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linux/fs/btrfs/scrub.c
Qu Wenruo a13467ee7a btrfs: scrub: move scrub_remap_extent() call into scrub_extent() 
[SUSPICIOUS CODE]
When refactoring scrub code, I noticed a very strange behavior around
scrub_remap_extent():

	if (sctx->is_dev_replace)
		scrub_remap_extent(fs_info, cur_logical, scrub_len,
				   &cur_physical, &target_dev, &cur_mirror);

As replace target is a 1:1 copy of the source device, thus physical
offset inside the target should be the same as physical inside source,
thus this remap call makes no sense to me.

[REAL FUNCTIONALITY]
After more investigation, the function name scrub_remap_extent()
doesn't tell anything of the truth, nor does its if () condition.

The real story behind this function is that, for scrub_pages() we never
expect missing device, even for replacing missing device.

What scrub_remap_extent() is really doing is to find a live mirror, and
make later scrub_pages() to read data from the good copy, other than
from the missing device and increase error counters unnecessarily.

[IMPROVEMENT]
We have no need to bother scrub_remap_extent() in scrub_simple_mirror()
at all, we only need to call it before we call scrub_pages().

And rename the function to scrub_find_live_copy(), add extra comments on
them.

By this we can remove one parameter from scrub_extent(), and reduce the
unnecessary calls to scrub_remap_extent() for regular replace.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-05-16 17:17:31 +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;
unsigned long bitmap[];
};
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,
u64 mapped_length,
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] + mapped_length)
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,
mapped_length,
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);
int ret;
int mirror_num;
bio->bi_iter.bi_sector = sector->logical >> 9;
bio->bi_private = &done;
bio->bi_end_io = scrub_bio_wait_endio;
mirror_num = sector->sblock->sectors[0]->mirror_num;
ret = raid56_parity_recover(bio, sector->recover->bioc,
sector->recover->map_length,
mirror_num, 0);
if (ret)
return ret;
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, length);
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, length,
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 inline int scrub_calc_parity_bitmap_len(int nsectors)
{
return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
}
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;
int bitmap_len;
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;
bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
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);
sparity->dbitmap = sparity->bitmap;
sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
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 map_lookup *map,
struct btrfs_device *scrub_dev,
int stripe_index, u64 dev_extent_len)
{
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;
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 physical_end = physical + dev_extent_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_extent_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, map, scrub_dev, i,
dev_extent_len);
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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