);
trans->block_rsv = rsv;
while (1) {
struct extent_state *cached_state = NULL;
const u64 new_size = inode->vfs_inode.i_size;
const u64 lock_start = ALIGN_DOWN(new_size, fs_info->sectorsize);
control.new_size = new_size;
lock_extent(&inode->io_tree, lock_start, (u64)-1, &cached_state);
/*
* We want to drop from the next block forward in case this new
* size is not block aligned since we will be keeping the last
* block of the extent just the way it is.
*/
btrfs_drop_extent_map_range(inode,
ALIGN(new_size, fs_info->sectorsize),
(u64)-1, false);
ret = btrfs_truncate_inode_items(trans, root, &control);
inode_sub_bytes(&inode->vfs_inode, control.sub_bytes);
btrfs_inode_safe_disk_i_size_write(inode, control.last_size);
unlock_extent(&inode->io_tree, lock_start, (u64)-1, &cached_state);
trans->block_rsv = &fs_info->trans_block_rsv;
if (ret != -ENOSPC && ret != -EAGAIN)
break;
ret = btrfs_update_inode(trans, root, inode);
if (ret)
break;
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
break;
}
btrfs_block_rsv_release(fs_info, rsv, -1, NULL);
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
rsv, min_size, false);
BUG_ON(ret); /* shouldn't happen */
trans->block_rsv = rsv;
}
/*
* We can't call btrfs_truncate_block inside a trans handle as we could
* deadlock with freeze, if we got BTRFS_NEED_TRUNCATE_BLOCK then we
* know we've truncated everything except the last little bit, and can
* do btrfs_truncate_block and then update the disk_i_size.
*/
if (ret == BTRFS_NEED_TRUNCATE_BLOCK) {
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
ret = btrfs_truncate_block(inode, inode->vfs_inode.i_size, 0, 0);
if (ret)
goto out;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_inode_safe_disk_i_size_write(inode, 0);
}
if (trans) {
int ret2;
trans->block_rsv = &fs_info->trans_block_rsv;
ret2 = btrfs_update_inode(trans, root, inode);
if (ret2 && !ret)
ret = ret2;
ret2 = btrfs_end_transaction(trans);
if (ret2 && !ret)
ret = ret2;
btrfs_btree_balance_dirty(fs_info);
}
out:
btrfs_free_block_rsv(fs_info, rsv);
/*
* So if we truncate and then write and fsync we normally would just
* write the extents that changed, which is a problem if we need to
* first truncate that entire inode. So set this flag so we write out
* all of the extents in the inode to the sync log so we're completely
* safe.
*
* If no extents were dropped or trimmed we don't need to force the next
* fsync to truncate all the inode's items from the log and re-log them
* all. This means the truncate operation did not change the file size,
* or changed it to a smaller size but there was only an implicit hole
* between the old i_size and the new i_size, and there were no prealloc
* extents beyond i_size to drop.
*/
if (control.extents_found > 0)
btrfs_set_inode_full_sync(inode);
return ret;
}
struct inode *btrfs_new_subvol_inode(struct mnt_idmap *idmap,
struct inode *dir)
{
struct inode *inode;
inode = new_inode(dir->i_sb);
if (inode) {
/*
* Subvolumes don't inherit the sgid bit or the parent's gid if
* the parent's sgid bit is set. This is probably a bug.
*/
inode_init_owner(idmap, inode, NULL,
S_IFDIR | (~current_umask() & S_IRWXUGO));
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
}
return inode;
}
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_inode *ei;
struct inode *inode;
ei = alloc_inode_sb(sb, btrfs_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
ei->root = NULL;
ei->generation = 0;
ei->last_trans = 0;
ei->last_sub_trans = 0;
ei->logged_trans = 0;
ei->delalloc_bytes = 0;
ei->new_delalloc_bytes = 0;
ei->defrag_bytes = 0;
ei->disk_i_size = 0;
ei->flags = 0;
ei->ro_flags = 0;
ei->csum_bytes = 0;
ei->index_cnt = (u64)-1;
ei->dir_index = 0;
ei->last_unlink_trans = 0;
ei->last_reflink_trans = 0;
ei->last_log_commit = 0;
spin_lock_init(&ei->lock);
ei->outstanding_extents = 0;
if (sb->s_magic != BTRFS_TEST_MAGIC)
btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
BTRFS_BLOCK_RSV_DELALLOC);
ei->runtime_flags = 0;
ei->prop_compress = BTRFS_COMPRESS_NONE;
ei->defrag_compress = BTRFS_COMPRESS_NONE;
ei->delayed_node = NULL;
ei->i_otime.tv_sec = 0;
ei->i_otime.tv_nsec = 0;
inode = &ei->vfs_inode;
extent_map_tree_init(&ei->extent_tree);
extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO);
ei->io_tree.inode = ei;
extent_io_tree_init(fs_info, &ei->file_extent_tree,
IO_TREE_INODE_FILE_EXTENT);
mutex_init(&ei->log_mutex);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->delalloc_inodes);
INIT_LIST_HEAD(&ei->delayed_iput);
RB_CLEAR_NODE(&ei->rb_node);
init_rwsem(&ei->i_mmap_lock);
return inode;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_destroy_inode(struct inode *inode)
{
btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (u64)-1, false);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
#endif
void btrfs_free_inode(struct inode *inode)
{
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
void btrfs_destroy_inode(struct inode *vfs_inode)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_inode *inode = BTRFS_I(vfs_inode);
struct btrfs_root *root = inode->root;
bool freespace_inode;
WARN_ON(!hlist_empty(&vfs_inode->i_dentry));
WARN_ON(vfs_inode->i_data.nrpages);
WARN_ON(inode->block_rsv.reserved);
WARN_ON(inode->block_rsv.size);
WARN_ON(inode->outstanding_extents);
if (!S_ISDIR(vfs_inode->i_mode)) {
WARN_ON(inode->delalloc_bytes);
WARN_ON(inode->new_delalloc_bytes);
}
WARN_ON(inode->csum_bytes);
WARN_ON(inode->defrag_bytes);
/*
* This can happen where we create an inode, but somebody else also
* created the same inode and we need to destroy the one we already
* created.
*/
if (!root)
return;
/*
* If this is a free space inode do not take the ordered extents lockdep
* map.
*/
freespace_inode = btrfs_is_free_space_inode(inode);
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
break;
else {
btrfs_err(root->fs_info,
"found ordered extent %llu %llu on inode cleanup",
ordered->file_offset, ordered->num_bytes);
if (!freespace_inode)
btrfs_lockdep_acquire(root->fs_info, btrfs_ordered_extent);
btrfs_remove_ordered_extent(inode, ordered);
btrfs_put_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
btrfs_qgroup_check_reserved_leak(inode);
inode_tree_del(inode);
btrfs_drop_extent_map_range(inode, 0, (u64)-1, false);
btrfs_inode_clear_file_extent_range(inode, 0, (u64)-1);
btrfs_put_root(inode->root);
}
int btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (root == NULL)
return 1;
/* the snap/subvol tree is on deleting */
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
else
return generic_drop_inode(inode);
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = foo;
inode_init_once(&ei->vfs_inode);
}
void __cold btrfs_destroy_cachep(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
bioset_exit(&btrfs_dio_bioset);
kmem_cache_destroy(btrfs_inode_cachep);
}
int __init btrfs_init_cachep(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
sizeof(struct btrfs_inode), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
init_once);
if (!btrfs_inode_cachep)
goto fail;
if (bioset_init(&btrfs_dio_bioset, BIO_POOL_SIZE,
offsetof(struct btrfs_dio_private, bbio.bio),
BIOSET_NEED_BVECS))
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(struct mnt_idmap *idmap,
const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags)
{
u64 delalloc_bytes;
u64 inode_bytes;
struct inode *inode = d_inode(path->dentry);
u32 blocksize = inode->i_sb->s_blocksize;
u32 bi_flags = BTRFS_I(inode)->flags;
u32 bi_ro_flags = BTRFS_I(inode)->ro_flags;
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
if (bi_flags & BTRFS_INODE_APPEND)
stat->attributes |= STATX_ATTR_APPEND;
if (bi_flags & BTRFS_INODE_COMPRESS)
stat->attributes |= STATX_ATTR_COMPRESSED;
if (bi_flags & BTRFS_INODE_IMMUTABLE)
stat->attributes |= STATX_ATTR_IMMUTABLE;
if (bi_flags & BTRFS_INODE_NODUMP)
stat->attributes |= STATX_ATTR_NODUMP;
if (bi_ro_flags & BTRFS_INODE_RO_VERITY)
stat->attributes |= STATX_ATTR_VERITY;
stat->attributes_mask |= (STATX_ATTR_APPEND |
STATX_ATTR_COMPRESSED |
STATX_ATTR_IMMUTABLE |
STATX_ATTR_NODUMP);
generic_fillattr(idmap, inode, stat);
stat->dev = BTRFS_I(inode)->root->anon_dev;
spin_lock(&BTRFS_I(inode)->lock);
delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
inode_bytes = inode_get_bytes(inode);
spin_unlock(&BTRFS_I(inode)->lock);
stat->blocks = (ALIGN(inode_bytes, blocksize) +
ALIGN(delalloc_bytes, blocksize)) >> SECTOR_SHIFT;
return 0;
}
static int btrfs_rename_exchange(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
struct btrfs_trans_handle *trans;
unsigned int trans_num_items;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = new_dentry->d_inode;
struct inode *old_inode = old_dentry->d_inode;
struct timespec64 ctime = current_time(old_inode);
struct btrfs_rename_ctx old_rename_ctx;
struct btrfs_rename_ctx new_rename_ctx;
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
u64 old_idx = 0;
u64 new_idx = 0;
int ret;
int ret2;
bool need_abort = false;
struct fscrypt_name old_fname, new_fname;
struct fscrypt_str *old_name, *new_name;
/*
* For non-subvolumes allow exchange only within one subvolume, in the
* same inode namespace. Two subvolumes (represented as directory) can
* be exchanged as they're a logical link and have a fixed inode number.
*/
if (root != dest &&
(old_ino != BTRFS_FIRST_FREE_OBJECTID ||
new_ino != BTRFS_FIRST_FREE_OBJECTID))
return -EXDEV;
ret = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_fname);
if (ret)
return ret;
ret = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_fname);
if (ret) {
fscrypt_free_filename(&old_fname);
return ret;
}
old_name = &old_fname.disk_name;
new_name = &new_fname.disk_name;
/* close the race window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID ||
new_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
/*
* For each inode:
* 1 to remove old dir item
* 1 to remove old dir index
* 1 to add new dir item
* 1 to add new dir index
* 1 to update parent inode
*
* If the parents are the same, we only need to account for one
*/
trans_num_items = (old_dir == new_dir ? 9 : 10);
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
/*
* 1 to remove old root ref
* 1 to remove old root backref
* 1 to add new root ref
* 1 to add new root backref
*/
trans_num_items += 4;
} else {
/*
* 1 to update inode item
* 1 to remove old inode ref
* 1 to add new inode ref
*/
trans_num_items += 3;
}
if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
trans_num_items += 4;
else
trans_num_items += 3;
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root) {
ret = btrfs_record_root_in_trans(trans, dest);
if (ret)
goto out_fail;
}
/*
* We need to find a free sequence number both in the source and
* in the destination directory for the exchange.
*/
ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
if (ret)
goto out_fail;
ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
BTRFS_I(new_inode)->dir_index = 0ULL;
/* Reference for the source. */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
ret = btrfs_insert_inode_ref(trans, dest, new_name, old_ino,
btrfs_ino(BTRFS_I(new_dir)),
old_idx);
if (ret)
goto out_fail;
need_abort = true;
}
/* And now for the dest. */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
ret = btrfs_insert_inode_ref(trans, root, old_name, new_ino,
btrfs_ino(BTRFS_I(old_dir)),
new_idx);
if (ret) {
if (need_abort)
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
/* Update inode version and ctime/mtime. */
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
inode_inc_iversion(new_inode);
old_dir->i_mtime = ctime;
old_dir->i_ctime = ctime;
new_dir->i_mtime = ctime;
new_dir->i_ctime = ctime;
old_inode->i_ctime = ctime;
new_inode->i_ctime = ctime;
if (old_dentry->d_parent != new_dentry->d_parent) {
btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
BTRFS_I(old_inode), true);
btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
BTRFS_I(new_inode), true);
}
/* src is a subvolume */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_unlink_subvol(trans, BTRFS_I(old_dir), old_dentry);
} else { /* src is an inode */
ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
BTRFS_I(old_dentry->d_inode),
old_name, &old_rename_ctx);
if (!ret)
ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
/* dest is a subvolume */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_unlink_subvol(trans, BTRFS_I(new_dir), new_dentry);
} else { /* dest is an inode */
ret = __btrfs_unlink_inode(trans, BTRFS_I(new_dir),
BTRFS_I(new_dentry->d_inode),
new_name, &new_rename_ctx);
if (!ret)
ret = btrfs_update_inode(trans, dest, BTRFS_I(new_inode));
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
new_name, 0, old_idx);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
old_name, 0, new_idx);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = old_idx;
if (new_inode->i_nlink == 1)
BTRFS_I(new_inode)->dir_index = new_idx;
/*
* Now pin the logs of the roots. We do it to ensure that no other task
* can sync the logs while we are in progress with the rename, because
* that could result in an inconsistency in case any of the inodes that
* are part of this rename operation were logged before.
*/
if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_pin_log_trans(root);
if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_pin_log_trans(dest);
/* Do the log updates for all inodes. */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
old_rename_ctx.index, new_dentry->d_parent);
if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_log_new_name(trans, new_dentry, BTRFS_I(new_dir),
new_rename_ctx.index, old_dentry->d_parent);
/* Now unpin the logs. */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_end_log_trans(root);
if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_end_log_trans(dest);
out_fail:
ret2 = btrfs_end_transaction(trans);
ret = ret ? ret : ret2;
out_notrans:
if (new_ino == BTRFS_FIRST_FREE_OBJECTID ||
old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
fscrypt_free_filename(&new_fname);
fscrypt_free_filename(&old_fname);
return ret;
}
static struct inode *new_whiteout_inode(struct mnt_idmap *idmap,
struct inode *dir)
{
struct inode *inode;
inode = new_inode(dir->i_sb);
if (inode) {
inode_init_owner(idmap, inode, dir,
S_IFCHR | WHITEOUT_MODE);
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
}
return inode;
}
static int btrfs_rename(struct mnt_idmap *idmap,
struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
struct btrfs_new_inode_args whiteout_args = {
.dir = old_dir,
.dentry = old_dentry,
};
struct btrfs_trans_handle *trans;
unsigned int trans_num_items;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = d_inode(new_dentry);
struct inode *old_inode = d_inode(old_dentry);
struct btrfs_rename_ctx rename_ctx;
u64 index = 0;
int ret;
int ret2;
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
struct fscrypt_name old_fname, new_fname;
if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return -EPERM;
/* we only allow rename subvolume link between subvolumes */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
return -EXDEV;
if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
(new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
return -ENOTEMPTY;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
ret = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_fname);
if (ret)
return ret;
ret = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_fname);
if (ret) {
fscrypt_free_filename(&old_fname);
return ret;
}
/* check for collisions, even if the name isn't there */
ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, &new_fname.disk_name);
if (ret) {
if (ret == -EEXIST) {
/* we shouldn't get
* eexist without a new_inode */
if (WARN_ON(!new_inode)) {
goto out_fscrypt_names;
}
} else {
/* maybe -EOVERFLOW */
goto out_fscrypt_names;
}
}
ret = 0;
/*
* we're using rename to replace one file with another. Start IO on it
* now so we don't add too much work to the end of the transaction
*/
if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
filemap_flush(old_inode->i_mapping);
if (flags & RENAME_WHITEOUT) {
whiteout_args.inode = new_whiteout_inode(idmap, old_dir);
if (!whiteout_args.inode) {
ret = -ENOMEM;
goto out_fscrypt_names;
}
ret = btrfs_new_inode_prepare(&whiteout_args, &trans_num_items);
if (ret)
goto out_whiteout_inode;
} else {
/* 1 to update the old parent inode. */
trans_num_items = 1;
}
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* Close the race window with snapshot create/destroy ioctl */
down_read(&fs_info->subvol_sem);
/*
* 1 to remove old root ref
* 1 to remove old root backref
* 1 to add new root ref
* 1 to add new root backref
*/
trans_num_items += 4;
} else {
/*
* 1 to update inode
* 1 to remove old inode ref
* 1 to add new inode ref
*/
trans_num_items += 3;
}
/*
* 1 to remove old dir item
* 1 to remove old dir index
* 1 to add new dir item
* 1 to add new dir index
*/
trans_num_items += 4;
/* 1 to update new parent inode if it's not the same as the old parent */
if (new_dir != old_dir)
trans_num_items++;
if (new_inode) {
/*
* 1 to update inode
* 1 to remove inode ref
* 1 to remove dir item
* 1 to remove dir index
* 1 to possibly add orphan item
*/
trans_num_items += 5;
}
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root) {
ret = btrfs_record_root_in_trans(trans, dest);
if (ret)
goto out_fail;
}
ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
ret = btrfs_insert_inode_ref(trans, dest, &new_fname.disk_name,
old_ino, btrfs_ino(BTRFS_I(new_dir)),
index);
if (ret)
goto out_fail;
}
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
old_dir->i_mtime = current_time(old_dir);
old_dir->i_ctime = old_dir->i_mtime;
new_dir->i_mtime = old_dir->i_mtime;
new_dir->i_ctime = old_dir->i_mtime;
old_inode->i_ctime = old_dir->i_mtime;
if (old_dentry->d_parent != new_dentry->d_parent)
btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
BTRFS_I(old_inode), true);
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_unlink_subvol(trans, BTRFS_I(old_dir), old_dentry);
} else {
ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
BTRFS_I(d_inode(old_dentry)),
&old_fname.disk_name, &rename_ctx);
if (!ret)
ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (new_inode) {
inode_inc_iversion(new_inode);
new_inode->i_ctime = current_time(new_inode);
if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
ret = btrfs_unlink_subvol(trans, BTRFS_I(new_dir), new_dentry);
BUG_ON(new_inode->i_nlink == 0);
} else {
ret = btrfs_unlink_inode(trans, BTRFS_I(new_dir),
BTRFS_I(d_inode(new_dentry)),
&new_fname.disk_name);
}
if (!ret && new_inode->i_nlink == 0)
ret = btrfs_orphan_add(trans,
BTRFS_I(d_inode(new_dentry)));
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
&new_fname.disk_name, 0, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = index;
if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
rename_ctx.index, new_dentry->d_parent);
if (flags & RENAME_WHITEOUT) {
ret = btrfs_create_new_inode(trans, &whiteout_args);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
} else {
unlock_new_inode(whiteout_args.inode);
iput(whiteout_args.inode);
whiteout_args.inode = NULL;
}
}
out_fail:
ret2 = btrfs_end_transaction(trans);
ret = ret ? ret : ret2;
out_notrans:
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
if (flags & RENAME_WHITEOUT)
btrfs_new_inode_args_destroy(&whiteout_args);
out_whiteout_inode:
if (flags & RENAME_WHITEOUT)
iput(whiteout_args.inode);
out_fscrypt_names:
fscrypt_free_filename(&old_fname);
fscrypt_free_filename(&new_fname);
return ret;
}
static int btrfs_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
struct dentry *old_dentry, struct inode *new_dir,
struct dentry *new_dentry, unsigned int flags)
{
int ret;
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
return -EINVAL;
if (flags & RENAME_EXCHANGE)
ret = btrfs_rename_exchange(old_dir, old_dentry, new_dir,
new_dentry);
else
ret = btrfs_rename(idmap, old_dir, old_dentry, new_dir,
new_dentry, flags);
btrfs_btree_balance_dirty(BTRFS_I(new_dir)->root->fs_info);
return ret;
}
struct btrfs_delalloc_work {
struct inode *inode;
struct completion completion;
struct list_head list;
struct btrfs_work work;
};
static void btrfs_run_delalloc_work(struct btrfs_work *work)
{
struct btrfs_delalloc_work *delalloc_work;
struct inode *inode;
delalloc_work = container_of(work, struct btrfs_delalloc_work,
work);
inode = delalloc_work->inode;
filemap_flush(inode->i_mapping);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_flush(inode->i_mapping);
iput(inode);
complete(&delalloc_work->completion);
}
static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
{
struct btrfs_delalloc_work *work;
work = kmalloc(sizeof(*work), GFP_NOFS);
if (!work)
return NULL;
init_completion(&work->completion);
INIT_LIST_HEAD(&work->list);
work->inode = inode;
btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
return work;
}
/*
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
static int start_delalloc_inodes(struct btrfs_root *root,
struct writeback_control *wbc, bool snapshot,
bool in_reclaim_context)
{
struct btrfs_inode *binode;
struct inode *inode;
struct btrfs_delalloc_work *work, *next;
struct list_head works;
struct list_head splice;
int ret = 0;
bool full_flush = wbc->nr_to_write == LONG_MAX;
INIT_LIST_HEAD(&works);
INIT_LIST_HEAD(&splice);
mutex_lock(&root->delalloc_mutex);
spin_lock(&root->delalloc_lock);
list_splice_init(&root->delalloc_inodes, &splice);
while (!list_empty(&splice)) {
binode = list_entry(splice.next, struct btrfs_inode,
delalloc_inodes);
list_move_tail(&binode->delalloc_inodes,
&root->delalloc_inodes);
if (in_reclaim_context &&
test_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &binode->runtime_flags))
continue;
inode = igrab(&binode->vfs_inode);
if (!inode) {
cond_resched_lock(&root->delalloc_lock);
continue;
}
spin_unlock(&root->delalloc_lock);
if (snapshot)
set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
&binode->runtime_flags);
if (full_flush) {
work = btrfs_alloc_delalloc_work(inode);
if (!work) {
iput(inode);
ret = -ENOMEM;
goto out;
}
list_add_tail(&work->list, &works);
btrfs_queue_work(root->fs_info->flush_workers,
&work->work);
} else {
ret = filemap_fdatawrite_wbc(inode->i_mapping, wbc);
btrfs_add_delayed_iput(BTRFS_I(inode));
if (ret || wbc->nr_to_write <= 0)
goto out;
}
cond_resched();
spin_lock(&root->delalloc_lock);
}
spin_unlock(&root->delalloc_lock);
out:
list_for_each_entry_safe(work, next, &works, list) {
list_del_init(&work->list);
wait_for_completion(&work->completion);
kfree(work);
}
if (!list_empty(&splice)) {
spin_lock(&root->delalloc_lock);
list_splice_tail(&splice, &root->delalloc_inodes);
spin_unlock(&root->delalloc_lock);
}
mutex_unlock(&root->delalloc_mutex);
return ret;
}
int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context)
{
struct writeback_control wbc = {
.nr_to_write = LONG_MAX,
.sync_mode = WB_SYNC_NONE,
.range_start = 0,
.range_end = LLONG_MAX,
};
struct btrfs_fs_info *fs_info = root->fs_info;
if (BTRFS_FS_ERROR(fs_info))
return -EROFS;
return start_delalloc_inodes(root, &wbc, true, in_reclaim_context);
}
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
bool in_reclaim_context)
{
struct writeback_control wbc = {
.nr_to_write = nr,
.sync_mode = WB_SYNC_NONE,
.range_start = 0,
.range_end = LLONG_MAX,
};
struct btrfs_root *root;
struct list_head splice;
int ret;
if (BTRFS_FS_ERROR(fs_info))
return -EROFS;
INIT_LIST_HEAD(&splice);
mutex_lock(&fs_info->delalloc_root_mutex);
spin_lock(&fs_info->delalloc_root_lock);
list_splice_init(&fs_info->delalloc_roots, &splice);
while (!list_empty(&splice)) {
/*
* Reset nr_to_write here so we know that we're doing a full
* flush.
*/
if (nr == LONG_MAX)
wbc.nr_to_write = LONG_MAX;
root = list_first_entry(&splice, struct btrfs_root,
delalloc_root);
root = btrfs_grab_root(root);
BUG_ON(!root);
list_move_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
ret = start_delalloc_inodes(root, &wbc, false, in_reclaim_context);
btrfs_put_root(root);
if (ret < 0 || wbc.nr_to_write <= 0)
goto out;
spin_lock(&fs_info->delalloc_root_lock);
}
spin_unlock(&fs_info->delalloc_root_lock);
ret = 0;
out:
if (!list_empty(&splice)) {
spin_lock(&fs_info->delalloc_root_lock);
list_splice_tail(&splice, &fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
mutex_unlock(&fs_info->delalloc_root_mutex);
return ret;
}
static int btrfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, const char *symname)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode;
struct btrfs_new_inode_args new_inode_args = {
.dir = dir,
.dentry = dentry,
};
unsigned int trans_num_items;
int err;
int name_len;
int datasize;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
name_len = strlen(symname);
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
return -ENAMETOOLONG;
inode = new_inode(dir->i_sb);
if (!inode)
return -ENOMEM;
inode_init_owner(idmap, inode, dir, S_IFLNK | S_IRWXUGO);
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_aops;
btrfs_i_size_write(BTRFS_I(inode), name_len);
inode_set_bytes(inode, name_len);
new_inode_args.inode = inode;
err = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
if (err)
goto out_inode;
/* 1 additional item for the inline extent */
trans_num_items++;
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_new_inode_args;
}
err = btrfs_create_new_inode(trans, &new_inode_args);
if (err)
goto out;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
btrfs_abort_transaction(trans, err);
discard_new_inode(inode);
inode = NULL;
goto out;
}
key.objectid = btrfs_ino(BTRFS_I(inode));
key.offset = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
btrfs_abort_transaction(trans, err);
btrfs_free_path(path);
discard_new_inode(inode);
inode = NULL;
goto out;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_compression(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
d_instantiate_new(dentry, inode);
err = 0;
out:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
out_new_inode_args:
btrfs_new_inode_args_destroy(&new_inode_args);
out_inode:
if (err)
iput(inode);
return err;
}
static struct btrfs_trans_handle *insert_prealloc_file_extent(
struct btrfs_trans_handle *trans_in,
struct btrfs_inode *inode,
struct btrfs_key *ins,
u64 file_offset)
{
struct btrfs_file_extent_item stack_fi;
struct btrfs_replace_extent_info extent_info;
struct btrfs_trans_handle *trans = trans_in;
struct btrfs_path *path;
u64 start = ins->objectid;
u64 len = ins->offset;
int qgroup_released;
int ret;
memset(&stack_fi, 0, sizeof(stack_fi));
btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_PREALLOC);
btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, start);
btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi, len);
btrfs_set_stack_file_extent_num_bytes(&stack_fi, len);
btrfs_set_stack_file_extent_ram_bytes(&stack_fi, len);
btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE);
/* Encryption and other encoding is reserved and all 0 */
qgroup_released = btrfs_qgroup_release_data(inode, file_offset, len);
if (qgroup_released < 0)
return ERR_PTR(qgroup_released);
if (trans) {
ret = insert_reserved_file_extent(trans, inode,
file_offset, &stack_fi,
true, qgroup_released);
if (ret)
goto free_qgroup;
return trans;
}
extent_info.disk_offset = start;
extent_info.disk_len = len;
extent_info.data_offset = 0;
extent_info.data_len = len;
extent_info.file_offset = file_offset;
extent_info.extent_buf = (char *)&stack_fi;
extent_info.is_new_extent = true;
extent_info.update_times = true;
extent_info.qgroup_reserved = qgroup_released;
extent_info.insertions = 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto free_qgroup;
}
ret = btrfs_replace_file_extents(inode, path, file_offset,
file_offset + len - 1, &extent_info,
&trans);
btrfs_free_path(path);
if (ret)
goto free_qgroup;
return trans;
free_qgroup:
/*
* We have released qgroup data range at the beginning of the function,
* and normally qgroup_released bytes will be freed when committing
* transaction.
* But if we error out early, we have to free what we have released
* or we leak qgroup data reservation.
*/
btrfs_qgroup_free_refroot(inode->root->fs_info,
inode->root->root_key.objectid, qgroup_released,
BTRFS_QGROUP_RSV_DATA);
return ERR_PTR(ret);
}
static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint,
struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
u64 clear_offset = start;
u64 i_size;
u64 cur_bytes;
u64 last_alloc = (u64)-1;
int ret = 0;
bool own_trans = true;
u64 end = start + num_bytes - 1;
if (trans)
own_trans = false;
while (num_bytes > 0) {
cur_bytes = min_t(u64, num_bytes, SZ_256M);
cur_bytes = max(cur_bytes, min_size);
/*
* If we are severely fragmented we could end up with really
* small allocations, so if the allocator is returning small
* chunks lets make its job easier by only searching for those
* sized chunks.
*/
cur_bytes = min(cur_bytes, last_alloc);
ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
min_size, 0, *alloc_hint, &ins, 1, 0);
if (ret)
break;
/*
* We've reserved this space, and thus converted it from
* ->bytes_may_use to ->bytes_reserved. Any error that happens
* from here on out we will only need to clear our reservation
* for the remaining unreserved area, so advance our
* clear_offset by our extent size.
*/
clear_offset += ins.offset;
last_alloc = ins.offset;
trans = insert_prealloc_file_extent(trans, BTRFS_I(inode),
&ins, cur_offset);
/*
* Now that we inserted the prealloc extent we can finally
* decrement the number of reservations in the block group.
* If we did it before, we could race with relocation and have
* relocation miss the reserved extent, making it fail later.
*/
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
btrfs_free_reserved_extent(fs_info, ins.objectid,
ins.offset, 0);
break;
}
em = alloc_extent_map();
if (!em) {
btrfs_drop_extent_map_range(BTRFS_I(inode), cur_offset,
cur_offset + ins.offset - 1, false);
btrfs_set_inode_full_sync(BTRFS_I(inode));
goto next;
}
em->start = cur_offset;
em->orig_start = cur_offset;
em->len = ins.offset;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ins.offset;
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
em->generation = trans->transid;
ret = btrfs_replace_extent_map_range(BTRFS_I(inode), em, true);
free_extent_map(em);
next:
num_bytes -= ins.offset;
cur_offset += ins.offset;
*alloc_hint = ins.objectid + ins.offset;
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {
if (cur_offset > actual_len)
i_size = actual_len;
else
i_size = cur_offset;
i_size_write(inode, i_size);
btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
}
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret) {
btrfs_abort_transaction(trans, ret);
if (own_trans)
btrfs_end_transaction(trans);
break;
}
if (own_trans) {
btrfs_end_transaction(trans);
trans = NULL;
}
}
if (clear_offset < end)
btrfs_free_reserved_data_space(BTRFS_I(inode), NULL, clear_offset,
end - clear_offset + 1);
return ret;
}
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint,
NULL);
}
int btrfs_prealloc_file_range_trans(struct inode *inode,
struct btrfs_trans_handle *trans, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint, trans);
}
static int btrfs_permission(struct mnt_idmap *idmap,
struct inode *inode, int mask)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
umode_t mode = inode->i_mode;
if (mask & MAY_WRITE &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
if (btrfs_root_readonly(root))
return -EROFS;
if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
return -EACCES;
}
return generic_permission(idmap, inode, mask);
}
static int btrfs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
struct file *file, umode_t mode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode;
struct btrfs_new_inode_args new_inode_args = {
.dir = dir,
.dentry = file->f_path.dentry,
.orphan = true,
};
unsigned int trans_num_items;
int ret;
inode = new_inode(dir->i_sb);
if (!inode)
return -ENOMEM;
inode_init_owner(idmap, inode, dir, mode);
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
new_inode_args.inode = inode;
ret = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
if (ret)
goto out_inode;
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_new_inode_args;
}
ret = btrfs_create_new_inode(trans, &new_inode_args);
/*
* We set number of links to 0 in btrfs_create_new_inode(), and here we
* set it to 1 because d_tmpfile() will issue a warning if the count is
* 0, through:
*
* d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
*/
set_nlink(inode, 1);
if (!ret) {
d_tmpfile(file, inode);
unlock_new_inode(inode);
mark_inode_dirty(inode);
}
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
out_new_inode_args:
btrfs_new_inode_args_destroy(&new_inode_args);
out_inode:
if (ret)
iput(inode);
return finish_open_simple(file, ret);
}
void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
unsigned long index = start >> PAGE_SHIFT;
unsigned long end_index = end >> PAGE_SHIFT;
struct page *page;
u32 len;
ASSERT(end + 1 - start <= U32_MAX);
len = end + 1 - start;
while (index <= end_index) {
page = find_get_page(inode->vfs_inode.i_mapping, index);
ASSERT(page); /* Pages should be in the extent_io_tree */
btrfs_page_set_writeback(fs_info, page, start, len);
put_page(page);
index++;
}
}
int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
int compress_type)
{
switch (compress_type) {
case BTRFS_COMPRESS_NONE:
return BTRFS_ENCODED_IO_COMPRESSION_NONE;
case BTRFS_COMPRESS_ZLIB:
return BTRFS_ENCODED_IO_COMPRESSION_ZLIB;
case BTRFS_COMPRESS_LZO:
/*
* The LZO format depends on the sector size. 64K is the maximum
* sector size that we support.
*/
if (fs_info->sectorsize < SZ_4K || fs_info->sectorsize > SZ_64K)
return -EINVAL;
return BTRFS_ENCODED_IO_COMPRESSION_LZO_4K +
(fs_info->sectorsize_bits - 12);
case BTRFS_COMPRESS_ZSTD:
return BTRFS_ENCODED_IO_COMPRESSION_ZSTD;
default:
return -EUCLEAN;
}
}
static ssize_t btrfs_encoded_read_inline(
struct kiocb *iocb,
struct iov_iter *iter, u64 start,
u64 lockend,
struct extent_state **cached_state,
u64 extent_start, size_t count,
struct btrfs_ioctl_encoded_io_args *encoded,
bool *unlocked)
{
struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *io_tree = &inode->io_tree;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *item;
u64 ram_bytes;
unsigned long ptr;
void *tmp;
ssize_t ret;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
extent_start, 0);
if (ret) {
if (ret > 0) {
/* The extent item disappeared? */
ret = -EIO;
}
goto out;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
ptr = btrfs_file_extent_inline_start(item);
encoded->len = min_t(u64, extent_start + ram_bytes,
inode->vfs_inode.i_size) - iocb->ki_pos;
ret = btrfs_encoded_io_compression_from_extent(fs_info,
btrfs_file_extent_compression(leaf, item));
if (ret < 0)
goto out;
encoded->compression = ret;
if (encoded->compression) {
size_t inline_size;
inline_size = btrfs_file_extent_inline_item_len(leaf,
path->slots[0]);
if (inline_size > count) {
ret = -ENOBUFS;
goto out;
}
count = inline_size;
encoded->unencoded_len = ram_bytes;
encoded->unencoded_offset = iocb->ki_pos - extent_start;
} else {
count = min_t(u64, count, encoded->len);
encoded->len = count;
encoded->unencoded_len = count;
ptr += iocb->ki_pos - extent_start;
}
tmp = kmalloc(count, GFP_NOFS);
if (!tmp) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(leaf, tmp, ptr, count);
btrfs_release_path(path);
unlock_extent(io_tree, start, lockend, cached_state);
btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
*unlocked = true;
ret = copy_to_iter(tmp, count, iter);
if (ret != count)
ret = -EFAULT;
kfree(tmp);
out:
btrfs_free_path(path);
return ret;
}
struct btrfs_encoded_read_private {
wait_queue_head_t wait;
atomic_t pending;
blk_status_t status;
};
static void btrfs_encoded_read_endio(struct btrfs_bio *bbio)
{
struct btrfs_encoded_read_private *priv = bbio->private;
if (bbio->bio.bi_status) {
/*
* The memory barrier implied by the atomic_dec_return() here
* pairs with the memory barrier implied by the
* atomic_dec_return() or io_wait_event() in
* btrfs_encoded_read_regular_fill_pages() to ensure that this
* write is observed before the load of status in
* btrfs_encoded_read_regular_fill_pages().
*/
WRITE_ONCE(priv->status, bbio->bio.bi_status);
}
if (!atomic_dec_return(&priv->pending))
wake_up(&priv->wait);
bio_put(&bbio->bio);
}
int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
u64 file_offset, u64 disk_bytenr,
u64 disk_io_size, struct page **pages)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_encoded_read_private priv = {
.pending = ATOMIC_INIT(1),
};
unsigned long i = 0;
struct btrfs_bio *bbio;
init_waitqueue_head(&priv.wait);
bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info,
btrfs_encoded_read_endio, &priv);
bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;
bbio->inode = inode;
do {
size_t bytes = min_t(u64, disk_io_size, PAGE_SIZE);
if (bio_add_page(&bbio->bio, pages[i], bytes, 0) < bytes) {
atomic_inc(&priv.pending);
btrfs_submit_bio(bbio, 0);
bbio = btrfs_bio_alloc(BIO_MAX_VECS, REQ_OP_READ, fs_info,
btrfs_encoded_read_endio, &priv);
bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;
bbio->inode = inode;
continue;
}
i++;
disk_bytenr += bytes;
disk_io_size -= bytes;
} while (disk_io_size);
atomic_inc(&priv.pending);
btrfs_submit_bio(bbio, 0);
if (atomic_dec_return(&priv.pending))
io_wait_event(priv.wait, !atomic_read(&priv.pending));
/* See btrfs_encoded_read_endio() for ordering. */
return blk_status_to_errno(READ_ONCE(priv.status));
}
static ssize_t btrfs_encoded_read_regular(struct kiocb *iocb,
struct iov_iter *iter,
u64 start, u64 lockend,
struct extent_state **cached_state,
u64 disk_bytenr, u64 disk_io_size,
size_t count, bool compressed,
bool *unlocked)
{
struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
struct extent_io_tree *io_tree = &inode->io_tree;
struct page **pages;
unsigned long nr_pages, i;
u64 cur;
size_t page_offset;
ssize_t ret;
nr_pages = DIV_ROUND_UP(disk_io_size, PAGE_SIZE);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages)
return -ENOMEM;
ret = btrfs_alloc_page_array(nr_pages, pages);
if (ret) {
ret = -ENOMEM;
goto out;
}
ret = btrfs_encoded_read_regular_fill_pages(inode, start, disk_bytenr,
disk_io_size, pages);
if (ret)
goto out;
unlock_extent(io_tree, start, lockend, cached_state);
btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
*unlocked = true;
if (compressed) {
i = 0;
page_offset = 0;
} else {
i = (iocb->ki_pos - start) >> PAGE_SHIFT;
page_offset = (iocb->ki_pos - start) & (PAGE_SIZE - 1);
}
cur = 0;
while (cur < count) {
size_t bytes = min_t(size_t, count - cur,
PAGE_SIZE - page_offset);
if (copy_page_to_iter(pages[i], page_offset, bytes,
iter) != bytes) {
ret = -EFAULT;
goto out;
}
i++;
cur += bytes;
page_offset = 0;
}
ret = count;
out:
for (i = 0; i < nr_pages; i++) {
if (pages[i])
__free_page(pages[i]);
}
kfree(pages);
return ret;
}
ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
struct btrfs_ioctl_encoded_io_args *encoded)
{
struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct extent_io_tree *io_tree = &inode->io_tree;
ssize_t ret;
size_t count = iov_iter_count(iter);
u64 start, lockend, disk_bytenr, disk_io_size;
struct extent_state *cached_state = NULL;
struct extent_map *em;
bool unlocked = false;
file_accessed(iocb->ki_filp);
btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
if (iocb->ki_pos >= inode->vfs_inode.i_size) {
btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
return 0;
}
start = ALIGN_DOWN(iocb->ki_pos, fs_info->sectorsize);
/*
* We don't know how long the extent containing iocb->ki_pos is, but if
* it's compressed we know that it won't be longer than this.
*/
lockend = start + BTRFS_MAX_UNCOMPRESSED - 1;
for (;;) {
struct btrfs_ordered_extent *ordered;
ret = btrfs_wait_ordered_range(&inode->vfs_inode, start,
lockend - start + 1);
if (ret)
goto out_unlock_inode;
lock_extent(io_tree, start, lockend, &cached_state);
ordered = btrfs_lookup_ordered_range(inode, start,
lockend - start + 1);
if (!ordered)
break;
btrfs_put_ordered_extent(ordered);
unlock_extent(io_tree, start, lockend, &cached_state);
cond_resched();
}
em = btrfs_get_extent(inode, NULL, 0, start, lockend - start + 1);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_unlock_extent;
}
if (em->block_start == EXTENT_MAP_INLINE) {
u64 extent_start = em->start;
/*
* For inline extents we get everything we need out of the
* extent item.
*/
free_extent_map(em);
em = NULL;
ret = btrfs_encoded_read_inline(iocb, iter, start, lockend,
&cached_state, extent_start,
count, encoded, &unlocked);
goto out;
}
/*
* We only want to return up to EOF even if the extent extends beyond
* that.
*/
encoded->len = min_t(u64, extent_map_end(em),
inode->vfs_inode.i_size) - iocb->ki_pos;
if (em->block_start == EXTENT_MAP_HOLE ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
disk_bytenr = EXTENT_MAP_HOLE;
count = min_t(u64, count, encoded->len);
encoded->len = count;
encoded->unencoded_len = count;
} else if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
disk_bytenr = em->block_start;
/*
* Bail if the buffer isn't large enough to return the whole
* compressed extent.
*/
if (em->block_len > count) {
ret = -ENOBUFS;
goto out_em;
}
disk_io_size = em->block_len;
count = em->block_len;
encoded->unencoded_len = em->ram_bytes;
encoded->unencoded_offset = iocb->ki_pos - em->orig_start;
ret = btrfs_encoded_io_compression_from_extent(fs_info,
em->compress_type);
if (ret < 0)
goto out_em;
encoded->compression = ret;
} else {
disk_bytenr = em->block_start + (start - em->start);
if (encoded->len > count)
encoded->len = count;
/*
* Don't read beyond what we locked. This also limits the page
* allocations that we'll do.
*/
disk_io_size = min(lockend + 1, iocb->ki_pos + encoded->len) - start;
count = start + disk_io_size - iocb->ki_pos;
encoded->len = count;
encoded->unencoded_len = count;
disk_io_size = ALIGN(disk_io_size, fs_info->sectorsize);
}
free_extent_map(em);
em = NULL;
if (disk_bytenr == EXTENT_MAP_HOLE) {
unlock_extent(io_tree, start, lockend, &cached_state);
btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
unlocked = true;
ret = iov_iter_zero(count, iter);
if (ret != count)
ret = -EFAULT;
} else {
ret = btrfs_encoded_read_regular(iocb, iter, start, lockend,
&cached_state, disk_bytenr,
disk_io_size, count,
encoded->compression,
&unlocked);
}
out:
if (ret >= 0)
iocb->ki_pos += encoded->len;
out_em:
free_extent_map(em);
out_unlock_extent:
if (!unlocked)
unlock_extent(io_tree, start, lockend, &cached_state);
out_unlock_inode:
if (!unlocked)
btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
return ret;
}
ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
const struct btrfs_ioctl_encoded_io_args *encoded)
{
struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *io_tree = &inode->io_tree;
struct extent_changeset *data_reserved = NULL;
struct extent_state *cached_state = NULL;
int compression;
size_t orig_count;
u64 start, end;
u64 num_bytes, ram_bytes, disk_num_bytes;
unsigned long nr_pages, i;
struct page **pages;
struct btrfs_key ins;
bool extent_reserved = false;
struct extent_map *em;
ssize_t ret;
switch (encoded->compression) {
case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
compression = BTRFS_COMPRESS_ZLIB;
break;
case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
compression = BTRFS_COMPRESS_ZSTD;
break;
case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
/* The sector size must match for LZO. */
if (encoded->compression -
BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12 !=
fs_info->sectorsize_bits)
return -EINVAL;
compression = BTRFS_COMPRESS_LZO;
break;
default:
return -EINVAL;
}
if (encoded->encryption != BTRFS_ENCODED_IO_ENCRYPTION_NONE)
return -EINVAL;
orig_count = iov_iter_count(from);
/* The extent size must be sane. */
if (encoded->unencoded_len > BTRFS_MAX_UNCOMPRESSED ||
orig_count > BTRFS_MAX_COMPRESSED || orig_count == 0)
return -EINVAL;
/*
* The compressed data must be smaller than the decompressed data.
*
* It's of course possible for data to compress to larger or the same
* size, but the buffered I/O path falls back to no compression for such
* data, and we don't want to break any assumptions by creating these
* extents.
*
* Note that this is less strict than the current check we have that the
* compressed data must be at least one sector smaller than the
* decompressed data. We only want to enforce the weaker requirement
* from old kernels that it is at least one byte smaller.
*/
if (orig_count >= encoded->unencoded_len)
return -EINVAL;
/* The extent must start on a sector boundary. */
start = iocb->ki_pos;
if (!IS_ALIGNED(start, fs_info->sectorsize))
return -EINVAL;
/*
* The extent must end on a sector boundary. However, we allow a write
* which ends at or extends i_size to have an unaligned length; we round
* up the extent size and set i_size to the unaligned end.
*/
if (start + encoded->len < inode->vfs_inode.i_size &&
!IS_ALIGNED(start + encoded->len, fs_info->sectorsize))
return -EINVAL;
/* Finally, the offset in the unencoded data must be sector-aligned. */
if (!IS_ALIGNED(encoded->unencoded_offset, fs_info->sectorsize))
return -EINVAL;
num_bytes = ALIGN(encoded->len, fs_info->sectorsize);
ram_bytes = ALIGN(encoded->unencoded_len, fs_info->sectorsize);
end = start + num_bytes - 1;
/*
* If the extent cannot be inline, the compressed data on disk must be
* sector-aligned. For convenience, we extend it with zeroes if it
* isn't.
*/
disk_num_bytes = ALIGN(orig_count, fs_info->sectorsize);
nr_pages = DIV_ROUND_UP(disk_num_bytes, PAGE_SIZE);
pages = kvcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL_ACCOUNT);
if (!pages)
return -ENOMEM;
for (i = 0; i < nr_pages; i++) {
size_t bytes = min_t(size_t, PAGE_SIZE, iov_iter_count(from));
char *kaddr;
pages[i] = alloc_page(GFP_KERNEL_ACCOUNT);
if (!pages[i]) {
ret = -ENOMEM;
goto out_pages;
}
kaddr = kmap_local_page(pages[i]);
if (copy_from_iter(kaddr, bytes, from) != bytes) {
kunmap_local(kaddr);
ret = -EFAULT;
goto out_pages;
}
if (bytes < PAGE_SIZE)
memset(kaddr + bytes, 0, PAGE_SIZE - bytes);
kunmap_local(kaddr);
}
for (;;) {
struct btrfs_ordered_extent *ordered;
ret = btrfs_wait_ordered_range(&inode->vfs_inode, start, num_bytes);
if (ret)
goto out_pages;
ret = invalidate_inode_pages2_range(inode->vfs_inode.i_mapping,
start >> PAGE_SHIFT,
end >> PAGE_SHIFT);
if (ret)
goto out_pages;
lock_extent(io_tree, start, end, &cached_state);
ordered = btrfs_lookup_ordered_range(inode, start, num_bytes);
if (!ordered &&
!filemap_range_has_page(inode->vfs_inode.i_mapping, start, end))
break;
if (ordered)
btrfs_put_ordered_extent(ordered);
unlock_extent(io_tree, start, end, &cached_state);
cond_resched();
}
/*
* We don't use the higher-level delalloc space functions because our
* num_bytes and disk_num_bytes are different.
*/
ret = btrfs_alloc_data_chunk_ondemand(inode, disk_num_bytes);
if (ret)
goto out_unlock;
ret = btrfs_qgroup_reserve_data(inode, &data_reserved, start, num_bytes);
if (ret)
goto out_free_data_space;
ret = btrfs_delalloc_reserve_metadata(inode, num_bytes, disk_num_bytes,
false);
if (ret)
goto out_qgroup_free_data;
/* Try an inline extent first. */
if (start == 0 && encoded->unencoded_len == encoded->len &&
encoded->unencoded_offset == 0) {
ret = cow_file_range_inline(inode, encoded->len, orig_count,
compression, pages, true);
if (ret <= 0) {
if (ret == 0)
ret = orig_count;
goto out_delalloc_release;
}
}
ret = btrfs_reserve_extent(root, disk_num_bytes, disk_num_bytes,
disk_num_bytes, 0, 0, &ins, 1, 1);
if (ret)
goto out_delalloc_release;
extent_reserved = true;
em = create_io_em(inode, start, num_bytes,
start - encoded->unencoded_offset, ins.objectid,
ins.offset, ins.offset, ram_bytes, compression,
BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_free_reserved;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, num_bytes, ram_bytes,
ins.objectid, ins.offset,
encoded->unencoded_offset,
(1 << BTRFS_ORDERED_ENCODED) |
(1 << BTRFS_ORDERED_COMPRESSED),
compression);
if (ret) {
btrfs_drop_extent_map_range(inode, start, end, false);
goto out_free_reserved;
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (start + encoded->len > inode->vfs_inode.i_size)
i_size_write(&inode->vfs_inode, start + encoded->len);
unlock_extent(io_tree, start, end, &cached_state);
btrfs_delalloc_release_extents(inode, num_bytes);
btrfs_submit_compressed_write(inode, start, num_bytes, ins.objectid,
ins.offset, pages, nr_pages, 0, false);
ret = orig_count;
goto out;
out_free_reserved:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_delalloc_release:
btrfs_delalloc_release_extents(inode, num_bytes);
btrfs_delalloc_release_metadata(inode, disk_num_bytes, ret < 0);
out_qgroup_free_data:
if (ret < 0)
btrfs_qgroup_free_data(inode, data_reserved, start, num_bytes);
out_free_data_space:
/*
* If btrfs_reserve_extent() succeeded, then we already decremented
* bytes_may_use.
*/
if (!extent_reserved)
btrfs_free_reserved_data_space_noquota(fs_info, disk_num_bytes);
out_unlock:
unlock_extent(io_tree, start, end, &cached_state);
out_pages:
for (i = 0; i < nr_pages; i++) {
if (pages[i])
__free_page(pages[i]);
}
kvfree(pages);
out:
if (ret >= 0)
iocb->ki_pos += encoded->len;
return ret;
}
#ifdef CONFIG_SWAP
/*
* Add an entry indicating a block group or device which is pinned by a
* swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
* negative errno on failure.
*/
static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
bool is_block_group)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_swapfile_pin *sp, *entry;
struct rb_node **p;
struct rb_node *parent = NULL;
sp = kmalloc(sizeof(*sp), GFP_NOFS);
if (!sp)
return -ENOMEM;
sp->ptr = ptr;
sp->inode = inode;
sp->is_block_group = is_block_group;
sp->bg_extent_count = 1;
spin_lock(&fs_info->swapfile_pins_lock);
p = &fs_info->swapfile_pins.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
if (sp->ptr < entry->ptr ||
(sp->ptr == entry->ptr && sp->inode < entry->inode)) {
p = &(*p)->rb_left;
} else if (sp->ptr > entry->ptr ||
(sp->ptr == entry->ptr && sp->inode > entry->inode)) {
p = &(*p)->rb_right;
} else {
if (is_block_group)
entry->bg_extent_count++;
spin_unlock(&fs_info->swapfile_pins_lock);
kfree(sp);
return 1;
}
}
rb_link_node(&sp->node, parent, p);
rb_insert_color(&sp->node, &fs_info->swapfile_pins);
spin_unlock(&fs_info->swapfile_pins_lock);
return 0;
}
/* Free all of the entries pinned by this swapfile. */
static void btrfs_free_swapfile_pins(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_swapfile_pin *sp;
struct rb_node *node, *next;
spin_lock(&fs_info->swapfile_pins_lock);
node = rb_first(&fs_info->swapfile_pins);
while (node) {
next = rb_next(node);
sp = rb_entry(node, struct btrfs_swapfile_pin, node);
if (sp->inode == inode) {
rb_erase(&sp->node, &fs_info->swapfile_pins);
if (sp->is_block_group) {
btrfs_dec_block_group_swap_extents(sp->ptr,
sp->bg_extent_count);
btrfs_put_block_group(sp->ptr);
}
kfree(sp);
}
node = next;
}
spin_unlock(&fs_info->swapfile_pins_lock);
}
struct btrfs_swap_info {
u64 start;
u64 block_start;
u64 block_len;
u64 lowest_ppage;
u64 highest_ppage;
unsigned long nr_pages;
int nr_extents;
};
static int btrfs_add_swap_extent(struct swap_info_struct *sis,
struct btrfs_swap_info *bsi)
{
unsigned long nr_pages;
unsigned long max_pages;
u64 first_ppage, first_ppage_reported, next_ppage;
int ret;
/*
* Our swapfile may have had its size extended after the swap header was
* written. In that case activating the swapfile should not go beyond
* the max size set in the swap header.
*/
if (bsi->nr_pages >= sis->max)
return 0;
max_pages = sis->max - bsi->nr_pages;
first_ppage = PAGE_ALIGN(bsi->block_start) >> PAGE_SHIFT;
next_ppage = PAGE_ALIGN_DOWN(bsi->block_start + bsi->block_len) >> PAGE_SHIFT;
if (first_ppage >= next_ppage)
return 0;
nr_pages = next_ppage - first_ppage;
nr_pages = min(nr_pages, max_pages);
first_ppage_reported = first_ppage;
if (bsi->start == 0)
first_ppage_reported++;
if (bsi->lowest_ppage > first_ppage_reported)
bsi->lowest_ppage = first_ppage_reported;
if (bsi->highest_ppage < (next_ppage - 1))
bsi->highest_ppage = next_ppage - 1;
ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
if (ret < 0)
return ret;
bsi->nr_extents += ret;
bsi->nr_pages += nr_pages;
return 0;
}
static void btrfs_swap_deactivate(struct file *file)
{
struct inode *inode = file_inode(file);
btrfs_free_swapfile_pins(inode);
atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
}
static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
struct extent_map *em = NULL;
struct btrfs_device *device = NULL;
struct btrfs_swap_info bsi = {
.lowest_ppage = (sector_t)-1ULL,
};
int ret = 0;
u64 isize;
u64 start;
/*
* If the swap file was just created, make sure delalloc is done. If the
* file changes again after this, the user is doing something stupid and
* we don't really care.
*/
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (ret)
return ret;
/*
* The inode is locked, so these flags won't change after we check them.
*/
if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
btrfs_warn(fs_info, "swapfile must not be compressed");
return -EINVAL;
}
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
btrfs_warn(fs_info, "swapfile must not be copy-on-write");
return -EINVAL;
}
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
btrfs_warn(fs_info, "swapfile must not be checksummed");
return -EINVAL;
}
/*
* Balance or device remove/replace/resize can move stuff around from
* under us. The exclop protection makes sure they aren't running/won't
* run concurrently while we are mapping the swap extents, and
* fs_info->swapfile_pins prevents them from running while the swap
* file is active and moving the extents. Note that this also prevents
* a concurrent device add which isn't actually necessary, but it's not
* really worth the trouble to allow it.
*/
if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_SWAP_ACTIVATE)) {
btrfs_warn(fs_info,
"cannot activate swapfile while exclusive operation is running");
return -EBUSY;
}
/*
* Prevent snapshot creation while we are activating the swap file.
* We do not want to race with snapshot creation. If snapshot creation
* already started before we bumped nr_swapfiles from 0 to 1 and
* completes before the first write into the swap file after it is
* activated, than that write would fallback to COW.
*/
if (!btrfs_drew_try_write_lock(&root->snapshot_lock)) {
btrfs_exclop_finish(fs_info);
btrfs_warn(fs_info,
"cannot activate swapfile because snapshot creation is in progress");
return -EINVAL;
}
/*
* Snapshots can create extents which require COW even if NODATACOW is
* set. We use this counter to prevent snapshots. We must increment it
* before walking the extents because we don't want a concurrent
* snapshot to run after we've already checked the extents.
*
* It is possible that subvolume is marked for deletion but still not
* removed yet. To prevent this race, we check the root status before
* activating the swapfile.
*/
spin_lock(&root->root_item_lock);
if (btrfs_root_dead(root)) {
spin_unlock(&root->root_item_lock);
btrfs_exclop_finish(fs_info);
btrfs_warn(fs_info,
"cannot activate swapfile because subvolume %llu is being deleted",
root->root_key.objectid);
return -EPERM;
}
atomic_inc(&root->nr_swapfiles);
spin_unlock(&root->root_item_lock);
isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
lock_extent(io_tree, 0, isize - 1, &cached_state);
start = 0;
while (start < isize) {
u64 logical_block_start, physical_block_start;
struct btrfs_block_group *bg;
u64 len = isize - start;
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
if (em->block_start == EXTENT_MAP_HOLE) {
btrfs_warn(fs_info, "swapfile must not have holes");
ret = -EINVAL;
goto out;
}
if (em->block_start == EXTENT_MAP_INLINE) {
/*
* It's unlikely we'll ever actually find ourselves
* here, as a file small enough to fit inline won't be
* big enough to store more than the swap header, but in
* case something changes in the future, let's catch it
* here rather than later.
*/
btrfs_warn(fs_info, "swapfile must not be inline");
ret = -EINVAL;
goto out;
}
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
btrfs_warn(fs_info, "swapfile must not be compressed");
ret = -EINVAL;
goto out;
}
logical_block_start = em->block_start + (start - em->start);
len = min(len, em->len - (start - em->start));
free_extent_map(em);
em = NULL;
ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, false, true);
if (ret < 0) {
goto out;
} else if (ret) {
ret = 0;
} else {
btrfs_warn(fs_info,
"swapfile must not be copy-on-write");
ret = -EINVAL;
goto out;
}
em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
btrfs_warn(fs_info,
"swapfile must have single data profile");
ret = -EINVAL;
goto out;
}
if (device == NULL) {
device = em->map_lookup->stripes[0].dev;
ret = btrfs_add_swapfile_pin(inode, device, false);
if (ret == 1)
ret = 0;
else if (ret)
goto out;
} else if (device != em->map_lookup->stripes[0].dev) {
btrfs_warn(fs_info, "swapfile must be on one device");
ret = -EINVAL;
goto out;
}
physical_block_start = (em->map_lookup->stripes[0].physical +
(logical_block_start - em->start));
len = min(len, em->len - (logical_block_start - em->start));
free_extent_map(em);
em = NULL;
bg = btrfs_lookup_block_group(fs_info, logical_block_start);
if (!bg) {
btrfs_warn(fs_info,
"could not find block group containing swapfile");
ret = -EINVAL;
goto out;
}
if (!btrfs_inc_block_group_swap_extents(bg)) {
btrfs_warn(fs_info,
"block group for swapfile at %llu is read-only%s",
bg->start,
atomic_read(&fs_info->scrubs_running) ?
" (scrub running)" : "");
btrfs_put_block_group(bg);
ret = -EINVAL;
goto out;
}
ret = btrfs_add_swapfile_pin(inode, bg, true);
if (ret) {
btrfs_put_block_group(bg);
if (ret == 1)
ret = 0;
else
goto out;
}
if (bsi.block_len &&
bsi.block_start + bsi.block_len == physical_block_start) {
bsi.block_len += len;
} else {
if (bsi.block_len) {
ret = btrfs_add_swap_extent(sis, &bsi);
if (ret)
goto out;
}
bsi.start = start;
bsi.block_start = physical_block_start;
bsi.block_len = len;
}
start += len;
}
if (bsi.block_len)
ret = btrfs_add_swap_extent(sis, &bsi);
out:
if (!IS_ERR_OR_NULL(em))
free_extent_map(em);
unlock_extent(io_tree, 0, isize - 1, &cached_state);
if (ret)
btrfs_swap_deactivate(file);
btrfs_drew_write_unlock(&root->snapshot_lock);
btrfs_exclop_finish(fs_info);
if (ret)
return ret;
if (device)
sis->bdev = device->bdev;
*span = bsi.highest_ppage - bsi.lowest_ppage + 1;
sis->max = bsi.nr_pages;
sis->pages = bsi.nr_pages - 1;
sis->highest_bit = bsi.nr_pages - 1;
return bsi.nr_extents;
}
#else
static void btrfs_swap_deactivate(struct file *file)
{
}
static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
return -EOPNOTSUPP;
}
#endif
/*
* Update the number of bytes used in the VFS' inode. When we replace extents in
* a range (clone, dedupe, fallocate's zero range), we must update the number of
* bytes used by the inode in an atomic manner, so that concurrent stat(2) calls
* always get a correct value.
*/
void btrfs_update_inode_bytes(struct btrfs_inode *inode,
const u64 add_bytes,
const u64 del_bytes)
{
if (add_bytes == del_bytes)
return;
spin_lock(&inode->lock);
if (del_bytes > 0)
inode_sub_bytes(&inode->vfs_inode, del_bytes);
if (add_bytes > 0)
inode_add_bytes(&inode->vfs_inode, add_bytes);
spin_unlock(&inode->lock);
}
/*
* Verify that there are no ordered extents for a given file range.
*
* @inode: The target inode.
* @start: Start offset of the file range, should be sector size aligned.
* @end: End offset (inclusive) of the file range, its value +1 should be
* sector size aligned.
*
* This should typically be used for cases where we locked an inode's VFS lock in
* exclusive mode, we have also locked the inode's i_mmap_lock in exclusive mode,
* we have flushed all delalloc in the range, we have waited for all ordered
* extents in the range to complete and finally we have locked the file range in
* the inode's io_tree.
*/
void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end)
{
struct btrfs_root *root = inode->root;
struct btrfs_ordered_extent *ordered;
if (!IS_ENABLED(CONFIG_BTRFS_ASSERT))
return;
ordered = btrfs_lookup_first_ordered_range(inode, start, end + 1 - start);
if (ordered) {
btrfs_err(root->fs_info,
"found unexpected ordered extent in file range [%llu, %llu] for inode %llu root %llu (ordered range [%llu, %llu])",
start, end, btrfs_ino(inode), root->root_key.objectid,
ordered->file_offset,
ordered->file_offset + ordered->num_bytes - 1);
btrfs_put_ordered_extent(ordered);
}
ASSERT(ordered == NULL);
}
static const struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename = btrfs_rename2,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.listxattr = btrfs_listxattr,
.permission = btrfs_permission,
.get_inode_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.tmpfile = btrfs_tmpfile,
.fileattr_get = btrfs_fileattr_get,
.fileattr_set = btrfs_fileattr_set,
};
static const struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = btrfs_real_readdir,
.open = btrfs_opendir,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_compat_ioctl,
#endif
.release = btrfs_release_file,
.fsync = btrfs_sync_file,
};
/*
* btrfs doesn't support the bmap operation because swapfiles
* use bmap to make a mapping of extents in the file. They assume
* these extents won't change over the life of the file and they
* use the bmap result to do IO directly to the drive.
*
* the btrfs bmap call would return logical addresses that aren't
* suitable for IO and they also will change frequently as COW
* operations happen. So, swapfile + btrfs == corruption.
*
* For now we're avoiding this by dropping bmap.
*/
static const struct address_space_operations btrfs_aops = {
.read_folio = btrfs_read_folio,
.writepages = btrfs_writepages,
.readahead = btrfs_readahead,
.direct_IO = noop_direct_IO,
.invalidate_folio = btrfs_invalidate_folio,
.release_folio = btrfs_release_folio,
.migrate_folio = btrfs_migrate_folio,
.dirty_folio = filemap_dirty_folio,
.error_remove_page = generic_error_remove_page,
.swap_activate = btrfs_swap_activate,
.swap_deactivate = btrfs_swap_deactivate,
};
static const struct inode_operations btrfs_file_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.listxattr = btrfs_listxattr,
.permission = btrfs_permission,
.fiemap = btrfs_fiemap,
.get_inode_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.fileattr_get = btrfs_fileattr_get,
.fileattr_set = btrfs_fileattr_set,
};
static const struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.listxattr = btrfs_listxattr,
.get_inode_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_symlink_inode_operations = {
.get_link = page_get_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.listxattr = btrfs_listxattr,
.update_time = btrfs_update_time,
};
const struct dentry_operations btrfs_dentry_operations = {
.d_delete = btrfs_dentry_delete,
};
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