linux/fs/btrfs/scrub.c
Qu Wenruo ced96edc48 btrfs: Skip scrubbing removed chunks to avoid -ENOENT.
When run scrub with balance, sometimes -ENOENT will be returned, since
in scrub_enumerate_chunks() will search dev_extent in *COMMIT_ROOT*, but
btrfs_lookup_block_group() will search block group in *MEMORY*, so if a
chunk is removed but not committed, -ENOENT will be returned.

However, there is no need to stop scrubbing since other chunks may be
scrubbed without problem.

So this patch changes the behavior to skip removed chunks and continue
to scrub the rest.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
2014-06-19 14:20:54 -07:00

3490 lines
93 KiB
C

/*
* Copyright (C) 2011, 2012 STRATO. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include "ctree.h"
#include "volumes.h"
#include "disk-io.h"
#include "ordered-data.h"
#include "transaction.h"
#include "backref.h"
#include "extent_io.h"
#include "dev-replace.h"
#include "check-integrity.h"
#include "rcu-string.h"
#include "raid56.h"
/*
* This is only the first step towards a full-features scrub. It reads all
* extent and super block and verifies the checksums. In case a bad checksum
* is found or the extent cannot be read, good data will be written back if
* any can be found.
*
* Future enhancements:
* - In case an unrepairable extent is encountered, track which files are
* affected and report them
* - track and record media errors, throw out bad devices
* - add a mode to also read unallocated space
*/
struct scrub_block;
struct scrub_ctx;
/*
* the following three values only influence the performance.
* The last one configures the number of parallel and outstanding I/O
* operations. The first two values configure an upper limit for the number
* of (dynamically allocated) pages that are added to a bio.
*/
#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
/*
* the following value times PAGE_SIZE needs to be large enough to match the
* largest node/leaf/sector size that shall be supported.
* Values larger than BTRFS_STRIPE_LEN are not supported.
*/
#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
struct scrub_page {
struct scrub_block *sblock;
struct page *page;
struct btrfs_device *dev;
u64 flags; /* extent flags */
u64 generation;
u64 logical;
u64 physical;
u64 physical_for_dev_replace;
atomic_t ref_count;
struct {
unsigned int mirror_num:8;
unsigned int have_csum:1;
unsigned int io_error:1;
};
u8 csum[BTRFS_CSUM_SIZE];
};
struct scrub_bio {
int index;
struct scrub_ctx *sctx;
struct btrfs_device *dev;
struct bio *bio;
int err;
u64 logical;
u64 physical;
#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
#else
struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
#endif
int page_count;
int next_free;
struct btrfs_work work;
};
struct scrub_block {
struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
int page_count;
atomic_t outstanding_pages;
atomic_t ref_count; /* free mem on transition to zero */
struct scrub_ctx *sctx;
struct {
unsigned int header_error:1;
unsigned int checksum_error:1;
unsigned int no_io_error_seen:1;
unsigned int generation_error:1; /* also sets header_error */
};
};
struct scrub_wr_ctx {
struct scrub_bio *wr_curr_bio;
struct btrfs_device *tgtdev;
int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
atomic_t flush_all_writes;
struct mutex wr_lock;
};
struct scrub_ctx {
struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
struct btrfs_root *dev_root;
int first_free;
int curr;
atomic_t bios_in_flight;
atomic_t workers_pending;
spinlock_t list_lock;
wait_queue_head_t list_wait;
u16 csum_size;
struct list_head csum_list;
atomic_t cancel_req;
int readonly;
int pages_per_rd_bio;
u32 sectorsize;
u32 nodesize;
u32 leafsize;
int is_dev_replace;
struct scrub_wr_ctx wr_ctx;
/*
* statistics
*/
struct btrfs_scrub_progress stat;
spinlock_t stat_lock;
};
struct scrub_fixup_nodatasum {
struct scrub_ctx *sctx;
struct btrfs_device *dev;
u64 logical;
struct btrfs_root *root;
struct btrfs_work work;
int mirror_num;
};
struct scrub_nocow_inode {
u64 inum;
u64 offset;
u64 root;
struct list_head list;
};
struct scrub_copy_nocow_ctx {
struct scrub_ctx *sctx;
u64 logical;
u64 len;
int mirror_num;
u64 physical_for_dev_replace;
struct list_head inodes;
struct btrfs_work work;
};
struct scrub_warning {
struct btrfs_path *path;
u64 extent_item_size;
char *scratch_buf;
char *msg_buf;
const char *errstr;
sector_t sector;
u64 logical;
struct btrfs_device *dev;
int msg_bufsize;
int scratch_bufsize;
};
static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
struct btrfs_fs_info *fs_info,
struct scrub_block *original_sblock,
u64 length, u64 logical,
struct scrub_block *sblocks_for_recheck);
static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock, int is_metadata,
int have_csum, u8 *csum, u64 generation,
u16 csum_size);
static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock,
int is_metadata, int have_csum,
const u8 *csum, u64 generation,
u16 csum_size);
static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int force_write);
static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int page_num, int force_write);
static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
int page_num);
static int scrub_checksum_data(struct scrub_block *sblock);
static int scrub_checksum_tree_block(struct scrub_block *sblock);
static int scrub_checksum_super(struct scrub_block *sblock);
static void scrub_block_get(struct scrub_block *sblock);
static void scrub_block_put(struct scrub_block *sblock);
static void scrub_page_get(struct scrub_page *spage);
static void scrub_page_put(struct scrub_page *spage);
static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
struct scrub_page *spage);
static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u8 *csum, int force,
u64 physical_for_dev_replace);
static void scrub_bio_end_io(struct bio *bio, int err);
static void scrub_bio_end_io_worker(struct btrfs_work *work);
static void scrub_block_complete(struct scrub_block *sblock);
static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
u64 extent_logical, u64 extent_len,
u64 *extent_physical,
struct btrfs_device **extent_dev,
int *extent_mirror_num);
static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
struct scrub_wr_ctx *wr_ctx,
struct btrfs_fs_info *fs_info,
struct btrfs_device *dev,
int is_dev_replace);
static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
struct scrub_page *spage);
static void scrub_wr_submit(struct scrub_ctx *sctx);
static void scrub_wr_bio_end_io(struct bio *bio, int err);
static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
static int write_page_nocow(struct scrub_ctx *sctx,
u64 physical_for_dev_replace, struct page *page);
static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
struct scrub_copy_nocow_ctx *ctx);
static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
int mirror_num, u64 physical_for_dev_replace);
static void copy_nocow_pages_worker(struct btrfs_work *work);
static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
{
atomic_inc(&sctx->bios_in_flight);
}
static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
{
atomic_dec(&sctx->bios_in_flight);
wake_up(&sctx->list_wait);
}
static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
while (atomic_read(&fs_info->scrub_pause_req)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrub_pause_req) == 0);
mutex_lock(&fs_info->scrub_lock);
}
}
static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
atomic_inc(&fs_info->scrubs_paused);
wake_up(&fs_info->scrub_pause_wait);
mutex_lock(&fs_info->scrub_lock);
__scrub_blocked_if_needed(fs_info);
atomic_dec(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
wake_up(&fs_info->scrub_pause_wait);
}
/*
* used for workers that require transaction commits (i.e., for the
* NOCOW case)
*/
static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
{
struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
/*
* increment scrubs_running to prevent cancel requests from
* completing as long as a worker is running. we must also
* increment scrubs_paused to prevent deadlocking on pause
* requests used for transactions commits (as the worker uses a
* transaction context). it is safe to regard the worker
* as paused for all matters practical. effectively, we only
* avoid cancellation requests from completing.
*/
mutex_lock(&fs_info->scrub_lock);
atomic_inc(&fs_info->scrubs_running);
atomic_inc(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
/*
* check if @scrubs_running=@scrubs_paused condition
* inside wait_event() is not an atomic operation.
* which means we may inc/dec @scrub_running/paused
* at any time. Let's wake up @scrub_pause_wait as
* much as we can to let commit transaction blocked less.
*/
wake_up(&fs_info->scrub_pause_wait);
atomic_inc(&sctx->workers_pending);
}
/* used for workers that require transaction commits */
static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
{
struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
/*
* see scrub_pending_trans_workers_inc() why we're pretending
* to be paused in the scrub counters
*/
mutex_lock(&fs_info->scrub_lock);
atomic_dec(&fs_info->scrubs_running);
atomic_dec(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
atomic_dec(&sctx->workers_pending);
wake_up(&fs_info->scrub_pause_wait);
wake_up(&sctx->list_wait);
}
static void scrub_free_csums(struct scrub_ctx *sctx)
{
while (!list_empty(&sctx->csum_list)) {
struct btrfs_ordered_sum *sum;
sum = list_first_entry(&sctx->csum_list,
struct btrfs_ordered_sum, list);
list_del(&sum->list);
kfree(sum);
}
}
static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
{
int i;
if (!sctx)
return;
scrub_free_wr_ctx(&sctx->wr_ctx);
/* this can happen when scrub is cancelled */
if (sctx->curr != -1) {
struct scrub_bio *sbio = sctx->bios[sctx->curr];
for (i = 0; i < sbio->page_count; i++) {
WARN_ON(!sbio->pagev[i]->page);
scrub_block_put(sbio->pagev[i]->sblock);
}
bio_put(sbio->bio);
}
for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
struct scrub_bio *sbio = sctx->bios[i];
if (!sbio)
break;
kfree(sbio);
}
scrub_free_csums(sctx);
kfree(sctx);
}
static noinline_for_stack
struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
{
struct scrub_ctx *sctx;
int i;
struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
int pages_per_rd_bio;
int ret;
/*
* the setting of pages_per_rd_bio is correct for scrub but might
* be wrong for the dev_replace code where we might read from
* different devices in the initial huge bios. However, that
* code is able to correctly handle the case when adding a page
* to a bio fails.
*/
if (dev->bdev)
pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO,
bio_get_nr_vecs(dev->bdev));
else
pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
if (!sctx)
goto nomem;
sctx->is_dev_replace = is_dev_replace;
sctx->pages_per_rd_bio = pages_per_rd_bio;
sctx->curr = -1;
sctx->dev_root = dev->dev_root;
for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
struct scrub_bio *sbio;
sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
if (!sbio)
goto nomem;
sctx->bios[i] = sbio;
sbio->index = i;
sbio->sctx = sctx;
sbio->page_count = 0;
btrfs_init_work(&sbio->work, scrub_bio_end_io_worker,
NULL, NULL);
if (i != SCRUB_BIOS_PER_SCTX - 1)
sctx->bios[i]->next_free = i + 1;
else
sctx->bios[i]->next_free = -1;
}
sctx->first_free = 0;
sctx->nodesize = dev->dev_root->nodesize;
sctx->leafsize = dev->dev_root->leafsize;
sctx->sectorsize = dev->dev_root->sectorsize;
atomic_set(&sctx->bios_in_flight, 0);
atomic_set(&sctx->workers_pending, 0);
atomic_set(&sctx->cancel_req, 0);
sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
INIT_LIST_HEAD(&sctx->csum_list);
spin_lock_init(&sctx->list_lock);
spin_lock_init(&sctx->stat_lock);
init_waitqueue_head(&sctx->list_wait);
ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
fs_info->dev_replace.tgtdev, is_dev_replace);
if (ret) {
scrub_free_ctx(sctx);
return ERR_PTR(ret);
}
return sctx;
nomem:
scrub_free_ctx(sctx);
return ERR_PTR(-ENOMEM);
}
static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
void *warn_ctx)
{
u64 isize;
u32 nlink;
int ret;
int i;
struct extent_buffer *eb;
struct btrfs_inode_item *inode_item;
struct scrub_warning *swarn = warn_ctx;
struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
struct inode_fs_paths *ipath = NULL;
struct btrfs_root *local_root;
struct btrfs_key root_key;
root_key.objectid = root;
root_key.type = BTRFS_ROOT_ITEM_KEY;
root_key.offset = (u64)-1;
local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
if (IS_ERR(local_root)) {
ret = PTR_ERR(local_root);
goto err;
}
ret = inode_item_info(inum, 0, local_root, swarn->path);
if (ret) {
btrfs_release_path(swarn->path);
goto err;
}
eb = swarn->path->nodes[0];
inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
struct btrfs_inode_item);
isize = btrfs_inode_size(eb, inode_item);
nlink = btrfs_inode_nlink(eb, inode_item);
btrfs_release_path(swarn->path);
ipath = init_ipath(4096, local_root, swarn->path);
if (IS_ERR(ipath)) {
ret = PTR_ERR(ipath);
ipath = NULL;
goto err;
}
ret = paths_from_inode(inum, ipath);
if (ret < 0)
goto err;
/*
* we deliberately ignore the bit ipath might have been too small to
* hold all of the paths here
*/
for (i = 0; i < ipath->fspath->elem_cnt; ++i)
printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
"%s, sector %llu, root %llu, inode %llu, offset %llu, "
"length %llu, links %u (path: %s)\n", swarn->errstr,
swarn->logical, rcu_str_deref(swarn->dev->name),
(unsigned long long)swarn->sector, root, inum, offset,
min(isize - offset, (u64)PAGE_SIZE), nlink,
(char *)(unsigned long)ipath->fspath->val[i]);
free_ipath(ipath);
return 0;
err:
printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
"%s, sector %llu, root %llu, inode %llu, offset %llu: path "
"resolving failed with ret=%d\n", swarn->errstr,
swarn->logical, rcu_str_deref(swarn->dev->name),
(unsigned long long)swarn->sector, root, inum, offset, ret);
free_ipath(ipath);
return 0;
}
static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
{
struct btrfs_device *dev;
struct btrfs_fs_info *fs_info;
struct btrfs_path *path;
struct btrfs_key found_key;
struct extent_buffer *eb;
struct btrfs_extent_item *ei;
struct scrub_warning swarn;
unsigned long ptr = 0;
u64 extent_item_pos;
u64 flags = 0;
u64 ref_root;
u32 item_size;
u8 ref_level;
const int bufsize = 4096;
int ret;
WARN_ON(sblock->page_count < 1);
dev = sblock->pagev[0]->dev;
fs_info = sblock->sctx->dev_root->fs_info;
path = btrfs_alloc_path();
swarn.scratch_buf = kmalloc(bufsize, GFP_NOFS);
swarn.msg_buf = kmalloc(bufsize, GFP_NOFS);
swarn.sector = (sblock->pagev[0]->physical) >> 9;
swarn.logical = sblock->pagev[0]->logical;
swarn.errstr = errstr;
swarn.dev = NULL;
swarn.msg_bufsize = bufsize;
swarn.scratch_bufsize = bufsize;
if (!path || !swarn.scratch_buf || !swarn.msg_buf)
goto out;
ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
&flags);
if (ret < 0)
goto out;
extent_item_pos = swarn.logical - found_key.objectid;
swarn.extent_item_size = found_key.offset;
eb = path->nodes[0];
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size_nr(eb, path->slots[0]);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
do {
ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
item_size, &ref_root,
&ref_level);
printk_in_rcu(KERN_WARNING
"BTRFS: %s at logical %llu on dev %s, "
"sector %llu: metadata %s (level %d) in tree "
"%llu\n", errstr, swarn.logical,
rcu_str_deref(dev->name),
(unsigned long long)swarn.sector,
ref_level ? "node" : "leaf",
ret < 0 ? -1 : ref_level,
ret < 0 ? -1 : ref_root);
} while (ret != 1);
btrfs_release_path(path);
} else {
btrfs_release_path(path);
swarn.path = path;
swarn.dev = dev;
iterate_extent_inodes(fs_info, found_key.objectid,
extent_item_pos, 1,
scrub_print_warning_inode, &swarn);
}
out:
btrfs_free_path(path);
kfree(swarn.scratch_buf);
kfree(swarn.msg_buf);
}
static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
{
struct page *page = NULL;
unsigned long index;
struct scrub_fixup_nodatasum *fixup = fixup_ctx;
int ret;
int corrected = 0;
struct btrfs_key key;
struct inode *inode = NULL;
struct btrfs_fs_info *fs_info;
u64 end = offset + PAGE_SIZE - 1;
struct btrfs_root *local_root;
int srcu_index;
key.objectid = root;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info = fixup->root->fs_info;
srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
local_root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(local_root)) {
srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
return PTR_ERR(local_root);
}
key.type = BTRFS_INODE_ITEM_KEY;
key.objectid = inum;
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
if (IS_ERR(inode))
return PTR_ERR(inode);
index = offset >> PAGE_CACHE_SHIFT;
page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
if (!page) {
ret = -ENOMEM;
goto out;
}
if (PageUptodate(page)) {
if (PageDirty(page)) {
/*
* we need to write the data to the defect sector. the
* data that was in that sector is not in memory,
* because the page was modified. we must not write the
* modified page to that sector.
*
* TODO: what could be done here: wait for the delalloc
* runner to write out that page (might involve
* COW) and see whether the sector is still
* referenced afterwards.
*
* For the meantime, we'll treat this error
* incorrectable, although there is a chance that a
* later scrub will find the bad sector again and that
* there's no dirty page in memory, then.
*/
ret = -EIO;
goto out;
}
fs_info = BTRFS_I(inode)->root->fs_info;
ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
fixup->logical, page,
fixup->mirror_num);
unlock_page(page);
corrected = !ret;
} else {
/*
* we need to get good data first. the general readpage path
* will call repair_io_failure for us, we just have to make
* sure we read the bad mirror.
*/
ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
EXTENT_DAMAGED, GFP_NOFS);
if (ret) {
/* set_extent_bits should give proper error */
WARN_ON(ret > 0);
if (ret > 0)
ret = -EFAULT;
goto out;
}
ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
btrfs_get_extent,
fixup->mirror_num);
wait_on_page_locked(page);
corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
end, EXTENT_DAMAGED, 0, NULL);
if (!corrected)
clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
EXTENT_DAMAGED, GFP_NOFS);
}
out:
if (page)
put_page(page);
iput(inode);
if (ret < 0)
return ret;
if (ret == 0 && corrected) {
/*
* we only need to call readpage for one of the inodes belonging
* to this extent. so make iterate_extent_inodes stop
*/
return 1;
}
return -EIO;
}
static void scrub_fixup_nodatasum(struct btrfs_work *work)
{
int ret;
struct scrub_fixup_nodatasum *fixup;
struct scrub_ctx *sctx;
struct btrfs_trans_handle *trans = NULL;
struct btrfs_path *path;
int uncorrectable = 0;
fixup = container_of(work, struct scrub_fixup_nodatasum, work);
sctx = fixup->sctx;
path = btrfs_alloc_path();
if (!path) {
spin_lock(&sctx->stat_lock);
++sctx->stat.malloc_errors;
spin_unlock(&sctx->stat_lock);
uncorrectable = 1;
goto out;
}
trans = btrfs_join_transaction(fixup->root);
if (IS_ERR(trans)) {
uncorrectable = 1;
goto out;
}
/*
* the idea is to trigger a regular read through the standard path. we
* read a page from the (failed) logical address by specifying the
* corresponding copynum of the failed sector. thus, that readpage is
* expected to fail.
* that is the point where on-the-fly error correction will kick in
* (once it's finished) and rewrite the failed sector if a good copy
* can be found.
*/
ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
path, scrub_fixup_readpage,
fixup);
if (ret < 0) {
uncorrectable = 1;
goto out;
}
WARN_ON(ret != 1);
spin_lock(&sctx->stat_lock);
++sctx->stat.corrected_errors;
spin_unlock(&sctx->stat_lock);
out:
if (trans && !IS_ERR(trans))
btrfs_end_transaction(trans, fixup->root);
if (uncorrectable) {
spin_lock(&sctx->stat_lock);
++sctx->stat.uncorrectable_errors;
spin_unlock(&sctx->stat_lock);
btrfs_dev_replace_stats_inc(
&sctx->dev_root->fs_info->dev_replace.
num_uncorrectable_read_errors);
printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
"unable to fixup (nodatasum) error at logical %llu on dev %s\n",
fixup->logical, rcu_str_deref(fixup->dev->name));
}
btrfs_free_path(path);
kfree(fixup);
scrub_pending_trans_workers_dec(sctx);
}
/*
* scrub_handle_errored_block gets called when either verification of the
* pages failed or the bio failed to read, e.g. with EIO. In the latter
* case, this function handles all pages in the bio, even though only one
* may be bad.
* The goal of this function is to repair the errored block by using the
* contents of one of the mirrors.
*/
static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
{
struct scrub_ctx *sctx = sblock_to_check->sctx;
struct btrfs_device *dev;
struct btrfs_fs_info *fs_info;
u64 length;
u64 logical;
u64 generation;
unsigned int failed_mirror_index;
unsigned int is_metadata;
unsigned int have_csum;
u8 *csum;
struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
struct scrub_block *sblock_bad;
int ret;
int mirror_index;
int page_num;
int success;
static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
BUG_ON(sblock_to_check->page_count < 1);
fs_info = sctx->dev_root->fs_info;
if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
/*
* if we find an error in a super block, we just report it.
* They will get written with the next transaction commit
* anyway
*/
spin_lock(&sctx->stat_lock);
++sctx->stat.super_errors;
spin_unlock(&sctx->stat_lock);
return 0;
}
length = sblock_to_check->page_count * PAGE_SIZE;
logical = sblock_to_check->pagev[0]->logical;
generation = sblock_to_check->pagev[0]->generation;
BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
is_metadata = !(sblock_to_check->pagev[0]->flags &
BTRFS_EXTENT_FLAG_DATA);
have_csum = sblock_to_check->pagev[0]->have_csum;
csum = sblock_to_check->pagev[0]->csum;
dev = sblock_to_check->pagev[0]->dev;
if (sctx->is_dev_replace && !is_metadata && !have_csum) {
sblocks_for_recheck = NULL;
goto nodatasum_case;
}
/*
* read all mirrors one after the other. This includes to
* re-read the extent or metadata block that failed (that was
* the cause that this fixup code is called) another time,
* page by page this time in order to know which pages
* caused I/O errors and which ones are good (for all mirrors).
* It is the goal to handle the situation when more than one
* mirror contains I/O errors, but the errors do not
* overlap, i.e. the data can be repaired by selecting the
* pages from those mirrors without I/O error on the
* particular pages. One example (with blocks >= 2 * PAGE_SIZE)
* would be that mirror #1 has an I/O error on the first page,
* the second page is good, and mirror #2 has an I/O error on
* the second page, but the first page is good.
* Then the first page of the first mirror can be repaired by
* taking the first page of the second mirror, and the
* second page of the second mirror can be repaired by
* copying the contents of the 2nd page of the 1st mirror.
* One more note: if the pages of one mirror contain I/O
* errors, the checksum cannot be verified. In order to get
* the best data for repairing, the first attempt is to find
* a mirror without I/O errors and with a validated checksum.
* Only if this is not possible, the pages are picked from
* mirrors with I/O errors without considering the checksum.
* If the latter is the case, at the end, the checksum of the
* repaired area is verified in order to correctly maintain
* the statistics.
*/
sblocks_for_recheck = kzalloc(BTRFS_MAX_MIRRORS *
sizeof(*sblocks_for_recheck),
GFP_NOFS);
if (!sblocks_for_recheck) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
sctx->stat.read_errors++;
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
goto out;
}
/* setup the context, map the logical blocks and alloc the pages */
ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
logical, sblocks_for_recheck);
if (ret) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors++;
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
goto out;
}
BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
sblock_bad = sblocks_for_recheck + failed_mirror_index;
/* build and submit the bios for the failed mirror, check checksums */
scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum,
csum, generation, sctx->csum_size);
if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
sblock_bad->no_io_error_seen) {
/*
* the error disappeared after reading page by page, or
* the area was part of a huge bio and other parts of the
* bio caused I/O errors, or the block layer merged several
* read requests into one and the error is caused by a
* different bio (usually one of the two latter cases is
* the cause)
*/
spin_lock(&sctx->stat_lock);
sctx->stat.unverified_errors++;
spin_unlock(&sctx->stat_lock);
if (sctx->is_dev_replace)
scrub_write_block_to_dev_replace(sblock_bad);
goto out;
}
if (!sblock_bad->no_io_error_seen) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors++;
spin_unlock(&sctx->stat_lock);
if (__ratelimit(&_rs))
scrub_print_warning("i/o error", sblock_to_check);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
} else if (sblock_bad->checksum_error) {
spin_lock(&sctx->stat_lock);
sctx->stat.csum_errors++;
spin_unlock(&sctx->stat_lock);
if (__ratelimit(&_rs))
scrub_print_warning("checksum error", sblock_to_check);
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
} else if (sblock_bad->header_error) {
spin_lock(&sctx->stat_lock);
sctx->stat.verify_errors++;
spin_unlock(&sctx->stat_lock);
if (__ratelimit(&_rs))
scrub_print_warning("checksum/header error",
sblock_to_check);
if (sblock_bad->generation_error)
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_GENERATION_ERRS);
else
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
}
if (sctx->readonly) {
ASSERT(!sctx->is_dev_replace);
goto out;
}
if (!is_metadata && !have_csum) {
struct scrub_fixup_nodatasum *fixup_nodatasum;
nodatasum_case:
WARN_ON(sctx->is_dev_replace);
/*
* !is_metadata and !have_csum, this means that the data
* might not be COW'ed, that it might be modified
* concurrently. The general strategy to work on the
* commit root does not help in the case when COW is not
* used.
*/
fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
if (!fixup_nodatasum)
goto did_not_correct_error;
fixup_nodatasum->sctx = sctx;
fixup_nodatasum->dev = dev;
fixup_nodatasum->logical = logical;
fixup_nodatasum->root = fs_info->extent_root;
fixup_nodatasum->mirror_num = failed_mirror_index + 1;
scrub_pending_trans_workers_inc(sctx);
btrfs_init_work(&fixup_nodatasum->work, scrub_fixup_nodatasum,
NULL, NULL);
btrfs_queue_work(fs_info->scrub_workers,
&fixup_nodatasum->work);
goto out;
}
/*
* now build and submit the bios for the other mirrors, check
* checksums.
* First try to pick the mirror which is completely without I/O
* errors and also does not have a checksum error.
* If one is found, and if a checksum is present, the full block
* that is known to contain an error is rewritten. Afterwards
* the block is known to be corrected.
* If a mirror is found which is completely correct, and no
* checksum is present, only those pages are rewritten that had
* an I/O error in the block to be repaired, since it cannot be
* determined, which copy of the other pages is better (and it
* could happen otherwise that a correct page would be
* overwritten by a bad one).
*/
for (mirror_index = 0;
mirror_index < BTRFS_MAX_MIRRORS &&
sblocks_for_recheck[mirror_index].page_count > 0;
mirror_index++) {
struct scrub_block *sblock_other;
if (mirror_index == failed_mirror_index)
continue;
sblock_other = sblocks_for_recheck + mirror_index;
/* build and submit the bios, check checksums */
scrub_recheck_block(fs_info, sblock_other, is_metadata,
have_csum, csum, generation,
sctx->csum_size);
if (!sblock_other->header_error &&
!sblock_other->checksum_error &&
sblock_other->no_io_error_seen) {
if (sctx->is_dev_replace) {
scrub_write_block_to_dev_replace(sblock_other);
} else {
int force_write = is_metadata || have_csum;
ret = scrub_repair_block_from_good_copy(
sblock_bad, sblock_other,
force_write);
}
if (0 == ret)
goto corrected_error;
}
}
/*
* for dev_replace, pick good pages and write to the target device.
*/
if (sctx->is_dev_replace) {
success = 1;
for (page_num = 0; page_num < sblock_bad->page_count;
page_num++) {
int sub_success;
sub_success = 0;
for (mirror_index = 0;
mirror_index < BTRFS_MAX_MIRRORS &&
sblocks_for_recheck[mirror_index].page_count > 0;
mirror_index++) {
struct scrub_block *sblock_other =
sblocks_for_recheck + mirror_index;
struct scrub_page *page_other =
sblock_other->pagev[page_num];
if (!page_other->io_error) {
ret = scrub_write_page_to_dev_replace(
sblock_other, page_num);
if (ret == 0) {
/* succeeded for this page */
sub_success = 1;
break;
} else {
btrfs_dev_replace_stats_inc(
&sctx->dev_root->
fs_info->dev_replace.
num_write_errors);
}
}
}
if (!sub_success) {
/*
* did not find a mirror to fetch the page
* from. scrub_write_page_to_dev_replace()
* handles this case (page->io_error), by
* filling the block with zeros before
* submitting the write request
*/
success = 0;
ret = scrub_write_page_to_dev_replace(
sblock_bad, page_num);
if (ret)
btrfs_dev_replace_stats_inc(
&sctx->dev_root->fs_info->
dev_replace.num_write_errors);
}
}
goto out;
}
/*
* for regular scrub, repair those pages that are errored.
* In case of I/O errors in the area that is supposed to be
* repaired, continue by picking good copies of those pages.
* Select the good pages from mirrors to rewrite bad pages from
* the area to fix. Afterwards verify the checksum of the block
* that is supposed to be repaired. This verification step is
* only done for the purpose of statistic counting and for the
* final scrub report, whether errors remain.
* A perfect algorithm could make use of the checksum and try
* all possible combinations of pages from the different mirrors
* until the checksum verification succeeds. For example, when
* the 2nd page of mirror #1 faces I/O errors, and the 2nd page
* of mirror #2 is readable but the final checksum test fails,
* then the 2nd page of mirror #3 could be tried, whether now
* the final checksum succeedes. But this would be a rare
* exception and is therefore not implemented. At least it is
* avoided that the good copy is overwritten.
* A more useful improvement would be to pick the sectors
* without I/O error based on sector sizes (512 bytes on legacy
* disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
* mirror could be repaired by taking 512 byte of a different
* mirror, even if other 512 byte sectors in the same PAGE_SIZE
* area are unreadable.
*/
/* can only fix I/O errors from here on */
if (sblock_bad->no_io_error_seen)
goto did_not_correct_error;
success = 1;
for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
struct scrub_page *page_bad = sblock_bad->pagev[page_num];
if (!page_bad->io_error)
continue;
for (mirror_index = 0;
mirror_index < BTRFS_MAX_MIRRORS &&
sblocks_for_recheck[mirror_index].page_count > 0;
mirror_index++) {
struct scrub_block *sblock_other = sblocks_for_recheck +
mirror_index;
struct scrub_page *page_other = sblock_other->pagev[
page_num];
if (!page_other->io_error) {
ret = scrub_repair_page_from_good_copy(
sblock_bad, sblock_other, page_num, 0);
if (0 == ret) {
page_bad->io_error = 0;
break; /* succeeded for this page */
}
}
}
if (page_bad->io_error) {
/* did not find a mirror to copy the page from */
success = 0;
}
}
if (success) {
if (is_metadata || have_csum) {
/*
* need to verify the checksum now that all
* sectors on disk are repaired (the write
* request for data to be repaired is on its way).
* Just be lazy and use scrub_recheck_block()
* which re-reads the data before the checksum
* is verified, but most likely the data comes out
* of the page cache.
*/
scrub_recheck_block(fs_info, sblock_bad,
is_metadata, have_csum, csum,
generation, sctx->csum_size);
if (!sblock_bad->header_error &&
!sblock_bad->checksum_error &&
sblock_bad->no_io_error_seen)
goto corrected_error;
else
goto did_not_correct_error;
} else {
corrected_error:
spin_lock(&sctx->stat_lock);
sctx->stat.corrected_errors++;
spin_unlock(&sctx->stat_lock);
printk_ratelimited_in_rcu(KERN_ERR
"BTRFS: fixed up error at logical %llu on dev %s\n",
logical, rcu_str_deref(dev->name));
}
} else {
did_not_correct_error:
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
printk_ratelimited_in_rcu(KERN_ERR
"BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
logical, rcu_str_deref(dev->name));
}
out:
if (sblocks_for_recheck) {
for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
mirror_index++) {
struct scrub_block *sblock = sblocks_for_recheck +
mirror_index;
int page_index;
for (page_index = 0; page_index < sblock->page_count;
page_index++) {
sblock->pagev[page_index]->sblock = NULL;
scrub_page_put(sblock->pagev[page_index]);
}
}
kfree(sblocks_for_recheck);
}
return 0;
}
static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
struct btrfs_fs_info *fs_info,
struct scrub_block *original_sblock,
u64 length, u64 logical,
struct scrub_block *sblocks_for_recheck)
{
int page_index;
int mirror_index;
int ret;
/*
* note: the two members ref_count and outstanding_pages
* are not used (and not set) in the blocks that are used for
* the recheck procedure
*/
page_index = 0;
while (length > 0) {
u64 sublen = min_t(u64, length, PAGE_SIZE);
u64 mapped_length = sublen;
struct btrfs_bio *bbio = NULL;
/*
* with a length of PAGE_SIZE, each returned stripe
* represents one mirror
*/
ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
&mapped_length, &bbio, 0);
if (ret || !bbio || mapped_length < sublen) {
kfree(bbio);
return -EIO;
}
BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
for (mirror_index = 0; mirror_index < (int)bbio->num_stripes;
mirror_index++) {
struct scrub_block *sblock;
struct scrub_page *page;
if (mirror_index >= BTRFS_MAX_MIRRORS)
continue;
sblock = sblocks_for_recheck + mirror_index;
sblock->sctx = sctx;
page = kzalloc(sizeof(*page), GFP_NOFS);
if (!page) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
kfree(bbio);
return -ENOMEM;
}
scrub_page_get(page);
sblock->pagev[page_index] = page;
page->logical = logical;
page->physical = bbio->stripes[mirror_index].physical;
BUG_ON(page_index >= original_sblock->page_count);
page->physical_for_dev_replace =
original_sblock->pagev[page_index]->
physical_for_dev_replace;
/* for missing devices, dev->bdev is NULL */
page->dev = bbio->stripes[mirror_index].dev;
page->mirror_num = mirror_index + 1;
sblock->page_count++;
page->page = alloc_page(GFP_NOFS);
if (!page->page)
goto leave_nomem;
}
kfree(bbio);
length -= sublen;
logical += sublen;
page_index++;
}
return 0;
}
/*
* this function will check the on disk data for checksum errors, header
* errors and read I/O errors. If any I/O errors happen, the exact pages
* which are errored are marked as being bad. The goal is to enable scrub
* to take those pages that are not errored from all the mirrors so that
* the pages that are errored in the just handled mirror can be repaired.
*/
static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock, int is_metadata,
int have_csum, u8 *csum, u64 generation,
u16 csum_size)
{
int page_num;
sblock->no_io_error_seen = 1;
sblock->header_error = 0;
sblock->checksum_error = 0;
for (page_num = 0; page_num < sblock->page_count; page_num++) {
struct bio *bio;
struct scrub_page *page = sblock->pagev[page_num];
if (page->dev->bdev == NULL) {
page->io_error = 1;
sblock->no_io_error_seen = 0;
continue;
}
WARN_ON(!page->page);
bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
if (!bio) {
page->io_error = 1;
sblock->no_io_error_seen = 0;
continue;
}
bio->bi_bdev = page->dev->bdev;
bio->bi_iter.bi_sector = page->physical >> 9;
bio_add_page(bio, page->page, PAGE_SIZE, 0);
if (btrfsic_submit_bio_wait(READ, bio))
sblock->no_io_error_seen = 0;
bio_put(bio);
}
if (sblock->no_io_error_seen)
scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
have_csum, csum, generation,
csum_size);
return;
}
static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock,
int is_metadata, int have_csum,
const u8 *csum, u64 generation,
u16 csum_size)
{
int page_num;
u8 calculated_csum[BTRFS_CSUM_SIZE];
u32 crc = ~(u32)0;
void *mapped_buffer;
WARN_ON(!sblock->pagev[0]->page);
if (is_metadata) {
struct btrfs_header *h;
mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
h = (struct btrfs_header *)mapped_buffer;
if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE) ||
memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
BTRFS_UUID_SIZE)) {
sblock->header_error = 1;
} else if (generation != btrfs_stack_header_generation(h)) {
sblock->header_error = 1;
sblock->generation_error = 1;
}
csum = h->csum;
} else {
if (!have_csum)
return;
mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
}
for (page_num = 0;;) {
if (page_num == 0 && is_metadata)
crc = btrfs_csum_data(
((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
else
crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
kunmap_atomic(mapped_buffer);
page_num++;
if (page_num >= sblock->page_count)
break;
WARN_ON(!sblock->pagev[page_num]->page);
mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
}
btrfs_csum_final(crc, calculated_csum);
if (memcmp(calculated_csum, csum, csum_size))
sblock->checksum_error = 1;
}
static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int force_write)
{
int page_num;
int ret = 0;
for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
int ret_sub;
ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
sblock_good,
page_num,
force_write);
if (ret_sub)
ret = ret_sub;
}
return ret;
}
static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int page_num, int force_write)
{
struct scrub_page *page_bad = sblock_bad->pagev[page_num];
struct scrub_page *page_good = sblock_good->pagev[page_num];
BUG_ON(page_bad->page == NULL);
BUG_ON(page_good->page == NULL);
if (force_write || sblock_bad->header_error ||
sblock_bad->checksum_error || page_bad->io_error) {
struct bio *bio;
int ret;
if (!page_bad->dev->bdev) {
printk_ratelimited(KERN_WARNING "BTRFS: "
"scrub_repair_page_from_good_copy(bdev == NULL) "
"is unexpected!\n");
return -EIO;
}
bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
if (!bio)
return -EIO;
bio->bi_bdev = page_bad->dev->bdev;
bio->bi_iter.bi_sector = page_bad->physical >> 9;
ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
if (PAGE_SIZE != ret) {
bio_put(bio);
return -EIO;
}
if (btrfsic_submit_bio_wait(WRITE, bio)) {
btrfs_dev_stat_inc_and_print(page_bad->dev,
BTRFS_DEV_STAT_WRITE_ERRS);
btrfs_dev_replace_stats_inc(
&sblock_bad->sctx->dev_root->fs_info->
dev_replace.num_write_errors);
bio_put(bio);
return -EIO;
}
bio_put(bio);
}
return 0;
}
static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
{
int page_num;
for (page_num = 0; page_num < sblock->page_count; page_num++) {
int ret;
ret = scrub_write_page_to_dev_replace(sblock, page_num);
if (ret)
btrfs_dev_replace_stats_inc(
&sblock->sctx->dev_root->fs_info->dev_replace.
num_write_errors);
}
}
static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
int page_num)
{
struct scrub_page *spage = sblock->pagev[page_num];
BUG_ON(spage->page == NULL);
if (spage->io_error) {
void *mapped_buffer = kmap_atomic(spage->page);
memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
flush_dcache_page(spage->page);
kunmap_atomic(mapped_buffer);
}
return scrub_add_page_to_wr_bio(sblock->sctx, spage);
}
static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
struct scrub_page *spage)
{
struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
struct scrub_bio *sbio;
int ret;
mutex_lock(&wr_ctx->wr_lock);
again:
if (!wr_ctx->wr_curr_bio) {
wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
GFP_NOFS);
if (!wr_ctx->wr_curr_bio) {
mutex_unlock(&wr_ctx->wr_lock);
return -ENOMEM;
}
wr_ctx->wr_curr_bio->sctx = sctx;
wr_ctx->wr_curr_bio->page_count = 0;
}
sbio = wr_ctx->wr_curr_bio;
if (sbio->page_count == 0) {
struct bio *bio;
sbio->physical = spage->physical_for_dev_replace;
sbio->logical = spage->logical;
sbio->dev = wr_ctx->tgtdev;
bio = sbio->bio;
if (!bio) {
bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
if (!bio) {
mutex_unlock(&wr_ctx->wr_lock);
return -ENOMEM;
}
sbio->bio = bio;
}
bio->bi_private = sbio;
bio->bi_end_io = scrub_wr_bio_end_io;
bio->bi_bdev = sbio->dev->bdev;
bio->bi_iter.bi_sector = sbio->physical >> 9;
sbio->err = 0;
} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
spage->physical_for_dev_replace ||
sbio->logical + sbio->page_count * PAGE_SIZE !=
spage->logical) {
scrub_wr_submit(sctx);
goto again;
}
ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
if (ret != PAGE_SIZE) {
if (sbio->page_count < 1) {
bio_put(sbio->bio);
sbio->bio = NULL;
mutex_unlock(&wr_ctx->wr_lock);
return -EIO;
}
scrub_wr_submit(sctx);
goto again;
}
sbio->pagev[sbio->page_count] = spage;
scrub_page_get(spage);
sbio->page_count++;
if (sbio->page_count == wr_ctx->pages_per_wr_bio)
scrub_wr_submit(sctx);
mutex_unlock(&wr_ctx->wr_lock);
return 0;
}
static void scrub_wr_submit(struct scrub_ctx *sctx)
{
struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
struct scrub_bio *sbio;
if (!wr_ctx->wr_curr_bio)
return;
sbio = wr_ctx->wr_curr_bio;
wr_ctx->wr_curr_bio = NULL;
WARN_ON(!sbio->bio->bi_bdev);
scrub_pending_bio_inc(sctx);
/* process all writes in a single worker thread. Then the block layer
* orders the requests before sending them to the driver which
* doubled the write performance on spinning disks when measured
* with Linux 3.5 */
btrfsic_submit_bio(WRITE, sbio->bio);
}
static void scrub_wr_bio_end_io(struct bio *bio, int err)
{
struct scrub_bio *sbio = bio->bi_private;
struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
sbio->err = err;
sbio->bio = bio;
btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL);
btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
}
static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
{
struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
struct scrub_ctx *sctx = sbio->sctx;
int i;
WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
if (sbio->err) {
struct btrfs_dev_replace *dev_replace =
&sbio->sctx->dev_root->fs_info->dev_replace;
for (i = 0; i < sbio->page_count; i++) {
struct scrub_page *spage = sbio->pagev[i];
spage->io_error = 1;
btrfs_dev_replace_stats_inc(&dev_replace->
num_write_errors);
}
}
for (i = 0; i < sbio->page_count; i++)
scrub_page_put(sbio->pagev[i]);
bio_put(sbio->bio);
kfree(sbio);
scrub_pending_bio_dec(sctx);
}
static int scrub_checksum(struct scrub_block *sblock)
{
u64 flags;
int ret;
WARN_ON(sblock->page_count < 1);
flags = sblock->pagev[0]->flags;
ret = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA)
ret = scrub_checksum_data(sblock);
else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
ret = scrub_checksum_tree_block(sblock);
else if (flags & BTRFS_EXTENT_FLAG_SUPER)
(void)scrub_checksum_super(sblock);
else
WARN_ON(1);
if (ret)
scrub_handle_errored_block(sblock);
return ret;
}
static int scrub_checksum_data(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
u8 csum[BTRFS_CSUM_SIZE];
u8 *on_disk_csum;
struct page *page;
void *buffer;
u32 crc = ~(u32)0;
int fail = 0;
u64 len;
int index;
BUG_ON(sblock->page_count < 1);
if (!sblock->pagev[0]->have_csum)
return 0;
on_disk_csum = sblock->pagev[0]->csum;
page = sblock->pagev[0]->page;
buffer = kmap_atomic(page);
len = sctx->sectorsize;
index = 0;
for (;;) {
u64 l = min_t(u64, len, PAGE_SIZE);
crc = btrfs_csum_data(buffer, crc, l);
kunmap_atomic(buffer);
len -= l;
if (len == 0)
break;
index++;
BUG_ON(index >= sblock->page_count);
BUG_ON(!sblock->pagev[index]->page);
page = sblock->pagev[index]->page;
buffer = kmap_atomic(page);
}
btrfs_csum_final(crc, csum);
if (memcmp(csum, on_disk_csum, sctx->csum_size))
fail = 1;
return fail;
}
static int scrub_checksum_tree_block(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_header *h;
struct btrfs_root *root = sctx->dev_root;
struct btrfs_fs_info *fs_info = root->fs_info;
u8 calculated_csum[BTRFS_CSUM_SIZE];
u8 on_disk_csum[BTRFS_CSUM_SIZE];
struct page *page;
void *mapped_buffer;
u64 mapped_size;
void *p;
u32 crc = ~(u32)0;
int fail = 0;
int crc_fail = 0;
u64 len;
int index;
BUG_ON(sblock->page_count < 1);
page = sblock->pagev[0]->page;
mapped_buffer = kmap_atomic(page);
h = (struct btrfs_header *)mapped_buffer;
memcpy(on_disk_csum, h->csum, sctx->csum_size);
/*
* we don't use the getter functions here, as we
* a) don't have an extent buffer and
* b) the page is already kmapped
*/
if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h))
++fail;
if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
++fail;
if (memcmp(h->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
++fail;
if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
BTRFS_UUID_SIZE))
++fail;
WARN_ON(sctx->nodesize != sctx->leafsize);
len = sctx->nodesize - BTRFS_CSUM_SIZE;
mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
index = 0;
for (;;) {
u64 l = min_t(u64, len, mapped_size);
crc = btrfs_csum_data(p, crc, l);
kunmap_atomic(mapped_buffer);
len -= l;
if (len == 0)
break;
index++;
BUG_ON(index >= sblock->page_count);
BUG_ON(!sblock->pagev[index]->page);
page = sblock->pagev[index]->page;
mapped_buffer = kmap_atomic(page);
mapped_size = PAGE_SIZE;
p = mapped_buffer;
}
btrfs_csum_final(crc, calculated_csum);
if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
++crc_fail;
return fail || crc_fail;
}
static int scrub_checksum_super(struct scrub_block *sblock)
{
struct btrfs_super_block *s;
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_root *root = sctx->dev_root;
struct btrfs_fs_info *fs_info = root->fs_info;
u8 calculated_csum[BTRFS_CSUM_SIZE];
u8 on_disk_csum[BTRFS_CSUM_SIZE];
struct page *page;
void *mapped_buffer;
u64 mapped_size;
void *p;
u32 crc = ~(u32)0;
int fail_gen = 0;
int fail_cor = 0;
u64 len;
int index;
BUG_ON(sblock->page_count < 1);
page = sblock->pagev[0]->page;
mapped_buffer = kmap_atomic(page);
s = (struct btrfs_super_block *)mapped_buffer;
memcpy(on_disk_csum, s->csum, sctx->csum_size);
if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
++fail_cor;
if (sblock->pagev[0]->generation != btrfs_super_generation(s))
++fail_gen;
if (memcmp(s->fsid, fs_info->fsid, BTRFS_UUID_SIZE))
++fail_cor;
len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
index = 0;
for (;;) {
u64 l = min_t(u64, len, mapped_size);
crc = btrfs_csum_data(p, crc, l);
kunmap_atomic(mapped_buffer);
len -= l;
if (len == 0)
break;
index++;
BUG_ON(index >= sblock->page_count);
BUG_ON(!sblock->pagev[index]->page);
page = sblock->pagev[index]->page;
mapped_buffer = kmap_atomic(page);
mapped_size = PAGE_SIZE;
p = mapped_buffer;
}
btrfs_csum_final(crc, calculated_csum);
if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
++fail_cor;
if (fail_cor + fail_gen) {
/*
* if we find an error in a super block, we just report it.
* They will get written with the next transaction commit
* anyway
*/
spin_lock(&sctx->stat_lock);
++sctx->stat.super_errors;
spin_unlock(&sctx->stat_lock);
if (fail_cor)
btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
else
btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
BTRFS_DEV_STAT_GENERATION_ERRS);
}
return fail_cor + fail_gen;
}
static void scrub_block_get(struct scrub_block *sblock)
{
atomic_inc(&sblock->ref_count);
}
static void scrub_block_put(struct scrub_block *sblock)
{
if (atomic_dec_and_test(&sblock->ref_count)) {
int i;
for (i = 0; i < sblock->page_count; i++)
scrub_page_put(sblock->pagev[i]);
kfree(sblock);
}
}
static void scrub_page_get(struct scrub_page *spage)
{
atomic_inc(&spage->ref_count);
}
static void scrub_page_put(struct scrub_page *spage)
{
if (atomic_dec_and_test(&spage->ref_count)) {
if (spage->page)
__free_page(spage->page);
kfree(spage);
}
}
static void scrub_submit(struct scrub_ctx *sctx)
{
struct scrub_bio *sbio;
if (sctx->curr == -1)
return;
sbio = sctx->bios[sctx->curr];
sctx->curr = -1;
scrub_pending_bio_inc(sctx);
if (!sbio->bio->bi_bdev) {
/*
* this case should not happen. If btrfs_map_block() is
* wrong, it could happen for dev-replace operations on
* missing devices when no mirrors are available, but in
* this case it should already fail the mount.
* This case is handled correctly (but _very_ slowly).
*/
printk_ratelimited(KERN_WARNING
"BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
bio_endio(sbio->bio, -EIO);
} else {
btrfsic_submit_bio(READ, sbio->bio);
}
}
static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
struct scrub_page *spage)
{
struct scrub_block *sblock = spage->sblock;
struct scrub_bio *sbio;
int ret;
again:
/*
* grab a fresh bio or wait for one to become available
*/
while (sctx->curr == -1) {
spin_lock(&sctx->list_lock);
sctx->curr = sctx->first_free;
if (sctx->curr != -1) {
sctx->first_free = sctx->bios[sctx->curr]->next_free;
sctx->bios[sctx->curr]->next_free = -1;
sctx->bios[sctx->curr]->page_count = 0;
spin_unlock(&sctx->list_lock);
} else {
spin_unlock(&sctx->list_lock);
wait_event(sctx->list_wait, sctx->first_free != -1);
}
}
sbio = sctx->bios[sctx->curr];
if (sbio->page_count == 0) {
struct bio *bio;
sbio->physical = spage->physical;
sbio->logical = spage->logical;
sbio->dev = spage->dev;
bio = sbio->bio;
if (!bio) {
bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
if (!bio)
return -ENOMEM;
sbio->bio = bio;
}
bio->bi_private = sbio;
bio->bi_end_io = scrub_bio_end_io;
bio->bi_bdev = sbio->dev->bdev;
bio->bi_iter.bi_sector = sbio->physical >> 9;
sbio->err = 0;
} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
spage->physical ||
sbio->logical + sbio->page_count * PAGE_SIZE !=
spage->logical ||
sbio->dev != spage->dev) {
scrub_submit(sctx);
goto again;
}
sbio->pagev[sbio->page_count] = spage;
ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
if (ret != PAGE_SIZE) {
if (sbio->page_count < 1) {
bio_put(sbio->bio);
sbio->bio = NULL;
return -EIO;
}
scrub_submit(sctx);
goto again;
}
scrub_block_get(sblock); /* one for the page added to the bio */
atomic_inc(&sblock->outstanding_pages);
sbio->page_count++;
if (sbio->page_count == sctx->pages_per_rd_bio)
scrub_submit(sctx);
return 0;
}
static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u8 *csum, int force,
u64 physical_for_dev_replace)
{
struct scrub_block *sblock;
int index;
sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
if (!sblock) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
/* one ref inside this function, plus one for each page added to
* a bio later on */
atomic_set(&sblock->ref_count, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
for (index = 0; len > 0; index++) {
struct scrub_page *spage;
u64 l = min_t(u64, len, PAGE_SIZE);
spage = kzalloc(sizeof(*spage), GFP_NOFS);
if (!spage) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_block_put(sblock);
return -ENOMEM;
}
BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
scrub_page_get(spage);
sblock->pagev[index] = spage;
spage->sblock = sblock;
spage->dev = dev;
spage->flags = flags;
spage->generation = gen;
spage->logical = logical;
spage->physical = physical;
spage->physical_for_dev_replace = physical_for_dev_replace;
spage->mirror_num = mirror_num;
if (csum) {
spage->have_csum = 1;
memcpy(spage->csum, csum, sctx->csum_size);
} else {
spage->have_csum = 0;
}
sblock->page_count++;
spage->page = alloc_page(GFP_NOFS);
if (!spage->page)
goto leave_nomem;
len -= l;
logical += l;
physical += l;
physical_for_dev_replace += l;
}
WARN_ON(sblock->page_count == 0);
for (index = 0; index < sblock->page_count; index++) {
struct scrub_page *spage = sblock->pagev[index];
int ret;
ret = scrub_add_page_to_rd_bio(sctx, spage);
if (ret) {
scrub_block_put(sblock);
return ret;
}
}
if (force)
scrub_submit(sctx);
/* last one frees, either here or in bio completion for last page */
scrub_block_put(sblock);
return 0;
}
static void scrub_bio_end_io(struct bio *bio, int err)
{
struct scrub_bio *sbio = bio->bi_private;
struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
sbio->err = err;
sbio->bio = bio;
btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
}
static void scrub_bio_end_io_worker(struct btrfs_work *work)
{
struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
struct scrub_ctx *sctx = sbio->sctx;
int i;
BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
if (sbio->err) {
for (i = 0; i < sbio->page_count; i++) {
struct scrub_page *spage = sbio->pagev[i];
spage->io_error = 1;
spage->sblock->no_io_error_seen = 0;
}
}
/* now complete the scrub_block items that have all pages completed */
for (i = 0; i < sbio->page_count; i++) {
struct scrub_page *spage = sbio->pagev[i];
struct scrub_block *sblock = spage->sblock;
if (atomic_dec_and_test(&sblock->outstanding_pages))
scrub_block_complete(sblock);
scrub_block_put(sblock);
}
bio_put(sbio->bio);
sbio->bio = NULL;
spin_lock(&sctx->list_lock);
sbio->next_free = sctx->first_free;
sctx->first_free = sbio->index;
spin_unlock(&sctx->list_lock);
if (sctx->is_dev_replace &&
atomic_read(&sctx->wr_ctx.flush_all_writes)) {
mutex_lock(&sctx->wr_ctx.wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_ctx.wr_lock);
}
scrub_pending_bio_dec(sctx);
}
static void scrub_block_complete(struct scrub_block *sblock)
{
if (!sblock->no_io_error_seen) {
scrub_handle_errored_block(sblock);
} else {
/*
* if has checksum error, write via repair mechanism in
* dev replace case, otherwise write here in dev replace
* case.
*/
if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace)
scrub_write_block_to_dev_replace(sblock);
}
}
static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
u8 *csum)
{
struct btrfs_ordered_sum *sum = NULL;
unsigned long index;
unsigned long num_sectors;
while (!list_empty(&sctx->csum_list)) {
sum = list_first_entry(&sctx->csum_list,
struct btrfs_ordered_sum, list);
if (sum->bytenr > logical)
return 0;
if (sum->bytenr + sum->len > logical)
break;
++sctx->stat.csum_discards;
list_del(&sum->list);
kfree(sum);
sum = NULL;
}
if (!sum)
return 0;
index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
num_sectors = sum->len / sctx->sectorsize;
memcpy(csum, sum->sums + index, sctx->csum_size);
if (index == num_sectors - 1) {
list_del(&sum->list);
kfree(sum);
}
return 1;
}
/* scrub extent tries to collect up to 64 kB for each bio */
static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u64 physical_for_dev_replace)
{
int ret;
u8 csum[BTRFS_CSUM_SIZE];
u32 blocksize;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
blocksize = sctx->sectorsize;
spin_lock(&sctx->stat_lock);
sctx->stat.data_extents_scrubbed++;
sctx->stat.data_bytes_scrubbed += len;
spin_unlock(&sctx->stat_lock);
} else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
WARN_ON(sctx->nodesize != sctx->leafsize);
blocksize = sctx->nodesize;
spin_lock(&sctx->stat_lock);
sctx->stat.tree_extents_scrubbed++;
sctx->stat.tree_bytes_scrubbed += len;
spin_unlock(&sctx->stat_lock);
} else {
blocksize = sctx->sectorsize;
WARN_ON(1);
}
while (len) {
u64 l = min_t(u64, len, blocksize);
int have_csum = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
/* push csums to sbio */
have_csum = scrub_find_csum(sctx, logical, l, csum);
if (have_csum == 0)
++sctx->stat.no_csum;
if (sctx->is_dev_replace && !have_csum) {
ret = copy_nocow_pages(sctx, logical, l,
mirror_num,
physical_for_dev_replace);
goto behind_scrub_pages;
}
}
ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
mirror_num, have_csum ? csum : NULL, 0,
physical_for_dev_replace);
behind_scrub_pages:
if (ret)
return ret;
len -= l;
logical += l;
physical += l;
physical_for_dev_replace += l;
}
return 0;
}
/*
* Given a physical address, this will calculate it's
* logical offset. if this is a parity stripe, it will return
* the most left data stripe's logical offset.
*
* return 0 if it is a data stripe, 1 means parity stripe.
*/
static int get_raid56_logic_offset(u64 physical, int num,
struct map_lookup *map, u64 *offset)
{
int i;
int j = 0;
u64 stripe_nr;
u64 last_offset;
int stripe_index;
int rot;
last_offset = (physical - map->stripes[num].physical) *
nr_data_stripes(map);
*offset = last_offset;
for (i = 0; i < nr_data_stripes(map); i++) {
*offset = last_offset + i * map->stripe_len;
stripe_nr = *offset;
do_div(stripe_nr, map->stripe_len);
do_div(stripe_nr, nr_data_stripes(map));
/* Work out the disk rotation on this stripe-set */
rot = do_div(stripe_nr, map->num_stripes);
/* calculate which stripe this data locates */
rot += i;
stripe_index = rot % map->num_stripes;
if (stripe_index == num)
return 0;
if (stripe_index < num)
j++;
}
*offset = last_offset + j * map->stripe_len;
return 1;
}
static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
struct map_lookup *map,
struct btrfs_device *scrub_dev,
int num, u64 base, u64 length,
int is_dev_replace)
{
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_root *csum_root = fs_info->csum_root;
struct btrfs_extent_item *extent;
struct blk_plug plug;
u64 flags;
int ret;
int slot;
u64 nstripes;
struct extent_buffer *l;
struct btrfs_key key;
u64 physical;
u64 logical;
u64 logic_end;
u64 physical_end;
u64 generation;
int mirror_num;
struct reada_control *reada1;
struct reada_control *reada2;
struct btrfs_key key_start;
struct btrfs_key key_end;
u64 increment = map->stripe_len;
u64 offset;
u64 extent_logical;
u64 extent_physical;
u64 extent_len;
struct btrfs_device *extent_dev;
int extent_mirror_num;
int stop_loop = 0;
nstripes = length;
physical = map->stripes[num].physical;
offset = 0;
do_div(nstripes, map->stripe_len);
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
offset = map->stripe_len * num;
increment = map->stripe_len * map->num_stripes;
mirror_num = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
int factor = map->num_stripes / map->sub_stripes;
offset = map->stripe_len * (num / map->sub_stripes);
increment = map->stripe_len * factor;
mirror_num = num % map->sub_stripes + 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
increment = map->stripe_len;
mirror_num = num % map->num_stripes + 1;
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
increment = map->stripe_len;
mirror_num = num % map->num_stripes + 1;
} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6)) {
get_raid56_logic_offset(physical, num, map, &offset);
increment = map->stripe_len * nr_data_stripes(map);
mirror_num = 1;
} else {
increment = map->stripe_len;
mirror_num = 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* work on commit root. The related disk blocks are static as
* long as COW is applied. This means, it is save to rewrite
* them to repair disk errors without any race conditions
*/
path->search_commit_root = 1;
path->skip_locking = 1;
/*
* trigger the readahead for extent tree csum tree and wait for
* completion. During readahead, the scrub is officially paused
* to not hold off transaction commits
*/
logical = base + offset;
physical_end = physical + nstripes * map->stripe_len;
if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6)) {
get_raid56_logic_offset(physical_end, num,
map, &logic_end);
logic_end += base;
} else {
logic_end = logical + increment * nstripes;
}
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
scrub_blocked_if_needed(fs_info);
/* FIXME it might be better to start readahead at commit root */
key_start.objectid = logical;
key_start.type = BTRFS_EXTENT_ITEM_KEY;
key_start.offset = (u64)0;
key_end.objectid = logic_end;
key_end.type = BTRFS_METADATA_ITEM_KEY;
key_end.offset = (u64)-1;
reada1 = btrfs_reada_add(root, &key_start, &key_end);
key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key_start.type = BTRFS_EXTENT_CSUM_KEY;
key_start.offset = logical;
key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key_end.type = BTRFS_EXTENT_CSUM_KEY;
key_end.offset = logic_end;
reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
if (!IS_ERR(reada1))
btrfs_reada_wait(reada1);
if (!IS_ERR(reada2))
btrfs_reada_wait(reada2);
/*
* collect all data csums for the stripe to avoid seeking during
* the scrub. This might currently (crc32) end up to be about 1MB
*/
blk_start_plug(&plug);
/*
* now find all extents for each stripe and scrub them
*/
ret = 0;
while (physical < physical_end) {
/* for raid56, we skip parity stripe */
if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6)) {
ret = get_raid56_logic_offset(physical, num,
map, &logical);
logical += base;
if (ret)
goto skip;
}
/*
* canceled?
*/
if (atomic_read(&fs_info->scrub_cancel_req) ||
atomic_read(&sctx->cancel_req)) {
ret = -ECANCELED;
goto out;
}
/*
* check to see if we have to pause
*/
if (atomic_read(&fs_info->scrub_pause_req)) {
/* push queued extents */
atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
scrub_submit(sctx);
mutex_lock(&sctx->wr_ctx.wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_ctx.wr_lock);
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
scrub_blocked_if_needed(fs_info);
}
if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
key.objectid = logical;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_extent_item(root, path, 0);
if (ret < 0)
goto out;
if (ret > 0) {
/* there's no smaller item, so stick with the
* larger one */
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &key,
path, 0, 0);
if (ret < 0)
goto out;
}
}
stop_loop = 0;
while (1) {
u64 bytes;
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
stop_loop = 1;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.type == BTRFS_METADATA_ITEM_KEY)
bytes = root->leafsize;
else
bytes = key.offset;
if (key.objectid + bytes <= logical)
goto next;
if (key.type != BTRFS_EXTENT_ITEM_KEY &&
key.type != BTRFS_METADATA_ITEM_KEY)
goto next;
if (key.objectid >= logical + map->stripe_len) {
/* out of this device extent */
if (key.objectid >= logic_end)
stop_loop = 1;
break;
}
extent = btrfs_item_ptr(l, slot,
struct btrfs_extent_item);
flags = btrfs_extent_flags(l, extent);
generation = btrfs_extent_generation(l, extent);
if (key.objectid < logical &&
(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
btrfs_err(fs_info,
"scrub: tree block %llu spanning "
"stripes, ignored. logical=%llu",
key.objectid, logical);
goto next;
}
again:
extent_logical = key.objectid;
extent_len = bytes;
/*
* trim extent to this stripe
*/
if (extent_logical < logical) {
extent_len -= logical - extent_logical;
extent_logical = logical;
}
if (extent_logical + extent_len >
logical + map->stripe_len) {
extent_len = logical + map->stripe_len -
extent_logical;
}
extent_physical = extent_logical - logical + physical;
extent_dev = scrub_dev;
extent_mirror_num = mirror_num;
if (is_dev_replace)
scrub_remap_extent(fs_info, extent_logical,
extent_len, &extent_physical,
&extent_dev,
&extent_mirror_num);
ret = btrfs_lookup_csums_range(csum_root, logical,
logical + map->stripe_len - 1,
&sctx->csum_list, 1);
if (ret)
goto out;
ret = scrub_extent(sctx, extent_logical, extent_len,
extent_physical, extent_dev, flags,
generation, extent_mirror_num,
extent_logical - logical + physical);
if (ret)
goto out;
scrub_free_csums(sctx);
if (extent_logical + extent_len <
key.objectid + bytes) {
if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6)) {
/*
* loop until we find next data stripe
* or we have finished all stripes.
*/
do {
physical += map->stripe_len;
ret = get_raid56_logic_offset(
physical, num,
map, &logical);
logical += base;
} while (physical < physical_end && ret);
} else {
physical += map->stripe_len;
logical += increment;
}
if (logical < key.objectid + bytes) {
cond_resched();
goto again;
}
if (physical >= physical_end) {
stop_loop = 1;
break;
}
}
next:
path->slots[0]++;
}
btrfs_release_path(path);
skip:
logical += increment;
physical += map->stripe_len;
spin_lock(&sctx->stat_lock);
if (stop_loop)
sctx->stat.last_physical = map->stripes[num].physical +
length;
else
sctx->stat.last_physical = physical;
spin_unlock(&sctx->stat_lock);
if (stop_loop)
break;
}
out:
/* push queued extents */
scrub_submit(sctx);
mutex_lock(&sctx->wr_ctx.wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_ctx.wr_lock);
blk_finish_plug(&plug);
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}
static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev,
u64 chunk_tree, u64 chunk_objectid,
u64 chunk_offset, u64 length,
u64 dev_offset, int is_dev_replace)
{
struct btrfs_mapping_tree *map_tree =
&sctx->dev_root->fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
int i;
int ret = 0;
read_lock(&map_tree->map_tree.lock);
em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
read_unlock(&map_tree->map_tree.lock);
if (!em)
return -EINVAL;
map = (struct map_lookup *)em->bdev;
if (em->start != chunk_offset)
goto out;
if (em->len < length)
goto out;
for (i = 0; i < map->num_stripes; ++i) {
if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
map->stripes[i].physical == dev_offset) {
ret = scrub_stripe(sctx, map, scrub_dev, i,
chunk_offset, length,
is_dev_replace);
if (ret)
goto out;
}
}
out:
free_extent_map(em);
return ret;
}
static noinline_for_stack
int scrub_enumerate_chunks(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev, u64 start, u64 end,
int is_dev_replace)
{
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
struct btrfs_root *root = sctx->dev_root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 length;
u64 chunk_tree;
u64 chunk_objectid;
u64 chunk_offset;
int ret;
int slot;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_block_group_cache *cache;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 2;
path->search_commit_root = 1;
path->skip_locking = 1;
key.objectid = scrub_dev->devid;
key.offset = 0ull;
key.type = BTRFS_DEV_EXTENT_KEY;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] >=
btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
}
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.objectid != scrub_dev->devid)
break;
if (btrfs_key_type(&found_key) != BTRFS_DEV_EXTENT_KEY)
break;
if (found_key.offset >= end)
break;
if (found_key.offset < key.offset)
break;
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
length = btrfs_dev_extent_length(l, dev_extent);
if (found_key.offset + length <= start)
goto skip;
chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
/*
* get a reference on the corresponding block group to prevent
* the chunk from going away while we scrub it
*/
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
/* some chunks are removed but not committed to disk yet,
* continue scrubbing */
if (!cache)
goto skip;
dev_replace->cursor_right = found_key.offset + length;
dev_replace->cursor_left = found_key.offset;
dev_replace->item_needs_writeback = 1;
ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
chunk_offset, length, found_key.offset,
is_dev_replace);
/*
* flush, submit all pending read and write bios, afterwards
* wait for them.
* Note that in the dev replace case, a read request causes
* write requests that are submitted in the read completion
* worker. Therefore in the current situation, it is required
* that all write requests are flushed, so that all read and
* write requests are really completed when bios_in_flight
* changes to 0.
*/
atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
scrub_submit(sctx);
mutex_lock(&sctx->wr_ctx.wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_ctx.wr_lock);
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
atomic_inc(&fs_info->scrubs_paused);
wake_up(&fs_info->scrub_pause_wait);
/*
* must be called before we decrease @scrub_paused.
* make sure we don't block transaction commit while
* we are waiting pending workers finished.
*/
wait_event(sctx->list_wait,
atomic_read(&sctx->workers_pending) == 0);
atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
mutex_lock(&fs_info->scrub_lock);
__scrub_blocked_if_needed(fs_info);
atomic_dec(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
wake_up(&fs_info->scrub_pause_wait);
btrfs_put_block_group(cache);
if (ret)
break;
if (is_dev_replace &&
atomic64_read(&dev_replace->num_write_errors) > 0) {
ret = -EIO;
break;
}
if (sctx->stat.malloc_errors > 0) {
ret = -ENOMEM;
break;
}
dev_replace->cursor_left = dev_replace->cursor_right;
dev_replace->item_needs_writeback = 1;
skip:
key.offset = found_key.offset + length;
btrfs_release_path(path);
}
btrfs_free_path(path);
/*
* ret can still be 1 from search_slot or next_leaf,
* that's not an error
*/
return ret < 0 ? ret : 0;
}
static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev)
{
int i;
u64 bytenr;
u64 gen;
int ret;
struct btrfs_root *root = sctx->dev_root;
if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
return -EIO;
gen = root->fs_info->last_trans_committed;
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE > scrub_dev->total_bytes)
break;
ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
NULL, 1, bytenr);
if (ret)
return ret;
}
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
return 0;
}
/*
* get a reference count on fs_info->scrub_workers. start worker if necessary
*/
static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
int is_dev_replace)
{
int ret = 0;
int flags = WQ_FREEZABLE | WQ_UNBOUND;
int max_active = fs_info->thread_pool_size;
if (fs_info->scrub_workers_refcnt == 0) {
if (is_dev_replace)
fs_info->scrub_workers =
btrfs_alloc_workqueue("btrfs-scrub", flags,
1, 4);
else
fs_info->scrub_workers =
btrfs_alloc_workqueue("btrfs-scrub", flags,
max_active, 4);
if (!fs_info->scrub_workers) {
ret = -ENOMEM;
goto out;
}
fs_info->scrub_wr_completion_workers =
btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
max_active, 2);
if (!fs_info->scrub_wr_completion_workers) {
ret = -ENOMEM;
goto out;
}
fs_info->scrub_nocow_workers =
btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
if (!fs_info->scrub_nocow_workers) {
ret = -ENOMEM;
goto out;
}
}
++fs_info->scrub_workers_refcnt;
out:
return ret;
}
static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
{
if (--fs_info->scrub_workers_refcnt == 0) {
btrfs_destroy_workqueue(fs_info->scrub_workers);
btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
}
WARN_ON(fs_info->scrub_workers_refcnt < 0);
}
int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
u64 end, struct btrfs_scrub_progress *progress,
int readonly, int is_dev_replace)
{
struct scrub_ctx *sctx;
int ret;
struct btrfs_device *dev;
if (btrfs_fs_closing(fs_info))
return -EINVAL;
/*
* check some assumptions
*/
if (fs_info->chunk_root->nodesize != fs_info->chunk_root->leafsize) {
btrfs_err(fs_info,
"scrub: size assumption nodesize == leafsize (%d == %d) fails",
fs_info->chunk_root->nodesize,
fs_info->chunk_root->leafsize);
return -EINVAL;
}
if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
/*
* in this case scrub is unable to calculate the checksum
* the way scrub is implemented. Do not handle this
* situation at all because it won't ever happen.
*/
btrfs_err(fs_info,
"scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
return -EINVAL;
}
if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
/* not supported for data w/o checksums */
btrfs_err(fs_info,
"scrub: size assumption sectorsize != PAGE_SIZE "
"(%d != %lu) fails",
fs_info->chunk_root->sectorsize, PAGE_SIZE);
return -EINVAL;
}
if (fs_info->chunk_root->nodesize >
PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
fs_info->chunk_root->sectorsize >
PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
/*
* would exhaust the array bounds of pagev member in
* struct scrub_block
*/
btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
"<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
fs_info->chunk_root->nodesize,
SCRUB_MAX_PAGES_PER_BLOCK,
fs_info->chunk_root->sectorsize,
SCRUB_MAX_PAGES_PER_BLOCK);
return -EINVAL;
}
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info, devid, NULL, NULL);
if (!dev || (dev->missing && !is_dev_replace)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return -ENODEV;
}
mutex_lock(&fs_info->scrub_lock);
if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return -EIO;
}
btrfs_dev_replace_lock(&fs_info->dev_replace);
if (dev->scrub_device ||
(!is_dev_replace &&
btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
btrfs_dev_replace_unlock(&fs_info->dev_replace);
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return -EINPROGRESS;
}
btrfs_dev_replace_unlock(&fs_info->dev_replace);
ret = scrub_workers_get(fs_info, is_dev_replace);
if (ret) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return ret;
}
sctx = scrub_setup_ctx(dev, is_dev_replace);
if (IS_ERR(sctx)) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
scrub_workers_put(fs_info);
return PTR_ERR(sctx);
}
sctx->readonly = readonly;
dev->scrub_device = sctx;
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
/*
* checking @scrub_pause_req here, we can avoid
* race between committing transaction and scrubbing.
*/
__scrub_blocked_if_needed(fs_info);
atomic_inc(&fs_info->scrubs_running);
mutex_unlock(&fs_info->scrub_lock);
if (!is_dev_replace) {
/*
* by holding device list mutex, we can
* kick off writing super in log tree sync.
*/
mutex_lock(&fs_info->fs_devices->device_list_mutex);
ret = scrub_supers(sctx, dev);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
}
if (!ret)
ret = scrub_enumerate_chunks(sctx, dev, start, end,
is_dev_replace);
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
atomic_dec(&fs_info->scrubs_running);
wake_up(&fs_info->scrub_pause_wait);
wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
if (progress)
memcpy(progress, &sctx->stat, sizeof(*progress));
mutex_lock(&fs_info->scrub_lock);
dev->scrub_device = NULL;
scrub_workers_put(fs_info);
mutex_unlock(&fs_info->scrub_lock);
scrub_free_ctx(sctx);
return ret;
}
void btrfs_scrub_pause(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
mutex_lock(&fs_info->scrub_lock);
atomic_inc(&fs_info->scrub_pause_req);
while (atomic_read(&fs_info->scrubs_paused) !=
atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrubs_paused) ==
atomic_read(&fs_info->scrubs_running));
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
}
void btrfs_scrub_continue(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
atomic_dec(&fs_info->scrub_pause_req);
wake_up(&fs_info->scrub_pause_wait);
}
int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
if (!atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&fs_info->scrub_cancel_req);
while (atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrubs_running) == 0);
mutex_lock(&fs_info->scrub_lock);
}
atomic_dec(&fs_info->scrub_cancel_req);
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
struct btrfs_device *dev)
{
struct scrub_ctx *sctx;
mutex_lock(&fs_info->scrub_lock);
sctx = dev->scrub_device;
if (!sctx) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&sctx->cancel_req);
while (dev->scrub_device) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
dev->scrub_device == NULL);
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
struct btrfs_scrub_progress *progress)
{
struct btrfs_device *dev;
struct scrub_ctx *sctx = NULL;
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
if (dev)
sctx = dev->scrub_device;
if (sctx)
memcpy(progress, &sctx->stat, sizeof(*progress));
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
}
static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
u64 extent_logical, u64 extent_len,
u64 *extent_physical,
struct btrfs_device **extent_dev,
int *extent_mirror_num)
{
u64 mapped_length;
struct btrfs_bio *bbio = NULL;
int ret;
mapped_length = extent_len;
ret = btrfs_map_block(fs_info, READ, extent_logical,
&mapped_length, &bbio, 0);
if (ret || !bbio || mapped_length < extent_len ||
!bbio->stripes[0].dev->bdev) {
kfree(bbio);
return;
}
*extent_physical = bbio->stripes[0].physical;
*extent_mirror_num = bbio->mirror_num;
*extent_dev = bbio->stripes[0].dev;
kfree(bbio);
}
static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
struct scrub_wr_ctx *wr_ctx,
struct btrfs_fs_info *fs_info,
struct btrfs_device *dev,
int is_dev_replace)
{
WARN_ON(wr_ctx->wr_curr_bio != NULL);
mutex_init(&wr_ctx->wr_lock);
wr_ctx->wr_curr_bio = NULL;
if (!is_dev_replace)
return 0;
WARN_ON(!dev->bdev);
wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
bio_get_nr_vecs(dev->bdev));
wr_ctx->tgtdev = dev;
atomic_set(&wr_ctx->flush_all_writes, 0);
return 0;
}
static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
{
mutex_lock(&wr_ctx->wr_lock);
kfree(wr_ctx->wr_curr_bio);
wr_ctx->wr_curr_bio = NULL;
mutex_unlock(&wr_ctx->wr_lock);
}
static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
int mirror_num, u64 physical_for_dev_replace)
{
struct scrub_copy_nocow_ctx *nocow_ctx;
struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
if (!nocow_ctx) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
scrub_pending_trans_workers_inc(sctx);
nocow_ctx->sctx = sctx;
nocow_ctx->logical = logical;
nocow_ctx->len = len;
nocow_ctx->mirror_num = mirror_num;
nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
btrfs_init_work(&nocow_ctx->work, copy_nocow_pages_worker, NULL, NULL);
INIT_LIST_HEAD(&nocow_ctx->inodes);
btrfs_queue_work(fs_info->scrub_nocow_workers,
&nocow_ctx->work);
return 0;
}
static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
{
struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
struct scrub_nocow_inode *nocow_inode;
nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
if (!nocow_inode)
return -ENOMEM;
nocow_inode->inum = inum;
nocow_inode->offset = offset;
nocow_inode->root = root;
list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
return 0;
}
#define COPY_COMPLETE 1
static void copy_nocow_pages_worker(struct btrfs_work *work)
{
struct scrub_copy_nocow_ctx *nocow_ctx =
container_of(work, struct scrub_copy_nocow_ctx, work);
struct scrub_ctx *sctx = nocow_ctx->sctx;
u64 logical = nocow_ctx->logical;
u64 len = nocow_ctx->len;
int mirror_num = nocow_ctx->mirror_num;
u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
int ret;
struct btrfs_trans_handle *trans = NULL;
struct btrfs_fs_info *fs_info;
struct btrfs_path *path;
struct btrfs_root *root;
int not_written = 0;
fs_info = sctx->dev_root->fs_info;
root = fs_info->extent_root;
path = btrfs_alloc_path();
if (!path) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
not_written = 1;
goto out;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
not_written = 1;
goto out;
}
ret = iterate_inodes_from_logical(logical, fs_info, path,
record_inode_for_nocow, nocow_ctx);
if (ret != 0 && ret != -ENOENT) {
btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
"phys %llu, len %llu, mir %u, ret %d",
logical, physical_for_dev_replace, len, mirror_num,
ret);
not_written = 1;
goto out;
}
btrfs_end_transaction(trans, root);
trans = NULL;
while (!list_empty(&nocow_ctx->inodes)) {
struct scrub_nocow_inode *entry;
entry = list_first_entry(&nocow_ctx->inodes,
struct scrub_nocow_inode,
list);
list_del_init(&entry->list);
ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
entry->root, nocow_ctx);
kfree(entry);
if (ret == COPY_COMPLETE) {
ret = 0;
break;
} else if (ret) {
break;
}
}
out:
while (!list_empty(&nocow_ctx->inodes)) {
struct scrub_nocow_inode *entry;
entry = list_first_entry(&nocow_ctx->inodes,
struct scrub_nocow_inode,
list);
list_del_init(&entry->list);
kfree(entry);
}
if (trans && !IS_ERR(trans))
btrfs_end_transaction(trans, root);
if (not_written)
btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
num_uncorrectable_read_errors);
btrfs_free_path(path);
kfree(nocow_ctx);
scrub_pending_trans_workers_dec(sctx);
}
static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
struct scrub_copy_nocow_ctx *nocow_ctx)
{
struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
struct btrfs_key key;
struct inode *inode;
struct page *page;
struct btrfs_root *local_root;
struct btrfs_ordered_extent *ordered;
struct extent_map *em;
struct extent_state *cached_state = NULL;
struct extent_io_tree *io_tree;
u64 physical_for_dev_replace;
u64 len = nocow_ctx->len;
u64 lockstart = offset, lockend = offset + len - 1;
unsigned long index;
int srcu_index;
int ret = 0;
int err = 0;
key.objectid = root;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
local_root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(local_root)) {
srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
return PTR_ERR(local_root);
}
key.type = BTRFS_INODE_ITEM_KEY;
key.objectid = inum;
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
if (IS_ERR(inode))
return PTR_ERR(inode);
/* Avoid truncate/dio/punch hole.. */
mutex_lock(&inode->i_mutex);
inode_dio_wait(inode);
physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
io_tree = &BTRFS_I(inode)->io_tree;
lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
if (ordered) {
btrfs_put_ordered_extent(ordered);
goto out_unlock;
}
em = btrfs_get_extent(inode, NULL, 0, lockstart, len, 0);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_unlock;
}
/*
* This extent does not actually cover the logical extent anymore,
* move on to the next inode.
*/
if (em->block_start > nocow_ctx->logical ||
em->block_start + em->block_len < nocow_ctx->logical + len) {
free_extent_map(em);
goto out_unlock;
}
free_extent_map(em);
while (len >= PAGE_CACHE_SIZE) {
index = offset >> PAGE_CACHE_SHIFT;
again:
page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
if (!page) {
btrfs_err(fs_info, "find_or_create_page() failed");
ret = -ENOMEM;
goto out;
}
if (PageUptodate(page)) {
if (PageDirty(page))
goto next_page;
} else {
ClearPageError(page);
err = extent_read_full_page_nolock(io_tree, page,
btrfs_get_extent,
nocow_ctx->mirror_num);
if (err) {
ret = err;
goto next_page;
}
lock_page(page);
/*
* If the page has been remove from the page cache,
* the data on it is meaningless, because it may be
* old one, the new data may be written into the new
* page in the page cache.
*/
if (page->mapping != inode->i_mapping) {
unlock_page(page);
page_cache_release(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto next_page;
}
}
err = write_page_nocow(nocow_ctx->sctx,
physical_for_dev_replace, page);
if (err)
ret = err;
next_page:
unlock_page(page);
page_cache_release(page);
if (ret)
break;
offset += PAGE_CACHE_SIZE;
physical_for_dev_replace += PAGE_CACHE_SIZE;
len -= PAGE_CACHE_SIZE;
}
ret = COPY_COMPLETE;
out_unlock:
unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
GFP_NOFS);
out:
mutex_unlock(&inode->i_mutex);
iput(inode);
return ret;
}
static int write_page_nocow(struct scrub_ctx *sctx,
u64 physical_for_dev_replace, struct page *page)
{
struct bio *bio;
struct btrfs_device *dev;
int ret;
dev = sctx->wr_ctx.tgtdev;
if (!dev)
return -EIO;
if (!dev->bdev) {
printk_ratelimited(KERN_WARNING
"BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
return -EIO;
}
bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
if (!bio) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
bio->bi_iter.bi_size = 0;
bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
bio->bi_bdev = dev->bdev;
ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
if (ret != PAGE_CACHE_SIZE) {
leave_with_eio:
bio_put(bio);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
return -EIO;
}
if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
goto leave_with_eio;
bio_put(bio);
return 0;
}