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linux-next/fs/btrfs/tree-log.c
Filipe Manana 723df2bcc9 btrfs: join running log transaction when logging new name 
When logging a new name, in case of a rename, we pin the log before
changing it. We then either delete a directory entry from the log or
insert a key range item to mark the old name for deletion on log replay.

However when doing one of those log changes we may have another task that
started writing out the log (at btrfs_sync_log()) and it started before
we pinned the log root. So we may end up changing a log tree while its
writeback is being started by another task syncing the log. This can lead
to inconsistencies in a log tree and other unexpected results during log
replay, because we can get some committed node pointing to a node/leaf
that ends up not getting written to disk before the next log commit.

The problem, conceptually, started to happen in commit 88d2beec7e
("btrfs: avoid logging all directory changes during renames"), because
there we started to update the log without joining its current transaction
first.

However the problem only became visible with commit 259c4b96d7
("btrfs: stop doing unnecessary log updates during a rename"), and that is
because we used to pin the log at btrfs_rename() and then before entering
btrfs_log_new_name(), when unlinking the old dentry, we ended up at
btrfs_del_inode_ref_in_log() and btrfs_del_dir_entries_in_log(). Both
of them join the current log transaction, effectively waiting for any log
transaction writeout (due to acquiring the root's log_mutex). This made it
safe even after leaving the current log transaction, because we remained
with the log pinned when we called btrfs_log_new_name().

Then in commit 259c4b96d7 ("btrfs: stop doing unnecessary log updates
during a rename"), we removed the log pinning from btrfs_rename() and
stopped calling btrfs_del_inode_ref_in_log() and
btrfs_del_dir_entries_in_log() during the rename, and started to do all
the needed work at btrfs_log_new_name(), but without joining the current
log transaction, only pinning the log, which is racy because another task
may have started writeout of the log tree right before we pinned the log.

Both commits landed in kernel 5.18, so it doesn't make any practical
difference which should be blamed, but I'm blaming the second commit only
because with the first one, by chance, the problem did not happen due to
the fact we joined the log transaction after pinning the log and unpinned
it only after calling btrfs_log_new_name().

So make btrfs_log_new_name() join the current log transaction instead of
pinning it, so that we never do log updates if it's writeout is starting.

Fixes: 259c4b96d7 ("btrfs: stop doing unnecessary log updates during a rename")
CC: stable@vger.kernel.org # 5.18+
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Tested-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:42 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2008 Oracle. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/list_sort.h>
#include <linux/iversion.h>
#include "misc.h"
#include "ctree.h"
#include "tree-log.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "backref.h"
#include "compression.h"
#include "qgroup.h"
#include "block-group.h"
#include "space-info.h"
#include "zoned.h"
#include "inode-item.h"
/* magic values for the inode_only field in btrfs_log_inode:
*
* LOG_INODE_ALL means to log everything
* LOG_INODE_EXISTS means to log just enough to recreate the inode
* during log replay
*/
enum {
LOG_INODE_ALL,
LOG_INODE_EXISTS,
LOG_OTHER_INODE,
LOG_OTHER_INODE_ALL,
};
/*
* directory trouble cases
*
* 1) on rename or unlink, if the inode being unlinked isn't in the fsync
* log, we must force a full commit before doing an fsync of the directory
* where the unlink was done.
* ---> record transid of last unlink/rename per directory
*
* mkdir foo/some_dir
* normal commit
* rename foo/some_dir foo2/some_dir
* mkdir foo/some_dir
* fsync foo/some_dir/some_file
*
* The fsync above will unlink the original some_dir without recording
* it in its new location (foo2). After a crash, some_dir will be gone
* unless the fsync of some_file forces a full commit
*
* 2) we must log any new names for any file or dir that is in the fsync
* log. ---> check inode while renaming/linking.
*
* 2a) we must log any new names for any file or dir during rename
* when the directory they are being removed from was logged.
* ---> check inode and old parent dir during rename
*
* 2a is actually the more important variant. With the extra logging
* a crash might unlink the old name without recreating the new one
*
* 3) after a crash, we must go through any directories with a link count
* of zero and redo the rm -rf
*
* mkdir f1/foo
* normal commit
* rm -rf f1/foo
* fsync(f1)
*
* The directory f1 was fully removed from the FS, but fsync was never
* called on f1, only its parent dir. After a crash the rm -rf must
* be replayed. This must be able to recurse down the entire
* directory tree. The inode link count fixup code takes care of the
* ugly details.
*/
/*
* stages for the tree walking. The first
* stage (0) is to only pin down the blocks we find
* the second stage (1) is to make sure that all the inodes
* we find in the log are created in the subvolume.
*
* The last stage is to deal with directories and links and extents
* and all the other fun semantics
*/
enum {
LOG_WALK_PIN_ONLY,
LOG_WALK_REPLAY_INODES,
LOG_WALK_REPLAY_DIR_INDEX,
LOG_WALK_REPLAY_ALL,
};
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
int inode_only,
struct btrfs_log_ctx *ctx);
static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid);
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all);
static void wait_log_commit(struct btrfs_root *root, int transid);
/*
* tree logging is a special write ahead log used to make sure that
* fsyncs and O_SYNCs can happen without doing full tree commits.
*
* Full tree commits are expensive because they require commonly
* modified blocks to be recowed, creating many dirty pages in the
* extent tree an 4x-6x higher write load than ext3.
*
* Instead of doing a tree commit on every fsync, we use the
* key ranges and transaction ids to find items for a given file or directory
* that have changed in this transaction. Those items are copied into
* a special tree (one per subvolume root), that tree is written to disk
* and then the fsync is considered complete.
*
* After a crash, items are copied out of the log-tree back into the
* subvolume tree. Any file data extents found are recorded in the extent
* allocation tree, and the log-tree freed.
*
* The log tree is read three times, once to pin down all the extents it is
* using in ram and once, once to create all the inodes logged in the tree
* and once to do all the other items.
*/
/*
* start a sub transaction and setup the log tree
* this increments the log tree writer count to make the people
* syncing the tree wait for us to finish
*/
static int start_log_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *tree_root = fs_info->tree_root;
const bool zoned = btrfs_is_zoned(fs_info);
int ret = 0;
bool created = false;
/*
* First check if the log root tree was already created. If not, create
* it before locking the root's log_mutex, just to keep lockdep happy.
*/
if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) {
mutex_lock(&tree_root->log_mutex);
if (!fs_info->log_root_tree) {
ret = btrfs_init_log_root_tree(trans, fs_info);
if (!ret) {
set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state);
created = true;
}
}
mutex_unlock(&tree_root->log_mutex);
if (ret)
return ret;
}
mutex_lock(&root->log_mutex);
again:
if (root->log_root) {
int index = (root->log_transid + 1) % 2;
if (btrfs_need_log_full_commit(trans)) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}
if (zoned && atomic_read(&root->log_commit[index])) {
wait_log_commit(root, root->log_transid - 1);
goto again;
}
if (!root->log_start_pid) {
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
} else if (root->log_start_pid != current->pid) {
set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
}
} else {
/*
* This means fs_info->log_root_tree was already created
* for some other FS trees. Do the full commit not to mix
* nodes from multiple log transactions to do sequential
* writing.
*/
if (zoned && !created) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}
ret = btrfs_add_log_tree(trans, root);
if (ret)
goto out;
set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
}
atomic_inc(&root->log_writers);
if (!ctx->logging_new_name) {
int index = root->log_transid % 2;
list_add_tail(&ctx->list, &root->log_ctxs[index]);
ctx->log_transid = root->log_transid;
}
out:
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* returns 0 if there was a log transaction running and we were able
* to join, or returns -ENOENT if there were not transactions
* in progress
*/
static int join_running_log_trans(struct btrfs_root *root)
{
const bool zoned = btrfs_is_zoned(root->fs_info);
int ret = -ENOENT;
if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
return ret;
mutex_lock(&root->log_mutex);
again:
if (root->log_root) {
int index = (root->log_transid + 1) % 2;
ret = 0;
if (zoned && atomic_read(&root->log_commit[index])) {
wait_log_commit(root, root->log_transid - 1);
goto again;
}
atomic_inc(&root->log_writers);
}
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* This either makes the current running log transaction wait
* until you call btrfs_end_log_trans() or it makes any future
* log transactions wait until you call btrfs_end_log_trans()
*/
void btrfs_pin_log_trans(struct btrfs_root *root)
{
atomic_inc(&root->log_writers);
}
/*
* indicate we're done making changes to the log tree
* and wake up anyone waiting to do a sync
*/
void btrfs_end_log_trans(struct btrfs_root *root)
{
if (atomic_dec_and_test(&root->log_writers)) {
/* atomic_dec_and_test implies a barrier */
cond_wake_up_nomb(&root->log_writer_wait);
}
}
static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
{
filemap_fdatawait_range(buf->pages[0]->mapping,
buf->start, buf->start + buf->len - 1);
}
/*
* the walk control struct is used to pass state down the chain when
* processing the log tree. The stage field tells us which part
* of the log tree processing we are currently doing. The others
* are state fields used for that specific part
*/
struct walk_control {
/* should we free the extent on disk when done? This is used
* at transaction commit time while freeing a log tree
*/
int free;
/* pin only walk, we record which extents on disk belong to the
* log trees
*/
int pin;
/* what stage of the replay code we're currently in */
int stage;
/*
* Ignore any items from the inode currently being processed. Needs
* to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
* the LOG_WALK_REPLAY_INODES stage.
*/
bool ignore_cur_inode;
/* the root we are currently replaying */
struct btrfs_root *replay_dest;
/* the trans handle for the current replay */
struct btrfs_trans_handle *trans;
/* the function that gets used to process blocks we find in the
* tree. Note the extent_buffer might not be up to date when it is
* passed in, and it must be checked or read if you need the data
* inside it
*/
int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level);
};
/*
* process_func used to pin down extents, write them or wait on them
*/
static int process_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
/*
* If this fs is mixed then we need to be able to process the leaves to
* pin down any logged extents, so we have to read the block.
*/
if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
if (ret)
return ret;
}
if (wc->pin) {
ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start,
eb->len);
if (ret)
return ret;
if (btrfs_buffer_uptodate(eb, gen, 0) &&
btrfs_header_level(eb) == 0)
ret = btrfs_exclude_logged_extents(eb);
}
return ret;
}
static int do_overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
u32 item_size;
u64 saved_i_size = 0;
int save_old_i_size = 0;
unsigned long src_ptr;
unsigned long dst_ptr;
int overwrite_root = 0;
bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
overwrite_root = 1;
item_size = btrfs_item_size(eb, slot);
src_ptr = btrfs_item_ptr_offset(eb, slot);
/* Our caller must have done a search for the key for us. */
ASSERT(path->nodes[0] != NULL);
/*
* And the slot must point to the exact key or the slot where the key
* should be at (the first item with a key greater than 'key')
*/
if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
struct btrfs_key found_key;
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
ret = btrfs_comp_cpu_keys(&found_key, key);
ASSERT(ret >= 0);
} else {
ret = 1;
}
if (ret == 0) {
char *src_copy;
char *dst_copy;
u32 dst_size = btrfs_item_size(path->nodes[0],
path->slots[0]);
if (dst_size != item_size)
goto insert;
if (item_size == 0) {
btrfs_release_path(path);
return 0;
}
dst_copy = kmalloc(item_size, GFP_NOFS);
src_copy = kmalloc(item_size, GFP_NOFS);
if (!dst_copy || !src_copy) {
btrfs_release_path(path);
kfree(dst_copy);
kfree(src_copy);
return -ENOMEM;
}
read_extent_buffer(eb, src_copy, src_ptr, item_size);
dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
item_size);
ret = memcmp(dst_copy, src_copy, item_size);
kfree(dst_copy);
kfree(src_copy);
/*
* they have the same contents, just return, this saves
* us from cowing blocks in the destination tree and doing
* extra writes that may not have been done by a previous
* sync
*/
if (ret == 0) {
btrfs_release_path(path);
return 0;
}
/*
* We need to load the old nbytes into the inode so when we
* replay the extents we've logged we get the right nbytes.
*/
if (inode_item) {
struct btrfs_inode_item *item;
u64 nbytes;
u32 mode;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
nbytes = btrfs_inode_nbytes(path->nodes[0], item);
item = btrfs_item_ptr(eb, slot,
struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, nbytes);
/*
* If this is a directory we need to reset the i_size to
* 0 so that we can set it up properly when replaying
* the rest of the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
} else if (inode_item) {
struct btrfs_inode_item *item;
u32 mode;
/*
* New inode, set nbytes to 0 so that the nbytes comes out
* properly when we replay the extents.
*/
item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, 0);
/*
* If this is a directory we need to reset the i_size to 0 so
* that we can set it up properly when replaying the rest of
* the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
insert:
btrfs_release_path(path);
/* try to insert the key into the destination tree */
path->skip_release_on_error = 1;
ret = btrfs_insert_empty_item(trans, root, path,
key, item_size);
path->skip_release_on_error = 0;
/* make sure any existing item is the correct size */
if (ret == -EEXIST || ret == -EOVERFLOW) {
u32 found_size;
found_size = btrfs_item_size(path->nodes[0],
path->slots[0]);
if (found_size > item_size)
btrfs_truncate_item(path, item_size, 1);
else if (found_size < item_size)
btrfs_extend_item(path, item_size - found_size);
} else if (ret) {
return ret;
}
dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
/* don't overwrite an existing inode if the generation number
* was logged as zero. This is done when the tree logging code
* is just logging an inode to make sure it exists after recovery.
*
* Also, don't overwrite i_size on directories during replay.
* log replay inserts and removes directory items based on the
* state of the tree found in the subvolume, and i_size is modified
* as it goes
*/
if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
struct btrfs_inode_item *src_item;
struct btrfs_inode_item *dst_item;
src_item = (struct btrfs_inode_item *)src_ptr;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(eb, src_item) == 0) {
struct extent_buffer *dst_eb = path->nodes[0];
const u64 ino_size = btrfs_inode_size(eb, src_item);
/*
* For regular files an ino_size == 0 is used only when
* logging that an inode exists, as part of a directory
* fsync, and the inode wasn't fsynced before. In this
* case don't set the size of the inode in the fs/subvol
* tree, otherwise we would be throwing valid data away.
*/
if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
ino_size != 0)
btrfs_set_inode_size(dst_eb, dst_item, ino_size);
goto no_copy;
}
if (overwrite_root &&
S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
save_old_i_size = 1;
saved_i_size = btrfs_inode_size(path->nodes[0],
dst_item);
}
}
copy_extent_buffer(path->nodes[0], eb, dst_ptr,
src_ptr, item_size);
if (save_old_i_size) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
}
/* make sure the generation is filled in */
if (key->type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
btrfs_set_inode_generation(path->nodes[0], dst_item,
trans->transid);
}
}
no_copy:
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
/*
* Item overwrite used by replay and tree logging. eb, slot and key all refer
* to the src data we are copying out.
*
* root is the tree we are copying into, and path is a scratch
* path for use in this function (it should be released on entry and
* will be released on exit).
*
* If the key is already in the destination tree the existing item is
* overwritten. If the existing item isn't big enough, it is extended.
* If it is too large, it is truncated.
*
* If the key isn't in the destination yet, a new item is inserted.
*/
static int overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
/* Look for the key in the destination tree. */
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
return ret;
return do_overwrite_item(trans, root, path, eb, slot, key);
}
/*
* simple helper to read an inode off the disk from a given root
* This can only be called for subvolume roots and not for the log
*/
static noinline struct inode *read_one_inode(struct btrfs_root *root,
u64 objectid)
{
struct inode *inode;
inode = btrfs_iget(root->fs_info->sb, objectid, root);
if (IS_ERR(inode))
inode = NULL;
return inode;
}
/* replays a single extent in 'eb' at 'slot' with 'key' into the
* subvolume 'root'. path is released on entry and should be released
* on exit.
*
* extents in the log tree have not been allocated out of the extent
* tree yet. So, this completes the allocation, taking a reference
* as required if the extent already exists or creating a new extent
* if it isn't in the extent allocation tree yet.
*
* The extent is inserted into the file, dropping any existing extents
* from the file that overlap the new one.
*/
static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_fs_info *fs_info = root->fs_info;
int found_type;
u64 extent_end;
u64 start = key->offset;
u64 nbytes = 0;
struct btrfs_file_extent_item *item;
struct inode *inode = NULL;
unsigned long size;
int ret = 0;
item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
nbytes = btrfs_file_extent_num_bytes(eb, item);
extent_end = start + nbytes;
/*
* We don't add to the inodes nbytes if we are prealloc or a
* hole.
*/
if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
nbytes = 0;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size = btrfs_file_extent_ram_bytes(eb, item);
nbytes = btrfs_file_extent_ram_bytes(eb, item);
extent_end = ALIGN(start + size,
fs_info->sectorsize);
} else {
ret = 0;
goto out;
}
inode = read_one_inode(root, key->objectid);
if (!inode) {
ret = -EIO;
goto out;
}
/*
* first check to see if we already have this extent in the
* file. This must be done before the btrfs_drop_extents run
* so we don't try to drop this extent.
*/
ret = btrfs_lookup_file_extent(trans, root, path,
btrfs_ino(BTRFS_I(inode)), start, 0);
if (ret == 0 &&
(found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
struct btrfs_file_extent_item cmp1;
struct btrfs_file_extent_item cmp2;
struct btrfs_file_extent_item *existing;
struct extent_buffer *leaf;
leaf = path->nodes[0];
existing = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
read_extent_buffer(eb, &cmp1, (unsigned long)item,
sizeof(cmp1));
read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
sizeof(cmp2));
/*
* we already have a pointer to this exact extent,
* we don't have to do anything
*/
if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
btrfs_release_path(path);
goto out;
}
}
btrfs_release_path(path);
/* drop any overlapping extents */
drop_args.start = start;
drop_args.end = extent_end;
drop_args.drop_cache = true;
ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args);
if (ret)
goto out;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 offset;
unsigned long dest_offset;
struct btrfs_key ins;
if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
btrfs_fs_incompat(fs_info, NO_HOLES))
goto update_inode;
ret = btrfs_insert_empty_item(trans, root, path, key,
sizeof(*item));
if (ret)
goto out;
dest_offset = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
copy_extent_buffer(path->nodes[0], eb, dest_offset,
(unsigned long)item, sizeof(*item));
ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
ins.type = BTRFS_EXTENT_ITEM_KEY;
offset = key->offset - btrfs_file_extent_offset(eb, item);
/*
* Manually record dirty extent, as here we did a shallow
* file extent item copy and skip normal backref update,
* but modifying extent tree all by ourselves.
* So need to manually record dirty extent for qgroup,
* as the owner of the file extent changed from log tree
* (doesn't affect qgroup) to fs/file tree(affects qgroup)
*/
ret = btrfs_qgroup_trace_extent(trans,
btrfs_file_extent_disk_bytenr(eb, item),
btrfs_file_extent_disk_num_bytes(eb, item),
GFP_NOFS);
if (ret < 0)
goto out;
if (ins.objectid > 0) {
struct btrfs_ref ref = { 0 };
u64 csum_start;
u64 csum_end;
LIST_HEAD(ordered_sums);
/*
* is this extent already allocated in the extent
* allocation tree? If so, just add a reference
*/
ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
ins.offset);
if (ret < 0) {
goto out;
} else if (ret == 0) {
btrfs_init_generic_ref(&ref,
BTRFS_ADD_DELAYED_REF,
ins.objectid, ins.offset, 0);
btrfs_init_data_ref(&ref,
root->root_key.objectid,
key->objectid, offset, 0, false);
ret = btrfs_inc_extent_ref(trans, &ref);
if (ret)
goto out;
} else {
/*
* insert the extent pointer in the extent
* allocation tree
*/
ret = btrfs_alloc_logged_file_extent(trans,
root->root_key.objectid,
key->objectid, offset, &ins);
if (ret)
goto out;
}
btrfs_release_path(path);
if (btrfs_file_extent_compression(eb, item)) {
csum_start = ins.objectid;
csum_end = csum_start + ins.offset;
} else {
csum_start = ins.objectid +
btrfs_file_extent_offset(eb, item);
csum_end = csum_start +
btrfs_file_extent_num_bytes(eb, item);
}
ret = btrfs_lookup_csums_range(root->log_root,
csum_start, csum_end - 1,
&ordered_sums, 0);
if (ret)
goto out;
/*
* Now delete all existing cums in the csum root that
* cover our range. We do this because we can have an
* extent that is completely referenced by one file
* extent item and partially referenced by another
* file extent item (like after using the clone or
* extent_same ioctls). In this case if we end up doing
* the replay of the one that partially references the
* extent first, and we do not do the csum deletion
* below, we can get 2 csum items in the csum tree that
* overlap each other. For example, imagine our log has
* the two following file extent items:
*
* key (257 EXTENT_DATA 409600)
* extent data disk byte 12845056 nr 102400
* extent data offset 20480 nr 20480 ram 102400
*
* key (257 EXTENT_DATA 819200)
* extent data disk byte 12845056 nr 102400
* extent data offset 0 nr 102400 ram 102400
*
* Where the second one fully references the 100K extent
* that starts at disk byte 12845056, and the log tree
* has a single csum item that covers the entire range
* of the extent:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
*
* After the first file extent item is replayed, the
* csum tree gets the following csum item:
*
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which covers the 20K sub-range starting at offset 20K
* of our extent. Now when we replay the second file
* extent item, if we do not delete existing csum items
* that cover any of its blocks, we end up getting two
* csum items in our csum tree that overlap each other:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which is a problem, because after this anyone trying
* to lookup up for the checksum of any block of our
* extent starting at an offset of 40K or higher, will
* end up looking at the second csum item only, which
* does not contain the checksum for any block starting
* at offset 40K or higher of our extent.
*/
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums;
struct btrfs_root *csum_root;
sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
csum_root = btrfs_csum_root(fs_info,
sums->bytenr);
if (!ret)
ret = btrfs_del_csums(trans, csum_root,
sums->bytenr,
sums->len);
if (!ret)
ret = btrfs_csum_file_blocks(trans,
csum_root,
sums);
list_del(&sums->list);
kfree(sums);
}
if (ret)
goto out;
} else {
btrfs_release_path(path);
}
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
/* inline extents are easy, we just overwrite them */
ret = overwrite_item(trans, root, path, eb, slot, key);
if (ret)
goto out;
}
ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start,
extent_end - start);
if (ret)
goto out;
update_inode:
btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
out:
iput(inode);
return ret;
}
static int unlink_inode_for_log_replay(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
const char *name,
int name_len)
{
int ret;
ret = btrfs_unlink_inode(trans, dir, inode, name, name_len);
if (ret)
return ret;
/*
* Whenever we need to check if a name exists or not, we check the
* fs/subvolume tree. So after an unlink we must run delayed items, so
* that future checks for a name during log replay see that the name
* does not exists anymore.
*/
return btrfs_run_delayed_items(trans);
}
/*
* when cleaning up conflicts between the directory names in the
* subvolume, directory names in the log and directory names in the
* inode back references, we may have to unlink inodes from directories.
*
* This is a helper function to do the unlink of a specific directory
* item
*/
static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_path *path,
struct btrfs_inode *dir,
struct btrfs_dir_item *di)
{
struct btrfs_root *root = dir->root;
struct inode *inode;
char *name;
int name_len;
struct extent_buffer *leaf;
struct btrfs_key location;
int ret;
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
name_len = btrfs_dir_name_len(leaf, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name)
return -ENOMEM;
read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
btrfs_release_path(path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
ret = -EIO;
goto out;
}
ret = link_to_fixup_dir(trans, root, path, location.objectid);
if (ret)
goto out;
ret = unlink_inode_for_log_replay(trans, dir, BTRFS_I(inode), name,
name_len);
out:
kfree(name);
iput(inode);
return ret;
}
/*
* See if a given name and sequence number found in an inode back reference are
* already in a directory and correctly point to this inode.
*
* Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it
* exists.
*/
static noinline int inode_in_dir(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, u64 objectid, u64 index,
const char *name, int name_len)
{
struct btrfs_dir_item *di;
struct btrfs_key location;
int ret = 0;
di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
index, name, name_len, 0);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
} else if (di) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else {
goto out;
}
btrfs_release_path(path);
di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
} else if (di) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid == objectid)
ret = 1;
}
out:
btrfs_release_path(path);
return ret;
}
/*
* helper function to check a log tree for a named back reference in
* an inode. This is used to decide if a back reference that is
* found in the subvolume conflicts with what we find in the log.
*
* inode backreferences may have multiple refs in a single item,
* during replay we process one reference at a time, and we don't
* want to delete valid links to a file from the subvolume if that
* link is also in the log.
*/
static noinline int backref_in_log(struct btrfs_root *log,
struct btrfs_key *key,
u64 ref_objectid,
const char *name, int namelen)
{
struct btrfs_path *path;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
if (ret < 0) {
goto out;
} else if (ret == 1) {
ret = 0;
goto out;
}
if (key->type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
path->slots[0],
ref_objectid,
name, namelen);
else
ret = !!btrfs_find_name_in_backref(path->nodes[0],
path->slots[0],
name, namelen);
out:
btrfs_free_path(path);
return ret;
}
static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_root *log_root,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
u64 inode_objectid, u64 parent_objectid,
u64 ref_index, char *name, int namelen,
int *search_done)
{
int ret;
char *victim_name;
int victim_name_len;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key search_key;
struct btrfs_inode_extref *extref;
again:
/* Search old style refs */
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = parent_objectid;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret == 0) {
struct btrfs_inode_ref *victim_ref;
unsigned long ptr;
unsigned long ptr_end;
leaf = path->nodes[0];
/* are we trying to overwrite a back ref for the root directory
* if so, just jump out, we're done
*/
if (search_key.objectid == search_key.offset)
return 1;
/* check all the names in this back reference to see
* if they are in the log. if so, we allow them to stay
* otherwise they must be unlinked as a conflict
*/
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
ptr_end = ptr + btrfs_item_size(leaf, path->slots[0]);
while (ptr < ptr_end) {
victim_ref = (struct btrfs_inode_ref *)ptr;
victim_name_len = btrfs_inode_ref_name_len(leaf,
victim_ref);
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name,
(unsigned long)(victim_ref + 1),
victim_name_len);
ret = backref_in_log(log_root, &search_key,
parent_objectid, victim_name,
victim_name_len);
if (ret < 0) {
kfree(victim_name);
return ret;
} else if (!ret) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = unlink_inode_for_log_replay(trans, dir, inode,
victim_name, victim_name_len);
kfree(victim_name);
if (ret)
return ret;
*search_done = 1;
goto again;
}
kfree(victim_name);
ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
}
/*
* NOTE: we have searched root tree and checked the
* corresponding ref, it does not need to check again.
*/
*search_done = 1;
}
btrfs_release_path(path);
/* Same search but for extended refs */
extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
inode_objectid, parent_objectid, 0,
0);
if (!IS_ERR_OR_NULL(extref)) {
u32 item_size;
u32 cur_offset = 0;
unsigned long base;
struct inode *victim_parent;
leaf = path->nodes[0];
item_size = btrfs_item_size(leaf, path->slots[0]);
base = btrfs_item_ptr_offset(leaf, path->slots[0]);
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *)(base + cur_offset);
victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
goto next;
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
victim_name_len);
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(parent_objectid,
victim_name,
victim_name_len);
ret = backref_in_log(log_root, &search_key,
parent_objectid, victim_name,
victim_name_len);
if (ret < 0) {
kfree(victim_name);
return ret;
} else if (!ret) {
ret = -ENOENT;
victim_parent = read_one_inode(root,
parent_objectid);
if (victim_parent) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = unlink_inode_for_log_replay(trans,
BTRFS_I(victim_parent),
inode,
victim_name,
victim_name_len);
}
iput(victim_parent);
kfree(victim_name);
if (ret)
return ret;
*search_done = 1;
goto again;
}
kfree(victim_name);
next:
cur_offset += victim_name_len + sizeof(*extref);
}
*search_done = 1;
}
btrfs_release_path(path);
/* look for a conflicting sequence number */
di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
ref_index, name, namelen, 0);
if (IS_ERR(di)) {
return PTR_ERR(di);
} else if (di) {
ret = drop_one_dir_item(trans, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
/* look for a conflicting name */
di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
name, namelen, 0);
if (IS_ERR(di)) {
return PTR_ERR(di);
} else if (di) {
ret = drop_one_dir_item(trans, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
return 0;
}
static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
u32 *namelen, char **name, u64 *index,
u64 *parent_objectid)
{
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ref_ptr;
*namelen = btrfs_inode_extref_name_len(eb, extref);
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)&extref->name,
*namelen);
if (index)
*index = btrfs_inode_extref_index(eb, extref);
if (parent_objectid)
*parent_objectid = btrfs_inode_extref_parent(eb, extref);
return 0;
}
static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
u32 *namelen, char **name, u64 *index)
{
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ref_ptr;
*namelen = btrfs_inode_ref_name_len(eb, ref);
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
if (index)
*index = btrfs_inode_ref_index(eb, ref);
return 0;
}
/*
* Take an inode reference item from the log tree and iterate all names from the
* inode reference item in the subvolume tree with the same key (if it exists).
* For any name that is not in the inode reference item from the log tree, do a
* proper unlink of that name (that is, remove its entry from the inode
* reference item and both dir index keys).
*/
static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_inode *inode,
struct extent_buffer *log_eb,
int log_slot,
struct btrfs_key *key)
{
int ret;
unsigned long ref_ptr;
unsigned long ref_end;
struct extent_buffer *eb;
again:
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret > 0) {
ret = 0;
goto out;
}
if (ret < 0)
goto out;
eb = path->nodes[0];
ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
ref_end = ref_ptr + btrfs_item_size(eb, path->slots[0]);
while (ref_ptr < ref_end) {
char *name = NULL;
int namelen;
u64 parent_id;
if (key->type == BTRFS_INODE_EXTREF_KEY) {
ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
NULL, &parent_id);
} else {
parent_id = key->offset;
ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
NULL);
}
if (ret)
goto out;
if (key->type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
parent_id, name,
namelen);
else
ret = !!btrfs_find_name_in_backref(log_eb, log_slot,
name, namelen);
if (!ret) {
struct inode *dir;
btrfs_release_path(path);
dir = read_one_inode(root, parent_id);
if (!dir) {
ret = -ENOENT;
kfree(name);
goto out;
}
ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir),
inode, name, namelen);
kfree(name);
iput(dir);
if (ret)
goto out;
goto again;
}
kfree(name);
ref_ptr += namelen;
if (key->type == BTRFS_INODE_EXTREF_KEY)
ref_ptr += sizeof(struct btrfs_inode_extref);
else
ref_ptr += sizeof(struct btrfs_inode_ref);
}
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir,
const u8 ref_type, const char *name,
const int namelen)
{
struct btrfs_key key;
struct btrfs_path *path;
const u64 parent_id = btrfs_ino(BTRFS_I(dir));
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = btrfs_ino(BTRFS_I(inode));
key.type = ref_type;
if (key.type == BTRFS_INODE_REF_KEY)
key.offset = parent_id;
else
key.offset = btrfs_extref_hash(parent_id, name, namelen);
ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
goto out;
}
if (key.type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
path->slots[0], parent_id, name, namelen);
else
ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
name, namelen);
out:
btrfs_free_path(path);
return ret;
}
static int add_link(struct btrfs_trans_handle *trans,
struct inode *dir, struct inode *inode, const char *name,
int namelen, u64 ref_index)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_dir_item *dir_item;
struct btrfs_key key;
struct btrfs_path *path;
struct inode *other_inode = NULL;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dir_item = btrfs_lookup_dir_item(NULL, root, path,
btrfs_ino(BTRFS_I(dir)),
name, namelen, 0);
if (!dir_item) {
btrfs_release_path(path);
goto add_link;
} else if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
/*
* Our inode's dentry collides with the dentry of another inode which is
* in the log but not yet processed since it has a higher inode number.
* So delete that other dentry.
*/
btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &key);
btrfs_release_path(path);
other_inode = read_one_inode(root, key.objectid);
if (!other_inode) {
ret = -ENOENT;
goto out;
}
ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(other_inode),
name, namelen);
if (ret)
goto out;
/*
* If we dropped the link count to 0, bump it so that later the iput()
* on the inode will not free it. We will fixup the link count later.
*/
if (other_inode->i_nlink == 0)
inc_nlink(other_inode);
add_link:
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
name, namelen, 0, ref_index);
out:
iput(other_inode);
btrfs_free_path(path);
return ret;
}
/*
* replay one inode back reference item found in the log tree.
* eb, slot and key refer to the buffer and key found in the log tree.
* root is the destination we are replaying into, and path is for temp
* use by this function. (it should be released on return).
*/
static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct inode *dir = NULL;
struct inode *inode = NULL;
unsigned long ref_ptr;
unsigned long ref_end;
char *name = NULL;
int namelen;
int ret;
int search_done = 0;
int log_ref_ver = 0;
u64 parent_objectid;
u64 inode_objectid;
u64 ref_index = 0;
int ref_struct_size;
ref_ptr = btrfs_item_ptr_offset(eb, slot);
ref_end = ref_ptr + btrfs_item_size(eb, slot);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *r;
ref_struct_size = sizeof(struct btrfs_inode_extref);
log_ref_ver = 1;
r = (struct btrfs_inode_extref *)ref_ptr;
parent_objectid = btrfs_inode_extref_parent(eb, r);
} else {
ref_struct_size = sizeof(struct btrfs_inode_ref);
parent_objectid = key->offset;
}
inode_objectid = key->objectid;
/*
* it is possible that we didn't log all the parent directories
* for a given inode. If we don't find the dir, just don't
* copy the back ref in. The link count fixup code will take
* care of the rest
*/
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
inode = read_one_inode(root, inode_objectid);
if (!inode) {
ret = -EIO;
goto out;
}
while (ref_ptr < ref_end) {
if (log_ref_ver) {
ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
&ref_index, &parent_objectid);
/*
* parent object can change from one array
* item to another.
*/
if (!dir)
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
} else {
ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
&ref_index);
}
if (ret)
goto out;
ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
btrfs_ino(BTRFS_I(inode)), ref_index,
name, namelen);
if (ret < 0) {
goto out;
} else if (ret == 0) {
/*
* look for a conflicting back reference in the
* metadata. if we find one we have to unlink that name
* of the file before we add our new link. Later on, we
* overwrite any existing back reference, and we don't
* want to create dangling pointers in the directory.
*/
if (!search_done) {
ret = __add_inode_ref(trans, root, path, log,
BTRFS_I(dir),
BTRFS_I(inode),
inode_objectid,
parent_objectid,
ref_index, name, namelen,
&search_done);
if (ret) {
if (ret == 1)
ret = 0;
goto out;
}
}
/*
* If a reference item already exists for this inode
* with the same parent and name, but different index,
* drop it and the corresponding directory index entries
* from the parent before adding the new reference item
* and dir index entries, otherwise we would fail with
* -EEXIST returned from btrfs_add_link() below.
*/
ret = btrfs_inode_ref_exists(inode, dir, key->type,
name, namelen);
if (ret > 0) {
ret = unlink_inode_for_log_replay(trans,
BTRFS_I(dir),
BTRFS_I(inode),
name, namelen);
/*
* If we dropped the link count to 0, bump it so
* that later the iput() on the inode will not
* free it. We will fixup the link count later.
*/
if (!ret && inode->i_nlink == 0)
inc_nlink(inode);
}
if (ret < 0)
goto out;
/* insert our name */
ret = add_link(trans, dir, inode, name, namelen,
ref_index);
if (ret)
goto out;
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret)
goto out;
}
/* Else, ret == 1, we already have a perfect match, we're done. */
ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
kfree(name);
name = NULL;
if (log_ref_ver) {
iput(dir);
dir = NULL;
}
}
/*
* Before we overwrite the inode reference item in the subvolume tree
* with the item from the log tree, we must unlink all names from the
* parent directory that are in the subvolume's tree inode reference
* item, otherwise we end up with an inconsistent subvolume tree where
* dir index entries exist for a name but there is no inode reference
* item with the same name.
*/
ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
key);
if (ret)
goto out;
/* finally write the back reference in the inode */
ret = overwrite_item(trans, root, path, eb, slot, key);
out:
btrfs_release_path(path);
kfree(name);
iput(dir);
iput(inode);
return ret;
}
static int count_inode_extrefs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret = 0;
int name_len;
unsigned int nlink = 0;
u32 item_size;
u32 cur_offset = 0;
u64 inode_objectid = btrfs_ino(inode);
u64 offset = 0;
unsigned long ptr;
struct btrfs_inode_extref *extref;
struct extent_buffer *leaf;
while (1) {
ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
&extref, &offset);
if (ret)
break;
leaf = path->nodes[0];
item_size = btrfs_item_size(leaf, path->slots[0]);
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
cur_offset = 0;
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
name_len = btrfs_inode_extref_name_len(leaf, extref);
nlink++;
cur_offset += name_len + sizeof(*extref);
}
offset++;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret < 0 && ret != -ENOENT)
return ret;
return nlink;
}
static int count_inode_refs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
unsigned int nlink = 0;
unsigned long ptr;
unsigned long ptr_end;
int name_len;
u64 ino = btrfs_ino(inode);
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
process_slot:
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid != ino ||
key.type != BTRFS_INODE_REF_KEY)
break;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
ptr_end = ptr + btrfs_item_size(path->nodes[0],
path->slots[0]);
while (ptr < ptr_end) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
name_len = btrfs_inode_ref_name_len(path->nodes[0],
ref);
ptr = (unsigned long)(ref + 1) + name_len;
nlink++;
}
if (key.offset == 0)
break;
if (path->slots[0] > 0) {
path->slots[0]--;
goto process_slot;
}
key.offset--;
btrfs_release_path(path);
}
btrfs_release_path(path);
return nlink;
}
/*
* There are a few corners where the link count of the file can't
* be properly maintained during replay. So, instead of adding
* lots of complexity to the log code, we just scan the backrefs
* for any file that has been through replay.
*
* The scan will update the link count on the inode to reflect the
* number of back refs found. If it goes down to zero, the iput
* will free the inode.
*/
static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_path *path;
int ret;
u64 nlink = 0;
u64 ino = btrfs_ino(BTRFS_I(inode));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = count_inode_refs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink = ret;
ret = count_inode_extrefs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink += ret;
ret = 0;
if (nlink != inode->i_nlink) {
set_nlink(inode, nlink);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret)
goto out;
}
BTRFS_I(inode)->index_cnt = (u64)-1;
if (inode->i_nlink == 0) {
if (S_ISDIR(inode->i_mode)) {
ret = replay_dir_deletes(trans, root, NULL, path,
ino, 1);
if (ret)
goto out;
}
ret = btrfs_insert_orphan_item(trans, root, ino);
if (ret == -EEXIST)
ret = 0;
}
out:
btrfs_free_path(path);
return ret;
}
static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
struct inode *inode;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
break;
if (ret == 1) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
ret = btrfs_del_item(trans, root, path);
if (ret)
break;
btrfs_release_path(path);
inode = read_one_inode(root, key.offset);
if (!inode) {
ret = -EIO;
break;
}
ret = fixup_inode_link_count(trans, root, inode);
iput(inode);
if (ret)
break;
/*
* fixup on a directory may create new entries,
* make sure we always look for the highset possible
* offset
*/
key.offset = (u64)-1;
}
btrfs_release_path(path);
return ret;
}
/*
* record a given inode in the fixup dir so we can check its link
* count when replay is done. The link count is incremented here
* so the inode won't go away until we check it
*/
static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid)
{
struct btrfs_key key;
int ret = 0;
struct inode *inode;
inode = read_one_inode(root, objectid);
if (!inode)
return -EIO;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = objectid;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(path);
if (ret == 0) {
if (!inode->i_nlink)
set_nlink(inode, 1);
else
inc_nlink(inode);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
} else if (ret == -EEXIST) {
ret = 0;
}
iput(inode);
return ret;
}
/*
* when replaying the log for a directory, we only insert names
* for inodes that actually exist. This means an fsync on a directory
* does not implicitly fsync all the new files in it
*/
static noinline int insert_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 dirid, u64 index,
char *name, int name_len,
struct btrfs_key *location)
{
struct inode *inode;
struct inode *dir;
int ret;
inode = read_one_inode(root, location->objectid);
if (!inode)
return -ENOENT;
dir = read_one_inode(root, dirid);
if (!dir) {
iput(inode);
return -EIO;
}
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
name_len, 1, index);
/* FIXME, put inode into FIXUP list */
iput(inode);
iput(dir);
return ret;
}
static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir,
struct btrfs_path *path,
struct btrfs_dir_item *dst_di,
const struct btrfs_key *log_key,
u8 log_type,
bool exists)
{
struct btrfs_key found_key;
btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
/* The existing dentry points to the same inode, don't delete it. */
if (found_key.objectid == log_key->objectid &&
found_key.type == log_key->type &&
found_key.offset == log_key->offset &&
btrfs_dir_type(path->nodes[0], dst_di) == log_type)
return 1;
/*
* Don't drop the conflicting directory entry if the inode for the new
* entry doesn't exist.
*/
if (!exists)
return 0;
return drop_one_dir_item(trans, path, dir, dst_di);
}
/*
* take a single entry in a log directory item and replay it into
* the subvolume.
*
* if a conflicting item exists in the subdirectory already,
* the inode it points to is unlinked and put into the link count
* fix up tree.
*
* If a name from the log points to a file or directory that does
* not exist in the FS, it is skipped. fsyncs on directories
* do not force down inodes inside that directory, just changes to the
* names or unlinks in a directory.
*
* Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
* non-existing inode) and 1 if the name was replayed.
*/
static noinline int replay_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb,
struct btrfs_dir_item *di,
struct btrfs_key *key)
{
char *name;
int name_len;
struct btrfs_dir_item *dir_dst_di;
struct btrfs_dir_item *index_dst_di;
bool dir_dst_matches = false;
bool index_dst_matches = false;
struct btrfs_key log_key;
struct btrfs_key search_key;
struct inode *dir;
u8 log_type;
bool exists;
int ret;
bool update_size = true;
bool name_added = false;
dir = read_one_inode(root, key->objectid);
if (!dir)
return -EIO;
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
log_type = btrfs_dir_type(eb, di);
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
btrfs_dir_item_key_to_cpu(eb, di, &log_key);
ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
btrfs_release_path(path);
if (ret < 0)
goto out;
exists = (ret == 0);
ret = 0;
dir_dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
name, name_len, 1);
if (IS_ERR(dir_dst_di)) {
ret = PTR_ERR(dir_dst_di);
goto out;
} else if (dir_dst_di) {
ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
dir_dst_di, &log_key, log_type,
exists);
if (ret < 0)
goto out;
dir_dst_matches = (ret == 1);
}
btrfs_release_path(path);
index_dst_di = btrfs_lookup_dir_index_item(trans, root, path,
key->objectid, key->offset,
name, name_len, 1);
if (IS_ERR(index_dst_di)) {
ret = PTR_ERR(index_dst_di);
goto out;
} else if (index_dst_di) {
ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
index_dst_di, &log_key,
log_type, exists);
if (ret < 0)
goto out;
index_dst_matches = (ret == 1);
}
btrfs_release_path(path);
if (dir_dst_matches && index_dst_matches) {
ret = 0;
update_size = false;
goto out;
}
/*
* Check if the inode reference exists in the log for the given name,
* inode and parent inode
*/
search_key.objectid = log_key.objectid;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = key->objectid;
ret = backref_in_log(root->log_root, &search_key, 0, name, name_len);
if (ret < 0) {
goto out;
} else if (ret) {
/* The dentry will be added later. */
ret = 0;
update_size = false;
goto out;
}
search_key.objectid = log_key.objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = key->objectid;
ret = backref_in_log(root->log_root, &search_key, key->objectid, name,
name_len);
if (ret < 0) {
goto out;
} else if (ret) {
/* The dentry will be added later. */
ret = 0;
update_size = false;
goto out;
}
btrfs_release_path(path);
ret = insert_one_name(trans, root, key->objectid, key->offset,
name, name_len, &log_key);
if (ret && ret != -ENOENT && ret != -EEXIST)
goto out;
if (!ret)
name_added = true;
update_size = false;
ret = 0;
out:
if (!ret && update_size) {
btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2);
ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
}
kfree(name);
iput(dir);
if (!ret && name_added)
ret = 1;
return ret;
}
/* Replay one dir item from a BTRFS_DIR_INDEX_KEY key. */
static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
struct btrfs_dir_item *di;
/* We only log dir index keys, which only contain a single dir item. */
ASSERT(key->type == BTRFS_DIR_INDEX_KEY);
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
ret = replay_one_name(trans, root, path, eb, di, key);
if (ret < 0)
return ret;
/*
* If this entry refers to a non-directory (directories can not have a
* link count > 1) and it was added in the transaction that was not
* committed, make sure we fixup the link count of the inode the entry
* points to. Otherwise something like the following would result in a
* directory pointing to an inode with a wrong link that does not account
* for this dir entry:
*
* mkdir testdir
* touch testdir/foo
* touch testdir/bar
* sync
*
* ln testdir/bar testdir/bar_link
* ln testdir/foo testdir/foo_link
* xfs_io -c "fsync" testdir/bar
*
* <power failure>
*
* mount fs, log replay happens
*
* File foo would remain with a link count of 1 when it has two entries
* pointing to it in the directory testdir. This would make it impossible
* to ever delete the parent directory has it would result in stale
* dentries that can never be deleted.
*/
if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
struct btrfs_path *fixup_path;
struct btrfs_key di_key;
fixup_path = btrfs_alloc_path();
if (!fixup_path)
return -ENOMEM;
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
ret = link_to_fixup_dir(trans, root, fixup_path, di_key.objectid);
btrfs_free_path(fixup_path);
}
return ret;
}
/*
* directory replay has two parts. There are the standard directory
* items in the log copied from the subvolume, and range items
* created in the log while the subvolume was logged.
*
* The range items tell us which parts of the key space the log
* is authoritative for. During replay, if a key in the subvolume
* directory is in a logged range item, but not actually in the log
* that means it was deleted from the directory before the fsync
* and should be removed.
*/
static noinline int find_dir_range(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid,
u64 *start_ret, u64 *end_ret)
{
struct btrfs_key key;
u64 found_end;
struct btrfs_dir_log_item *item;
int ret;
int nritems;
if (*start_ret == (u64)-1)
return 1;
key.objectid = dirid;
key.type = BTRFS_DIR_LOG_INDEX_KEY;
key.offset = *start_ret;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
if (ret != 0)
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
ret = 1;
goto next;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
if (*start_ret >= key.offset && *start_ret <= found_end) {
ret = 0;
*start_ret = key.offset;
*end_ret = found_end;
goto out;
}
ret = 1;
next:
/* check the next slot in the tree to see if it is a valid item */
nritems = btrfs_header_nritems(path->nodes[0]);
path->slots[0]++;
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
ret = 1;
goto out;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
*start_ret = key.offset;
*end_ret = found_end;
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* this looks for a given directory item in the log. If the directory
* item is not in the log, the item is removed and the inode it points
* to is unlinked
*/
static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_path *log_path,
struct inode *dir,
struct btrfs_key *dir_key)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret;
struct extent_buffer *eb;
int slot;
struct btrfs_dir_item *di;
int name_len;
char *name;
struct inode *inode = NULL;
struct btrfs_key location;
/*
* Currently we only log dir index keys. Even if we replay a log created
* by an older kernel that logged both dir index and dir item keys, all
* we need to do is process the dir index keys, we (and our caller) can
* safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY).
*/
ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY);
eb = path->nodes[0];
slot = path->slots[0];
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(eb, name, (unsigned long)(di + 1), name_len);
if (log) {
struct btrfs_dir_item *log_di;
log_di = btrfs_lookup_dir_index_item(trans, log, log_path,
dir_key->objectid,
dir_key->offset,
name, name_len, 0);
if (IS_ERR(log_di)) {
ret = PTR_ERR(log_di);
goto out;
} else if (log_di) {
/* The dentry exists in the log, we have nothing to do. */
ret = 0;
goto out;
}
}
btrfs_dir_item_key_to_cpu(eb, di, &location);
btrfs_release_path(path);
btrfs_release_path(log_path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
ret = -EIO;
goto out;
}
ret = link_to_fixup_dir(trans, root, path, location.objectid);
if (ret)
goto out;
inc_nlink(inode);
ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(inode),
name, name_len);
/*
* Unlike dir item keys, dir index keys can only have one name (entry) in
* them, as there are no key collisions since each key has a unique offset
* (an index number), so we're done.
*/
out:
btrfs_release_path(path);
btrfs_release_path(log_path);
kfree(name);
iput(inode);
return ret;
}
static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
const u64 ino)
{
struct btrfs_key search_key;
struct btrfs_path *log_path;
int i;
int nritems;
int ret;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_XATTR_ITEM_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
process_leaf:
nritems = btrfs_header_nritems(path->nodes[0]);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_key key;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
u32 total_size;
u32 cur;
btrfs_item_key_to_cpu(path->nodes[0], &key, i);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
ret = 0;
goto out;
}
di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
total_size = btrfs_item_size(path->nodes[0], i);
cur = 0;
while (cur < total_size) {
u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
u32 this_len = sizeof(*di) + name_len + data_len;
char *name;
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(path->nodes[0], name,
(unsigned long)(di + 1), name_len);
log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
name, name_len, 0);
btrfs_release_path(log_path);
if (!log_di) {
/* Doesn't exist in log tree, so delete it. */
btrfs_release_path(path);
di = btrfs_lookup_xattr(trans, root, path, ino,
name, name_len, -1);
kfree(name);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
ASSERT(di);
ret = btrfs_delete_one_dir_name(trans, root,
path, di);
if (ret)
goto out;
btrfs_release_path(path);
search_key = key;
goto again;
}
kfree(name);
if (IS_ERR(log_di)) {
ret = PTR_ERR(log_di);
goto out;
}
cur += this_len;
di = (struct btrfs_dir_item *)((char *)di + this_len);
}
}
ret = btrfs_next_leaf(root, path);
if (ret > 0)
ret = 0;
else if (ret == 0)
goto process_leaf;
out:
btrfs_free_path(log_path);
btrfs_release_path(path);
return ret;
}
/*
* deletion replay happens before we copy any new directory items
* out of the log or out of backreferences from inodes. It
* scans the log to find ranges of keys that log is authoritative for,
* and then scans the directory to find items in those ranges that are
* not present in the log.
*
* Anything we don't find in the log is unlinked and removed from the
* directory.
*/
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all)
{
u64 range_start;
u64 range_end;
int ret = 0;
struct btrfs_key dir_key;
struct btrfs_key found_key;
struct btrfs_path *log_path;
struct inode *dir;
dir_key.objectid = dirid;
dir_key.type = BTRFS_DIR_INDEX_KEY;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
dir = read_one_inode(root, dirid);
/* it isn't an error if the inode isn't there, that can happen
* because we replay the deletes before we copy in the inode item
* from the log
*/
if (!dir) {
btrfs_free_path(log_path);
return 0;
}
range_start = 0;
range_end = 0;
while (1) {
if (del_all)
range_end = (u64)-1;
else {
ret = find_dir_range(log, path, dirid,
&range_start, &range_end);
if (ret < 0)
goto out;
else if (ret > 0)
break;
}
dir_key.offset = range_start;
while (1) {
int nritems;
ret = btrfs_search_slot(NULL, root, &dir_key, path,
0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret == 1)
break;
else if (ret < 0)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != dirid ||
found_key.type != dir_key.type) {
ret = 0;
goto out;
}
if (found_key.offset > range_end)
break;
ret = check_item_in_log(trans, log, path,
log_path, dir,
&found_key);
if (ret)
goto out;
if (found_key.offset == (u64)-1)
break;
dir_key.offset = found_key.offset + 1;
}
btrfs_release_path(path);
if (range_end == (u64)-1)
break;
range_start = range_end + 1;
}
ret = 0;
out:
btrfs_release_path(path);
btrfs_free_path(log_path);
iput(dir);
return ret;
}
/*
* the process_func used to replay items from the log tree. This
* gets called in two different stages. The first stage just looks
* for inodes and makes sure they are all copied into the subvolume.
*
* The second stage copies all the other item types from the log into
* the subvolume. The two stage approach is slower, but gets rid of
* lots of complexity around inodes referencing other inodes that exist
* only in the log (references come from either directory items or inode
* back refs).
*/
static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level)
{
int nritems;
struct btrfs_path *path;
struct btrfs_root *root = wc->replay_dest;
struct btrfs_key key;
int i;
int ret;
ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
if (ret)
return ret;
level = btrfs_header_level(eb);
if (level != 0)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
nritems = btrfs_header_nritems(eb);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
/* inode keys are done during the first stage */
if (key.type == BTRFS_INODE_ITEM_KEY &&
wc->stage == LOG_WALK_REPLAY_INODES) {
struct btrfs_inode_item *inode_item;
u32 mode;
inode_item = btrfs_item_ptr(eb, i,
struct btrfs_inode_item);
/*
* If we have a tmpfile (O_TMPFILE) that got fsync'ed
* and never got linked before the fsync, skip it, as
* replaying it is pointless since it would be deleted
* later. We skip logging tmpfiles, but it's always
* possible we are replaying a log created with a kernel
* that used to log tmpfiles.
*/
if (btrfs_inode_nlink(eb, inode_item) == 0) {
wc->ignore_cur_inode = true;
continue;
} else {
wc->ignore_cur_inode = false;
}
ret = replay_xattr_deletes(wc->trans, root, log,
path, key.objectid);
if (ret)
break;
mode = btrfs_inode_mode(eb, inode_item);
if (S_ISDIR(mode)) {
ret = replay_dir_deletes(wc->trans,
root, log, path, key.objectid, 0);
if (ret)
break;
}
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
/*
* Before replaying extents, truncate the inode to its
* size. We need to do it now and not after log replay
* because before an fsync we can have prealloc extents
* added beyond the inode's i_size. If we did it after,
* through orphan cleanup for example, we would drop
* those prealloc extents just after replaying them.
*/
if (S_ISREG(mode)) {
struct btrfs_drop_extents_args drop_args = { 0 };
struct inode *inode;
u64 from;
inode = read_one_inode(root, key.objectid);
if (!inode) {
ret = -EIO;
break;
}
from = ALIGN(i_size_read(inode),
root->fs_info->sectorsize);
drop_args.start = from;
drop_args.end = (u64)-1;
drop_args.drop_cache = true;
ret = btrfs_drop_extents(wc->trans, root,
BTRFS_I(inode),
&drop_args);
if (!ret) {
inode_sub_bytes(inode,
drop_args.bytes_found);
/* Update the inode's nbytes. */
ret = btrfs_update_inode(wc->trans,
root, BTRFS_I(inode));
}
iput(inode);
if (ret)
break;
}
ret = link_to_fixup_dir(wc->trans, root,
path, key.objectid);
if (ret)
break;
}
if (wc->ignore_cur_inode)
continue;
if (key.type == BTRFS_DIR_INDEX_KEY &&
wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
if (wc->stage < LOG_WALK_REPLAY_ALL)
continue;
/* these keys are simply copied */
if (key.type == BTRFS_XATTR_ITEM_KEY) {
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
} else if (key.type == BTRFS_INODE_REF_KEY ||
key.type == BTRFS_INODE_EXTREF_KEY) {
ret = add_inode_ref(wc->trans, root, log, path,
eb, i, &key);
if (ret && ret != -ENOENT)
break;
ret = 0;
} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
ret = replay_one_extent(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
/*
* We don't log BTRFS_DIR_ITEM_KEY keys anymore, only the
* BTRFS_DIR_INDEX_KEY items which we use to derive the
* BTRFS_DIR_ITEM_KEY items. If we are replaying a log from an
* older kernel with such keys, ignore them.
*/
}
btrfs_free_path(path);
return ret;
}
/*
* Correctly adjust the reserved bytes occupied by a log tree extent buffer
*/
static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
{
struct btrfs_block_group *cache;
cache = btrfs_lookup_block_group(fs_info, start);
if (!cache) {
btrfs_err(fs_info, "unable to find block group for %llu", start);
return;
}
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->reserved -= fs_info->nodesize;
cache->space_info->bytes_reserved -= fs_info->nodesize;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
btrfs_put_block_group(cache);
}
static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
u32 blocksize;
int ret = 0;
while (*level > 0) {
struct btrfs_key first_key;
cur = path->nodes[*level];
WARN_ON(btrfs_header_level(cur) != *level);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
blocksize = fs_info->nodesize;
next = btrfs_find_create_tree_block(fs_info, bytenr,
btrfs_header_owner(cur),
*level - 1);
if (IS_ERR(next))
return PTR_ERR(next);
if (*level == 1) {
ret = wc->process_func(root, next, wc, ptr_gen,
*level - 1);
if (ret) {
free_extent_buffer(next);
return ret;
}
path->slots[*level]++;
if (wc->free) {
ret = btrfs_read_extent_buffer(next, ptr_gen,
*level - 1, &first_key);
if (ret) {
free_extent_buffer(next);
return ret;
}
if (trans) {
btrfs_tree_lock(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_pin_reserved_extent(trans,
bytenr, blocksize);
if (ret) {
free_extent_buffer(next);
return ret;
}
btrfs_redirty_list_add(
trans->transaction, next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
unaccount_log_buffer(fs_info, bytenr);
}
}
free_extent_buffer(next);
continue;
}
ret = btrfs_read_extent_buffer(next, ptr_gen, *level - 1, &first_key);
if (ret) {
free_extent_buffer(next);
return ret;
}
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
cond_resched();
return 0;
}
static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int i;
int slot;
int ret;
for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
return 0;
} else {
ret = wc->process_func(root, path->nodes[*level], wc,
btrfs_header_generation(path->nodes[*level]),
*level);
if (ret)
return ret;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[*level];
if (trans) {
btrfs_tree_lock(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_pin_reserved_extent(trans,
path->nodes[*level]->start,
path->nodes[*level]->len);
if (ret)
return ret;
btrfs_redirty_list_add(trans->transaction,
next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
unaccount_log_buffer(fs_info,
path->nodes[*level]->start);
}
}
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
static int walk_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int orig_level;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
level = btrfs_header_level(log->node);
orig_level = level;
path->nodes[level] = log->node;
atomic_inc(&log->node->refs);
path->slots[level] = 0;
while (1) {
wret = walk_down_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
wret = walk_up_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
}
/* was the root node processed? if not, catch it here */
if (path->nodes[orig_level]) {
ret = wc->process_func(log, path->nodes[orig_level], wc,
btrfs_header_generation(path->nodes[orig_level]),
orig_level);
if (ret)
goto out;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[orig_level];
if (trans) {
btrfs_tree_lock(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_pin_reserved_extent(trans,
next->start, next->len);
if (ret)
goto out;
btrfs_redirty_list_add(trans->transaction, next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
unaccount_log_buffer(fs_info, next->start);
}
}
}
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function to update the item for a given subvolumes log root
* in the tree of log roots
*/
static int update_log_root(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_root_item *root_item)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret;
if (log->log_transid == 1) {
/* insert root item on the first sync */
ret = btrfs_insert_root(trans, fs_info->log_root_tree,
&log->root_key, root_item);
} else {
ret = btrfs_update_root(trans, fs_info->log_root_tree,
&log->root_key, root_item);
}
return ret;
}
static void wait_log_commit(struct btrfs_root *root, int transid)
{
DEFINE_WAIT(wait);
int index = transid % 2;
/*
* we only allow two pending log transactions at a time,
* so we know that if ours is more than 2 older than the
* current transaction, we're done
*/
for (;;) {
prepare_to_wait(&root->log_commit_wait[index],
&wait, TASK_UNINTERRUPTIBLE);
if (!(root->log_transid_committed < transid &&
atomic_read(&root->log_commit[index])))
break;
mutex_unlock(&root->log_mutex);
schedule();
mutex_lock(&root->log_mutex);
}
finish_wait(&root->log_commit_wait[index], &wait);
}
static void wait_for_writer(struct btrfs_root *root)
{
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(&root->log_writer_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (!atomic_read(&root->log_writers))
break;
mutex_unlock(&root->log_mutex);
schedule();
mutex_lock(&root->log_mutex);
}
finish_wait(&root->log_writer_wait, &wait);
}
static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
mutex_lock(&root->log_mutex);
list_del_init(&ctx->list);
mutex_unlock(&root->log_mutex);
}
/*
* Invoked in log mutex context, or be sure there is no other task which
* can access the list.
*/
static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
int index, int error)
{
struct btrfs_log_ctx *ctx;
struct btrfs_log_ctx *safe;
list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
list_del_init(&ctx->list);
ctx->log_ret = error;
}
}
/*
* btrfs_sync_log does sends a given tree log down to the disk and
* updates the super blocks to record it. When this call is done,
* you know that any inodes previously logged are safely on disk only
* if it returns 0.
*
* Any other return value means you need to call btrfs_commit_transaction.
* Some of the edge cases for fsyncing directories that have had unlinks
* or renames done in the past mean that sometimes the only safe
* fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
* that has happened.
*/
int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_log_ctx *ctx)
{
int index1;
int index2;
int mark;
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *log = root->log_root;
struct btrfs_root *log_root_tree = fs_info->log_root_tree;
struct btrfs_root_item new_root_item;
int log_transid = 0;
struct btrfs_log_ctx root_log_ctx;
struct blk_plug plug;
u64 log_root_start;
u64 log_root_level;
mutex_lock(&root->log_mutex);
log_transid = ctx->log_transid;
if (root->log_transid_committed >= log_transid) {
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
index1 = log_transid % 2;
if (atomic_read(&root->log_commit[index1])) {
wait_log_commit(root, log_transid);
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
ASSERT(log_transid == root->log_transid);
atomic_set(&root->log_commit[index1], 1);
/* wait for previous tree log sync to complete */
if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
wait_log_commit(root, log_transid - 1);
while (1) {
int batch = atomic_read(&root->log_batch);
/* when we're on an ssd, just kick the log commit out */
if (!btrfs_test_opt(fs_info, SSD) &&
test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
mutex_unlock(&root->log_mutex);
schedule_timeout_uninterruptible(1);
mutex_lock(&root->log_mutex);
}
wait_for_writer(root);
if (batch == atomic_read(&root->log_batch))
break;
}
/* bail out if we need to do a full commit */
if (btrfs_need_log_full_commit(trans)) {
ret = BTRFS_LOG_FORCE_COMMIT;
mutex_unlock(&root->log_mutex);
goto out;
}
if (log_transid % 2 == 0)
mark = EXTENT_DIRTY;
else
mark = EXTENT_NEW;
/* we start IO on all the marked extents here, but we don't actually
* wait for them until later.
*/
blk_start_plug(&plug);
ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
/*
* -EAGAIN happens when someone, e.g., a concurrent transaction
* commit, writes a dirty extent in this tree-log commit. This
* concurrent write will create a hole writing out the extents,
* and we cannot proceed on a zoned filesystem, requiring
* sequential writing. While we can bail out to a full commit
* here, but we can continue hoping the concurrent writing fills
* the hole.
*/
if (ret == -EAGAIN && btrfs_is_zoned(fs_info))
ret = 0;
if (ret) {
blk_finish_plug(&plug);
btrfs_abort_transaction(trans, ret);
btrfs_set_log_full_commit(trans);
mutex_unlock(&root->log_mutex);
goto out;
}
/*
* We _must_ update under the root->log_mutex in order to make sure we
* have a consistent view of the log root we are trying to commit at
* this moment.
*
* We _must_ copy this into a local copy, because we are not holding the
* log_root_tree->log_mutex yet. This is important because when we
* commit the log_root_tree we must have a consistent view of the
* log_root_tree when we update the super block to point at the
* log_root_tree bytenr. If we update the log_root_tree here we'll race
* with the commit and possibly point at the new block which we may not
* have written out.
*/
btrfs_set_root_node(&log->root_item, log->node);
memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
root->log_transid++;
log->log_transid = root->log_transid;
root->log_start_pid = 0;
/*
* IO has been started, blocks of the log tree have WRITTEN flag set
* in their headers. new modifications of the log will be written to
* new positions. so it's safe to allow log writers to go in.
*/
mutex_unlock(&root->log_mutex);
if (btrfs_is_zoned(fs_info)) {
mutex_lock(&fs_info->tree_root->log_mutex);
if (!log_root_tree->node) {
ret = btrfs_alloc_log_tree_node(trans, log_root_tree);
if (ret) {
mutex_unlock(&fs_info->tree_root->log_mutex);
blk_finish_plug(&plug);
goto out;
}
}
mutex_unlock(&fs_info->tree_root->log_mutex);
}
btrfs_init_log_ctx(&root_log_ctx, NULL);
mutex_lock(&log_root_tree->log_mutex);
index2 = log_root_tree->log_transid % 2;
list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
root_log_ctx.log_transid = log_root_tree->log_transid;
/*
* Now we are safe to update the log_root_tree because we're under the
* log_mutex, and we're a current writer so we're holding the commit
* open until we drop the log_mutex.
*/
ret = update_log_root(trans, log, &new_root_item);
if (ret) {
if (!list_empty(&root_log_ctx.list))
list_del_init(&root_log_ctx.list);
blk_finish_plug(&plug);
btrfs_set_log_full_commit(trans);
if (ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out;
}
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}
if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
blk_finish_plug(&plug);
list_del_init(&root_log_ctx.list);
mutex_unlock(&log_root_tree->log_mutex);
ret = root_log_ctx.log_ret;
goto out;
}
index2 = root_log_ctx.log_transid % 2;
if (atomic_read(&log_root_tree->log_commit[index2])) {
blk_finish_plug(&plug);
ret = btrfs_wait_tree_log_extents(log, mark);
wait_log_commit(log_root_tree,
root_log_ctx.log_transid);
mutex_unlock(&log_root_tree->log_mutex);
if (!ret)
ret = root_log_ctx.log_ret;
goto out;
}
ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
atomic_set(&log_root_tree->log_commit[index2], 1);
if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
wait_log_commit(log_root_tree,
root_log_ctx.log_transid - 1);
}
/*
* now that we've moved on to the tree of log tree roots,
* check the full commit flag again
*/
if (btrfs_need_log_full_commit(trans)) {
blk_finish_plug(&plug);
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
ret = BTRFS_LOG_FORCE_COMMIT;
goto out_wake_log_root;
}
ret = btrfs_write_marked_extents(fs_info,
&log_root_tree->dirty_log_pages,
EXTENT_DIRTY | EXTENT_NEW);
blk_finish_plug(&plug);
/*
* As described above, -EAGAIN indicates a hole in the extents. We
* cannot wait for these write outs since the waiting cause a
* deadlock. Bail out to the full commit instead.
*/
if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) {
btrfs_set_log_full_commit(trans);
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
} else if (ret) {
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
ret = btrfs_wait_tree_log_extents(log, mark);
if (!ret)
ret = btrfs_wait_tree_log_extents(log_root_tree,
EXTENT_NEW | EXTENT_DIRTY);
if (ret) {
btrfs_set_log_full_commit(trans);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
log_root_start = log_root_tree->node->start;
log_root_level = btrfs_header_level(log_root_tree->node);
log_root_tree->log_transid++;
mutex_unlock(&log_root_tree->log_mutex);
/*
* Here we are guaranteed that nobody is going to write the superblock
* for the current transaction before us and that neither we do write
* our superblock before the previous transaction finishes its commit
* and writes its superblock, because:
*
* 1) We are holding a handle on the current transaction, so no body
* can commit it until we release the handle;
*
* 2) Before writing our superblock we acquire the tree_log_mutex, so
* if the previous transaction is still committing, and hasn't yet
* written its superblock, we wait for it to do it, because a
* transaction commit acquires the tree_log_mutex when the commit
* begins and releases it only after writing its superblock.
*/
mutex_lock(&fs_info->tree_log_mutex);
/*
* The previous transaction writeout phase could have failed, and thus
* marked the fs in an error state. We must not commit here, as we
* could have updated our generation in the super_for_commit and
* writing the super here would result in transid mismatches. If there
* is an error here just bail.
*/
if (BTRFS_FS_ERROR(fs_info)) {
ret = -EIO;
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
mutex_unlock(&fs_info->tree_log_mutex);
goto out_wake_log_root;
}
btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
ret = write_all_supers(fs_info, 1);
mutex_unlock(&fs_info->tree_log_mutex);
if (ret) {
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
goto out_wake_log_root;
}
/*
* We know there can only be one task here, since we have not yet set
* root->log_commit[index1] to 0 and any task attempting to sync the
* log must wait for the previous log transaction to commit if it's
* still in progress or wait for the current log transaction commit if
* someone else already started it. We use <= and not < because the
* first log transaction has an ID of 0.
*/
ASSERT(root->last_log_commit <= log_transid);
root->last_log_commit = log_transid;
out_wake_log_root:
mutex_lock(&log_root_tree->log_mutex);
btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
log_root_tree->log_transid_committed++;
atomic_set(&log_root_tree->log_commit[index2], 0);
mutex_unlock(&log_root_tree->log_mutex);
/*
* The barrier before waitqueue_active (in cond_wake_up) is needed so
* all the updates above are seen by the woken threads. It might not be
* necessary, but proving that seems to be hard.
*/
cond_wake_up(&log_root_tree->log_commit_wait[index2]);
out:
mutex_lock(&root->log_mutex);
btrfs_remove_all_log_ctxs(root, index1, ret);
root->log_transid_committed++;
atomic_set(&root->log_commit[index1], 0);
mutex_unlock(&root->log_mutex);
/*
* The barrier before waitqueue_active (in cond_wake_up) is needed so
* all the updates above are seen by the woken threads. It might not be
* necessary, but proving that seems to be hard.
*/
cond_wake_up(&root->log_commit_wait[index1]);
return ret;
}
static void free_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
int ret;
struct walk_control wc = {
.free = 1,
.process_func = process_one_buffer
};
if (log->node) {
ret = walk_log_tree(trans, log, &wc);
if (ret) {
/*
* We weren't able to traverse the entire log tree, the
* typical scenario is getting an -EIO when reading an
* extent buffer of the tree, due to a previous writeback
* failure of it.
*/
set_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
&log->fs_info->fs_state);
/*
* Some extent buffers of the log tree may still be dirty
* and not yet written back to storage, because we may
* have updates to a log tree without syncing a log tree,
* such as during rename and link operations. So flush
* them out and wait for their writeback to complete, so
* that we properly cleanup their state and pages.
*/
btrfs_write_marked_extents(log->fs_info,
&log->dirty_log_pages,
EXTENT_DIRTY | EXTENT_NEW);
btrfs_wait_tree_log_extents(log,
EXTENT_DIRTY | EXTENT_NEW);
if (trans)
btrfs_abort_transaction(trans, ret);
else
btrfs_handle_fs_error(log->fs_info, ret, NULL);
}
}
clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
extent_io_tree_release(&log->log_csum_range);
btrfs_put_root(log);
}
/*
* free all the extents used by the tree log. This should be called
* at commit time of the full transaction
*/
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
{
if (root->log_root) {
free_log_tree(trans, root->log_root);
root->log_root = NULL;
clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
}
return 0;
}
int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
if (fs_info->log_root_tree) {
free_log_tree(trans, fs_info->log_root_tree);
fs_info->log_root_tree = NULL;
clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state);
}
return 0;
}
/*
* Check if an inode was logged in the current transaction. This correctly deals
* with the case where the inode was logged but has a logged_trans of 0, which
* happens if the inode is evicted and loaded again, as logged_trans is an in
* memory only field (not persisted).
*
* Returns 1 if the inode was logged before in the transaction, 0 if it was not,
* and < 0 on error.
*/
static int inode_logged(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path_in)
{
struct btrfs_path *path = path_in;
struct btrfs_key key;
int ret;
if (inode->logged_trans == trans->transid)
return 1;
/*
* If logged_trans is not 0, then we know the inode logged was not logged
* in this transaction, so we can return false right away.
*/
if (inode->logged_trans > 0)
return 0;
/*
* If no log tree was created for this root in this transaction, then
* the inode can not have been logged in this transaction. In that case
* set logged_trans to anything greater than 0 and less than the current
* transaction's ID, to avoid the search below in a future call in case
* a log tree gets created after this.
*/
if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) {
inode->logged_trans = trans->transid - 1;
return 0;
}
/*
* We have a log tree and the inode's logged_trans is 0. We can't tell
* for sure if the inode was logged before in this transaction by looking
* only at logged_trans. We could be pessimistic and assume it was, but
* that can lead to unnecessarily logging an inode during rename and link
* operations, and then further updating the log in followup rename and
* link operations, specially if it's a directory, which adds latency
* visible to applications doing a series of rename or link operations.
*
* A logged_trans of 0 here can mean several things:
*
* 1) The inode was never logged since the filesystem was mounted, and may
* or may have not been evicted and loaded again;
*
* 2) The inode was logged in a previous transaction, then evicted and
* then loaded again;
*
* 3) The inode was logged in the current transaction, then evicted and
* then loaded again.
*
* For cases 1) and 2) we don't want to return true, but we need to detect
* case 3) and return true. So we do a search in the log root for the inode
* item.
*/
key.objectid = btrfs_ino(inode);
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
if (path_in)
btrfs_release_path(path);
else
btrfs_free_path(path);
/*
* Logging an inode always results in logging its inode item. So if we
* did not find the item we know the inode was not logged for sure.
*/
if (ret < 0) {
return ret;
} else if (ret > 0) {
/*
* Set logged_trans to a value greater than 0 and less then the
* current transaction to avoid doing the search in future calls.
*/
inode->logged_trans = trans->transid - 1;
return 0;
}
/*
* The inode was previously logged and then evicted, set logged_trans to
* the current transacion's ID, to avoid future tree searches as long as
* the inode is not evicted again.
*/
inode->logged_trans = trans->transid;
/*
* If it's a directory, then we must set last_dir_index_offset to the
* maximum possible value, so that the next attempt to log the inode does
* not skip checking if dir index keys found in modified subvolume tree
* leaves have been logged before, otherwise it would result in attempts
* to insert duplicate dir index keys in the log tree. This must be done
* because last_dir_index_offset is an in-memory only field, not persisted
* in the inode item or any other on-disk structure, so its value is lost
* once the inode is evicted.
*/
if (S_ISDIR(inode->vfs_inode.i_mode))
inode->last_dir_index_offset = (u64)-1;
return 1;
}
/*
* Delete a directory entry from the log if it exists.
*
* Returns < 0 on error
* 1 if the entry does not exists
* 0 if the entry existed and was successfully deleted
*/
static int del_logged_dentry(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dir_ino,
const char *name, int name_len,
u64 index)
{
struct btrfs_dir_item *di;
/*
* We only log dir index items of a directory, so we don't need to look
* for dir item keys.
*/
di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
index, name, name_len, -1);
if (IS_ERR(di))
return PTR_ERR(di);
else if (!di)
return 1;
/*
* We do not need to update the size field of the directory's
* inode item because on log replay we update the field to reflect
* all existing entries in the directory (see overwrite_item()).
*/
return btrfs_delete_one_dir_name(trans, log, path, di);
}
/*
* If both a file and directory are logged, and unlinks or renames are
* mixed in, we have a few interesting corners:
*
* create file X in dir Y
* link file X to X.link in dir Y
* fsync file X
* unlink file X but leave X.link
* fsync dir Y
*
* After a crash we would expect only X.link to exist. But file X
* didn't get fsync'd again so the log has back refs for X and X.link.
*
* We solve this by removing directory entries and inode backrefs from the
* log when a file that was logged in the current transaction is
* unlinked. Any later fsync will include the updated log entries, and
* we'll be able to reconstruct the proper directory items from backrefs.
*
* This optimizations allows us to avoid relogging the entire inode
* or the entire directory.
*/
void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *dir, u64 index)
{
struct btrfs_path *path;
int ret;
ret = inode_logged(trans, dir, NULL);
if (ret == 0)
return;
else if (ret < 0) {
btrfs_set_log_full_commit(trans);
return;
}
ret = join_running_log_trans(root);
if (ret)
return;
mutex_lock(&dir->log_mutex);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out_unlock;
}
ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
name, name_len, index);
btrfs_free_path(path);
out_unlock:
mutex_unlock(&dir->log_mutex);
if (ret < 0)
btrfs_set_log_full_commit(trans);
btrfs_end_log_trans(root);
}
/* see comments for btrfs_del_dir_entries_in_log */
void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *inode, u64 dirid)
{
struct btrfs_root *log;
u64 index;
int ret;
ret = inode_logged(trans, inode, NULL);
if (ret == 0)
return;
else if (ret < 0) {
btrfs_set_log_full_commit(trans);
return;
}
ret = join_running_log_trans(root);
if (ret)
return;
log = root->log_root;
mutex_lock(&inode->log_mutex);
ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
dirid, &index);
mutex_unlock(&inode->log_mutex);
if (ret < 0 && ret != -ENOENT)
btrfs_set_log_full_commit(trans);
btrfs_end_log_trans(root);
}
/*
* creates a range item in the log for 'dirid'. first_offset and
* last_offset tell us which parts of the key space the log should
* be considered authoritative for.
*/
static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid,
u64 first_offset, u64 last_offset)
{
int ret;
struct btrfs_key key;
struct btrfs_dir_log_item *item;
key.objectid = dirid;
key.offset = first_offset;
key.type = BTRFS_DIR_LOG_INDEX_KEY;
ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
/*
* -EEXIST is fine and can happen sporadically when we are logging a
* directory and have concurrent insertions in the subvolume's tree for
* items from other inodes and that result in pushing off some dir items
* from one leaf to another in order to accommodate for the new items.
* This results in logging the same dir index range key.
*/
if (ret && ret != -EEXIST)
return ret;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
if (ret == -EEXIST) {
const u64 curr_end = btrfs_dir_log_end(path->nodes[0], item);
/*
* btrfs_del_dir_entries_in_log() might have been called during
* an unlink between the initial insertion of this key and the
* current update, or we might be logging a single entry deletion
* during a rename, so set the new last_offset to the max value.
*/
last_offset = max(last_offset, curr_end);
}
btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct extent_buffer *src,
struct btrfs_path *dst_path,
int start_slot,
int count)
{
char *ins_data = NULL;
struct btrfs_item_batch batch;
struct extent_buffer *dst;
unsigned long src_offset;
unsigned long dst_offset;
struct btrfs_key key;
u32 item_size;
int ret;
int i;
ASSERT(count > 0);
batch.nr = count;
if (count == 1) {
btrfs_item_key_to_cpu(src, &key, start_slot);
item_size = btrfs_item_size(src, start_slot);
batch.keys = &key;
batch.data_sizes = &item_size;
batch.total_data_size = item_size;
} else {
struct btrfs_key *ins_keys;
u32 *ins_sizes;
ins_data = kmalloc(count * sizeof(u32) +
count * sizeof(struct btrfs_key), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32));
batch.keys = ins_keys;
batch.data_sizes = ins_sizes;
batch.total_data_size = 0;
for (i = 0; i < count; i++) {
const int slot = start_slot + i;
btrfs_item_key_to_cpu(src, &ins_keys[i], slot);
ins_sizes[i] = btrfs_item_size(src, slot);
batch.total_data_size += ins_sizes[i];
}
}
ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
if (ret)
goto out;
dst = dst_path->nodes[0];
/*
* Copy all the items in bulk, in a single copy operation. Item data is
* organized such that it's placed at the end of a leaf and from right
* to left. For example, the data for the second item ends at an offset
* that matches the offset where the data for the first item starts, the
* data for the third item ends at an offset that matches the offset
* where the data of the second items starts, and so on.
* Therefore our source and destination start offsets for copy match the
* offsets of the last items (highest slots).
*/
dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1);
src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1);
copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size);
btrfs_release_path(dst_path);
out:
kfree(ins_data);
return ret;
}
static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx,
u64 *last_old_dentry_offset)
{
struct btrfs_root *log = inode->root->log_root;
struct extent_buffer *src = path->nodes[0];
const int nritems = btrfs_header_nritems(src);
const u64 ino = btrfs_ino(inode);
bool last_found = false;
int batch_start = 0;
int batch_size = 0;
int i;
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key key;
int ret;
btrfs_item_key_to_cpu(src, &key, i);
if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) {
last_found = true;
break;
}
di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
ctx->last_dir_item_offset = key.offset;
/*
* Skip ranges of items that consist only of dir item keys created
* in past transactions. However if we find a gap, we must log a
* dir index range item for that gap, so that index keys in that
* gap are deleted during log replay.
*/
if (btrfs_dir_transid(src, di) < trans->transid) {
if (key.offset > *last_old_dentry_offset + 1) {
ret = insert_dir_log_key(trans, log, dst_path,
ino, *last_old_dentry_offset + 1,
key.offset - 1);
if (ret < 0)
return ret;
}
*last_old_dentry_offset = key.offset;
continue;
}
/*
* We must make sure that when we log a directory entry, the
* corresponding inode, after log replay, has a matching link
* count. For example:
*
* touch foo
* mkdir mydir
* sync
* ln foo mydir/bar
* xfs_io -c "fsync" mydir
* <crash>
* <mount fs and log replay>
*
* Would result in a fsync log that when replayed, our file inode
* would have a link count of 1, but we get two directory entries
* pointing to the same inode. After removing one of the names,
* it would not be possible to remove the other name, which
* resulted always in stale file handle errors, and would not be
* possible to rmdir the parent directory, since its i_size could
* never be decremented to the value BTRFS_EMPTY_DIR_SIZE,
* resulting in -ENOTEMPTY errors.
*/
if (!ctx->log_new_dentries) {
struct btrfs_key di_key;
btrfs_dir_item_key_to_cpu(src, di, &di_key);
if (di_key.type != BTRFS_ROOT_ITEM_KEY)
ctx->log_new_dentries = true;
}
if (!ctx->logged_before)
goto add_to_batch;
/*
* If we were logged before and have logged dir items, we can skip
* checking if any item with a key offset larger than the last one
* we logged is in the log tree, saving time and avoiding adding
* contention on the log tree. We can only rely on the value of
* last_dir_index_offset when we know for sure that the inode was
* previously logged in the current transaction.
*/
if (key.offset > inode->last_dir_index_offset)
goto add_to_batch;
/*
* Check if the key was already logged before. If not we can add
* it to a batch for bulk insertion.
*/
ret = btrfs_search_slot(NULL, log, &key, dst_path, 0, 0);
if (ret < 0) {
return ret;
} else if (ret > 0) {
btrfs_release_path(dst_path);
goto add_to_batch;
}
/*
* Item exists in the log. Overwrite the item in the log if it
* has different content or do nothing if it has exactly the same
* content. And then flush the current batch if any - do it after
* overwriting the current item, or we would deadlock otherwise,
* since we are holding a path for the existing item.
*/
ret = do_overwrite_item(trans, log, dst_path, src, i, &key);
if (ret < 0)
return ret;
if (batch_size > 0) {
ret = flush_dir_items_batch(trans, log, src, dst_path,
batch_start, batch_size);
if (ret < 0)
return ret;
batch_size = 0;
}
continue;
add_to_batch:
if (batch_size == 0)
batch_start = i;
batch_size++;
}
if (batch_size > 0) {
int ret;
ret = flush_dir_items_batch(trans, log, src, dst_path,
batch_start, batch_size);
if (ret < 0)
return ret;
}
return last_found ? 1 : 0;
}
/*
* log all the items included in the current transaction for a given
* directory. This also creates the range items in the log tree required
* to replay anything deleted before the fsync
*/
static noinline int log_dir_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx,
u64 min_offset, u64 *last_offset_ret)
{
struct btrfs_key min_key;
struct btrfs_root *root = inode->root;
struct btrfs_root *log = root->log_root;
int err = 0;
int ret;
u64 last_old_dentry_offset = min_offset - 1;
u64 last_offset = (u64)-1;
u64 ino = btrfs_ino(inode);
min_key.objectid = ino;
min_key.type = BTRFS_DIR_INDEX_KEY;
min_key.offset = min_offset;
ret = btrfs_search_forward(root, &min_key, path, trans->transid);
/*
* we didn't find anything from this transaction, see if there
* is anything at all
*/
if (ret != 0 || min_key.objectid != ino ||
min_key.type != BTRFS_DIR_INDEX_KEY) {
min_key.objectid = ino;
min_key.type = BTRFS_DIR_INDEX_KEY;
min_key.offset = (u64)-1;
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret < 0) {
btrfs_release_path(path);
return ret;
}
ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
/* if ret == 0 there are items for this type,
* create a range to tell us the last key of this type.
* otherwise, there are no items in this directory after
* *min_offset, and we create a range to indicate that.
*/
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp,
path->slots[0]);
if (tmp.type == BTRFS_DIR_INDEX_KEY)
last_old_dentry_offset = tmp.offset;
}
goto done;
}
/* go backward to find any previous key */
ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
/*
* The dir index key before the first one we found that needs to
* be logged might be in a previous leaf, and there might be a
* gap between these keys, meaning that we had deletions that
* happened. So the key range item we log (key type
* BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the
* previous key's offset plus 1, so that those deletes are replayed.
*/
if (tmp.type == BTRFS_DIR_INDEX_KEY)
last_old_dentry_offset = tmp.offset;
}
btrfs_release_path(path);
/*
* Find the first key from this transaction again. See the note for
* log_new_dir_dentries, if we're logging a directory recursively we
* won't be holding its i_mutex, which means we can modify the directory
* while we're logging it. If we remove an entry between our first
* search and this search we'll not find the key again and can just
* bail.
*/
search:
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret != 0)
goto done;
/*
* we have a block from this transaction, log every item in it
* from our directory
*/
while (1) {
ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx,
&last_old_dentry_offset);
if (ret != 0) {
if (ret < 0)
err = ret;
goto done;
}
path->slots[0] = btrfs_header_nritems(path->nodes[0]);
/*
* look ahead to the next item and see if it is also
* from this directory and from this transaction
*/
ret = btrfs_next_leaf(root, path);
if (ret) {
if (ret == 1)
last_offset = (u64)-1;
else
err = ret;
goto done;
}
btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]);
if (min_key.objectid != ino || min_key.type != BTRFS_DIR_INDEX_KEY) {
last_offset = (u64)-1;
goto done;
}
if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
/*
* The next leaf was not changed in the current transaction
* and has at least one dir index key.
* We check for the next key because there might have been
* one or more deletions between the last key we logged and
* that next key. So the key range item we log (key type
* BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's
* offset minus 1, so that those deletes are replayed.
*/
last_offset = min_key.offset - 1;
goto done;
}
if (need_resched()) {
btrfs_release_path(path);
cond_resched();
goto search;
}
}
done:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (err == 0) {
*last_offset_ret = last_offset;
/*
* In case the leaf was changed in the current transaction but
* all its dir items are from a past transaction, the last item
* in the leaf is a dir item and there's no gap between that last
* dir item and the first one on the next leaf (which did not
* change in the current transaction), then we don't need to log
* a range, last_old_dentry_offset is == to last_offset.
*/
ASSERT(last_old_dentry_offset <= last_offset);
if (last_old_dentry_offset < last_offset) {
ret = insert_dir_log_key(trans, log, path, ino,
last_old_dentry_offset + 1,
last_offset);
if (ret)
err = ret;
}
}
return err;
}
/*
* logging directories is very similar to logging inodes, We find all the items
* from the current transaction and write them to the log.
*
* The recovery code scans the directory in the subvolume, and if it finds a
* key in the range logged that is not present in the log tree, then it means
* that dir entry was unlinked during the transaction.
*
* In order for that scan to work, we must include one key smaller than
* the smallest logged by this transaction and one key larger than the largest
* key logged by this transaction.
*/
static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx)
{
u64 min_key;
u64 max_key;
int ret;
min_key = BTRFS_DIR_START_INDEX;
max_key = 0;
ctx->last_dir_item_offset = inode->last_dir_index_offset;
while (1) {
ret = log_dir_items(trans, inode, path, dst_path,
ctx, min_key, &max_key);
if (ret)
return ret;
if (max_key == (u64)-1)
break;
min_key = max_key + 1;
}
inode->last_dir_index_offset = ctx->last_dir_item_offset;
return 0;
}
/*
* a helper function to drop items from the log before we relog an
* inode. max_key_type indicates the highest item type to remove.
* This cannot be run for file data extents because it does not
* free the extents they point to.
*/
static int drop_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_inode *inode,
int max_key_type)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
int start_slot;
key.objectid = btrfs_ino(inode);
key.type = max_key_type;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
BUG_ON(ret == 0); /* Logic error */
if (ret < 0)
break;
if (path->slots[0] == 0)
break;
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != key.objectid)
break;
found_key.offset = 0;
found_key.type = 0;
ret = btrfs_bin_search(path->nodes[0], &found_key, &start_slot);
if (ret < 0)
break;
ret = btrfs_del_items(trans, log, path, start_slot,
path->slots[0] - start_slot + 1);
/*
* If start slot isn't 0 then we don't need to re-search, we've
* found the last guy with the objectid in this tree.
*/
if (ret || start_slot != 0)
break;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret > 0)
ret = 0;
return ret;
}
static int truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log_root,
struct btrfs_inode *inode,
u64 new_size, u32 min_type)
{
struct btrfs_truncate_control control = {
.new_size = new_size,
.ino = btrfs_ino(inode),
.min_type = min_type,
.skip_ref_updates = true,
};
return btrfs_truncate_inode_items(trans, log_root, &control);
}
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode, int log_inode_only,
u64 logged_isize)
{
struct btrfs_map_token token;
u64 flags;
btrfs_init_map_token(&token, leaf);
if (log_inode_only) {
/* set the generation to zero so the recover code
* can tell the difference between an logging
* just to say 'this inode exists' and a logging
* to say 'update this inode with these values'
*/
btrfs_set_token_inode_generation(&token, item, 0);
btrfs_set_token_inode_size(&token, item, logged_isize);
} else {
btrfs_set_token_inode_generation(&token, item,
BTRFS_I(inode)->generation);
btrfs_set_token_inode_size(&token, item, inode->i_size);
}
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_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);
/*
* We do not need to set the nbytes field, in fact during a fast fsync
* its value may not even be correct, since a fast fsync does not wait
* for ordered extent completion, which is where we update nbytes, it
* only waits for writeback to complete. During log replay as we find
* file extent items and replay them, we adjust the nbytes field of the
* inode item in subvolume tree as needed (see overwrite_item()).
*/
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);
}
static int log_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct btrfs_path *path,
struct btrfs_inode *inode, bool inode_item_dropped)
{
struct btrfs_inode_item *inode_item;
int ret;
/*
* If we are doing a fast fsync and the inode was logged before in the
* current transaction, then we know the inode was previously logged and
* it exists in the log tree. For performance reasons, in this case use
* btrfs_search_slot() directly with ins_len set to 0 so that we never
* attempt a write lock on the leaf's parent, which adds unnecessary lock
* contention in case there are concurrent fsyncs for other inodes of the
* same subvolume. Using btrfs_insert_empty_item() when the inode item
* already exists can also result in unnecessarily splitting a leaf.
*/
if (!inode_item_dropped && inode->logged_trans == trans->transid) {
ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1);
ASSERT(ret <= 0);
if (ret > 0)
ret = -ENOENT;
} else {
/*
* This means it is the first fsync in the current transaction,
* so the inode item is not in the log and we need to insert it.
* We can never get -EEXIST because we are only called for a fast
* fsync and in case an inode eviction happens after the inode was
* logged before in the current transaction, when we load again
* the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
* flags and set ->logged_trans to 0.
*/
ret = btrfs_insert_empty_item(trans, log, path, &inode->location,
sizeof(*inode_item));
ASSERT(ret != -EEXIST);
}
if (ret)
return ret;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
0, 0);
btrfs_release_path(path);
return 0;
}
static int log_csums(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_root *log_root,
struct btrfs_ordered_sum *sums)
{
const u64 lock_end = sums->bytenr + sums->len - 1;
struct extent_state *cached_state = NULL;
int ret;
/*
* If this inode was not used for reflink operations in the current
* transaction with new extents, then do the fast path, no need to
* worry about logging checksum items with overlapping ranges.
*/
if (inode->last_reflink_trans < trans->transid)
return btrfs_csum_file_blocks(trans, log_root, sums);
/*
* Serialize logging for checksums. This is to avoid racing with the
* same checksum being logged by another task that is logging another
* file which happens to refer to the same extent as well. Such races
* can leave checksum items in the log with overlapping ranges.
*/
ret = lock_extent_bits(&log_root->log_csum_range, sums->bytenr,
lock_end, &cached_state);
if (ret)
return ret;
/*
* Due to extent cloning, we might have logged a csum item that covers a
* subrange of a cloned extent, and later we can end up logging a csum
* item for a larger subrange of the same extent or the entire range.
* This would leave csum items in the log tree that cover the same range
* and break the searches for checksums in the log tree, resulting in
* some checksums missing in the fs/subvolume tree. So just delete (or
* trim and adjust) any existing csum items in the log for this range.
*/
ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len);
if (!ret)
ret = btrfs_csum_file_blocks(trans, log_root, sums);
unlock_extent_cached(&log_root->log_csum_range, sums->bytenr, lock_end,
&cached_state);
return ret;
}
static noinline int copy_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *dst_path,
struct btrfs_path *src_path,
int start_slot, int nr, int inode_only,
u64 logged_isize)
{
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item *extent;
struct extent_buffer *src = src_path->nodes[0];
int ret = 0;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
struct btrfs_item_batch batch;
char *ins_data;
int i;
int dst_index;
const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
const u64 i_size = i_size_read(&inode->vfs_inode);
ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
nr * sizeof(u32), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
batch.keys = ins_keys;
batch.data_sizes = ins_sizes;
batch.total_data_size = 0;
batch.nr = 0;
dst_index = 0;
for (i = 0; i < nr; i++) {
const int src_slot = start_slot + i;
struct btrfs_root *csum_root;
struct btrfs_ordered_sum *sums;
struct btrfs_ordered_sum *sums_next;
LIST_HEAD(ordered_sums);
u64 disk_bytenr;
u64 disk_num_bytes;
u64 extent_offset;
u64 extent_num_bytes;
bool is_old_extent;
btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot);
if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY)
goto add_to_batch;
extent = btrfs_item_ptr(src, src_slot,
struct btrfs_file_extent_item);
is_old_extent = (btrfs_file_extent_generation(src, extent) <
trans->transid);
/*
* Don't copy extents from past generations. That would make us
* log a lot more metadata for common cases like doing only a
* few random writes into a file and then fsync it for the first
* time or after the full sync flag is set on the inode. We can
* get leaves full of extent items, most of which are from past
* generations, so we can skip them - as long as the inode has
* not been the target of a reflink operation in this transaction,
* as in that case it might have had file extent items with old
* generations copied into it. We also must always log prealloc
* extents that start at or beyond eof, otherwise we would lose
* them on log replay.
*/
if (is_old_extent &&
ins_keys[dst_index].offset < i_size &&
inode->last_reflink_trans < trans->transid)
continue;
if (skip_csum)
goto add_to_batch;
/* Only regular extents have checksums. */
if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG)
goto add_to_batch;
/*
* If it's an extent created in a past transaction, then its
* checksums are already accessible from the committed csum tree,
* no need to log them.
*/
if (is_old_extent)
goto add_to_batch;
disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent);
/* If it's an explicit hole, there are no checksums. */
if (disk_bytenr == 0)
goto add_to_batch;
disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent);
if (btrfs_file_extent_compression(src, extent)) {
extent_offset = 0;
extent_num_bytes = disk_num_bytes;
} else {
extent_offset = btrfs_file_extent_offset(src, extent);
extent_num_bytes = btrfs_file_extent_num_bytes(src, extent);
}
csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr);
disk_bytenr += extent_offset;
ret = btrfs_lookup_csums_range(csum_root, disk_bytenr,
disk_bytenr + extent_num_bytes - 1,
&ordered_sums, 0);
if (ret)
goto out;
list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
if (!ret)
ret = log_csums(trans, inode, log, sums);
list_del(&sums->list);
kfree(sums);
}
if (ret)
goto out;
add_to_batch:
ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
batch.total_data_size += ins_sizes[dst_index];
batch.nr++;
dst_index++;
}
/*
* We have a leaf full of old extent items that don't need to be logged,
* so we don't need to do anything.
*/
if (batch.nr == 0)
goto out;
ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
if (ret)
goto out;
dst_index = 0;
for (i = 0; i < nr; i++) {
const int src_slot = start_slot + i;
const int dst_slot = dst_path->slots[0] + dst_index;
struct btrfs_key key;
unsigned long src_offset;
unsigned long dst_offset;
/*
* We're done, all the remaining items in the source leaf
* correspond to old file extent items.
*/
if (dst_index >= batch.nr)
break;
btrfs_item_key_to_cpu(src, &key, src_slot);
if (key.type != BTRFS_EXTENT_DATA_KEY)
goto copy_item;
extent = btrfs_item_ptr(src, src_slot,
struct btrfs_file_extent_item);
/* See the comment in the previous loop, same logic. */
if (btrfs_file_extent_generation(src, extent) < trans->transid &&
key.offset < i_size &&
inode->last_reflink_trans < trans->transid)
continue;
copy_item:
dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot);
src_offset = btrfs_item_ptr_offset(src, src_slot);
if (key.type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *inode_item;
inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot,
struct btrfs_inode_item);
fill_inode_item(trans, dst_path->nodes[0], inode_item,
&inode->vfs_inode,
inode_only == LOG_INODE_EXISTS,
logged_isize);
} else {
copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
src_offset, ins_sizes[dst_index]);
}
dst_index++;
}
btrfs_mark_buffer_dirty(dst_path->nodes[0]);
btrfs_release_path(dst_path);
out:
kfree(ins_data);
return ret;
}
static int extent_cmp(void *priv, const struct list_head *a,
const struct list_head *b)
{
const struct extent_map *em1, *em2;
em1 = list_entry(a, struct extent_map, list);
em2 = list_entry(b, struct extent_map, list);
if (em1->start < em2->start)
return -1;
else if (em1->start > em2->start)
return 1;
return 0;
}
static int log_extent_csums(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_root *log_root,
const struct extent_map *em,
struct btrfs_log_ctx *ctx)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_root *csum_root;
u64 csum_offset;
u64 csum_len;
u64 mod_start = em->mod_start;
u64 mod_len = em->mod_len;
LIST_HEAD(ordered_sums);
int ret = 0;
if (inode->flags & BTRFS_INODE_NODATASUM ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
em->block_start == EXTENT_MAP_HOLE)
return 0;
list_for_each_entry(ordered, &ctx->ordered_extents, log_list) {
const u64 ordered_end = ordered->file_offset + ordered->num_bytes;
const u64 mod_end = mod_start + mod_len;
struct btrfs_ordered_sum *sums;
if (mod_len == 0)
break;
if (ordered_end <= mod_start)
continue;
if (mod_end <= ordered->file_offset)
break;
/*
* We are going to copy all the csums on this ordered extent, so
* go ahead and adjust mod_start and mod_len in case this ordered
* extent has already been logged.
*/
if (ordered->file_offset > mod_start) {
if (ordered_end >= mod_end)
mod_len = ordered->file_offset - mod_start;
/*
* If we have this case
*
* |--------- logged extent ---------|
* |----- ordered extent ----|
*
* Just don't mess with mod_start and mod_len, we'll
* just end up logging more csums than we need and it
* will be ok.
*/
} else {
if (ordered_end < mod_end) {
mod_len = mod_end - ordered_end;
mod_start = ordered_end;
} else {
mod_len = 0;
}
}
/*
* To keep us from looping for the above case of an ordered
* extent that falls inside of the logged extent.
*/
if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags))
continue;
list_for_each_entry(sums, &ordered->list, list) {
ret = log_csums(trans, inode, log_root, sums);
if (ret)
return ret;
}
}
/* We're done, found all csums in the ordered extents. */
if (mod_len == 0)
return 0;
/* If we're compressed we have to save the entire range of csums. */
if (em->compress_type) {
csum_offset = 0;
csum_len = max(em->block_len, em->orig_block_len);
} else {
csum_offset = mod_start - em->start;
csum_len = mod_len;
}
/* block start is already adjusted for the file extent offset. */
csum_root = btrfs_csum_root(trans->fs_info, em->block_start);
ret = btrfs_lookup_csums_range(csum_root,
em->block_start + csum_offset,
em->block_start + csum_offset +
csum_len - 1, &ordered_sums, 0);
if (ret)
return ret;
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = log_csums(trans, inode, log_root, sums);
list_del(&sums->list);
kfree(sums);
}
return ret;
}
static int log_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
const struct extent_map *em,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item fi = { 0 };
struct extent_buffer *leaf;
struct btrfs_key key;
u64 extent_offset = em->start - em->orig_start;
u64 block_len;
int ret;
btrfs_set_stack_file_extent_generation(&fi, trans->transid);
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC);
else
btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG);
block_len = max(em->block_len, em->orig_block_len);
if (em->compress_type != BTRFS_COMPRESS_NONE) {
btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start);
btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start -
extent_offset);
btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
}
btrfs_set_stack_file_extent_offset(&fi, extent_offset);
btrfs_set_stack_file_extent_num_bytes(&fi, em->len);
btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes);
btrfs_set_stack_file_extent_compression(&fi, em->compress_type);
ret = log_extent_csums(trans, inode, log, em, ctx);
if (ret)
return ret;
/*
* If this is the first time we are logging the inode in the current
* transaction, we can avoid btrfs_drop_extents(), which is expensive
* because it does a deletion search, which always acquires write locks
* for extent buffers at levels 2, 1 and 0. This not only wastes time
* but also adds significant contention in a log tree, since log trees
* are small, with a root at level 2 or 3 at most, due to their short
* life span.
*/
if (ctx->logged_before) {
drop_args.path = path;
drop_args.start = em->start;
drop_args.end = em->start + em->len;
drop_args.replace_extent = true;
drop_args.extent_item_size = sizeof(fi);
ret = btrfs_drop_extents(trans, log, inode, &drop_args);
if (ret)
return ret;
}
if (!drop_args.extent_inserted) {
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = em->start;
ret = btrfs_insert_empty_item(trans, log, path, &key,
sizeof(fi));
if (ret)
return ret;
}
leaf = path->nodes[0];
write_extent_buffer(leaf, &fi,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(fi));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
return ret;
}
/*
* Log all prealloc extents beyond the inode's i_size to make sure we do not
* lose them after doing a full/fast fsync and replaying the log. We scan the
* subvolume's root instead of iterating the inode's extent map tree because
* otherwise we can log incorrect extent items based on extent map conversion.
* That can happen due to the fact that extent maps are merged when they
* are not in the extent map tree's list of modified extents.
*/
static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path)
{
struct btrfs_root *root = inode->root;
struct btrfs_key key;
const u64 i_size = i_size_read(&inode->vfs_inode);
const u64 ino = btrfs_ino(inode);
struct btrfs_path *dst_path = NULL;
bool dropped_extents = false;
u64 truncate_offset = i_size;
struct extent_buffer *leaf;
int slot;
int ins_nr = 0;
int start_slot;
int ret;
if (!(inode->flags & BTRFS_INODE_PREALLOC))
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = i_size;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* We must check if there is a prealloc extent that starts before the
* i_size and crosses the i_size boundary. This is to ensure later we
* truncate down to the end of that extent and not to the i_size, as
* otherwise we end up losing part of the prealloc extent after a log
* replay and with an implicit hole if there is another prealloc extent
* that starts at an offset beyond i_size.
*/
ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
if (ret < 0)
goto out;
if (ret == 0) {
struct btrfs_file_extent_item *ei;
leaf = path->nodes[0];
slot = path->slots[0];
ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, ei) ==
BTRFS_FILE_EXTENT_PREALLOC) {
u64 extent_end;
btrfs_item_key_to_cpu(leaf, &key, slot);
extent_end = key.offset +
btrfs_file_extent_num_bytes(leaf, ei);
if (extent_end > i_size)
truncate_offset = extent_end;
}
} else {
ret = 0;
}
while (true) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
if (ret < 0)
goto out;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid > ino)
break;
if (WARN_ON_ONCE(key.objectid < ino) ||
key.type < BTRFS_EXTENT_DATA_KEY ||
key.offset < i_size) {
path->slots[0]++;
continue;
}
if (!dropped_extents) {
/*
* Avoid logging extent items logged in past fsync calls
* and leading to duplicate keys in the log tree.
*/
ret = truncate_inode_items(trans, root->log_root, inode,
truncate_offset,
BTRFS_EXTENT_DATA_KEY);
if (ret)
goto out;
dropped_extents = true;
}
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
if (!dst_path) {
dst_path = btrfs_alloc_path();
if (!dst_path) {
ret = -ENOMEM;
goto out;
}
}
}
if (ins_nr > 0)
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
out:
btrfs_release_path(path);
btrfs_free_path(dst_path);
return ret;
}
static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_ordered_extent *tmp;
struct extent_map *em, *n;
struct list_head extents;
struct extent_map_tree *tree = &inode->extent_tree;
int ret = 0;
int num = 0;
INIT_LIST_HEAD(&extents);
write_lock(&tree->lock);
list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
list_del_init(&em->list);
/*
* Just an arbitrary number, this can be really CPU intensive
* once we start getting a lot of extents, and really once we
* have a bunch of extents we just want to commit since it will
* be faster.
*/
if (++num > 32768) {
list_del_init(&tree->modified_extents);
ret = -EFBIG;
goto process;
}
if (em->generation < trans->transid)
continue;
/* We log prealloc extents beyond eof later. */
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) &&
em->start >= i_size_read(&inode->vfs_inode))
continue;
/* Need a ref to keep it from getting evicted from cache */
refcount_inc(&em->refs);
set_bit(EXTENT_FLAG_LOGGING, &em->flags);
list_add_tail(&em->list, &extents);
num++;
}
list_sort(NULL, &extents, extent_cmp);
process:
while (!list_empty(&extents)) {
em = list_entry(extents.next, struct extent_map, list);
list_del_init(&em->list);
/*
* If we had an error we just need to delete everybody from our
* private list.
*/
if (ret) {
clear_em_logging(tree, em);
free_extent_map(em);
continue;
}
write_unlock(&tree->lock);
ret = log_one_extent(trans, inode, em, path, ctx);
write_lock(&tree->lock);
clear_em_logging(tree, em);
free_extent_map(em);
}
WARN_ON(!list_empty(&extents));
write_unlock(&tree->lock);
if (!ret)
ret = btrfs_log_prealloc_extents(trans, inode, path);
if (ret)
return ret;
/*
* We have logged all extents successfully, now make sure the commit of
* the current transaction waits for the ordered extents to complete
* before it commits and wipes out the log trees, otherwise we would
* lose data if an ordered extents completes after the transaction
* commits and a power failure happens after the transaction commit.
*/
list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
list_del_init(&ordered->log_list);
set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags);
if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
spin_lock_irq(&inode->ordered_tree.lock);
if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
atomic_inc(&trans->transaction->pending_ordered);
}
spin_unlock_irq(&inode->ordered_tree.lock);
}
btrfs_put_ordered_extent(ordered);
}
return 0;
}
static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
struct btrfs_path *path, u64 *size_ret)
{
struct btrfs_key key;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
if (ret < 0) {
return ret;
} else if (ret > 0) {
*size_ret = 0;
} else {
struct btrfs_inode_item *item;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
*size_ret = btrfs_inode_size(path->nodes[0], item);
/*
* If the in-memory inode's i_size is smaller then the inode
* size stored in the btree, return the inode's i_size, so
* that we get a correct inode size after replaying the log
* when before a power failure we had a shrinking truncate
* followed by addition of a new name (rename / new hard link).
* Otherwise return the inode size from the btree, to avoid
* data loss when replaying a log due to previously doing a
* write that expands the inode's size and logging a new name
* immediately after.
*/
if (*size_ret > inode->vfs_inode.i_size)
*size_ret = inode->vfs_inode.i_size;
}
btrfs_release_path(path);
return 0;
}
/*
* At the moment we always log all xattrs. This is to figure out at log replay
* time which xattrs must have their deletion replayed. If a xattr is missing
* in the log tree and exists in the fs/subvol tree, we delete it. This is
* because if a xattr is deleted, the inode is fsynced and a power failure
* happens, causing the log to be replayed the next time the fs is mounted,
* we want the xattr to not exist anymore (same behaviour as other filesystems
* with a journal, ext3/4, xfs, f2fs, etc).
*/
static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path)
{
struct btrfs_root *root = inode->root;
int ret;
struct btrfs_key key;
const u64 ino = btrfs_ino(inode);
int ins_nr = 0;
int start_slot = 0;
bool found_xattrs = false;
if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags))
return 0;
key.objectid = ino;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
while (true) {
int slot = path->slots[0];
struct extent_buffer *leaf = path->nodes[0];
int nritems = btrfs_header_nritems(leaf);
if (slot >= nritems) {
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
if (ret < 0)
return ret;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
break;
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
found_xattrs = true;
cond_resched();
}
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
if (ret < 0)
return ret;
}
if (!found_xattrs)
set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags);
return 0;
}
/*
* When using the NO_HOLES feature if we punched a hole that causes the
* deletion of entire leafs or all the extent items of the first leaf (the one
* that contains the inode item and references) we may end up not processing
* any extents, because there are no leafs with a generation matching the
* current transaction that have extent items for our inode. So we need to find
* if any holes exist and then log them. We also need to log holes after any
* truncate operation that changes the inode's size.
*/
static int btrfs_log_holes(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
const u64 ino = btrfs_ino(inode);
const u64 i_size = i_size_read(&inode->vfs_inode);
u64 prev_extent_end = 0;
int ret;
if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0)
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
if (ret > 0) {
ret = 0;
break;
}
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
break;
/* We have a hole, log it. */
if (prev_extent_end < key.offset) {
const u64 hole_len = key.offset - prev_extent_end;
/*
* Release the path to avoid deadlocks with other code
* paths that search the root while holding locks on
* leafs from the log root.
*/
btrfs_release_path(path);
ret = btrfs_insert_file_extent(trans, root->log_root,
ino, prev_extent_end, 0,
0, hole_len, 0, hole_len,
0, 0, 0);
if (ret < 0)
return ret;
/*
* Search for the same key again in the root. Since it's
* an extent item and we are holding the inode lock, the
* key must still exist. If it doesn't just emit warning
* and return an error to fall back to a transaction
* commit.
*/
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
if (WARN_ON(ret > 0))
return -ENOENT;
leaf = path->nodes[0];
}
prev_extent_end = btrfs_file_extent_end(path);
path->slots[0]++;
cond_resched();
}
if (prev_extent_end < i_size) {
u64 hole_len;
btrfs_release_path(path);
hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize);
ret = btrfs_insert_file_extent(trans, root->log_root,
ino, prev_extent_end, 0, 0,
hole_len, 0, hole_len,
0, 0, 0);
if (ret < 0)
return ret;
}
return 0;
}
/*
* When we are logging a new inode X, check if it doesn't have a reference that
* matches the reference from some other inode Y created in a past transaction
* and that was renamed in the current transaction. If we don't do this, then at
* log replay time we can lose inode Y (and all its files if it's a directory):
*
* mkdir /mnt/x
* echo "hello world" > /mnt/x/foobar
* sync
* mv /mnt/x /mnt/y
* mkdir /mnt/x # or touch /mnt/x
* xfs_io -c fsync /mnt/x
* <power fail>
* mount fs, trigger log replay
*
* After the log replay procedure, we would lose the first directory and all its
* files (file foobar).
* For the case where inode Y is not a directory we simply end up losing it:
*
* echo "123" > /mnt/foo
* sync
* mv /mnt/foo /mnt/bar
* echo "abc" > /mnt/foo
* xfs_io -c fsync /mnt/foo
* <power fail>
*
* We also need this for cases where a snapshot entry is replaced by some other
* entry (file or directory) otherwise we end up with an unreplayable log due to
* attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
* if it were a regular entry:
*
* mkdir /mnt/x
* btrfs subvolume snapshot /mnt /mnt/x/snap
* btrfs subvolume delete /mnt/x/snap
* rmdir /mnt/x
* mkdir /mnt/x
* fsync /mnt/x or fsync some new file inside it
* <power fail>
*
* The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
* the same transaction.
*/
static int btrfs_check_ref_name_override(struct extent_buffer *eb,
const int slot,
const struct btrfs_key *key,
struct btrfs_inode *inode,
u64 *other_ino, u64 *other_parent)
{
int ret;
struct btrfs_path *search_path;
char *name = NULL;
u32 name_len = 0;
u32 item_size = btrfs_item_size(eb, slot);
u32 cur_offset = 0;
unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
search_path = btrfs_alloc_path();
if (!search_path)
return -ENOMEM;
search_path->search_commit_root = 1;
search_path->skip_locking = 1;
while (cur_offset < item_size) {
u64 parent;
u32 this_name_len;
u32 this_len;
unsigned long name_ptr;
struct btrfs_dir_item *di;
if (key->type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *iref;
iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
parent = key->offset;
this_name_len = btrfs_inode_ref_name_len(eb, iref);
name_ptr = (unsigned long)(iref + 1);
this_len = sizeof(*iref) + this_name_len;
} else {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)(ptr +
cur_offset);
parent = btrfs_inode_extref_parent(eb, extref);
this_name_len = btrfs_inode_extref_name_len(eb, extref);
name_ptr = (unsigned long)&extref->name;
this_len = sizeof(*extref) + this_name_len;
}
if (this_name_len > name_len) {
char *new_name;
new_name = krealloc(name, this_name_len, GFP_NOFS);
if (!new_name) {
ret = -ENOMEM;
goto out;
}
name_len = this_name_len;
name = new_name;
}
read_extent_buffer(eb, name, name_ptr, this_name_len);
di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
parent, name, this_name_len, 0);
if (di && !IS_ERR(di)) {
struct btrfs_key di_key;
btrfs_dir_item_key_to_cpu(search_path->nodes[0],
di, &di_key);
if (di_key.type == BTRFS_INODE_ITEM_KEY) {
if (di_key.objectid != key->objectid) {
ret = 1;
*other_ino = di_key.objectid;
*other_parent = parent;
} else {
ret = 0;
}
} else {
ret = -EAGAIN;
}
goto out;
} else if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
btrfs_release_path(search_path);
cur_offset += this_len;
}
ret = 0;
out:
btrfs_free_path(search_path);
kfree(name);
return ret;
}
struct btrfs_ino_list {
u64 ino;
u64 parent;
struct list_head list;
};
static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx,
u64 ino, u64 parent)
{
struct btrfs_ino_list *ino_elem;
LIST_HEAD(inode_list);
int ret = 0;
ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
if (!ino_elem)
return -ENOMEM;
ino_elem->ino = ino;
ino_elem->parent = parent;
list_add_tail(&ino_elem->list, &inode_list);
while (!list_empty(&inode_list)) {
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
struct inode *inode;
ino_elem = list_first_entry(&inode_list, struct btrfs_ino_list,
list);
ino = ino_elem->ino;
parent = ino_elem->parent;
list_del(&ino_elem->list);
kfree(ino_elem);
if (ret)
continue;
btrfs_release_path(path);
inode = btrfs_iget(fs_info->sb, ino, root);
/*
* If the other inode that had a conflicting dir entry was
* deleted in the current transaction, we need to log its parent
* directory.
*/
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
if (ret == -ENOENT) {
inode = btrfs_iget(fs_info->sb, parent, root);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
} else {
ret = btrfs_log_inode(trans,
BTRFS_I(inode),
LOG_OTHER_INODE_ALL,
ctx);
btrfs_add_delayed_iput(inode);
}
}
continue;
}
/*
* If the inode was already logged skip it - otherwise we can
* hit an infinite loop. Example:
*
* From the commit root (previous transaction) we have the
* following inodes:
*
* inode 257 a directory
* inode 258 with references "zz" and "zz_link" on inode 257
* inode 259 with reference "a" on inode 257
*
* And in the current (uncommitted) transaction we have:
*
* inode 257 a directory, unchanged
* inode 258 with references "a" and "a2" on inode 257
* inode 259 with reference "zz_link" on inode 257
* inode 261 with reference "zz" on inode 257
*
* When logging inode 261 the following infinite loop could
* happen if we don't skip already logged inodes:
*
* - we detect inode 258 as a conflicting inode, with inode 261
* on reference "zz", and log it;
*
* - we detect inode 259 as a conflicting inode, with inode 258
* on reference "a", and log it;
*
* - we detect inode 258 as a conflicting inode, with inode 259
* on reference "zz_link", and log it - again! After this we
* repeat the above steps forever.
*/
spin_lock(&BTRFS_I(inode)->lock);
/*
* Check the inode's logged_trans only instead of
* btrfs_inode_in_log(). This is because the last_log_commit of
* the inode is not updated when we only log that it exists (see
* btrfs_log_inode()).
*/
if (BTRFS_I(inode)->logged_trans == trans->transid) {
spin_unlock(&BTRFS_I(inode)->lock);
btrfs_add_delayed_iput(inode);
continue;
}
spin_unlock(&BTRFS_I(inode)->lock);
/*
* We are safe logging the other inode without acquiring its
* lock as long as we log with the LOG_INODE_EXISTS mode. We
* are safe against concurrent renames of the other inode as
* well because during a rename we pin the log and update the
* log with the new name before we unpin it.
*/
ret = btrfs_log_inode(trans, BTRFS_I(inode), LOG_OTHER_INODE, ctx);
if (ret) {
btrfs_add_delayed_iput(inode);
continue;
}
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
btrfs_add_delayed_iput(inode);
continue;
}
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
u64 other_ino = 0;
u64 other_parent = 0;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
break;
} else if (ret > 0) {
ret = 0;
break;
}
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino ||
(key.type != BTRFS_INODE_REF_KEY &&
key.type != BTRFS_INODE_EXTREF_KEY)) {
ret = 0;
break;
}
ret = btrfs_check_ref_name_override(leaf, slot, &key,
BTRFS_I(inode), &other_ino,
&other_parent);
if (ret < 0)
break;
if (ret > 0) {
ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
if (!ino_elem) {
ret = -ENOMEM;
break;
}
ino_elem->ino = other_ino;
ino_elem->parent = other_parent;
list_add_tail(&ino_elem->list, &inode_list);
ret = 0;
}
path->slots[0]++;
}
btrfs_add_delayed_iput(inode);
}
return ret;
}
static int copy_inode_items_to_log(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_key *min_key,
const struct btrfs_key *max_key,
struct btrfs_path *path,
struct btrfs_path *dst_path,
const u64 logged_isize,
const bool recursive_logging,
const int inode_only,
struct btrfs_log_ctx *ctx,
bool *need_log_inode_item)
{
const u64 i_size = i_size_read(&inode->vfs_inode);
struct btrfs_root *root = inode->root;
int ins_start_slot = 0;
int ins_nr = 0;
int ret;
while (1) {
ret = btrfs_search_forward(root, min_key, path, trans->transid);
if (ret < 0)
return ret;
if (ret > 0) {
ret = 0;
break;
}
again:
/* Note, ins_nr might be > 0 here, cleanup outside the loop */
if (min_key->objectid != max_key->objectid)
break;
if (min_key->type > max_key->type)
break;
if (min_key->type == BTRFS_INODE_ITEM_KEY) {
*need_log_inode_item = false;
} else if (min_key->type == BTRFS_EXTENT_DATA_KEY &&
min_key->offset >= i_size) {
/*
* Extents at and beyond eof are logged with
* btrfs_log_prealloc_extents().
* Only regular files have BTRFS_EXTENT_DATA_KEY keys,
* and no keys greater than that, so bail out.
*/
break;
} else if ((min_key->type == BTRFS_INODE_REF_KEY ||
min_key->type == BTRFS_INODE_EXTREF_KEY) &&
inode->generation == trans->transid &&
!recursive_logging) {
u64 other_ino = 0;
u64 other_parent = 0;
ret = btrfs_check_ref_name_override(path->nodes[0],
path->slots[0], min_key, inode,
&other_ino, &other_parent);
if (ret < 0) {
return ret;
} else if (ret > 0 &&
other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
if (ins_nr > 0) {
ins_nr++;
} else {
ins_nr = 1;
ins_start_slot = path->slots[0];
}
ret = copy_items(trans, inode, dst_path, path,
ins_start_slot, ins_nr,
inode_only, logged_isize);
if (ret < 0)
return ret;
ins_nr = 0;
ret = log_conflicting_inodes(trans, root, path,
ctx, other_ino, other_parent);
if (ret)
return ret;
btrfs_release_path(path);
goto next_key;
}
} else if (min_key->type == BTRFS_XATTR_ITEM_KEY) {
/* Skip xattrs, logged later with btrfs_log_all_xattrs() */
if (ins_nr == 0)
goto next_slot;
ret = copy_items(trans, inode, dst_path, path,
ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0)
return ret;
ins_nr = 0;
goto next_slot;
}
if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
ins_nr++;
goto next_slot;
} else if (!ins_nr) {
ins_start_slot = path->slots[0];
ins_nr = 1;
goto next_slot;
}
ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0)
return ret;
ins_nr = 1;
ins_start_slot = path->slots[0];
next_slot:
path->slots[0]++;
if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
btrfs_item_key_to_cpu(path->nodes[0], min_key,
path->slots[0]);
goto again;
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path,
ins_start_slot, ins_nr, inode_only,
logged_isize);
if (ret < 0)
return ret;
ins_nr = 0;
}
btrfs_release_path(path);
next_key:
if (min_key->offset < (u64)-1) {
min_key->offset++;
} else if (min_key->type < max_key->type) {
min_key->type++;
min_key->offset = 0;
} else {
break;
}
/*
* We may process many leaves full of items for our inode, so
* avoid monopolizing a cpu for too long by rescheduling while
* not holding locks on any tree.
*/
cond_resched();
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret)
return ret;
}
if (inode_only == LOG_INODE_ALL && S_ISREG(inode->vfs_inode.i_mode)) {
/*
* Release the path because otherwise we might attempt to double
* lock the same leaf with btrfs_log_prealloc_extents() below.
*/
btrfs_release_path(path);
ret = btrfs_log_prealloc_extents(trans, inode, dst_path);
}
return ret;
}
/* log a single inode in the tree log.
* At least one parent directory for this inode must exist in the tree
* or be logged already.
*
* Any items from this inode changed by the current transaction are copied
* to the log tree. An extra reference is taken on any extents in this
* file, allowing us to avoid a whole pile of corner cases around logging
* blocks that have been removed from the tree.
*
* See LOG_INODE_ALL and related defines for a description of what inode_only
* does.
*
* This handles both files and directories.
*/
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
int inode_only,
struct btrfs_log_ctx *ctx)
{
struct btrfs_path *path;
struct btrfs_path *dst_path;
struct btrfs_key min_key;
struct btrfs_key max_key;
struct btrfs_root *log = inode->root->log_root;
int ret;
bool fast_search = false;
u64 ino = btrfs_ino(inode);
struct extent_map_tree *em_tree = &inode->extent_tree;
u64 logged_isize = 0;
bool need_log_inode_item = true;
bool xattrs_logged = false;
bool recursive_logging = false;
bool inode_item_dropped = true;
const bool orig_logged_before = ctx->logged_before;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dst_path = btrfs_alloc_path();
if (!dst_path) {
btrfs_free_path(path);
return -ENOMEM;
}
min_key.objectid = ino;
min_key.type = BTRFS_INODE_ITEM_KEY;
min_key.offset = 0;
max_key.objectid = ino;
/* today the code can only do partial logging of directories */
if (S_ISDIR(inode->vfs_inode.i_mode) ||
(!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags) &&
inode_only >= LOG_INODE_EXISTS))
max_key.type = BTRFS_XATTR_ITEM_KEY;
else
max_key.type = (u8)-1;
max_key.offset = (u64)-1;
/*
* Only run delayed items if we are a directory. We want to make sure
* all directory indexes hit the fs/subvolume tree so we can find them
* and figure out which index ranges have to be logged.
*/
if (S_ISDIR(inode->vfs_inode.i_mode)) {
ret = btrfs_commit_inode_delayed_items(trans, inode);
if (ret)
goto out;
}
if (inode_only == LOG_OTHER_INODE || inode_only == LOG_OTHER_INODE_ALL) {
recursive_logging = true;
if (inode_only == LOG_OTHER_INODE)
inode_only = LOG_INODE_EXISTS;
else
inode_only = LOG_INODE_ALL;
mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING);
} else {
mutex_lock(&inode->log_mutex);
}
/*
* For symlinks, we must always log their content, which is stored in an
* inline extent, otherwise we could end up with an empty symlink after
* log replay, which is invalid on linux (symlink(2) returns -ENOENT if
* one attempts to create an empty symlink).
* We don't need to worry about flushing delalloc, because when we create
* the inline extent when the symlink is created (we never have delalloc
* for symlinks).
*/
if (S_ISLNK(inode->vfs_inode.i_mode))
inode_only = LOG_INODE_ALL;
/*
* Before logging the inode item, cache the value returned by
* inode_logged(), because after that we have the need to figure out if
* the inode was previously logged in this transaction.
*/
ret = inode_logged(trans, inode, path);
if (ret < 0)
goto out_unlock;
ctx->logged_before = (ret == 1);
ret = 0;
/*
* This is for cases where logging a directory could result in losing a
* a file after replaying the log. For example, if we move a file from a
* directory A to a directory B, then fsync directory A, we have no way
* to known the file was moved from A to B, so logging just A would
* result in losing the file after a log replay.
*/
if (S_ISDIR(inode->vfs_inode.i_mode) &&
inode_only == LOG_INODE_ALL &&
inode->last_unlink_trans >= trans->transid) {
btrfs_set_log_full_commit(trans);
ret = BTRFS_LOG_FORCE_COMMIT;
goto out_unlock;
}
/*
* a brute force approach to making sure we get the most uptodate
* copies of everything.
*/
if (S_ISDIR(inode->vfs_inode.i_mode)) {
int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
if (inode_only == LOG_INODE_EXISTS)
max_key_type = BTRFS_XATTR_ITEM_KEY;
if (ctx->logged_before)
ret = drop_inode_items(trans, log, path, inode,
max_key_type);
} else {
if (inode_only == LOG_INODE_EXISTS && ctx->logged_before) {
/*
* Make sure the new inode item we write to the log has
* the same isize as the current one (if it exists).
* This is necessary to prevent data loss after log
* replay, and also to prevent doing a wrong expanding
* truncate - for e.g. create file, write 4K into offset
* 0, fsync, write 4K into offset 4096, add hard link,
* fsync some other file (to sync log), power fail - if
* we use the inode's current i_size, after log replay
* we get a 8Kb file, with the last 4Kb extent as a hole
* (zeroes), as if an expanding truncate happened,
* instead of getting a file of 4Kb only.
*/
ret = logged_inode_size(log, inode, path, &logged_isize);
if (ret)
goto out_unlock;
}
if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags)) {
if (inode_only == LOG_INODE_EXISTS) {
max_key.type = BTRFS_XATTR_ITEM_KEY;
if (ctx->logged_before)
ret = drop_inode_items(trans, log, path,
inode, max_key.type);
} else {
clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags);
clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags);
if (ctx->logged_before)
ret = truncate_inode_items(trans, log,
inode, 0, 0);
}
} else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags) ||
inode_only == LOG_INODE_EXISTS) {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
max_key.type = BTRFS_XATTR_ITEM_KEY;
if (ctx->logged_before)
ret = drop_inode_items(trans, log, path, inode,
max_key.type);
} else {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
inode_item_dropped = false;
goto log_extents;
}
}
if (ret)
goto out_unlock;
ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
path, dst_path, logged_isize,
recursive_logging, inode_only, ctx,
&need_log_inode_item);
if (ret)
goto out_unlock;
btrfs_release_path(path);
btrfs_release_path(dst_path);
ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
if (ret)
goto out_unlock;
xattrs_logged = true;
if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
btrfs_release_path(path);
btrfs_release_path(dst_path);
ret = btrfs_log_holes(trans, inode, path);
if (ret)
goto out_unlock;
}
log_extents:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (need_log_inode_item) {
ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
if (ret)
goto out_unlock;
/*
* If we are doing a fast fsync and the inode was logged before
* in this transaction, we don't need to log the xattrs because
* they were logged before. If xattrs were added, changed or
* deleted since the last time we logged the inode, then we have
* already logged them because the inode had the runtime flag
* BTRFS_INODE_COPY_EVERYTHING set.
*/
if (!xattrs_logged && inode->logged_trans < trans->transid) {
ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
if (ret)
goto out_unlock;
btrfs_release_path(path);
}
}
if (fast_search) {
ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx);
if (ret)
goto out_unlock;
} else if (inode_only == LOG_INODE_ALL) {
struct extent_map *em, *n;
write_lock(&em_tree->lock);
list_for_each_entry_safe(em, n, &em_tree->modified_extents, list)
list_del_init(&em->list);
write_unlock(&em_tree->lock);
}
if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) {
ret = log_directory_changes(trans, inode, path, dst_path, ctx);
if (ret)
goto out_unlock;
}
spin_lock(&inode->lock);
inode->logged_trans = trans->transid;
/*
* Don't update last_log_commit if we logged that an inode exists.
* We do this for three reasons:
*
* 1) We might have had buffered writes to this inode that were
* flushed and had their ordered extents completed in this
* transaction, but we did not previously log the inode with
* LOG_INODE_ALL. Later the inode was evicted and after that
* it was loaded again and this LOG_INODE_EXISTS log operation
* happened. We must make sure that if an explicit fsync against
* the inode is performed later, it logs the new extents, an
* updated inode item, etc, and syncs the log. The same logic
* applies to direct IO writes instead of buffered writes.
*
* 2) When we log the inode with LOG_INODE_EXISTS, its inode item
* is logged with an i_size of 0 or whatever value was logged
* before. If later the i_size of the inode is increased by a
* truncate operation, the log is synced through an fsync of
* some other inode and then finally an explicit fsync against
* this inode is made, we must make sure this fsync logs the
* inode with the new i_size, the hole between old i_size and
* the new i_size, and syncs the log.
*
* 3) If we are logging that an ancestor inode exists as part of
* logging a new name from a link or rename operation, don't update
* its last_log_commit - otherwise if an explicit fsync is made
* against an ancestor, the fsync considers the inode in the log
* and doesn't sync the log, resulting in the ancestor missing after
* a power failure unless the log was synced as part of an fsync
* against any other unrelated inode.
*/
if (inode_only != LOG_INODE_EXISTS)
inode->last_log_commit = inode->last_sub_trans;
spin_unlock(&inode->lock);
/*
* Reset the last_reflink_trans so that the next fsync does not need to
* go through the slower path when logging extents and their checksums.
*/
if (inode_only == LOG_INODE_ALL)
inode->last_reflink_trans = 0;
out_unlock:
mutex_unlock(&inode->log_mutex);
out:
btrfs_free_path(path);
btrfs_free_path(dst_path);
if (recursive_logging)
ctx->logged_before = orig_logged_before;
return ret;
}
/*
* Check if we need to log an inode. This is used in contexts where while
* logging an inode we need to log another inode (either that it exists or in
* full mode). This is used instead of btrfs_inode_in_log() because the later
* requires the inode to be in the log and have the log transaction committed,
* while here we do not care if the log transaction was already committed - our
* caller will commit the log later - and we want to avoid logging an inode
* multiple times when multiple tasks have joined the same log transaction.
*/
static bool need_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
/*
* If a directory was not modified, no dentries added or removed, we can
* and should avoid logging it.
*/
if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid)
return false;
/*
* If this inode does not have new/updated/deleted xattrs since the last
* time it was logged and is flagged as logged in the current transaction,
* we can skip logging it. As for new/deleted names, those are updated in
* the log by link/unlink/rename operations.
* In case the inode was logged and then evicted and reloaded, its
* logged_trans will be 0, in which case we have to fully log it since
* logged_trans is a transient field, not persisted.
*/
if (inode->logged_trans == trans->transid &&
!test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
return false;
return true;
}
struct btrfs_dir_list {
u64 ino;
struct list_head list;
};
/*
* Log the inodes of the new dentries of a directory. See log_dir_items() for
* details about the why it is needed.
* This is a recursive operation - if an existing dentry corresponds to a
* directory, that directory's new entries are logged too (same behaviour as
* ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
* the dentries point to we do not lock their i_mutex, otherwise lockdep
* complains about the following circular lock dependency / possible deadlock:
*
* CPU0 CPU1
* ---- ----
* lock(&type->i_mutex_dir_key#3/2);
* lock(sb_internal#2);
* lock(&type->i_mutex_dir_key#3/2);
* lock(&sb->s_type->i_mutex_key#14);
*
* Where sb_internal is the lock (a counter that works as a lock) acquired by
* sb_start_intwrite() in btrfs_start_transaction().
* Not locking i_mutex of the inodes is still safe because:
*
* 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
* that while logging the inode new references (names) are added or removed
* from the inode, leaving the logged inode item with a link count that does
* not match the number of logged inode reference items. This is fine because
* at log replay time we compute the real number of links and correct the
* link count in the inode item (see replay_one_buffer() and
* link_to_fixup_dir());
*
* 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
* while logging the inode's items new index items (key type
* BTRFS_DIR_INDEX_KEY) are added to fs/subvol tree and the logged inode item
* has a size that doesn't match the sum of the lengths of all the logged
* names - this is ok, not a problem, because at log replay time we set the
* directory's i_size to the correct value (see replay_one_name() and
* do_overwrite_item()).
*/
static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *start_inode,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
LIST_HEAD(dir_list);
struct btrfs_dir_list *dir_elem;
int ret = 0;
/*
* If we are logging a new name, as part of a link or rename operation,
* don't bother logging new dentries, as we just want to log the names
* of an inode and that any new parents exist.
*/
if (ctx->logging_new_name)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
if (!dir_elem) {
btrfs_free_path(path);
return -ENOMEM;
}
dir_elem->ino = btrfs_ino(start_inode);
list_add_tail(&dir_elem->list, &dir_list);
while (!list_empty(&dir_list)) {
struct extent_buffer *leaf;
struct btrfs_key min_key;
int nritems;
int i;
dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list,
list);
if (ret)
goto next_dir_inode;
min_key.objectid = dir_elem->ino;
min_key.type = BTRFS_DIR_INDEX_KEY;
min_key.offset = 0;
again:
btrfs_release_path(path);
ret = btrfs_search_forward(root, &min_key, path, trans->transid);
if (ret < 0) {
goto next_dir_inode;
} else if (ret > 0) {
ret = 0;
goto next_dir_inode;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key di_key;
struct inode *di_inode;
struct btrfs_dir_list *new_dir_elem;
int log_mode = LOG_INODE_EXISTS;
int type;
btrfs_item_key_to_cpu(leaf, &min_key, i);
if (min_key.objectid != dir_elem->ino ||
min_key.type != BTRFS_DIR_INDEX_KEY)
goto next_dir_inode;
di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
type = btrfs_dir_type(leaf, di);
if (btrfs_dir_transid(leaf, di) < trans->transid)
continue;
btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
if (di_key.type == BTRFS_ROOT_ITEM_KEY)
continue;
btrfs_release_path(path);
di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root);
if (IS_ERR(di_inode)) {
ret = PTR_ERR(di_inode);
goto next_dir_inode;
}
if (!need_log_inode(trans, BTRFS_I(di_inode))) {
btrfs_add_delayed_iput(di_inode);
break;
}
ctx->log_new_dentries = false;
if (type == BTRFS_FT_DIR)
log_mode = LOG_INODE_ALL;
ret = btrfs_log_inode(trans, BTRFS_I(di_inode),
log_mode, ctx);
btrfs_add_delayed_iput(di_inode);
if (ret)
goto next_dir_inode;
if (ctx->log_new_dentries) {
new_dir_elem = kmalloc(sizeof(*new_dir_elem),
GFP_NOFS);
if (!new_dir_elem) {
ret = -ENOMEM;
goto next_dir_inode;
}
new_dir_elem->ino = di_key.objectid;
list_add_tail(&new_dir_elem->list, &dir_list);
}
break;
}
if (min_key.offset < (u64)-1) {
min_key.offset++;
goto again;
}
next_dir_inode:
list_del(&dir_elem->list);
kfree(dir_elem);
}
btrfs_free_path(path);
return ret;
}
static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->skip_locking = 1;
path->search_commit_root = 1;
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
u32 cur_offset = 0;
u32 item_size;
unsigned long ptr;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
/* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
break;
item_size = btrfs_item_size(leaf, slot);
ptr = btrfs_item_ptr_offset(leaf, slot);
while (cur_offset < item_size) {
struct btrfs_key inode_key;
struct inode *dir_inode;
inode_key.type = BTRFS_INODE_ITEM_KEY;
inode_key.offset = 0;
if (key.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)
(ptr + cur_offset);
inode_key.objectid = btrfs_inode_extref_parent(
leaf, extref);
cur_offset += sizeof(*extref);
cur_offset += btrfs_inode_extref_name_len(leaf,
extref);
} else {
inode_key.objectid = key.offset;
cur_offset = item_size;
}
dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid,
root);
/*
* If the parent inode was deleted, return an error to
* fallback to a transaction commit. This is to prevent
* getting an inode that was moved from one parent A to
* a parent B, got its former parent A deleted and then
* it got fsync'ed, from existing at both parents after
* a log replay (and the old parent still existing).
* Example:
*
* mkdir /mnt/A
* mkdir /mnt/B
* touch /mnt/B/bar
* sync
* mv /mnt/B/bar /mnt/A/bar
* mv -T /mnt/A /mnt/B
* fsync /mnt/B/bar
* <power fail>
*
* If we ignore the old parent B which got deleted,
* after a log replay we would have file bar linked
* at both parents and the old parent B would still
* exist.
*/
if (IS_ERR(dir_inode)) {
ret = PTR_ERR(dir_inode);
goto out;
}
if (!need_log_inode(trans, BTRFS_I(dir_inode))) {
btrfs_add_delayed_iput(dir_inode);
continue;
}
ctx->log_new_dentries = false;
ret = btrfs_log_inode(trans, BTRFS_I(dir_inode),
LOG_INODE_ALL, ctx);
if (!ret && ctx->log_new_dentries)
ret = log_new_dir_dentries(trans, root,
BTRFS_I(dir_inode), ctx);
btrfs_add_delayed_iput(dir_inode);
if (ret)
goto out;
}
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
static int log_new_ancestors(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_key found_key;
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
while (true) {
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_key search_key;
struct inode *inode;
u64 ino;
int ret = 0;
btrfs_release_path(path);
ino = found_key.offset;
search_key.objectid = found_key.offset;
search_key.type = BTRFS_INODE_ITEM_KEY;
search_key.offset = 0;
inode = btrfs_iget(fs_info->sb, ino, root);
if (IS_ERR(inode))
return PTR_ERR(inode);
if (BTRFS_I(inode)->generation >= trans->transid &&
need_log_inode(trans, BTRFS_I(inode)))
ret = btrfs_log_inode(trans, BTRFS_I(inode),
LOG_INODE_EXISTS, ctx);
btrfs_add_delayed_iput(inode);
if (ret)
return ret;
if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
break;
search_key.type = BTRFS_INODE_REF_KEY;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
return ret;
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
return -ENOENT;
leaf = path->nodes[0];
slot = path->slots[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != search_key.objectid ||
found_key.type != BTRFS_INODE_REF_KEY)
return -ENOENT;
}
return 0;
}
static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
struct dentry *old_parent = NULL;
struct super_block *sb = inode->vfs_inode.i_sb;
int ret = 0;
while (true) {
if (!parent || d_really_is_negative(parent) ||
sb != parent->d_sb)
break;
inode = BTRFS_I(d_inode(parent));
if (root != inode->root)
break;
if (inode->generation >= trans->transid &&
need_log_inode(trans, inode)) {
ret = btrfs_log_inode(trans, inode,
LOG_INODE_EXISTS, ctx);
if (ret)
break;
}
if (IS_ROOT(parent))
break;
parent = dget_parent(parent);
dput(old_parent);
old_parent = parent;
}
dput(old_parent);
return ret;
}
static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
struct btrfs_path *path;
struct btrfs_key search_key;
int ret;
/*
* For a single hard link case, go through a fast path that does not
* need to iterate the fs/subvolume tree.
*/
if (inode->vfs_inode.i_nlink < 2)
return log_new_ancestors_fast(trans, inode, parent, ctx);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
if (ret == 0)
path->slots[0]++;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_key found_key;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != ino ||
found_key.type > BTRFS_INODE_EXTREF_KEY)
break;
/*
* Don't deal with extended references because they are rare
* cases and too complex to deal with (we would need to keep
* track of which subitem we are processing for each item in
* this loop, etc). So just return some error to fallback to
* a transaction commit.
*/
if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
ret = -EMLINK;
goto out;
}
/*
* Logging ancestors needs to do more searches on the fs/subvol
* tree, so it releases the path as needed to avoid deadlocks.
* Keep track of the last inode ref key and resume from that key
* after logging all new ancestors for the current hard link.
*/
memcpy(&search_key, &found_key, sizeof(search_key));
ret = log_new_ancestors(trans, root, path, ctx);
if (ret)
goto out;
btrfs_release_path(path);
goto again;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function around btrfs_log_inode to make sure newly created
* parent directories also end up in the log. A minimal inode and backref
* only logging is done of any parent directories that are older than
* the last committed transaction
*/
static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
int inode_only,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
bool log_dentries = false;
if (btrfs_test_opt(fs_info, NOTREELOG)) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto end_no_trans;
}
if (btrfs_root_refs(&root->root_item) == 0) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto end_no_trans;
}
/*
* Skip already logged inodes or inodes corresponding to tmpfiles
* (since logging them is pointless, a link count of 0 means they
* will never be accessible).
*/
if ((btrfs_inode_in_log(inode, trans->transid) &&
list_empty(&ctx->ordered_extents)) ||
inode->vfs_inode.i_nlink == 0) {
ret = BTRFS_NO_LOG_SYNC;
goto end_no_trans;
}
ret = start_log_trans(trans, root, ctx);
if (ret)
goto end_no_trans;
ret = btrfs_log_inode(trans, inode, inode_only, ctx);
if (ret)
goto end_trans;
/*
* for regular files, if its inode is already on disk, we don't
* have to worry about the parents at all. This is because
* we can use the last_unlink_trans field to record renames
* and other fun in this file.
*/
if (S_ISREG(inode->vfs_inode.i_mode) &&
inode->generation < trans->transid &&
inode->last_unlink_trans < trans->transid) {
ret = 0;
goto end_trans;
}
if (S_ISDIR(inode->vfs_inode.i_mode) && ctx->log_new_dentries)
log_dentries = true;
/*
* On unlink we must make sure all our current and old parent directory
* inodes are fully logged. This is to prevent leaving dangling
* directory index entries in directories that were our parents but are
* not anymore. Not doing this results in old parent directory being
* impossible to delete after log replay (rmdir will always fail with
* error -ENOTEMPTY).
*
* Example 1:
*
* mkdir testdir
* touch testdir/foo
* ln testdir/foo testdir/bar
* sync
* unlink testdir/bar
* xfs_io -c fsync testdir/foo
* <power failure>
* mount fs, triggers log replay
*
* If we don't log the parent directory (testdir), after log replay the
* directory still has an entry pointing to the file inode using the bar
* name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
* the file inode has a link count of 1.
*
* Example 2:
*
* mkdir testdir
* touch foo
* ln foo testdir/foo2
* ln foo testdir/foo3
* sync
* unlink testdir/foo3
* xfs_io -c fsync foo
* <power failure>
* mount fs, triggers log replay
*
* Similar as the first example, after log replay the parent directory
* testdir still has an entry pointing to the inode file with name foo3
* but the file inode does not have a matching BTRFS_INODE_REF_KEY item
* and has a link count of 2.
*/
if (inode->last_unlink_trans >= trans->transid) {
ret = btrfs_log_all_parents(trans, inode, ctx);
if (ret)
goto end_trans;
}
ret = log_all_new_ancestors(trans, inode, parent, ctx);
if (ret)
goto end_trans;
if (log_dentries)
ret = log_new_dir_dentries(trans, root, inode, ctx);
else
ret = 0;
end_trans:
if (ret < 0) {
btrfs_set_log_full_commit(trans);
ret = BTRFS_LOG_FORCE_COMMIT;
}
if (ret)
btrfs_remove_log_ctx(root, ctx);
btrfs_end_log_trans(root);
end_no_trans:
return ret;
}
/*
* it is not safe to log dentry if the chunk root has added new
* chunks. This returns 0 if the dentry was logged, and 1 otherwise.
* If this returns 1, you must commit the transaction to safely get your
* data on disk.
*/
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct dentry *dentry,
struct btrfs_log_ctx *ctx)
{
struct dentry *parent = dget_parent(dentry);
int ret;
ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
LOG_INODE_ALL, ctx);
dput(parent);
return ret;
}
/*
* should be called during mount to recover any replay any log trees
* from the FS
*/
int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
{
int ret;
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_root *log;
struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
struct walk_control wc = {
.process_func = process_one_buffer,
.stage = LOG_WALK_PIN_ONLY,
};
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
trans = btrfs_start_transaction(fs_info->tree_root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto error;
}
wc.trans = trans;
wc.pin = 1;
ret = walk_log_tree(trans, log_root_tree, &wc);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error;
}
again:
key.objectid = BTRFS_TREE_LOG_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_ROOT_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto error;
}
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
btrfs_release_path(path);
if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
break;
log = btrfs_read_tree_root(log_root_tree, &found_key);
if (IS_ERR(log)) {
ret = PTR_ERR(log);
btrfs_abort_transaction(trans, ret);
goto error;
}
wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset,
true);
if (IS_ERR(wc.replay_dest)) {
ret = PTR_ERR(wc.replay_dest);
/*
* We didn't find the subvol, likely because it was
* deleted. This is ok, simply skip this log and go to
* the next one.
*
* We need to exclude the root because we can't have
* other log replays overwriting this log as we'll read
* it back in a few more times. This will keep our
* block from being modified, and we'll just bail for
* each subsequent pass.
*/
if (ret == -ENOENT)
ret = btrfs_pin_extent_for_log_replay(trans,
log->node->start,
log->node->len);
btrfs_put_root(log);
if (!ret)
goto next;
btrfs_abort_transaction(trans, ret);
goto error;
}
wc.replay_dest->log_root = log;
ret = btrfs_record_root_in_trans(trans, wc.replay_dest);
if (ret)
/* The loop needs to continue due to the root refs */
btrfs_abort_transaction(trans, ret);
else
ret = walk_log_tree(trans, log, &wc);
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
ret = fixup_inode_link_counts(trans, wc.replay_dest,
path);
if (ret)
btrfs_abort_transaction(trans, ret);
}
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
struct btrfs_root *root = wc.replay_dest;
btrfs_release_path(path);
/*
* We have just replayed everything, and the highest
* objectid of fs roots probably has changed in case
* some inode_item's got replayed.
*
* root->objectid_mutex is not acquired as log replay
* could only happen during mount.
*/
ret = btrfs_init_root_free_objectid(root);
if (ret)
btrfs_abort_transaction(trans, ret);
}
wc.replay_dest->log_root = NULL;
btrfs_put_root(wc.replay_dest);
btrfs_put_root(log);
if (ret)
goto error;
next:
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
btrfs_release_path(path);
/* step one is to pin it all, step two is to replay just inodes */
if (wc.pin) {
wc.pin = 0;
wc.process_func = replay_one_buffer;
wc.stage = LOG_WALK_REPLAY_INODES;
goto again;
}
/* step three is to replay everything */
if (wc.stage < LOG_WALK_REPLAY_ALL) {
wc.stage++;
goto again;
}
btrfs_free_path(path);
/* step 4: commit the transaction, which also unpins the blocks */
ret = btrfs_commit_transaction(trans);
if (ret)
return ret;
log_root_tree->log_root = NULL;
clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
btrfs_put_root(log_root_tree);
return 0;
error:
if (wc.trans)
btrfs_end_transaction(wc.trans);
clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
btrfs_free_path(path);
return ret;
}
/*
* there are some corner cases where we want to force a full
* commit instead of allowing a directory to be logged.
*
* They revolve around files there were unlinked from the directory, and
* this function updates the parent directory so that a full commit is
* properly done if it is fsync'd later after the unlinks are done.
*
* Must be called before the unlink operations (updates to the subvolume tree,
* inodes, etc) are done.
*/
void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
int for_rename)
{
/*
* when we're logging a file, if it hasn't been renamed
* or unlinked, and its inode is fully committed on disk,
* we don't have to worry about walking up the directory chain
* to log its parents.
*
* So, we use the last_unlink_trans field to put this transid
* into the file. When the file is logged we check it and
* don't log the parents if the file is fully on disk.
*/
mutex_lock(&inode->log_mutex);
inode->last_unlink_trans = trans->transid;
mutex_unlock(&inode->log_mutex);
/*
* if this directory was already logged any new
* names for this file/dir will get recorded
*/
if (dir->logged_trans == trans->transid)
return;
/*
* if the inode we're about to unlink was logged,
* the log will be properly updated for any new names
*/
if (inode->logged_trans == trans->transid)
return;
/*
* when renaming files across directories, if the directory
* there we're unlinking from gets fsync'd later on, there's
* no way to find the destination directory later and fsync it
* properly. So, we have to be conservative and force commits
* so the new name gets discovered.
*/
if (for_rename)
goto record;
/* we can safely do the unlink without any special recording */
return;
record:
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
}
/*
* Make sure that if someone attempts to fsync the parent directory of a deleted
* snapshot, it ends up triggering a transaction commit. This is to guarantee
* that after replaying the log tree of the parent directory's root we will not
* see the snapshot anymore and at log replay time we will not see any log tree
* corresponding to the deleted snapshot's root, which could lead to replaying
* it after replaying the log tree of the parent directory (which would replay
* the snapshot delete operation).
*
* Must be called before the actual snapshot destroy operation (updates to the
* parent root and tree of tree roots trees, etc) are done.
*/
void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir)
{
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
}
/**
* Update the log after adding a new name for an inode.
*
* @trans: Transaction handle.
* @old_dentry: The dentry associated with the old name and the old
* parent directory.
* @old_dir: The inode of the previous parent directory for the case
* of a rename. For a link operation, it must be NULL.
* @old_dir_index: The index number associated with the old name, meaningful
* only for rename operations (when @old_dir is not NULL).
* Ignored for link operations.
* @parent: The dentry associated with the directory under which the
* new name is located.
*
* Call this after adding a new name for an inode, as a result of a link or
* rename operation, and it will properly update the log to reflect the new name.
*/
void btrfs_log_new_name(struct btrfs_trans_handle *trans,
struct dentry *old_dentry, struct btrfs_inode *old_dir,
u64 old_dir_index, struct dentry *parent)
{
struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
struct btrfs_root *root = inode->root;
struct btrfs_log_ctx ctx;
bool log_pinned = false;
int ret;
/*
* this will force the logging code to walk the dentry chain
* up for the file
*/
if (!S_ISDIR(inode->vfs_inode.i_mode))
inode->last_unlink_trans = trans->transid;
/*
* if this inode hasn't been logged and directory we're renaming it
* from hasn't been logged, we don't need to log it
*/
ret = inode_logged(trans, inode, NULL);
if (ret < 0) {
goto out;
} else if (ret == 0) {
if (!old_dir)
return;
/*
* If the inode was not logged and we are doing a rename (old_dir is not
* NULL), check if old_dir was logged - if it was not we can return and
* do nothing.
*/
ret = inode_logged(trans, old_dir, NULL);
if (ret < 0)
goto out;
else if (ret == 0)
return;
}
ret = 0;
/*
* If we are doing a rename (old_dir is not NULL) from a directory that
* was previously logged, make sure that on log replay we get the old
* dir entry deleted. This is needed because we will also log the new
* name of the renamed inode, so we need to make sure that after log
* replay we don't end up with both the new and old dir entries existing.
*/
if (old_dir && old_dir->logged_trans == trans->transid) {
struct btrfs_root *log = old_dir->root->log_root;
struct btrfs_path *path;
ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX);
/*
* We have two inodes to update in the log, the old directory and
* the inode that got renamed, so we must pin the log to prevent
* anyone from syncing the log until we have updated both inodes
* in the log.
*/
ret = join_running_log_trans(root);
/*
* At least one of the inodes was logged before, so this should
* not fail, but if it does, it's not serious, just bail out and
* mark the log for a full commit.
*/
if (WARN_ON_ONCE(ret < 0))
goto out;
log_pinned = true;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/*
* Other concurrent task might be logging the old directory,
* as it can be triggered when logging other inode that had or
* still has a dentry in the old directory. We lock the old
* directory's log_mutex to ensure the deletion of the old
* name is persisted, because during directory logging we
* delete all BTRFS_DIR_LOG_INDEX_KEY keys and the deletion of
* the old name's dir index item is in the delayed items, so
* it could be missed by an in progress directory logging.
*/
mutex_lock(&old_dir->log_mutex);
ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir),
old_dentry->d_name.name,
old_dentry->d_name.len, old_dir_index);
if (ret > 0) {
/*
* The dentry does not exist in the log, so record its
* deletion.
*/
btrfs_release_path(path);
ret = insert_dir_log_key(trans, log, path,
btrfs_ino(old_dir),
old_dir_index, old_dir_index);
}
mutex_unlock(&old_dir->log_mutex);
btrfs_free_path(path);
if (ret < 0)
goto out;
}
btrfs_init_log_ctx(&ctx, &inode->vfs_inode);
ctx.logging_new_name = true;
/*
* We don't care about the return value. If we fail to log the new name
* then we know the next attempt to sync the log will fallback to a full
* transaction commit (due to a call to btrfs_set_log_full_commit()), so
* we don't need to worry about getting a log committed that has an
* inconsistent state after a rename operation.
*/
btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
out:
/*
* If an error happened mark the log for a full commit because it's not
* consistent and up to date or we couldn't find out if one of the
* inodes was logged before in this transaction. Do it before unpinning
* the log, to avoid any races with someone else trying to commit it.
*/
if (ret < 0)
btrfs_set_log_full_commit(trans);
if (log_pinned)
btrfs_end_log_trans(root);
}
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