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btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure

Browse source 
Switch scrub_simple_mirror() to the new scrub_stripe infrastructure.

Since scrub_simple_mirror() is the core part of scrub (only RAID56
P/Q stripes don't utilize it), we can get rid of a big chunk of code,
mostly scrub_extent(), scrub_sectors() and directly called functions.

There is a functionality change:

- Scrub speed throttle now only affects read on the scrubbing device
  Writes (for repair and replace), and reads from other mirrors won't
  be limited by the set limits.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2023-03-20 10:12:58 +08:00 committed by David Sterba
parent 54765392a1
commit e02ee89baa
2 changed files with 28 additions and 473 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

491
fs/btrfs/scrub.c
View file

@ -582,10 +582,6 @@ 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);
@ -2952,22 +2948,15 @@ static void scrub_sector_put(struct scrub_sector *sector)
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)
static void scrub_throttle_dev_io(struct scrub_ctx *sctx, struct btrfs_device *device,
unsigned int bio_size)
{
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;
@ -2989,7 +2978,7 @@ static void scrub_throttle(struct scrub_ctx *sctx)
/* 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;
sctx->throttle_sent += bio_size;
if (sctx->throttle_sent <= div_u64(bwlimit, div))
return;
@ -3011,6 +3000,17 @@ static void scrub_throttle(struct scrub_ctx *sctx)
sctx->throttle_deadline = 0;
}
/*
* 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)
{
struct scrub_bio *sbio = sctx->bios[sctx->curr];
scrub_throttle_dev_io(sctx, sbio->dev, sbio->bio->bi_iter.bi_size);
}
static void scrub_submit(struct scrub_ctx *sctx)
{
struct scrub_bio *sbio;
@ -3095,202 +3095,6 @@ static int scrub_add_sector_to_rd_bio(struct scrub_ctx *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;
btrfs_bio_counter_dec(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->logical;
dev = sblock->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, btrfs_dev_name(dev));
} 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, btrfs_dev_name(dev));
} 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->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)
goto bioc_out;
if (WARN_ON(!sctx->is_dev_replace ||
!(bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
/*
* We shouldn't be scrubbing a missing device. Even for dev
* replace, we should only get here for RAID 5/6. We either
* managed to mount something with no mirrors remaining or
* there's a bug in scrub_find_good_copy()/btrfs_map_block().
*/
goto bioc_out;
}
bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
bio->bi_iter.bi_sector = logical >> 9;
bio->bi_private = sblock;
bio->bi_end_io = scrub_missing_raid56_end_io;
rbio = raid56_alloc_missing_rbio(bio, bioc);
if (!rbio)
goto rbio_out;
for (i = 0; i < sblock->sector_count; i++) {
struct scrub_sector *sector = sblock->sectors[i];
raid56_add_scrub_pages(rbio, scrub_sector_get_page(sector),
scrub_sector_get_page_offset(sector),
sector->offset + sector->sblock->logical);
}
INIT_WORK(&sblock->work, scrub_missing_raid56_worker);
scrub_block_get(sblock);
scrub_pending_bio_inc(sctx);
raid56_submit_missing_rbio(rbio);
btrfs_put_bioc(bioc);
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 = alloc_scrub_block(sctx, dev, logical, physical,
physical_for_dev_replace, mirror_num);
if (!sblock) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
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 = alloc_scrub_sector(sblock, logical);
if (!sector) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_block_put(sblock);
return -ENOMEM;
}
sector->flags = flags;
sector->generation = gen;
if (csum) {
sector->have_csum = 1;
memcpy(sector->csum, csum, sctx->fs_info->csum_size);
} else {
sector->have_csum = 0;
}
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;
@ -3475,179 +3279,6 @@ static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
return 1;
}
static bool should_use_device(struct btrfs_fs_info *fs_info,
struct btrfs_device *dev,
bool follow_replace_read_mode)
{
struct btrfs_device *replace_srcdev = fs_info->dev_replace.srcdev;
struct btrfs_device *replace_tgtdev = fs_info->dev_replace.tgtdev;
if (!dev->bdev)
return false;
/*
* We're doing scrub/replace, if it's pure scrub, no tgtdev should be
* here. If it's replace, we're going to write data to tgtdev, thus
* the current data of the tgtdev is all garbage, thus we can not use
* it at all.
*/
if (dev == replace_tgtdev)
return false;
/* No need to follow replace read mode, any existing device is fine. */
if (!follow_replace_read_mode)
return true;
/* Need to follow the mode. */
if (fs_info->dev_replace.cont_reading_from_srcdev_mode ==
BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
return dev != replace_srcdev;
return true;
}
static int 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;
int i;
mapped_length = extent_len;
ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
extent_logical, &mapped_length, &bioc, 0);
if (ret || !bioc || mapped_length < extent_len) {
btrfs_put_bioc(bioc);
btrfs_err_rl(fs_info, "btrfs_map_block() failed for logical %llu: %d",
extent_logical, ret);
return -EIO;
}
/*
* First loop to exclude all missing devices and the source device if
* needed. And we don't want to use target device as mirror either, as
* we're doing the replace, the target device range contains nothing.
*/
for (i = 0; i < bioc->num_stripes - bioc->replace_nr_stripes; i++) {
struct btrfs_io_stripe *stripe = &bioc->stripes[i];
if (!should_use_device(fs_info, stripe->dev, true))
continue;
goto found;
}
/*
* We didn't find any alternative mirrors, we have to break our replace
* read mode, or we can not read at all.
*/
for (i = 0; i < bioc->num_stripes - bioc->replace_nr_stripes; i++) {
struct btrfs_io_stripe *stripe = &bioc->stripes[i];
if (!should_use_device(fs_info, stripe->dev, false))
continue;
goto found;
}
btrfs_err_rl(fs_info, "failed to find any live mirror for logical %llu",
extent_logical);
return -EIO;
found:
*extent_physical = bioc->stripes[i].physical;
*extent_mirror_num = i + 1;
*extent_dev = bioc->stripes[i].dev;
btrfs_put_bioc(bioc);
return 0;
}
static bool scrub_need_different_mirror(struct scrub_ctx *sctx,
struct map_lookup *map,
struct btrfs_device *dev)
{
/*
* For RAID56, all the extra mirrors are rebuilt from other P/Q,
* cannot utilize other mirrors directly.
*/
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
return false;
if (!dev->bdev)
return true;
return sctx->fs_info->dev_replace.cont_reading_from_srcdev_mode ==
BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID;
}
/* 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 = BTRFS_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 = BTRFS_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, or
* we want to avoid reading from the source device if possible.
*/
if (sctx->is_dev_replace && scrub_need_different_mirror(sctx, map, dev)) {
ret = scrub_find_good_copy(sctx->fs_info, logical, len,
&src_physical, &src_dev, &src_mirror);
if (ret < 0)
return ret;
}
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,
@ -4230,20 +3861,6 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
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)
{
@ -4488,6 +4105,9 @@ static void flush_scrub_stripes(struct scrub_ctx *sctx)
return;
ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state));
scrub_throttle_dev_io(sctx, sctx->stripes[0].dev,
nr_stripes << BTRFS_STRIPE_LEN_SHIFT);
for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];
scrub_submit_initial_read(sctx, stripe);
@ -4551,9 +4171,9 @@ static void flush_scrub_stripes(struct scrub_ctx *sctx)
sctx->cur_stripe = 0;
}
int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg,
struct btrfs_device *dev, int mirror_num,
u64 logical, u32 length, u64 physical)
static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg,
struct btrfs_device *dev, int mirror_num,
u64 logical, u32 length, u64 physical)
{
struct scrub_stripe *stripe;
int ret;
@ -4591,11 +4211,8 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
u64 physical, int mirror_num)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *csum_root = btrfs_csum_root(fs_info, bg->start);
struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start);
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;
@ -4607,11 +4224,7 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
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;
u64 cur_physical = physical + cur_logical - logical_start;
/* Canceled? */
if (atomic_read(&fs_info->scrub_cancel_req) ||
@ -4641,8 +4254,9 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
}
spin_unlock(&bg->lock);
ret = find_first_extent_item(extent_root, &path, cur_logical,
logical_end - cur_logical);
ret = queue_scrub_stripe(sctx, bg, device, mirror_num,
cur_logical, logical_end - cur_logical,
cur_physical);
if (ret > 0) {
/* No more extent, just update the accounting */
sctx->stat.last_physical = physical + logical_length;
@ -4651,52 +4265,11 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
}
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;
ASSERT(sctx->cur_stripe > 0);
cur_logical = sctx->stripes[sctx->cur_stripe - 1].logical
+ BTRFS_STRIPE_LEN;
if (extent_flags & BTRFS_EXTENT_FLAG_DATA) {
ret = btrfs_lookup_csums_list(csum_root, cur_logical,
cur_logical + scrub_len - 1,
&sctx->csum_list, 1, false);
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();
}
@ -4781,7 +4354,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
int stripe_index)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct blk_plug plug;
struct map_lookup *map = em->map_lookup;
const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
const u64 chunk_logical = bg->start;
@ -4803,12 +4375,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
atomic_read(&sctx->bios_in_flight) == 0);
scrub_blocked_if_needed(fs_info);
/*
* 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);
@ -4910,8 +4476,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
blk_finish_plug(&plug);
flush_scrub_stripes(sctx);
if (sctx->is_dev_replace && ret >= 0) {
int ret2;

10
fs/btrfs/scrub.h
View file

@ -13,14 +13,4 @@ int btrfs_scrub_cancel_dev(struct btrfs_device *dev);
int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
struct btrfs_scrub_progress *progress);
/*
* The following functions are temporary exports to avoid warning on unused
* static functions.
*/
struct scrub_stripe;
int queue_scrub_stripe(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct btrfs_device *dev, int mirror_num,
u64 logical, u32 length, u64 physical);
#endif