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linux/fs/btrfs/scrub.c
Christoph Hellwig 6065fd95da btrfs: do not return errors from raid56_parity_recover 
Always consume the bio and call the end_io handler on error instead of
returning an error and letting the caller handle it.  This matches what
the block layer submission does and avoids any confusion on who
needs to handle errors.

Also use the proper bool type for the generic_io argument.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25 17:45:39 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011, 2012 STRATO. All rights reserved.
*/
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include "ctree.h"
#include "discard.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"
#include "block-group.h"
#include "zoned.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 one configures an upper limit for the number
* of (dynamically allocated) pages that are added to a bio.
*/
#define SCRUB_SECTORS_PER_BIO 32 /* 128KiB per bio for 4KiB pages */
#define SCRUB_BIOS_PER_SCTX 64 /* 8MiB per device in flight for 4KiB pages */
/*
* The following value times PAGE_SIZE needs to be large enough to match the
* largest node/leaf/sector size that shall be supported.
*/
#define SCRUB_MAX_SECTORS_PER_BLOCK (BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K)
struct scrub_recover {
refcount_t refs;
struct btrfs_io_context *bioc;
u64 map_length;
};
struct scrub_sector {
struct scrub_block *sblock;
struct page *page;
struct btrfs_device *dev;
struct list_head list;
u64 flags; /* extent flags */
u64 generation;
u64 logical;
u64 physical;
u64 physical_for_dev_replace;
atomic_t refs;
u8 mirror_num;
unsigned int have_csum:1;
unsigned int io_error:1;
u8 csum[BTRFS_CSUM_SIZE];
struct scrub_recover *recover;
};
struct scrub_bio {
int index;
struct scrub_ctx *sctx;
struct btrfs_device *dev;
struct bio *bio;
blk_status_t status;
u64 logical;
u64 physical;
struct scrub_sector *sectors[SCRUB_SECTORS_PER_BIO];
int sector_count;
int next_free;
struct work_struct work;
};
struct scrub_block {
struct scrub_sector *sectors[SCRUB_MAX_SECTORS_PER_BLOCK];
int sector_count;
atomic_t outstanding_sectors;
refcount_t refs; /* free mem on transition to zero */
struct scrub_ctx *sctx;
struct scrub_parity *sparity;
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 */
/* The following is for the data used to check parity */
/* It is for the data with checksum */
unsigned int data_corrected:1;
};
struct work_struct work;
};
/* Used for the chunks with parity stripe such RAID5/6 */
struct scrub_parity {
struct scrub_ctx *sctx;
struct btrfs_device *scrub_dev;
u64 logic_start;
u64 logic_end;
int nsectors;
u32 stripe_len;
refcount_t refs;
struct list_head sectors_list;
/* Work of parity check and repair */
struct work_struct work;
/* Mark the parity blocks which have data */
unsigned long dbitmap;
/*
* Mark the parity blocks which have data, but errors happen when
* read data or check data
*/
unsigned long ebitmap;
};
struct scrub_ctx {
struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
struct btrfs_fs_info *fs_info;
int first_free;
int curr;
atomic_t bios_in_flight;
atomic_t workers_pending;
spinlock_t list_lock;
wait_queue_head_t list_wait;
struct list_head csum_list;
atomic_t cancel_req;
int readonly;
int sectors_per_bio;
/* State of IO submission throttling affecting the associated device */
ktime_t throttle_deadline;
u64 throttle_sent;
int is_dev_replace;
u64 write_pointer;
struct scrub_bio *wr_curr_bio;
struct mutex wr_lock;
struct btrfs_device *wr_tgtdev;
bool flush_all_writes;
/*
* statistics
*/
struct btrfs_scrub_progress stat;
spinlock_t stat_lock;
/*
* Use a ref counter to avoid use-after-free issues. Scrub workers
* decrement bios_in_flight and workers_pending and then do a wakeup
* on the list_wait wait queue. We must ensure the main scrub task
* doesn't free the scrub context before or while the workers are
* doing the wakeup() call.
*/
refcount_t refs;
};
struct scrub_warning {
struct btrfs_path *path;
u64 extent_item_size;
const char *errstr;
u64 physical;
u64 logical;
struct btrfs_device *dev;
};
struct full_stripe_lock {
struct rb_node node;
u64 logical;
u64 refs;
struct mutex mutex;
};
static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
struct scrub_block *sblocks_for_recheck);
static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock,
int retry_failed_mirror);
static void scrub_recheck_block_checksum(struct scrub_block *sblock);
static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good);
static int scrub_repair_sector_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int sector_num, int force_write);
static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
static int scrub_write_sector_to_dev_replace(struct scrub_block *sblock,
int sector_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_put(struct scrub_block *sblock);
static void scrub_sector_get(struct scrub_sector *sector);
static void scrub_sector_put(struct scrub_sector *sector);
static void scrub_parity_get(struct scrub_parity *sparity);
static void scrub_parity_put(struct scrub_parity *sparity);
static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u8 *csum,
u64 physical_for_dev_replace);
static void scrub_bio_end_io(struct bio *bio);
static void scrub_bio_end_io_worker(struct work_struct *work);
static void scrub_block_complete(struct scrub_block *sblock);
static void scrub_find_good_copy(struct btrfs_fs_info *fs_info,
u64 extent_logical, u32 extent_len,
u64 *extent_physical,
struct btrfs_device **extent_dev,
int *extent_mirror_num);
static int scrub_add_sector_to_wr_bio(struct scrub_ctx *sctx,
struct scrub_sector *sector);
static void scrub_wr_submit(struct scrub_ctx *sctx);
static void scrub_wr_bio_end_io(struct bio *bio);
static void scrub_wr_bio_end_io_worker(struct work_struct *work);
static void scrub_put_ctx(struct scrub_ctx *sctx);
static inline int scrub_is_page_on_raid56(struct scrub_sector *sector)
{
return sector->recover &&
(sector->recover->bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
}
static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
{
refcount_inc(&sctx->refs);
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);
scrub_put_ctx(sctx);
}
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_pause_on(struct btrfs_fs_info *fs_info)
{
atomic_inc(&fs_info->scrubs_paused);
wake_up(&fs_info->scrub_pause_wait);
}
static void scrub_pause_off(struct btrfs_fs_info *fs_info)
{
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);
}
static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
scrub_pause_on(fs_info);
scrub_pause_off(fs_info);
}
/*
* Insert new full stripe lock into full stripe locks tree
*
* Return pointer to existing or newly inserted full_stripe_lock structure if
* everything works well.
* Return ERR_PTR(-ENOMEM) if we failed to allocate memory
*
* NOTE: caller must hold full_stripe_locks_root->lock before calling this
* function
*/
static struct full_stripe_lock *insert_full_stripe_lock(
struct btrfs_full_stripe_locks_tree *locks_root,
u64 fstripe_logical)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct full_stripe_lock *entry;
struct full_stripe_lock *ret;
lockdep_assert_held(&locks_root->lock);
p = &locks_root->root.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct full_stripe_lock, node);
if (fstripe_logical < entry->logical) {
p = &(*p)->rb_left;
} else if (fstripe_logical > entry->logical) {
p = &(*p)->rb_right;
} else {
entry->refs++;
return entry;
}
}
/*
* Insert new lock.
*/
ret = kmalloc(sizeof(*ret), GFP_KERNEL);
if (!ret)
return ERR_PTR(-ENOMEM);
ret->logical = fstripe_logical;
ret->refs = 1;
mutex_init(&ret->mutex);
rb_link_node(&ret->node, parent, p);
rb_insert_color(&ret->node, &locks_root->root);
return ret;
}
/*
* Search for a full stripe lock of a block group
*
* Return pointer to existing full stripe lock if found
* Return NULL if not found
*/
static struct full_stripe_lock *search_full_stripe_lock(
struct btrfs_full_stripe_locks_tree *locks_root,
u64 fstripe_logical)
{
struct rb_node *node;
struct full_stripe_lock *entry;
lockdep_assert_held(&locks_root->lock);
node = locks_root->root.rb_node;
while (node) {
entry = rb_entry(node, struct full_stripe_lock, node);
if (fstripe_logical < entry->logical)
node = node->rb_left;
else if (fstripe_logical > entry->logical)
node = node->rb_right;
else
return entry;
}
return NULL;
}
/*
* Helper to get full stripe logical from a normal bytenr.
*
* Caller must ensure @cache is a RAID56 block group.
*/
static u64 get_full_stripe_logical(struct btrfs_block_group *cache, u64 bytenr)
{
u64 ret;
/*
* Due to chunk item size limit, full stripe length should not be
* larger than U32_MAX. Just a sanity check here.
*/
WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
/*
* round_down() can only handle power of 2, while RAID56 full
* stripe length can be 64KiB * n, so we need to manually round down.
*/
ret = div64_u64(bytenr - cache->start, cache->full_stripe_len) *
cache->full_stripe_len + cache->start;
return ret;
}
/*
* Lock a full stripe to avoid concurrency of recovery and read
*
* It's only used for profiles with parities (RAID5/6), for other profiles it
* does nothing.
*
* Return 0 if we locked full stripe covering @bytenr, with a mutex held.
* So caller must call unlock_full_stripe() at the same context.
*
* Return <0 if encounters error.
*/
static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
bool *locked_ret)
{
struct btrfs_block_group *bg_cache;
struct btrfs_full_stripe_locks_tree *locks_root;
struct full_stripe_lock *existing;
u64 fstripe_start;
int ret = 0;
*locked_ret = false;
bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
if (!bg_cache) {
ASSERT(0);
return -ENOENT;
}
/* Profiles not based on parity don't need full stripe lock */
if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
goto out;
locks_root = &bg_cache->full_stripe_locks_root;
fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
/* Now insert the full stripe lock */
mutex_lock(&locks_root->lock);
existing = insert_full_stripe_lock(locks_root, fstripe_start);
mutex_unlock(&locks_root->lock);
if (IS_ERR(existing)) {
ret = PTR_ERR(existing);
goto out;
}
mutex_lock(&existing->mutex);
*locked_ret = true;
out:
btrfs_put_block_group(bg_cache);
return ret;
}
/*
* Unlock a full stripe.
*
* NOTE: Caller must ensure it's the same context calling corresponding
* lock_full_stripe().
*
* Return 0 if we unlock full stripe without problem.
* Return <0 for error
*/
static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
bool locked)
{
struct btrfs_block_group *bg_cache;
struct btrfs_full_stripe_locks_tree *locks_root;
struct full_stripe_lock *fstripe_lock;
u64 fstripe_start;
bool freeit = false;
int ret = 0;
/* If we didn't acquire full stripe lock, no need to continue */
if (!locked)
return 0;
bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
if (!bg_cache) {
ASSERT(0);
return -ENOENT;
}
if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
goto out;
locks_root = &bg_cache->full_stripe_locks_root;
fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
mutex_lock(&locks_root->lock);
fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
/* Unpaired unlock_full_stripe() detected */
if (!fstripe_lock) {
WARN_ON(1);
ret = -ENOENT;
mutex_unlock(&locks_root->lock);
goto out;
}
if (fstripe_lock->refs == 0) {
WARN_ON(1);
btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
fstripe_lock->logical);
} else {
fstripe_lock->refs--;
}
if (fstripe_lock->refs == 0) {
rb_erase(&fstripe_lock->node, &locks_root->root);
freeit = true;
}
mutex_unlock(&locks_root->lock);
mutex_unlock(&fstripe_lock->mutex);
if (freeit)
kfree(fstripe_lock);
out:
btrfs_put_block_group(bg_cache);
return ret;
}
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;
/* this can happen when scrub is cancelled */
if (sctx->curr != -1) {
struct scrub_bio *sbio = sctx->bios[sctx->curr];
for (i = 0; i < sbio->sector_count; i++) {
WARN_ON(!sbio->sectors[i]->page);
scrub_block_put(sbio->sectors[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);
}
kfree(sctx->wr_curr_bio);
scrub_free_csums(sctx);
kfree(sctx);
}
static void scrub_put_ctx(struct scrub_ctx *sctx)
{
if (refcount_dec_and_test(&sctx->refs))
scrub_free_ctx(sctx);
}
static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
struct btrfs_fs_info *fs_info, int is_dev_replace)
{
struct scrub_ctx *sctx;
int i;
sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
if (!sctx)
goto nomem;
refcount_set(&sctx->refs, 1);
sctx->is_dev_replace = is_dev_replace;
sctx->sectors_per_bio = SCRUB_SECTORS_PER_BIO;
sctx->curr = -1;
sctx->fs_info = fs_info;
INIT_LIST_HEAD(&sctx->csum_list);
for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
struct scrub_bio *sbio;
sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
if (!sbio)
goto nomem;
sctx->bios[i] = sbio;
sbio->index = i;
sbio->sctx = sctx;
sbio->sector_count = 0;
INIT_WORK(&sbio->work, scrub_bio_end_io_worker);
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;
atomic_set(&sctx->bios_in_flight, 0);
atomic_set(&sctx->workers_pending, 0);
atomic_set(&sctx->cancel_req, 0);
spin_lock_init(&sctx->list_lock);
spin_lock_init(&sctx->stat_lock);
init_waitqueue_head(&sctx->list_wait);
sctx->throttle_deadline = 0;
WARN_ON(sctx->wr_curr_bio != NULL);
mutex_init(&sctx->wr_lock);
sctx->wr_curr_bio = NULL;
if (is_dev_replace) {
WARN_ON(!fs_info->dev_replace.tgtdev);
sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
sctx->flush_all_writes = false;
}
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)
{
u32 nlink;
int ret;
int i;
unsigned nofs_flag;
struct extent_buffer *eb;
struct btrfs_inode_item *inode_item;
struct scrub_warning *swarn = warn_ctx;
struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
struct inode_fs_paths *ipath = NULL;
struct btrfs_root *local_root;
struct btrfs_key key;
local_root = btrfs_get_fs_root(fs_info, root, true);
if (IS_ERR(local_root)) {
ret = PTR_ERR(local_root);
goto err;
}
/*
* this makes the path point to (inum INODE_ITEM ioff)
*/
key.objectid = inum;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
if (ret) {
btrfs_put_root(local_root);
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);
nlink = btrfs_inode_nlink(eb, inode_item);
btrfs_release_path(swarn->path);
/*
* init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
* uses GFP_NOFS in this context, so we keep it consistent but it does
* not seem to be strictly necessary.
*/
nofs_flag = memalloc_nofs_save();
ipath = init_ipath(4096, local_root, swarn->path);
memalloc_nofs_restore(nofs_flag);
if (IS_ERR(ipath)) {
btrfs_put_root(local_root);
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)
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %u, links %u (path: %s)",
swarn->errstr, swarn->logical,
rcu_str_deref(swarn->dev->name),
swarn->physical,
root, inum, offset,
fs_info->sectorsize, nlink,
(char *)(unsigned long)ipath->fspath->val[i]);
btrfs_put_root(local_root);
free_ipath(ipath);
return 0;
err:
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
swarn->errstr, swarn->logical,
rcu_str_deref(swarn->dev->name),
swarn->physical,
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 = 0;
int ret;
WARN_ON(sblock->sector_count < 1);
dev = sblock->sectors[0]->dev;
fs_info = sblock->sctx->fs_info;
path = btrfs_alloc_path();
if (!path)
return;
swarn.physical = sblock->sectors[0]->physical;
swarn.logical = sblock->sectors[0]->logical;
swarn.errstr = errstr;
swarn.dev = NULL;
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(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);
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
errstr, swarn.logical,
rcu_str_deref(dev->name),
swarn.physical,
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, false);
}
out:
btrfs_free_path(path);
}
static inline void scrub_get_recover(struct scrub_recover *recover)
{
refcount_inc(&recover->refs);
}
static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
struct scrub_recover *recover)
{
if (refcount_dec_and_test(&recover->refs)) {
btrfs_bio_counter_dec(fs_info);
btrfs_put_bioc(recover->bioc);
kfree(recover);
}
}
/*
* scrub_handle_errored_block gets called when either verification of the
* sectors failed or the bio failed to read, e.g. with EIO. In the latter
* case, this function handles all sectors 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 logical;
unsigned int failed_mirror_index;
unsigned int is_metadata;
unsigned int have_csum;
struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
struct scrub_block *sblock_bad;
int ret;
int mirror_index;
int sector_num;
int success;
bool full_stripe_locked;
unsigned int nofs_flag;
static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
BUG_ON(sblock_to_check->sector_count < 1);
fs_info = sctx->fs_info;
if (sblock_to_check->sectors[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;
}
logical = sblock_to_check->sectors[0]->logical;
BUG_ON(sblock_to_check->sectors[0]->mirror_num < 1);
failed_mirror_index = sblock_to_check->sectors[0]->mirror_num - 1;
is_metadata = !(sblock_to_check->sectors[0]->flags &
BTRFS_EXTENT_FLAG_DATA);
have_csum = sblock_to_check->sectors[0]->have_csum;
dev = sblock_to_check->sectors[0]->dev;
if (!sctx->is_dev_replace && btrfs_repair_one_zone(fs_info, logical))
return 0;
/*
* We must use GFP_NOFS because the scrub task might be waiting for a
* worker task executing this function and in turn a transaction commit
* might be waiting the scrub task to pause (which needs to wait for all
* the worker tasks to complete before pausing).
* We do allocations in the workers through insert_full_stripe_lock()
* and scrub_add_sector_to_wr_bio(), which happens down the call chain of
* this function.
*/
nofs_flag = memalloc_nofs_save();
/*
* For RAID5/6, race can happen for a different device scrub thread.
* For data corruption, Parity and Data threads will both try
* to recovery the data.
* Race can lead to doubly added csum error, or even unrecoverable
* error.
*/
ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
if (ret < 0) {
memalloc_nofs_restore(nofs_flag);
spin_lock(&sctx->stat_lock);
if (ret == -ENOMEM)
sctx->stat.malloc_errors++;
sctx->stat.read_errors++;
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
return ret;
}
/*
* 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,
* sector by sector this time in order to know which sectors
* 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
* sectors from those mirrors without I/O error on the
* particular sectors. One example (with blocks >= 2 * sectorsize)
* would be that mirror #1 has an I/O error on the first sector,
* the second sector is good, and mirror #2 has an I/O error on
* the second sector, but the first sector is good.
* Then the first sector of the first mirror can be repaired by
* taking the first sector of the second mirror, and the
* second sector of the second mirror can be repaired by
* copying the contents of the 2nd sector of the 1st mirror.
* One more note: if the sectors 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 sectors 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 = kcalloc(BTRFS_MAX_MIRRORS,
sizeof(*sblocks_for_recheck), GFP_KERNEL);
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 sectors */
ret = scrub_setup_recheck_block(sblock_to_check, 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, 1);
if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
sblock_bad->no_io_error_seen) {
/*
* The error disappeared after reading sector by sector, 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++;
sblock_to_check->data_corrected = 1;
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;
}
/*
* 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 sectors are rewritten that had
* an I/O error in the block to be repaired, since it cannot be
* determined, which copy of the other sectors is better (and it
* could happen otherwise that a correct sector would be
* overwritten by a bad one).
*/
for (mirror_index = 0; ;mirror_index++) {
struct scrub_block *sblock_other;
if (mirror_index == failed_mirror_index)
continue;
/* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
if (!scrub_is_page_on_raid56(sblock_bad->sectors[0])) {
if (mirror_index >= BTRFS_MAX_MIRRORS)
break;
if (!sblocks_for_recheck[mirror_index].sector_count)
break;
sblock_other = sblocks_for_recheck + mirror_index;
} else {
struct scrub_recover *r = sblock_bad->sectors[0]->recover;
int max_allowed = r->bioc->num_stripes - r->bioc->num_tgtdevs;
if (mirror_index >= max_allowed)
break;
if (!sblocks_for_recheck[1].sector_count)
break;
ASSERT(failed_mirror_index == 0);
sblock_other = sblocks_for_recheck + 1;
sblock_other->sectors[0]->mirror_num = 1 + mirror_index;
}
/* build and submit the bios, check checksums */
scrub_recheck_block(fs_info, sblock_other, 0);
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);
goto corrected_error;
} else {
ret = scrub_repair_block_from_good_copy(
sblock_bad, sblock_other);
if (!ret)
goto corrected_error;
}
}
}
if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
goto did_not_correct_error;
/*
* In case of I/O errors in the area that is supposed to be
* repaired, continue by picking good copies of those sectors.
* Select the good sectors from mirrors to rewrite bad sectors 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 sectors from the different mirrors
* until the checksum verification succeeds. For example, when
* the 2nd sector of mirror #1 faces I/O errors, and the 2nd sector
* of mirror #2 is readable but the final checksum test fails,
* then the 2nd sector of mirror #3 could be tried, whether now
* the final checksum succeeds. 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 sectorsize. 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 sectorsize
* area are unreadable.
*/
success = 1;
for (sector_num = 0; sector_num < sblock_bad->sector_count;
sector_num++) {
struct scrub_sector *sector_bad = sblock_bad->sectors[sector_num];
struct scrub_block *sblock_other = NULL;
/* Skip no-io-error sectors in scrub */
if (!sector_bad->io_error && !sctx->is_dev_replace)
continue;
if (scrub_is_page_on_raid56(sblock_bad->sectors[0])) {
/*
* In case of dev replace, if raid56 rebuild process
* didn't work out correct data, then copy the content
* in sblock_bad to make sure target device is identical
* to source device, instead of writing garbage data in
* sblock_for_recheck array to target device.
*/
sblock_other = NULL;
} else if (sector_bad->io_error) {
/* Try to find no-io-error sector in mirrors */
for (mirror_index = 0;
mirror_index < BTRFS_MAX_MIRRORS &&
sblocks_for_recheck[mirror_index].sector_count > 0;
mirror_index++) {
if (!sblocks_for_recheck[mirror_index].
sectors[sector_num]->io_error) {
sblock_other = sblocks_for_recheck +
mirror_index;
break;
}
}
if (!sblock_other)
success = 0;
}
if (sctx->is_dev_replace) {
/*
* Did not find a mirror to fetch the sector from.
* scrub_write_sector_to_dev_replace() handles this
* case (sector->io_error), by filling the block with
* zeros before submitting the write request
*/
if (!sblock_other)
sblock_other = sblock_bad;
if (scrub_write_sector_to_dev_replace(sblock_other,
sector_num) != 0) {
atomic64_inc(
&fs_info->dev_replace.num_write_errors);
success = 0;
}
} else if (sblock_other) {
ret = scrub_repair_sector_from_good_copy(sblock_bad,
sblock_other,
sector_num, 0);
if (0 == ret)
sector_bad->io_error = 0;
else
success = 0;
}
}
if (success && !sctx->is_dev_replace) {
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, 1);
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++;
sblock_to_check->data_corrected = 1;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"fixed up error at logical %llu on dev %s",
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);
btrfs_err_rl_in_rcu(fs_info,
"unable to fixup (regular) error at logical %llu on dev %s",
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;
struct scrub_recover *recover;
int i;
for (i = 0; i < sblock->sector_count; i++) {
sblock->sectors[i]->sblock = NULL;
recover = sblock->sectors[i]->recover;
if (recover) {
scrub_put_recover(fs_info, recover);
sblock->sectors[i]->recover = NULL;
}
scrub_sector_put(sblock->sectors[i]);
}
}
kfree(sblocks_for_recheck);
}
ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
memalloc_nofs_restore(nofs_flag);
if (ret < 0)
return ret;
return 0;
}
static inline int scrub_nr_raid_mirrors(struct btrfs_io_context *bioc)
{
if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID5)
return 2;
else if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID6)
return 3;
else
return (int)bioc->num_stripes;
}
static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
u64 *raid_map,
int nstripes, int mirror,
int *stripe_index,
u64 *stripe_offset)
{
int i;
if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
/* RAID5/6 */
for (i = 0; i < nstripes; i++) {
if (raid_map[i] == RAID6_Q_STRIPE ||
raid_map[i] == RAID5_P_STRIPE)
continue;
if (logical >= raid_map[i] &&
logical < raid_map[i] + BTRFS_STRIPE_LEN)
break;
}
*stripe_index = i;
*stripe_offset = logical - raid_map[i];
} else {
/* The other RAID type */
*stripe_index = mirror;
*stripe_offset = 0;
}
}
static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
struct scrub_block *sblocks_for_recheck)
{
struct scrub_ctx *sctx = original_sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
u64 length = original_sblock->sector_count << fs_info->sectorsize_bits;
u64 logical = original_sblock->sectors[0]->logical;
u64 generation = original_sblock->sectors[0]->generation;
u64 flags = original_sblock->sectors[0]->flags;
u64 have_csum = original_sblock->sectors[0]->have_csum;
struct scrub_recover *recover;
struct btrfs_io_context *bioc;
u64 sublen;
u64 mapped_length;
u64 stripe_offset;
int stripe_index;
int sector_index = 0;
int mirror_index;
int nmirrors;
int ret;
/*
* Note: the two members refs and outstanding_sectors are not used (and
* not set) in the blocks that are used for the recheck procedure.
*/
while (length > 0) {
sublen = min_t(u64, length, fs_info->sectorsize);
mapped_length = sublen;
bioc = NULL;
/*
* With a length of sectorsize, each returned stripe represents
* one mirror
*/
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
logical, &mapped_length, &bioc);
if (ret || !bioc || mapped_length < sublen) {
btrfs_put_bioc(bioc);
btrfs_bio_counter_dec(fs_info);
return -EIO;
}
recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
if (!recover) {
btrfs_put_bioc(bioc);
btrfs_bio_counter_dec(fs_info);
return -ENOMEM;
}
refcount_set(&recover->refs, 1);
recover->bioc = bioc;
recover->map_length = mapped_length;
ASSERT(sector_index < SCRUB_MAX_SECTORS_PER_BLOCK);
nmirrors = min(scrub_nr_raid_mirrors(bioc), BTRFS_MAX_MIRRORS);
for (mirror_index = 0; mirror_index < nmirrors;
mirror_index++) {
struct scrub_block *sblock;
struct scrub_sector *sector;
sblock = sblocks_for_recheck + mirror_index;
sblock->sctx = sctx;
sector = kzalloc(sizeof(*sector), GFP_NOFS);
if (!sector) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_put_recover(fs_info, recover);
return -ENOMEM;
}
scrub_sector_get(sector);
sblock->sectors[sector_index] = sector;
sector->sblock = sblock;
sector->flags = flags;
sector->generation = generation;
sector->logical = logical;
sector->have_csum = have_csum;
if (have_csum)
memcpy(sector->csum,
original_sblock->sectors[0]->csum,
sctx->fs_info->csum_size);
scrub_stripe_index_and_offset(logical,
bioc->map_type,
bioc->raid_map,
bioc->num_stripes -
bioc->num_tgtdevs,
mirror_index,
&stripe_index,
&stripe_offset);
sector->physical = bioc->stripes[stripe_index].physical +
stripe_offset;
sector->dev = bioc->stripes[stripe_index].dev;
BUG_ON(sector_index >= original_sblock->sector_count);
sector->physical_for_dev_replace =
original_sblock->sectors[sector_index]->
physical_for_dev_replace;
/* For missing devices, dev->bdev is NULL */
sector->mirror_num = mirror_index + 1;
sblock->sector_count++;
sector->page = alloc_page(GFP_NOFS);
if (!sector->page)
goto leave_nomem;
scrub_get_recover(recover);
sector->recover = recover;
}
scrub_put_recover(fs_info, recover);
length -= sublen;
logical += sublen;
sector_index++;
}
return 0;
}
static void scrub_bio_wait_endio(struct bio *bio)
{
complete(bio->bi_private);
}
static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
struct bio *bio,
struct scrub_sector *sector)
{
DECLARE_COMPLETION_ONSTACK(done);
bio->bi_iter.bi_sector = sector->logical >> 9;
bio->bi_private = &done;
bio->bi_end_io = scrub_bio_wait_endio;
raid56_parity_recover(bio, sector->recover->bioc,
sector->sblock->sectors[0]->mirror_num, false);
wait_for_completion_io(&done);
return blk_status_to_errno(bio->bi_status);
}
static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock)
{
struct scrub_sector *first_sector = sblock->sectors[0];
struct bio *bio;
int i;
/* All sectors in sblock belong to the same stripe on the same device. */
ASSERT(first_sector->dev);
if (!first_sector->dev->bdev)
goto out;
bio = bio_alloc(first_sector->dev->bdev, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
for (i = 0; i < sblock->sector_count; i++) {
struct scrub_sector *sector = sblock->sectors[i];
WARN_ON(!sector->page);
bio_add_page(bio, sector->page, PAGE_SIZE, 0);
}
if (scrub_submit_raid56_bio_wait(fs_info, bio, first_sector)) {
bio_put(bio);
goto out;
}
bio_put(bio);
scrub_recheck_block_checksum(sblock);
return;
out:
for (i = 0; i < sblock->sector_count; i++)
sblock->sectors[i]->io_error = 1;
sblock->no_io_error_seen = 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 sectors which are
* errored are marked as being bad. The goal is to enable scrub to take those
* sectors that are not errored from all the mirrors so that the sectors 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 retry_failed_mirror)
{
int i;
sblock->no_io_error_seen = 1;
/* short cut for raid56 */
if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->sectors[0]))
return scrub_recheck_block_on_raid56(fs_info, sblock);
for (i = 0; i < sblock->sector_count; i++) {
struct scrub_sector *sector = sblock->sectors[i];
struct bio bio;
struct bio_vec bvec;
if (sector->dev->bdev == NULL) {
sector->io_error = 1;
sblock->no_io_error_seen = 0;
continue;
}
WARN_ON(!sector->page);
bio_init(&bio, sector->dev->bdev, &bvec, 1, REQ_OP_READ);
bio_add_page(&bio, sector->page, fs_info->sectorsize, 0);
bio.bi_iter.bi_sector = sector->physical >> 9;
btrfsic_check_bio(&bio);
if (submit_bio_wait(&bio)) {
sector->io_error = 1;
sblock->no_io_error_seen = 0;
}
bio_uninit(&bio);
}
if (sblock->no_io_error_seen)
scrub_recheck_block_checksum(sblock);
}
static inline int scrub_check_fsid(u8 fsid[], struct scrub_sector *sector)
{
struct btrfs_fs_devices *fs_devices = sector->dev->fs_devices;
int ret;
ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
return !ret;
}
static void scrub_recheck_block_checksum(struct scrub_block *sblock)
{
sblock->header_error = 0;
sblock->checksum_error = 0;
sblock->generation_error = 0;
if (sblock->sectors[0]->flags & BTRFS_EXTENT_FLAG_DATA)
scrub_checksum_data(sblock);
else
scrub_checksum_tree_block(sblock);
}
static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good)
{
int i;
int ret = 0;
for (i = 0; i < sblock_bad->sector_count; i++) {
int ret_sub;
ret_sub = scrub_repair_sector_from_good_copy(sblock_bad,
sblock_good, i, 1);
if (ret_sub)
ret = ret_sub;
}
return ret;
}
static int scrub_repair_sector_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int sector_num, int force_write)
{
struct scrub_sector *sector_bad = sblock_bad->sectors[sector_num];
struct scrub_sector *sector_good = sblock_good->sectors[sector_num];
struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
const u32 sectorsize = fs_info->sectorsize;
BUG_ON(sector_bad->page == NULL);
BUG_ON(sector_good->page == NULL);
if (force_write || sblock_bad->header_error ||
sblock_bad->checksum_error || sector_bad->io_error) {
struct bio bio;
struct bio_vec bvec;
int ret;
if (!sector_bad->dev->bdev) {
btrfs_warn_rl(fs_info,
"scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
return -EIO;
}
bio_init(&bio, sector_bad->dev->bdev, &bvec, 1, REQ_OP_WRITE);
bio.bi_iter.bi_sector = sector_bad->physical >> 9;
__bio_add_page(&bio, sector_good->page, sectorsize, 0);
btrfsic_check_bio(&bio);
ret = submit_bio_wait(&bio);
bio_uninit(&bio);
if (ret) {
btrfs_dev_stat_inc_and_print(sector_bad->dev,
BTRFS_DEV_STAT_WRITE_ERRS);
atomic64_inc(&fs_info->dev_replace.num_write_errors);
return -EIO;
}
}
return 0;
}
static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
{
struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
int i;
/*
* This block is used for the check of the parity on the source device,
* so the data needn't be written into the destination device.
*/
if (sblock->sparity)
return;
for (i = 0; i < sblock->sector_count; i++) {
int ret;
ret = scrub_write_sector_to_dev_replace(sblock, i);
if (ret)
atomic64_inc(&fs_info->dev_replace.num_write_errors);
}
}
static int scrub_write_sector_to_dev_replace(struct scrub_block *sblock, int sector_num)
{
struct scrub_sector *sector = sblock->sectors[sector_num];
BUG_ON(sector->page == NULL);
if (sector->io_error)
clear_page(page_address(sector->page));
return scrub_add_sector_to_wr_bio(sblock->sctx, sector);
}
static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
{
int ret = 0;
u64 length;
if (!btrfs_is_zoned(sctx->fs_info))
return 0;
if (!btrfs_dev_is_sequential(sctx->wr_tgtdev, physical))
return 0;
if (sctx->write_pointer < physical) {
length = physical - sctx->write_pointer;
ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
sctx->write_pointer, length);
if (!ret)
sctx->write_pointer = physical;
}
return ret;
}
static int scrub_add_sector_to_wr_bio(struct scrub_ctx *sctx,
struct scrub_sector *sector)
{
struct scrub_bio *sbio;
int ret;
const u32 sectorsize = sctx->fs_info->sectorsize;
mutex_lock(&sctx->wr_lock);
again:
if (!sctx->wr_curr_bio) {
sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
GFP_KERNEL);
if (!sctx->wr_curr_bio) {
mutex_unlock(&sctx->wr_lock);
return -ENOMEM;
}
sctx->wr_curr_bio->sctx = sctx;
sctx->wr_curr_bio->sector_count = 0;
}
sbio = sctx->wr_curr_bio;
if (sbio->sector_count == 0) {
ret = fill_writer_pointer_gap(sctx, sector->physical_for_dev_replace);
if (ret) {
mutex_unlock(&sctx->wr_lock);
return ret;
}
sbio->physical = sector->physical_for_dev_replace;
sbio->logical = sector->logical;
sbio->dev = sctx->wr_tgtdev;
if (!sbio->bio) {
sbio->bio = bio_alloc(sbio->dev->bdev, sctx->sectors_per_bio,
REQ_OP_WRITE, GFP_NOFS);
}
sbio->bio->bi_private = sbio;
sbio->bio->bi_end_io = scrub_wr_bio_end_io;
sbio->bio->bi_iter.bi_sector = sbio->physical >> 9;
sbio->status = 0;
} else if (sbio->physical + sbio->sector_count * sectorsize !=
sector->physical_for_dev_replace ||
sbio->logical + sbio->sector_count * sectorsize !=
sector->logical) {
scrub_wr_submit(sctx);
goto again;
}
ret = bio_add_page(sbio->bio, sector->page, sectorsize, 0);
if (ret != sectorsize) {
if (sbio->sector_count < 1) {
bio_put(sbio->bio);
sbio->bio = NULL;
mutex_unlock(&sctx->wr_lock);
return -EIO;
}
scrub_wr_submit(sctx);
goto again;
}
sbio->sectors[sbio->sector_count] = sector;
scrub_sector_get(sector);
sbio->sector_count++;
if (sbio->sector_count == sctx->sectors_per_bio)
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
return 0;
}
static void scrub_wr_submit(struct scrub_ctx *sctx)
{
struct scrub_bio *sbio;
if (!sctx->wr_curr_bio)
return;
sbio = sctx->wr_curr_bio;
sctx->wr_curr_bio = NULL;
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_check_bio(sbio->bio);
submit_bio(sbio->bio);
if (btrfs_is_zoned(sctx->fs_info))
sctx->write_pointer = sbio->physical + sbio->sector_count *
sctx->fs_info->sectorsize;
}
static void scrub_wr_bio_end_io(struct bio *bio)
{
struct scrub_bio *sbio = bio->bi_private;
struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
sbio->status = bio->bi_status;
sbio->bio = bio;
INIT_WORK(&sbio->work, scrub_wr_bio_end_io_worker);
queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
}
static void scrub_wr_bio_end_io_worker(struct work_struct *work)
{
struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
struct scrub_ctx *sctx = sbio->sctx;
int i;
ASSERT(sbio->sector_count <= SCRUB_SECTORS_PER_BIO);
if (sbio->status) {
struct btrfs_dev_replace *dev_replace =
&sbio->sctx->fs_info->dev_replace;
for (i = 0; i < sbio->sector_count; i++) {
struct scrub_sector *sector = sbio->sectors[i];
sector->io_error = 1;
atomic64_inc(&dev_replace->num_write_errors);
}
}
for (i = 0; i < sbio->sector_count; i++)
scrub_sector_put(sbio->sectors[i]);
bio_put(sbio->bio);
kfree(sbio);
scrub_pending_bio_dec(sctx);
}
static int scrub_checksum(struct scrub_block *sblock)
{
u64 flags;
int ret;
/*
* No need to initialize these stats currently,
* because this function only use return value
* instead of these stats value.
*
* Todo:
* always use stats
*/
sblock->header_error = 0;
sblock->generation_error = 0;
sblock->checksum_error = 0;
WARN_ON(sblock->sector_count < 1);
flags = sblock->sectors[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;
struct btrfs_fs_info *fs_info = sctx->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 csum[BTRFS_CSUM_SIZE];
struct scrub_sector *sector;
char *kaddr;
BUG_ON(sblock->sector_count < 1);
sector = sblock->sectors[0];
if (!sector->have_csum)
return 0;
kaddr = page_address(sector->page);
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
/*
* In scrub_sectors() and scrub_sectors_for_parity() we ensure each sector
* only contains one sector of data.
*/
crypto_shash_digest(shash, kaddr, fs_info->sectorsize, csum);
if (memcmp(csum, sector->csum, fs_info->csum_size))
sblock->checksum_error = 1;
return sblock->checksum_error;
}
static int scrub_checksum_tree_block(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_header *h;
struct btrfs_fs_info *fs_info = sctx->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 calculated_csum[BTRFS_CSUM_SIZE];
u8 on_disk_csum[BTRFS_CSUM_SIZE];
/*
* This is done in sectorsize steps even for metadata as there's a
* constraint for nodesize to be aligned to sectorsize. This will need
* to change so we don't misuse data and metadata units like that.
*/
const u32 sectorsize = sctx->fs_info->sectorsize;
const int num_sectors = fs_info->nodesize >> fs_info->sectorsize_bits;
int i;
struct scrub_sector *sector;
char *kaddr;
BUG_ON(sblock->sector_count < 1);
/* Each member in sectors is just one sector */
ASSERT(sblock->sector_count == num_sectors);
sector = sblock->sectors[0];
kaddr = page_address(sector->page);
h = (struct btrfs_header *)kaddr;
memcpy(on_disk_csum, h->csum, sctx->fs_info->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 (sector->logical != btrfs_stack_header_bytenr(h))
sblock->header_error = 1;
if (sector->generation != btrfs_stack_header_generation(h)) {
sblock->header_error = 1;
sblock->generation_error = 1;
}
if (!scrub_check_fsid(h->fsid, sector))
sblock->header_error = 1;
if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
BTRFS_UUID_SIZE))
sblock->header_error = 1;
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
sectorsize - BTRFS_CSUM_SIZE);
for (i = 1; i < num_sectors; i++) {
kaddr = page_address(sblock->sectors[i]->page);
crypto_shash_update(shash, kaddr, sectorsize);
}
crypto_shash_final(shash, calculated_csum);
if (memcmp(calculated_csum, on_disk_csum, sctx->fs_info->csum_size))
sblock->checksum_error = 1;
return sblock->header_error || sblock->checksum_error;
}
static int scrub_checksum_super(struct scrub_block *sblock)
{
struct btrfs_super_block *s;
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 calculated_csum[BTRFS_CSUM_SIZE];
struct scrub_sector *sector;
char *kaddr;
int fail_gen = 0;
int fail_cor = 0;
BUG_ON(sblock->sector_count < 1);
sector = sblock->sectors[0];
kaddr = page_address(sector->page);
s = (struct btrfs_super_block *)kaddr;
if (sector->logical != btrfs_super_bytenr(s))
++fail_cor;
if (sector->generation != btrfs_super_generation(s))
++fail_gen;
if (!scrub_check_fsid(s->fsid, sector))
++fail_cor;
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_digest(shash, kaddr + BTRFS_CSUM_SIZE,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, calculated_csum);
if (memcmp(calculated_csum, s->csum, sctx->fs_info->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(sector->dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
else
btrfs_dev_stat_inc_and_print(sector->dev,
BTRFS_DEV_STAT_GENERATION_ERRS);
}
return fail_cor + fail_gen;
}
static void scrub_block_get(struct scrub_block *sblock)
{
refcount_inc(&sblock->refs);
}
static void scrub_block_put(struct scrub_block *sblock)
{
if (refcount_dec_and_test(&sblock->refs)) {
int i;
if (sblock->sparity)
scrub_parity_put(sblock->sparity);
for (i = 0; i < sblock->sector_count; i++)
scrub_sector_put(sblock->sectors[i]);
kfree(sblock);
}
}
static void scrub_sector_get(struct scrub_sector *sector)
{
atomic_inc(&sector->refs);
}
static void scrub_sector_put(struct scrub_sector *sector)
{
if (atomic_dec_and_test(&sector->refs)) {
if (sector->page)
__free_page(sector->page);
kfree(sector);
}
}
/*
* Throttling of IO submission, bandwidth-limit based, the timeslice is 1
* second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max.
*/
static void scrub_throttle(struct scrub_ctx *sctx)
{
const int time_slice = 1000;
struct scrub_bio *sbio;
struct btrfs_device *device;
s64 delta;
ktime_t now;
u32 div;
u64 bwlimit;
sbio = sctx->bios[sctx->curr];
device = sbio->dev;
bwlimit = READ_ONCE(device->scrub_speed_max);
if (bwlimit == 0)
return;
/*
* Slice is divided into intervals when the IO is submitted, adjust by
* bwlimit and maximum of 64 intervals.
*/
div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024)));
div = min_t(u32, 64, div);
/* Start new epoch, set deadline */
now = ktime_get();
if (sctx->throttle_deadline == 0) {
sctx->throttle_deadline = ktime_add_ms(now, time_slice / div);
sctx->throttle_sent = 0;
}
/* Still in the time to send? */
if (ktime_before(now, sctx->throttle_deadline)) {
/* If current bio is within the limit, send it */
sctx->throttle_sent += sbio->bio->bi_iter.bi_size;
if (sctx->throttle_sent <= div_u64(bwlimit, div))
return;
/* We're over the limit, sleep until the rest of the slice */
delta = ktime_ms_delta(sctx->throttle_deadline, now);
} else {
/* New request after deadline, start new epoch */
delta = 0;
}
if (delta) {
long timeout;
timeout = div_u64(delta * HZ, 1000);
schedule_timeout_interruptible(timeout);
}
/* Next call will start the deadline period */
sctx->throttle_deadline = 0;
}
static void scrub_submit(struct scrub_ctx *sctx)
{
struct scrub_bio *sbio;
if (sctx->curr == -1)
return;
scrub_throttle(sctx);
sbio = sctx->bios[sctx->curr];
sctx->curr = -1;
scrub_pending_bio_inc(sctx);
btrfsic_check_bio(sbio->bio);
submit_bio(sbio->bio);
}
static int scrub_add_sector_to_rd_bio(struct scrub_ctx *sctx,
struct scrub_sector *sector)
{
struct scrub_block *sblock = sector->sblock;
struct scrub_bio *sbio;
const u32 sectorsize = sctx->fs_info->sectorsize;
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]->sector_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->sector_count == 0) {
sbio->physical = sector->physical;
sbio->logical = sector->logical;
sbio->dev = sector->dev;
if (!sbio->bio) {
sbio->bio = bio_alloc(sbio->dev->bdev, sctx->sectors_per_bio,
REQ_OP_READ, GFP_NOFS);
}
sbio->bio->bi_private = sbio;
sbio->bio->bi_end_io = scrub_bio_end_io;
sbio->bio->bi_iter.bi_sector = sbio->physical >> 9;
sbio->status = 0;
} else if (sbio->physical + sbio->sector_count * sectorsize !=
sector->physical ||
sbio->logical + sbio->sector_count * sectorsize !=
sector->logical ||
sbio->dev != sector->dev) {
scrub_submit(sctx);
goto again;
}
sbio->sectors[sbio->sector_count] = sector;
ret = bio_add_page(sbio->bio, sector->page, sectorsize, 0);
if (ret != sectorsize) {
if (sbio->sector_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_sectors);
sbio->sector_count++;
if (sbio->sector_count == sctx->sectors_per_bio)
scrub_submit(sctx);
return 0;
}
static void scrub_missing_raid56_end_io(struct bio *bio)
{
struct scrub_block *sblock = bio->bi_private;
struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
if (bio->bi_status)
sblock->no_io_error_seen = 0;
bio_put(bio);
queue_work(fs_info->scrub_workers, &sblock->work);
}
static void scrub_missing_raid56_worker(struct work_struct *work)
{
struct scrub_block *sblock = container_of(work, struct scrub_block, work);
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
u64 logical;
struct btrfs_device *dev;
logical = sblock->sectors[0]->logical;
dev = sblock->sectors[0]->dev;
if (sblock->no_io_error_seen)
scrub_recheck_block_checksum(sblock);
if (!sblock->no_io_error_seen) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"IO error rebuilding logical %llu for dev %s",
logical, rcu_str_deref(dev->name));
} else if (sblock->header_error || sblock->checksum_error) {
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"failed to rebuild valid logical %llu for dev %s",
logical, rcu_str_deref(dev->name));
} else {
scrub_write_block_to_dev_replace(sblock);
}
if (sctx->is_dev_replace && sctx->flush_all_writes) {
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
}
scrub_block_put(sblock);
scrub_pending_bio_dec(sctx);
}
static void scrub_missing_raid56_pages(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
u64 length = sblock->sector_count << fs_info->sectorsize_bits;
u64 logical = sblock->sectors[0]->logical;
struct btrfs_io_context *bioc = NULL;
struct bio *bio;
struct btrfs_raid_bio *rbio;
int ret;
int i;
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
&length, &bioc);
if (ret || !bioc || !bioc->raid_map)
goto bioc_out;
if (WARN_ON(!sctx->is_dev_replace ||
!(bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
/*
* We shouldn't be scrubbing a missing device. Even for dev
* replace, we should only get here for RAID 5/6. We either
* managed to mount something with no mirrors remaining or
* there's a bug in scrub_find_good_copy()/btrfs_map_block().
*/
goto bioc_out;
}
bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
bio->bi_iter.bi_sector = logical >> 9;
bio->bi_private = sblock;
bio->bi_end_io = scrub_missing_raid56_end_io;
rbio = raid56_alloc_missing_rbio(bio, bioc);
if (!rbio)
goto rbio_out;
for (i = 0; i < sblock->sector_count; i++) {
struct scrub_sector *sector = sblock->sectors[i];
/*
* For now, our scrub is still one page per sector, so pgoff
* is always 0.
*/
raid56_add_scrub_pages(rbio, sector->page, 0, sector->logical);
}
INIT_WORK(&sblock->work, scrub_missing_raid56_worker);
scrub_block_get(sblock);
scrub_pending_bio_inc(sctx);
raid56_submit_missing_rbio(rbio);
return;
rbio_out:
bio_put(bio);
bioc_out:
btrfs_bio_counter_dec(fs_info);
btrfs_put_bioc(bioc);
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
}
static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u8 *csum,
u64 physical_for_dev_replace)
{
struct scrub_block *sblock;
const u32 sectorsize = sctx->fs_info->sectorsize;
int index;
sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
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 */
refcount_set(&sblock->refs, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
for (index = 0; len > 0; index++) {
struct scrub_sector *sector;
/*
* Here we will allocate one page for one sector to scrub.
* This is fine if PAGE_SIZE == sectorsize, but will cost
* more memory for PAGE_SIZE > sectorsize case.
*/
u32 l = min(sectorsize, len);
sector = kzalloc(sizeof(*sector), GFP_KERNEL);
if (!sector) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_block_put(sblock);
return -ENOMEM;
}
ASSERT(index < SCRUB_MAX_SECTORS_PER_BLOCK);
scrub_sector_get(sector);
sblock->sectors[index] = sector;
sector->sblock = sblock;
sector->dev = dev;
sector->flags = flags;
sector->generation = gen;
sector->logical = logical;
sector->physical = physical;
sector->physical_for_dev_replace = physical_for_dev_replace;
sector->mirror_num = mirror_num;
if (csum) {
sector->have_csum = 1;
memcpy(sector->csum, csum, sctx->fs_info->csum_size);
} else {
sector->have_csum = 0;
}
sblock->sector_count++;
sector->page = alloc_page(GFP_KERNEL);
if (!sector->page)
goto leave_nomem;
len -= l;
logical += l;
physical += l;
physical_for_dev_replace += l;
}
WARN_ON(sblock->sector_count == 0);
if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
/*
* This case should only be hit for RAID 5/6 device replace. See
* the comment in scrub_missing_raid56_pages() for details.
*/
scrub_missing_raid56_pages(sblock);
} else {
for (index = 0; index < sblock->sector_count; index++) {
struct scrub_sector *sector = sblock->sectors[index];
int ret;
ret = scrub_add_sector_to_rd_bio(sctx, sector);
if (ret) {
scrub_block_put(sblock);
return ret;
}
}
if (flags & BTRFS_EXTENT_FLAG_SUPER)
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)
{
struct scrub_bio *sbio = bio->bi_private;
struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
sbio->status = bio->bi_status;
sbio->bio = bio;
queue_work(fs_info->scrub_workers, &sbio->work);
}
static void scrub_bio_end_io_worker(struct work_struct *work)
{
struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
struct scrub_ctx *sctx = sbio->sctx;
int i;
ASSERT(sbio->sector_count <= SCRUB_SECTORS_PER_BIO);
if (sbio->status) {
for (i = 0; i < sbio->sector_count; i++) {
struct scrub_sector *sector = sbio->sectors[i];
sector->io_error = 1;
sector->sblock->no_io_error_seen = 0;
}
}
/* Now complete the scrub_block items that have all pages completed */
for (i = 0; i < sbio->sector_count; i++) {
struct scrub_sector *sector = sbio->sectors[i];
struct scrub_block *sblock = sector->sblock;
if (atomic_dec_and_test(&sblock->outstanding_sectors))
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 && sctx->flush_all_writes) {
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
}
scrub_pending_bio_dec(sctx);
}
static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
unsigned long *bitmap,
u64 start, u32 len)
{
u64 offset;
u32 nsectors;
u32 sectorsize_bits = sparity->sctx->fs_info->sectorsize_bits;
if (len >= sparity->stripe_len) {
bitmap_set(bitmap, 0, sparity->nsectors);
return;
}
start -= sparity->logic_start;
start = div64_u64_rem(start, sparity->stripe_len, &offset);
offset = offset >> sectorsize_bits;
nsectors = len >> sectorsize_bits;
if (offset + nsectors <= sparity->nsectors) {
bitmap_set(bitmap, offset, nsectors);
return;
}
bitmap_set(bitmap, offset, sparity->nsectors - offset);
bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
}
static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
u64 start, u32 len)
{
__scrub_mark_bitmap(sparity, &sparity->ebitmap, start, len);
}
static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
u64 start, u32 len)
{
__scrub_mark_bitmap(sparity, &sparity->dbitmap, start, len);
}
static void scrub_block_complete(struct scrub_block *sblock)
{
int corrupted = 0;
if (!sblock->no_io_error_seen) {
corrupted = 1;
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.
*/
corrupted = scrub_checksum(sblock);
if (!corrupted && sblock->sctx->is_dev_replace)
scrub_write_block_to_dev_replace(sblock);
}
if (sblock->sparity && corrupted && !sblock->data_corrected) {
u64 start = sblock->sectors[0]->logical;
u64 end = sblock->sectors[sblock->sector_count - 1]->logical +
sblock->sctx->fs_info->sectorsize;
ASSERT(end - start <= U32_MAX);
scrub_parity_mark_sectors_error(sblock->sparity,
start, end - start);
}
}
static void drop_csum_range(struct scrub_ctx *sctx, struct btrfs_ordered_sum *sum)
{
sctx->stat.csum_discards += sum->len >> sctx->fs_info->sectorsize_bits;
list_del(&sum->list);
kfree(sum);
}
/*
* Find the desired csum for range [logical, logical + sectorsize), and store
* the csum into @csum.
*
* The search source is sctx->csum_list, which is a pre-populated list
* storing bytenr ordered csum ranges. We're responsible to cleanup any range
* that is before @logical.
*
* Return 0 if there is no csum for the range.
* Return 1 if there is csum for the range and copied to @csum.
*/
static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
{
bool found = false;
while (!list_empty(&sctx->csum_list)) {
struct btrfs_ordered_sum *sum = NULL;
unsigned long index;
unsigned long num_sectors;
sum = list_first_entry(&sctx->csum_list,
struct btrfs_ordered_sum, list);
/* The current csum range is beyond our range, no csum found */
if (sum->bytenr > logical)
break;
/*
* The current sum is before our bytenr, since scrub is always
* done in bytenr order, the csum will never be used anymore,
* clean it up so that later calls won't bother with the range,
* and continue search the next range.
*/
if (sum->bytenr + sum->len <= logical) {
drop_csum_range(sctx, sum);
continue;
}
/* Now the csum range covers our bytenr, copy the csum */
found = true;
index = (logical - sum->bytenr) >> sctx->fs_info->sectorsize_bits;
num_sectors = sum->len >> sctx->fs_info->sectorsize_bits;
memcpy(csum, sum->sums + index * sctx->fs_info->csum_size,
sctx->fs_info->csum_size);
/* Cleanup the range if we're at the end of the csum range */
if (index == num_sectors - 1)
drop_csum_range(sctx, sum);
break;
}
if (!found)
return 0;
return 1;
}
/* scrub extent tries to collect up to 64 kB for each bio */
static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
u64 logical, u32 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num)
{
struct btrfs_device *src_dev = dev;
u64 src_physical = physical;
int src_mirror = mirror_num;
int ret;
u8 csum[BTRFS_CSUM_SIZE];
u32 blocksize;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
blocksize = map->stripe_len;
else
blocksize = sctx->fs_info->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) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
blocksize = map->stripe_len;
else
blocksize = sctx->fs_info->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->fs_info->sectorsize;
WARN_ON(1);
}
/*
* For dev-replace case, we can have @dev being a missing device.
* Regular scrub will avoid its execution on missing device at all,
* as that would trigger tons of read error.
*
* Reading from missing device will cause read error counts to
* increase unnecessarily.
* So here we change the read source to a good mirror.
*/
if (sctx->is_dev_replace && !dev->bdev)
scrub_find_good_copy(sctx->fs_info, logical, len, &src_physical,
&src_dev, &src_mirror);
while (len) {
u32 l = min(len, blocksize);
int have_csum = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
/* push csums to sbio */
have_csum = scrub_find_csum(sctx, logical, csum);
if (have_csum == 0)
++sctx->stat.no_csum;
}
ret = scrub_sectors(sctx, logical, l, src_physical, src_dev,
flags, gen, src_mirror,
have_csum ? csum : NULL, physical);
if (ret)
return ret;
len -= l;
logical += l;
physical += l;
src_physical += l;
}
return 0;
}
static int scrub_sectors_for_parity(struct scrub_parity *sparity,
u64 logical, u32 len,
u64 physical, struct btrfs_device *dev,
u64 flags, u64 gen, int mirror_num, u8 *csum)
{
struct scrub_ctx *sctx = sparity->sctx;
struct scrub_block *sblock;
const u32 sectorsize = sctx->fs_info->sectorsize;
int index;
ASSERT(IS_ALIGNED(len, sectorsize));
sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
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 */
refcount_set(&sblock->refs, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
sblock->sparity = sparity;
scrub_parity_get(sparity);
for (index = 0; len > 0; index++) {
struct scrub_sector *sector;
sector = kzalloc(sizeof(*sector), GFP_KERNEL);
if (!sector) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_block_put(sblock);
return -ENOMEM;
}
ASSERT(index < SCRUB_MAX_SECTORS_PER_BLOCK);
/* For scrub block */
scrub_sector_get(sector);
sblock->sectors[index] = sector;
/* For scrub parity */
scrub_sector_get(sector);
list_add_tail(&sector->list, &sparity->sectors_list);
sector->sblock = sblock;
sector->dev = dev;
sector->flags = flags;
sector->generation = gen;
sector->logical = logical;
sector->physical = physical;
sector->mirror_num = mirror_num;
if (csum) {
sector->have_csum = 1;
memcpy(sector->csum, csum, sctx->fs_info->csum_size);
} else {
sector->have_csum = 0;
}
sblock->sector_count++;
sector->page = alloc_page(GFP_KERNEL);
if (!sector->page)
goto leave_nomem;
/* Iterate over the stripe range in sectorsize steps */
len -= sectorsize;
logical += sectorsize;
physical += sectorsize;
}
WARN_ON(sblock->sector_count == 0);
for (index = 0; index < sblock->sector_count; index++) {
struct scrub_sector *sector = sblock->sectors[index];
int ret;
ret = scrub_add_sector_to_rd_bio(sctx, sector);
if (ret) {
scrub_block_put(sblock);
return ret;
}
}
/* Last one frees, either here or in bio completion for last sector */
scrub_block_put(sblock);
return 0;
}
static int scrub_extent_for_parity(struct scrub_parity *sparity,
u64 logical, u32 len,
u64 physical, struct btrfs_device *dev,
u64 flags, u64 gen, int mirror_num)
{
struct scrub_ctx *sctx = sparity->sctx;
int ret;
u8 csum[BTRFS_CSUM_SIZE];
u32 blocksize;
if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
scrub_parity_mark_sectors_error(sparity, logical, len);
return 0;
}
if (flags & BTRFS_EXTENT_FLAG_DATA) {
blocksize = sparity->stripe_len;
} else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
blocksize = sparity->stripe_len;
} else {
blocksize = sctx->fs_info->sectorsize;
WARN_ON(1);
}
while (len) {
u32 l = min(len, blocksize);
int have_csum = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
/* push csums to sbio */
have_csum = scrub_find_csum(sctx, logical, csum);
if (have_csum == 0)
goto skip;
}
ret = scrub_sectors_for_parity(sparity, logical, l, physical, dev,
flags, gen, mirror_num,
have_csum ? csum : NULL);
if (ret)
return ret;
skip:
len -= l;
logical += l;
physical += 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,
u64 *stripe_start)
{
int i;
int j = 0;
u64 stripe_nr;
u64 last_offset;
u32 stripe_index;
u32 rot;
const int data_stripes = nr_data_stripes(map);
last_offset = (physical - map->stripes[num].physical) * data_stripes;
if (stripe_start)
*stripe_start = last_offset;
*offset = last_offset;
for (i = 0; i < data_stripes; i++) {
*offset = last_offset + i * map->stripe_len;
stripe_nr = div64_u64(*offset, map->stripe_len);
stripe_nr = div_u64(stripe_nr, data_stripes);
/* Work out the disk rotation on this stripe-set */
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
/* 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 void scrub_free_parity(struct scrub_parity *sparity)
{
struct scrub_ctx *sctx = sparity->sctx;
struct scrub_sector *curr, *next;
int nbits;
nbits = bitmap_weight(&sparity->ebitmap, sparity->nsectors);
if (nbits) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors += nbits;
sctx->stat.uncorrectable_errors += nbits;
spin_unlock(&sctx->stat_lock);
}
list_for_each_entry_safe(curr, next, &sparity->sectors_list, list) {
list_del_init(&curr->list);
scrub_sector_put(curr);
}
kfree(sparity);
}
static void scrub_parity_bio_endio_worker(struct work_struct *work)
{
struct scrub_parity *sparity = container_of(work, struct scrub_parity,
work);
struct scrub_ctx *sctx = sparity->sctx;
scrub_free_parity(sparity);
scrub_pending_bio_dec(sctx);
}
static void scrub_parity_bio_endio(struct bio *bio)
{
struct scrub_parity *sparity = bio->bi_private;
struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
if (bio->bi_status)
bitmap_or(&sparity->ebitmap, &sparity->ebitmap,
&sparity->dbitmap, sparity->nsectors);
bio_put(bio);
INIT_WORK(&sparity->work, scrub_parity_bio_endio_worker);
queue_work(fs_info->scrub_parity_workers, &sparity->work);
}
static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
{
struct scrub_ctx *sctx = sparity->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct bio *bio;
struct btrfs_raid_bio *rbio;
struct btrfs_io_context *bioc = NULL;
u64 length;
int ret;
if (!bitmap_andnot(&sparity->dbitmap, &sparity->dbitmap,
&sparity->ebitmap, sparity->nsectors))
goto out;
length = sparity->logic_end - sparity->logic_start;
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
&length, &bioc);
if (ret || !bioc || !bioc->raid_map)
goto bioc_out;
bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
bio->bi_iter.bi_sector = sparity->logic_start >> 9;
bio->bi_private = sparity;
bio->bi_end_io = scrub_parity_bio_endio;
rbio = raid56_parity_alloc_scrub_rbio(bio, bioc,
sparity->scrub_dev,
&sparity->dbitmap,
sparity->nsectors);
if (!rbio)
goto rbio_out;
scrub_pending_bio_inc(sctx);
raid56_parity_submit_scrub_rbio(rbio);
return;
rbio_out:
bio_put(bio);
bioc_out:
btrfs_bio_counter_dec(fs_info);
btrfs_put_bioc(bioc);
bitmap_or(&sparity->ebitmap, &sparity->ebitmap, &sparity->dbitmap,
sparity->nsectors);
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
out:
scrub_free_parity(sparity);
}
static void scrub_parity_get(struct scrub_parity *sparity)
{
refcount_inc(&sparity->refs);
}
static void scrub_parity_put(struct scrub_parity *sparity)
{
if (!refcount_dec_and_test(&sparity->refs))
return;
scrub_parity_check_and_repair(sparity);
}
/*
* Return 0 if the extent item range covers any byte of the range.
* Return <0 if the extent item is before @search_start.
* Return >0 if the extent item is after @start_start + @search_len.
*/
static int compare_extent_item_range(struct btrfs_path *path,
u64 search_start, u64 search_len)
{
struct btrfs_fs_info *fs_info = path->nodes[0]->fs_info;
u64 len;
struct btrfs_key key;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
ASSERT(key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY);
if (key.type == BTRFS_METADATA_ITEM_KEY)
len = fs_info->nodesize;
else
len = key.offset;
if (key.objectid + len <= search_start)
return -1;
if (key.objectid >= search_start + search_len)
return 1;
return 0;
}
/*
* Locate one extent item which covers any byte in range
* [@search_start, @search_start + @search_length)
*
* If the path is not initialized, we will initialize the search by doing
* a btrfs_search_slot().
* If the path is already initialized, we will use the path as the initial
* slot, to avoid duplicated btrfs_search_slot() calls.
*
* NOTE: If an extent item starts before @search_start, we will still
* return the extent item. This is for data extent crossing stripe boundary.
*
* Return 0 if we found such extent item, and @path will point to the extent item.
* Return >0 if no such extent item can be found, and @path will be released.
* Return <0 if hit fatal error, and @path will be released.
*/
static int find_first_extent_item(struct btrfs_root *extent_root,
struct btrfs_path *path,
u64 search_start, u64 search_len)
{
struct btrfs_fs_info *fs_info = extent_root->fs_info;
struct btrfs_key key;
int ret;
/* Continue using the existing path */
if (path->nodes[0])
goto search_forward;
if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
key.objectid = search_start;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
return ret;
ASSERT(ret > 0);
/*
* Here we intentionally pass 0 as @min_objectid, as there could be
* an extent item starting before @search_start.
*/
ret = btrfs_previous_extent_item(extent_root, path, 0);
if (ret < 0)
return ret;
/*
* No matter whether we have found an extent item, the next loop will
* properly do every check on the key.
*/
search_forward:
while (true) {
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid >= search_start + search_len)
break;
if (key.type != BTRFS_METADATA_ITEM_KEY &&
key.type != BTRFS_EXTENT_ITEM_KEY)
goto next;
ret = compare_extent_item_range(path, search_start, search_len);
if (ret == 0)
return ret;
if (ret > 0)
break;
next:
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(extent_root, path);
if (ret) {
/* Either no more item or fatal error */
btrfs_release_path(path);
return ret;
}
}
}
btrfs_release_path(path);
return 1;
}
static void get_extent_info(struct btrfs_path *path, u64 *extent_start_ret,
u64 *size_ret, u64 *flags_ret, u64 *generation_ret)
{
struct btrfs_key key;
struct btrfs_extent_item *ei;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
ASSERT(key.type == BTRFS_METADATA_ITEM_KEY ||
key.type == BTRFS_EXTENT_ITEM_KEY);
*extent_start_ret = key.objectid;
if (key.type == BTRFS_METADATA_ITEM_KEY)
*size_ret = path->nodes[0]->fs_info->nodesize;
else
*size_ret = key.offset;
ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item);
*flags_ret = btrfs_extent_flags(path->nodes[0], ei);
*generation_ret = btrfs_extent_generation(path->nodes[0], ei);
}
static bool does_range_cross_boundary(u64 extent_start, u64 extent_len,
u64 boundary_start, u64 boudary_len)
{
return (extent_start < boundary_start &&
extent_start + extent_len > boundary_start) ||
(extent_start < boundary_start + boudary_len &&
extent_start + extent_len > boundary_start + boudary_len);
}
static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,
struct scrub_parity *sparity,
struct map_lookup *map,
struct btrfs_device *sdev,
struct btrfs_path *path,
u64 logical)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *extent_root = btrfs_extent_root(fs_info, logical);
struct btrfs_root *csum_root = btrfs_csum_root(fs_info, logical);
u64 cur_logical = logical;
int ret;
ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
/* Path must not be populated */
ASSERT(!path->nodes[0]);
while (cur_logical < logical + map->stripe_len) {
struct btrfs_io_context *bioc = NULL;
struct btrfs_device *extent_dev;
u64 extent_start;
u64 extent_size;
u64 mapped_length;
u64 extent_flags;
u64 extent_gen;
u64 extent_physical;
u64 extent_mirror_num;
ret = find_first_extent_item(extent_root, path, cur_logical,
logical + map->stripe_len - cur_logical);
/* No more extent item in this data stripe */
if (ret > 0) {
ret = 0;
break;
}
if (ret < 0)
break;
get_extent_info(path, &extent_start, &extent_size, &extent_flags,
&extent_gen);
/* Metadata should not cross stripe boundaries */
if ((extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
does_range_cross_boundary(extent_start, extent_size,
logical, map->stripe_len)) {
btrfs_err(fs_info,
"scrub: tree block %llu spanning stripes, ignored. logical=%llu",
extent_start, logical);
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
cur_logical += extent_size;
continue;
}
/* Skip hole range which doesn't have any extent */
cur_logical = max(extent_start, cur_logical);
/* Truncate the range inside this data stripe */
extent_size = min(extent_start + extent_size,
logical + map->stripe_len) - cur_logical;
extent_start = cur_logical;
ASSERT(extent_size <= U32_MAX);
scrub_parity_mark_sectors_data(sparity, extent_start, extent_size);
mapped_length = extent_size;
ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_start,
&mapped_length, &bioc, 0);
if (!ret && (!bioc || mapped_length < extent_size))
ret = -EIO;
if (ret) {
btrfs_put_bioc(bioc);
scrub_parity_mark_sectors_error(sparity, extent_start,
extent_size);
break;
}
extent_physical = bioc->stripes[0].physical;
extent_mirror_num = bioc->mirror_num;
extent_dev = bioc->stripes[0].dev;
btrfs_put_bioc(bioc);
ret = btrfs_lookup_csums_range(csum_root, extent_start,
extent_start + extent_size - 1,
&sctx->csum_list, 1);
if (ret) {
scrub_parity_mark_sectors_error(sparity, extent_start,
extent_size);
break;
}
ret = scrub_extent_for_parity(sparity, extent_start,
extent_size, extent_physical,
extent_dev, extent_flags,
extent_gen, extent_mirror_num);
scrub_free_csums(sctx);
if (ret) {
scrub_parity_mark_sectors_error(sparity, extent_start,
extent_size);
break;
}
cond_resched();
cur_logical += extent_size;
}
btrfs_release_path(path);
return ret;
}
static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
struct map_lookup *map,
struct btrfs_device *sdev,
u64 logic_start,
u64 logic_end)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_path *path;
u64 cur_logical;
int ret;
struct scrub_parity *sparity;
int nsectors;
path = btrfs_alloc_path();
if (!path) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
path->search_commit_root = 1;
path->skip_locking = 1;
ASSERT(map->stripe_len <= U32_MAX);
nsectors = map->stripe_len >> fs_info->sectorsize_bits;
ASSERT(nsectors <= BITS_PER_LONG);
sparity = kzalloc(sizeof(struct scrub_parity), GFP_NOFS);
if (!sparity) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_free_path(path);
return -ENOMEM;
}
ASSERT(map->stripe_len <= U32_MAX);
sparity->stripe_len = map->stripe_len;
sparity->nsectors = nsectors;
sparity->sctx = sctx;
sparity->scrub_dev = sdev;
sparity->logic_start = logic_start;
sparity->logic_end = logic_end;
refcount_set(&sparity->refs, 1);
INIT_LIST_HEAD(&sparity->sectors_list);
ret = 0;
for (cur_logical = logic_start; cur_logical < logic_end;
cur_logical += map->stripe_len) {
ret = scrub_raid56_data_stripe_for_parity(sctx, sparity, map,
sdev, path, cur_logical);
if (ret < 0)
break;
}
scrub_parity_put(sparity);
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
btrfs_free_path(path);
return ret < 0 ? ret : 0;
}
static void sync_replace_for_zoned(struct scrub_ctx *sctx)
{
if (!btrfs_is_zoned(sctx->fs_info))
return;
sctx->flush_all_writes = true;
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
}
static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
u64 physical, u64 physical_end)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
int ret = 0;
if (!btrfs_is_zoned(fs_info))
return 0;
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
mutex_lock(&sctx->wr_lock);
if (sctx->write_pointer < physical_end) {
ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical,
physical,
sctx->write_pointer);
if (ret)
btrfs_err(fs_info,
"zoned: failed to recover write pointer");
}
mutex_unlock(&sctx->wr_lock);
btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical);
return ret;
}
/*
* Scrub one range which can only has simple mirror based profile.
* (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in
* RAID0/RAID10).
*
* Since we may need to handle a subset of block group, we need @logical_start
* and @logical_length parameter.
*/
static int scrub_simple_mirror(struct scrub_ctx *sctx,
struct btrfs_root *extent_root,
struct btrfs_root *csum_root,
struct btrfs_block_group *bg,
struct map_lookup *map,
u64 logical_start, u64 logical_length,
struct btrfs_device *device,
u64 physical, int mirror_num)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
const u64 logical_end = logical_start + logical_length;
/* An artificial limit, inherit from old scrub behavior */
const u32 max_length = SZ_64K;
struct btrfs_path path = { 0 };
u64 cur_logical = logical_start;
int ret;
/* The range must be inside the bg */
ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
path.search_commit_root = 1;
path.skip_locking = 1;
/* Go through each extent items inside the logical range */
while (cur_logical < logical_end) {
u64 extent_start;
u64 extent_len;
u64 extent_flags;
u64 extent_gen;
u64 scrub_len;
/* Canceled? */
if (atomic_read(&fs_info->scrub_cancel_req) ||
atomic_read(&sctx->cancel_req)) {
ret = -ECANCELED;
break;
}
/* Paused? */
if (atomic_read(&fs_info->scrub_pause_req)) {
/* Push queued extents */
sctx->flush_all_writes = true;
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
sctx->flush_all_writes = false;
scrub_blocked_if_needed(fs_info);
}
/* Block group removed? */
spin_lock(&bg->lock);
if (bg->removed) {
spin_unlock(&bg->lock);
ret = 0;
break;
}
spin_unlock(&bg->lock);
ret = find_first_extent_item(extent_root, &path, cur_logical,
logical_end - cur_logical);
if (ret > 0) {
/* No more extent, just update the accounting */
sctx->stat.last_physical = physical + logical_length;
ret = 0;
break;
}
if (ret < 0)
break;
get_extent_info(&path, &extent_start, &extent_len,
&extent_flags, &extent_gen);
/* Skip hole range which doesn't have any extent */
cur_logical = max(extent_start, cur_logical);
/*
* Scrub len has three limits:
* - Extent size limit
* - Scrub range limit
* This is especially imporatant for RAID0/RAID10 to reuse
* this function
* - Max scrub size limit
*/
scrub_len = min(min(extent_start + extent_len,
logical_end), cur_logical + max_length) -
cur_logical;
if (extent_flags & BTRFS_EXTENT_FLAG_DATA) {
ret = btrfs_lookup_csums_range(csum_root, cur_logical,
cur_logical + scrub_len - 1,
&sctx->csum_list, 1);
if (ret)
break;
}
if ((extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
does_range_cross_boundary(extent_start, extent_len,
logical_start, logical_length)) {
btrfs_err(fs_info,
"scrub: tree block %llu spanning boundaries, ignored. boundary=[%llu, %llu)",
extent_start, logical_start, logical_end);
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
cur_logical += scrub_len;
continue;
}
ret = scrub_extent(sctx, map, cur_logical, scrub_len,
cur_logical - logical_start + physical,
device, extent_flags, extent_gen,
mirror_num);
scrub_free_csums(sctx);
if (ret)
break;
if (sctx->is_dev_replace)
sync_replace_for_zoned(sctx);
cur_logical += scrub_len;
/* Don't hold CPU for too long time */
cond_resched();
}
btrfs_release_path(&path);
return ret;
}
/* Calculate the full stripe length for simple stripe based profiles */
static u64 simple_stripe_full_stripe_len(const struct map_lookup *map)
{
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));
return map->num_stripes / map->sub_stripes * map->stripe_len;
}
/* Get the logical bytenr for the stripe */
static u64 simple_stripe_get_logical(struct map_lookup *map,
struct btrfs_block_group *bg,
int stripe_index)
{
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));
ASSERT(stripe_index < map->num_stripes);
/*
* (stripe_index / sub_stripes) gives how many data stripes we need to
* skip.
*/
return (stripe_index / map->sub_stripes) * map->stripe_len + bg->start;
}
/* Get the mirror number for the stripe */
static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index)
{
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));
ASSERT(stripe_index < map->num_stripes);
/* For RAID0, it's fixed to 1, for RAID10 it's 0,1,0,1... */
return stripe_index % map->sub_stripes + 1;
}
static int scrub_simple_stripe(struct scrub_ctx *sctx,
struct btrfs_root *extent_root,
struct btrfs_root *csum_root,
struct btrfs_block_group *bg,
struct map_lookup *map,
struct btrfs_device *device,
int stripe_index)
{
const u64 logical_increment = simple_stripe_full_stripe_len(map);
const u64 orig_logical = simple_stripe_get_logical(map, bg, stripe_index);
const u64 orig_physical = map->stripes[stripe_index].physical;
const int mirror_num = simple_stripe_mirror_num(map, stripe_index);
u64 cur_logical = orig_logical;
u64 cur_physical = orig_physical;
int ret = 0;
while (cur_logical < bg->start + bg->length) {
/*
* Inside each stripe, RAID0 is just SINGLE, and RAID10 is
* just RAID1, so we can reuse scrub_simple_mirror() to scrub
* this stripe.
*/
ret = scrub_simple_mirror(sctx, extent_root, csum_root, bg, map,
cur_logical, map->stripe_len, device,
cur_physical, mirror_num);
if (ret)
return ret;
/* Skip to next stripe which belongs to the target device */
cur_logical += logical_increment;
/* For physical offset, we just go to next stripe */
cur_physical += map->stripe_len;
}
return ret;
}
static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct extent_map *em,
struct btrfs_device *scrub_dev,
int stripe_index)
{
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *root;
struct btrfs_root *csum_root;
struct blk_plug plug;
struct map_lookup *map = em->map_lookup;
const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
const u64 chunk_logical = bg->start;
int ret;
u64 physical = map->stripes[stripe_index].physical;
const u64 dev_stripe_len = btrfs_calc_stripe_length(em);
const u64 physical_end = physical + dev_stripe_len;
u64 logical;
u64 logic_end;
/* The logical increment after finishing one stripe */
u64 increment;
/* Offset inside the chunk */
u64 offset;
u64 stripe_logical;
u64 stripe_end;
int stop_loop = 0;
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;
path->reada = READA_FORWARD;
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
scrub_blocked_if_needed(fs_info);
root = btrfs_extent_root(fs_info, bg->start);
csum_root = btrfs_csum_root(fs_info, bg->start);
/*
* 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);
if (sctx->is_dev_replace &&
btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
mutex_lock(&sctx->wr_lock);
sctx->write_pointer = physical;
mutex_unlock(&sctx->wr_lock);
sctx->flush_all_writes = true;
}
/*
* There used to be a big double loop to handle all profiles using the
* same routine, which grows larger and more gross over time.
*
* So here we handle each profile differently, so simpler profiles
* have simpler scrubbing function.
*/
if (!(profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID56_MASK))) {
/*
* Above check rules out all complex profile, the remaining
* profiles are SINGLE|DUP|RAID1|RAID1C*, which is simple
* mirrored duplication without stripe.
*
* Only @physical and @mirror_num needs to calculated using
* @stripe_index.
*/
ret = scrub_simple_mirror(sctx, root, csum_root, bg, map,
bg->start, bg->length, scrub_dev,
map->stripes[stripe_index].physical,
stripe_index + 1);
offset = 0;
goto out;
}
if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
ret = scrub_simple_stripe(sctx, root, csum_root, bg, map,
scrub_dev, stripe_index);
offset = map->stripe_len * (stripe_index / map->sub_stripes);
goto out;
}
/* Only RAID56 goes through the old code */
ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
ret = 0;
/* Calculate the logical end of the stripe */
get_raid56_logic_offset(physical_end, stripe_index,
map, &logic_end, NULL);
logic_end += chunk_logical;
/* Initialize @offset in case we need to go to out: label */
get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
increment = map->stripe_len * nr_data_stripes(map);
/*
* Due to the rotation, for RAID56 it's better to iterate each stripe
* using their physical offset.
*/
while (physical < physical_end) {
ret = get_raid56_logic_offset(physical, stripe_index, map,
&logical, &stripe_logical);
logical += chunk_logical;
if (ret) {
/* it is parity strip */
stripe_logical += chunk_logical;
stripe_end = stripe_logical + increment;
ret = scrub_raid56_parity(sctx, map, scrub_dev,
stripe_logical,
stripe_end);
if (ret)
goto out;
goto next;
}
/*
* Now we're at a data stripe, scrub each extents in the range.
*
* At this stage, if we ignore the repair part, inside each data
* stripe it is no different than SINGLE profile.
* We can reuse scrub_simple_mirror() here, as the repair part
* is still based on @mirror_num.
*/
ret = scrub_simple_mirror(sctx, root, csum_root, bg, map,
logical, map->stripe_len,
scrub_dev, physical, 1);
if (ret < 0)
goto out;
next:
logical += increment;
physical += map->stripe_len;
spin_lock(&sctx->stat_lock);
if (stop_loop)
sctx->stat.last_physical =
map->stripes[stripe_index].physical + dev_stripe_len;
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_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
blk_finish_plug(&plug);
btrfs_free_path(path);
if (sctx->is_dev_replace && ret >= 0) {
int ret2;
ret2 = sync_write_pointer_for_zoned(sctx,
chunk_logical + offset,
map->stripes[stripe_index].physical,
physical_end);
if (ret2)
ret = ret2;
}
return ret < 0 ? ret : 0;
}
static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct btrfs_device *scrub_dev,
u64 dev_offset,
u64 dev_extent_len)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
int i;
int ret = 0;
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, bg->start, bg->length);
read_unlock(&map_tree->lock);
if (!em) {
/*
* Might have been an unused block group deleted by the cleaner
* kthread or relocation.
*/
spin_lock(&bg->lock);
if (!bg->removed)
ret = -EINVAL;
spin_unlock(&bg->lock);
return ret;
}
if (em->start != bg->start)
goto out;
if (em->len < dev_extent_len)
goto out;
map = em->map_lookup;
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, bg, em, scrub_dev, i);
if (ret)
goto out;
}
}
out:
free_extent_map(em);
return ret;
}
static int finish_extent_writes_for_zoned(struct btrfs_root *root,
struct btrfs_block_group *cache)
{
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_trans_handle *trans;
if (!btrfs_is_zoned(fs_info))
return 0;
btrfs_wait_block_group_reservations(cache);
btrfs_wait_nocow_writers(cache);
btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
return btrfs_commit_transaction(trans);
}
static noinline_for_stack
int scrub_enumerate_chunks(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev, u64 start, u64 end)
{
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *root = fs_info->dev_root;
u64 chunk_offset;
int ret = 0;
int ro_set;
int slot;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_block_group *cache;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
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) {
u64 dev_extent_len;
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 < 0)
break;
if (ret > 0) {
ret = 0;
break;
}
} else {
ret = 0;
}
}
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 (found_key.type != 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);
dev_extent_len = btrfs_dev_extent_length(l, dev_extent);
if (found_key.offset + dev_extent_len <= start)
goto skip;
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;
ASSERT(cache->start <= chunk_offset);
/*
* We are using the commit root to search for device extents, so
* that means we could have found a device extent item from a
* block group that was deleted in the current transaction. The
* logical start offset of the deleted block group, stored at
* @chunk_offset, might be part of the logical address range of
* a new block group (which uses different physical extents).
* In this case btrfs_lookup_block_group() has returned the new
* block group, and its start address is less than @chunk_offset.
*
* We skip such new block groups, because it's pointless to
* process them, as we won't find their extents because we search
* for them using the commit root of the extent tree. For a device
* replace it's also fine to skip it, we won't miss copying them
* to the target device because we have the write duplication
* setup through the regular write path (by btrfs_map_block()),
* and we have committed a transaction when we started the device
* replace, right after setting up the device replace state.
*/
if (cache->start < chunk_offset) {
btrfs_put_block_group(cache);
goto skip;
}
if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) {
spin_lock(&cache->lock);
if (!cache->to_copy) {
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
goto skip;
}
spin_unlock(&cache->lock);
}
/*
* Make sure that while we are scrubbing the corresponding block
* group doesn't get its logical address and its device extents
* reused for another block group, which can possibly be of a
* different type and different profile. We do this to prevent
* false error detections and crashes due to bogus attempts to
* repair extents.
*/
spin_lock(&cache->lock);
if (cache->removed) {
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
goto skip;
}
btrfs_freeze_block_group(cache);
spin_unlock(&cache->lock);
/*
* we need call btrfs_inc_block_group_ro() with scrubs_paused,
* to avoid deadlock caused by:
* btrfs_inc_block_group_ro()
* -> btrfs_wait_for_commit()
* -> btrfs_commit_transaction()
* -> btrfs_scrub_pause()
*/
scrub_pause_on(fs_info);
/*
* Don't do chunk preallocation for scrub.
*
* This is especially important for SYSTEM bgs, or we can hit
* -EFBIG from btrfs_finish_chunk_alloc() like:
* 1. The only SYSTEM bg is marked RO.
* Since SYSTEM bg is small, that's pretty common.
* 2. New SYSTEM bg will be allocated
* Due to regular version will allocate new chunk.
* 3. New SYSTEM bg is empty and will get cleaned up
* Before cleanup really happens, it's marked RO again.
* 4. Empty SYSTEM bg get scrubbed
* We go back to 2.
*
* This can easily boost the amount of SYSTEM chunks if cleaner
* thread can't be triggered fast enough, and use up all space
* of btrfs_super_block::sys_chunk_array
*
* While for dev replace, we need to try our best to mark block
* group RO, to prevent race between:
* - Write duplication
* Contains latest data
* - Scrub copy
* Contains data from commit tree
*
* If target block group is not marked RO, nocow writes can
* be overwritten by scrub copy, causing data corruption.
* So for dev-replace, it's not allowed to continue if a block
* group is not RO.
*/
ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
if (!ret && sctx->is_dev_replace) {
ret = finish_extent_writes_for_zoned(root, cache);
if (ret) {
btrfs_dec_block_group_ro(cache);
scrub_pause_off(fs_info);
btrfs_put_block_group(cache);
break;
}
}
if (ret == 0) {
ro_set = 1;
} else if (ret == -ENOSPC && !sctx->is_dev_replace) {
/*
* btrfs_inc_block_group_ro return -ENOSPC when it
* failed in creating new chunk for metadata.
* It is not a problem for scrub, because
* metadata are always cowed, and our scrub paused
* commit_transactions.
*/
ro_set = 0;
} else if (ret == -ETXTBSY) {
btrfs_warn(fs_info,
"skipping scrub of block group %llu due to active swapfile",
cache->start);
scrub_pause_off(fs_info);
ret = 0;
goto skip_unfreeze;
} else {
btrfs_warn(fs_info,
"failed setting block group ro: %d", ret);
btrfs_unfreeze_block_group(cache);
btrfs_put_block_group(cache);
scrub_pause_off(fs_info);
break;
}
/*
* Now the target block is marked RO, wait for nocow writes to
* finish before dev-replace.
* COW is fine, as COW never overwrites extents in commit tree.
*/
if (sctx->is_dev_replace) {
btrfs_wait_nocow_writers(cache);
btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start,
cache->length);
}
scrub_pause_off(fs_info);
down_write(&dev_replace->rwsem);
dev_replace->cursor_right = found_key.offset + dev_extent_len;
dev_replace->cursor_left = found_key.offset;
dev_replace->item_needs_writeback = 1;
up_write(&dev_replace->rwsem);
ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset,
dev_extent_len);
/*
* 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.
*/
sctx->flush_all_writes = true;
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
scrub_pause_on(fs_info);
/*
* 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);
sctx->flush_all_writes = false;
scrub_pause_off(fs_info);
if (sctx->is_dev_replace &&
!btrfs_finish_block_group_to_copy(dev_replace->srcdev,
cache, found_key.offset))
ro_set = 0;
down_write(&dev_replace->rwsem);
dev_replace->cursor_left = dev_replace->cursor_right;
dev_replace->item_needs_writeback = 1;
up_write(&dev_replace->rwsem);
if (ro_set)
btrfs_dec_block_group_ro(cache);
/*
* We might have prevented the cleaner kthread from deleting
* this block group if it was already unused because we raced
* and set it to RO mode first. So add it back to the unused
* list, otherwise it might not ever be deleted unless a manual
* balance is triggered or it becomes used and unused again.
*/
spin_lock(&cache->lock);
if (!cache->removed && !cache->ro && cache->reserved == 0 &&
cache->used == 0) {
spin_unlock(&cache->lock);
if (btrfs_test_opt(fs_info, DISCARD_ASYNC))
btrfs_discard_queue_work(&fs_info->discard_ctl,
cache);
else
btrfs_mark_bg_unused(cache);
} else {
spin_unlock(&cache->lock);
}
skip_unfreeze:
btrfs_unfreeze_block_group(cache);
btrfs_put_block_group(cache);
if (ret)
break;
if (sctx->is_dev_replace &&
atomic64_read(&dev_replace->num_write_errors) > 0) {
ret = -EIO;
break;
}
if (sctx->stat.malloc_errors > 0) {
ret = -ENOMEM;
break;
}
skip:
key.offset = found_key.offset + dev_extent_len;
btrfs_release_path(path);
}
btrfs_free_path(path);
return ret;
}
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_fs_info *fs_info = sctx->fs_info;
if (BTRFS_FS_ERROR(fs_info))
return -EROFS;
/* Seed devices of a new filesystem has their own generation. */
if (scrub_dev->fs_devices != fs_info->fs_devices)
gen = scrub_dev->generation;
else
gen = 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->commit_total_bytes)
break;
if (!btrfs_check_super_location(scrub_dev, bytenr))
continue;
ret = scrub_sectors(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
NULL, bytenr);
if (ret)
return ret;
}
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
return 0;
}
static void scrub_workers_put(struct btrfs_fs_info *fs_info)
{
if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt,
&fs_info->scrub_lock)) {
struct workqueue_struct *scrub_workers = fs_info->scrub_workers;
struct workqueue_struct *scrub_wr_comp =
fs_info->scrub_wr_completion_workers;
struct workqueue_struct *scrub_parity =
fs_info->scrub_parity_workers;
fs_info->scrub_workers = NULL;
fs_info->scrub_wr_completion_workers = NULL;
fs_info->scrub_parity_workers = NULL;
mutex_unlock(&fs_info->scrub_lock);
if (scrub_workers)
destroy_workqueue(scrub_workers);
if (scrub_wr_comp)
destroy_workqueue(scrub_wr_comp);
if (scrub_parity)
destroy_workqueue(scrub_parity);
}
}
/*
* 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)
{
struct workqueue_struct *scrub_workers = NULL;
struct workqueue_struct *scrub_wr_comp = NULL;
struct workqueue_struct *scrub_parity = NULL;
unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
int max_active = fs_info->thread_pool_size;
int ret = -ENOMEM;
if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
return 0;
scrub_workers = alloc_workqueue("btrfs-scrub", flags,
is_dev_replace ? 1 : max_active);
if (!scrub_workers)
goto fail_scrub_workers;
scrub_wr_comp = alloc_workqueue("btrfs-scrubwrc", flags, max_active);
if (!scrub_wr_comp)
goto fail_scrub_wr_completion_workers;
scrub_parity = alloc_workqueue("btrfs-scrubparity", flags, max_active);
if (!scrub_parity)
goto fail_scrub_parity_workers;
mutex_lock(&fs_info->scrub_lock);
if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
ASSERT(fs_info->scrub_workers == NULL &&
fs_info->scrub_wr_completion_workers == NULL &&
fs_info->scrub_parity_workers == NULL);
fs_info->scrub_workers = scrub_workers;
fs_info->scrub_wr_completion_workers = scrub_wr_comp;
fs_info->scrub_parity_workers = scrub_parity;
refcount_set(&fs_info->scrub_workers_refcnt, 1);
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
/* Other thread raced in and created the workers for us */
refcount_inc(&fs_info->scrub_workers_refcnt);
mutex_unlock(&fs_info->scrub_lock);
ret = 0;
destroy_workqueue(scrub_parity);
fail_scrub_parity_workers:
destroy_workqueue(scrub_wr_comp);
fail_scrub_wr_completion_workers:
destroy_workqueue(scrub_workers);
fail_scrub_workers:
return ret;
}
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 btrfs_dev_lookup_args args = { .devid = devid };
struct scrub_ctx *sctx;
int ret;
struct btrfs_device *dev;
unsigned int nofs_flag;
if (btrfs_fs_closing(fs_info))
return -EAGAIN;
if (fs_info->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->nodesize,
BTRFS_STRIPE_LEN);
return -EINVAL;
}
if (fs_info->nodesize >
SCRUB_MAX_SECTORS_PER_BLOCK << fs_info->sectorsize_bits ||
fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_SECTORS_PER_BLOCK) {
/*
* Would exhaust the array bounds of sectorv member in
* struct scrub_block
*/
btrfs_err(fs_info,
"scrub: nodesize and sectorsize <= SCRUB_MAX_SECTORS_PER_BLOCK (%d <= %d && %d <= %d) fails",
fs_info->nodesize, SCRUB_MAX_SECTORS_PER_BLOCK,
fs_info->sectorsize, SCRUB_MAX_SECTORS_PER_BLOCK);
return -EINVAL;
}
/* Allocate outside of device_list_mutex */
sctx = scrub_setup_ctx(fs_info, is_dev_replace);
if (IS_ERR(sctx))
return PTR_ERR(sctx);
ret = scrub_workers_get(fs_info, is_dev_replace);
if (ret)
goto out_free_ctx;
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, &args);
if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
!is_dev_replace)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -ENODEV;
goto out;
}
if (!is_dev_replace && !readonly &&
!test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
btrfs_err_in_rcu(fs_info,
"scrub on devid %llu: filesystem on %s is not writable",
devid, rcu_str_deref(dev->name));
ret = -EROFS;
goto out;
}
mutex_lock(&fs_info->scrub_lock);
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -EIO;
goto out;
}
down_read(&fs_info->dev_replace.rwsem);
if (dev->scrub_ctx ||
(!is_dev_replace &&
btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
up_read(&fs_info->dev_replace.rwsem);
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -EINPROGRESS;
goto out;
}
up_read(&fs_info->dev_replace.rwsem);
sctx->readonly = readonly;
dev->scrub_ctx = 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);
/*
* In order to avoid deadlock with reclaim when there is a transaction
* trying to pause scrub, make sure we use GFP_NOFS for all the
* allocations done at btrfs_scrub_sectors() and scrub_sectors_for_parity()
* invoked by our callees. The pausing request is done when the
* transaction commit starts, and it blocks the transaction until scrub
* is paused (done at specific points at scrub_stripe() or right above
* before incrementing fs_info->scrubs_running).
*/
nofs_flag = memalloc_nofs_save();
if (!is_dev_replace) {
btrfs_info(fs_info, "scrub: started on devid %llu", devid);
/*
* 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);
memalloc_nofs_restore(nofs_flag);
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));
if (!is_dev_replace)
btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
ret ? "not finished" : "finished", devid, ret);
mutex_lock(&fs_info->scrub_lock);
dev->scrub_ctx = NULL;
mutex_unlock(&fs_info->scrub_lock);
scrub_workers_put(fs_info);
scrub_put_ctx(sctx);
return ret;
out:
scrub_workers_put(fs_info);
out_free_ctx:
scrub_free_ctx(sctx);
return ret;
}
void btrfs_scrub_pause(struct btrfs_fs_info *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_fs_info *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_device *dev)
{
struct btrfs_fs_info *fs_info = dev->fs_info;
struct scrub_ctx *sctx;
mutex_lock(&fs_info->scrub_lock);
sctx = dev->scrub_ctx;
if (!sctx) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&sctx->cancel_req);
while (dev->scrub_ctx) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
dev->scrub_ctx == NULL);
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
struct btrfs_scrub_progress *progress)
{
struct btrfs_dev_lookup_args args = { .devid = devid };
struct btrfs_device *dev;
struct scrub_ctx *sctx = NULL;
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, &args);
if (dev)
sctx = dev->scrub_ctx;
if (sctx)
memcpy(progress, &sctx->stat, sizeof(*progress));
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
}
static void scrub_find_good_copy(struct btrfs_fs_info *fs_info,
u64 extent_logical, u32 extent_len,
u64 *extent_physical,
struct btrfs_device **extent_dev,
int *extent_mirror_num)
{
u64 mapped_length;
struct btrfs_io_context *bioc = NULL;
int ret;
mapped_length = extent_len;
ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
&mapped_length, &bioc, 0);
if (ret || !bioc || mapped_length < extent_len ||
!bioc->stripes[0].dev->bdev) {
btrfs_put_bioc(bioc);
return;
}
*extent_physical = bioc->stripes[0].physical;
*extent_mirror_num = bioc->mirror_num;
*extent_dev = bioc->stripes[0].dev;
btrfs_put_bioc(bioc);
}
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