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| author | Qu Wenruo <wqu@suse.com> | 2022-11-07 07:23:26 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2022-11-07 14:35:14 +0100 |
| commit | b75b51f886e9dd8cdfca1392ad43f4e542611c00 (patch) | |
| tree | d9b4cf926cf581b104bfb5e07b66b2c49b8d7b3f /fs/btrfs/scrub.c | |
| parent | 8bb808c6ad91ec3d332f072ce8f8aa4b16e307e0 (diff) | |
| download | linux-b75b51f886e9dd8cdfca1392ad43f4e542611c00.tar.bz2 | |
Revert "btrfs: scrub: use larger block size for data extent scrub"
This reverts commit 786672e9e1a39a231806313e3c445c236588ceef.
[BUG]
Since commit 786672e9e1a3 ("btrfs: scrub: use larger block size for data
extent scrub"), btrfs scrub no longer reports errors if the corruption
is not in the first sector of a STRIPE_LEN.
The following script can expose the problem:
mkfs.btrfs -f $dev
mount $dev $mnt
xfs_io -f -c "pwrite -S 0xff 0 8k" $mnt/foobar
umount $mnt
# 13631488 is the logical bytenr of above 8K extent
btrfs-map-logical -l 13631488 -b 4096 $dev
mirror 1 logical 13631488 physical 13631488 device /dev/test/scratch1
# Corrupt the 2nd sector of that extent
xfs_io -f -c "pwrite -S 0x00 13635584 4k" $dev
mount $dev $mnt
btrfs scrub start -B $mnt
scrub done for 54e63f9f-0c30-4c84-a33b-5c56014629b7
Scrub started: Mon Nov 7 07:18:27 2022
Status: finished
Duration: 0:00:00
Total to scrub: 536.00MiB
Rate: 0.00B/s
Error summary: no errors found <<<
[CAUSE]
That offending commit enlarges the data extent scrub size from sector
size to BTRFS_STRIPE_LEN, to avoid extra scrub_block to be allocated.
But unfortunately the data extent scrub is still heavily relying on the
fact that there is only one scrub_sector per scrub_block.
Thus it will only check the first sector, and ignoring the remaining
sectors.
Furthermore the error reporting is not able to handle multiple sectors
either.
[FIX]
For now just revert the offending commit.
The consequence is just extra memory usage during scrub.
We will need a proper change to make the remaining data scrub path to
handle multiple sectors before we enlarging the data scrub size.
Reported-by: Li Zhang <zhanglikernel@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/scrub.c')
| -rw-r--r-- | fs/btrfs/scrub.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index f260c53829e5..b659c67af1e0 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2672,17 +2672,11 @@ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map, u8 csum[BTRFS_CSUM_SIZE]; u32 blocksize; - /* - * Block size determines how many scrub_block will be allocated. Here - * we use BTRFS_STRIPE_LEN (64KiB) as default limit, so we won't - * allocate too many scrub_block, while still won't cause too large - * bios for large extents. - */ if (flags & BTRFS_EXTENT_FLAG_DATA) { if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) blocksize = map->stripe_len; else - blocksize = BTRFS_STRIPE_LEN; + blocksize = sctx->fs_info->sectorsize; spin_lock(&sctx->stat_lock); sctx->stat.data_extents_scrubbed++; sctx->stat.data_bytes_scrubbed += len; |