diff options
author | Qu Wenruo <wqu@suse.com> | 2022-08-02 09:53:03 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 14:25:51 +0300 |
commit | 70f8b48d0b61b2b31f58cc2890ba86fdf89e5c53 (patch) | |
tree | 2c38acac3799e21af09febc2487ee6307aa584f2 /fs/btrfs | |
parent | 8f554dd23c18fa4a1ca77c8ce2a49e6fb8d8f9c8 (diff) | |
download | linux-70f8b48d0b61b2b31f58cc2890ba86fdf89e5c53.tar.xz |
btrfs: scrub: try to fix super block errors
[ Upstream commit f9eab5f0bba76742af654f33d517bf62a0db8f12 ]
[BUG]
The following script shows that, although scrub can detect super block
errors, it never tries to fix it:
mkfs.btrfs -f -d raid1 -m raid1 $dev1 $dev2
xfs_io -c "pwrite 67108864 4k" $dev2
mount $dev1 $mnt
btrfs scrub start -B $dev2
btrfs scrub start -Br $dev2
umount $mnt
The first scrub reports the super error correctly:
scrub done for f3289218-abd3-41ac-a630-202f766c0859
Scrub started: Tue Aug 2 14:44:11 2022
Status: finished
Duration: 0:00:00
Total to scrub: 1.26GiB
Rate: 0.00B/s
Error summary: super=1
Corrected: 0
Uncorrectable: 0
Unverified: 0
But the second read-only scrub still reports the same super error:
Scrub started: Tue Aug 2 14:44:11 2022
Status: finished
Duration: 0:00:00
Total to scrub: 1.26GiB
Rate: 0.00B/s
Error summary: super=1
Corrected: 0
Uncorrectable: 0
Unverified: 0
[CAUSE]
The comments already shows that super block can be easily fixed by
committing a transaction:
/*
* If we find an error in a super block, we just report it.
* They will get written with the next transaction commit
* anyway
*/
But the truth is, such assumption is not always true, and since scrub
should try to repair every error it found (except for read-only scrub),
we should really actively commit a transaction to fix this.
[FIX]
Just commit a transaction if we found any super block errors, after
everything else is done.
We cannot do this just after scrub_supers(), as
btrfs_commit_transaction() will try to pause and wait for the running
scrub, thus we can not call it with scrub_lock hold.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/btrfs')
-rw-r--r-- | fs/btrfs/scrub.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 0392c556af60..88b9a5394561 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3811,6 +3811,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, int ret; struct btrfs_device *dev; unsigned int nofs_flag; + bool need_commit = false; if (btrfs_fs_closing(fs_info)) return -EAGAIN; @@ -3924,6 +3925,12 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, */ nofs_flag = memalloc_nofs_save(); if (!is_dev_replace) { + u64 old_super_errors; + + spin_lock(&sctx->stat_lock); + old_super_errors = sctx->stat.super_errors; + spin_unlock(&sctx->stat_lock); + btrfs_info(fs_info, "scrub: started on devid %llu", devid); /* * by holding device list mutex, we can @@ -3932,6 +3939,16 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, mutex_lock(&fs_info->fs_devices->device_list_mutex); ret = scrub_supers(sctx, dev); mutex_unlock(&fs_info->fs_devices->device_list_mutex); + + spin_lock(&sctx->stat_lock); + /* + * Super block errors found, but we can not commit transaction + * at current context, since btrfs_commit_transaction() needs + * to pause the current running scrub (hold by ourselves). + */ + if (sctx->stat.super_errors > old_super_errors && !sctx->readonly) + need_commit = true; + spin_unlock(&sctx->stat_lock); } if (!ret) @@ -3958,6 +3975,25 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, scrub_workers_put(fs_info); scrub_put_ctx(sctx); + /* + * We found some super block errors before, now try to force a + * transaction commit, as scrub has finished. + */ + if (need_commit) { + struct btrfs_trans_handle *trans; + + trans = btrfs_start_transaction(fs_info->tree_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + btrfs_err(fs_info, + "scrub: failed to start transaction to fix super block errors: %d", ret); + return ret; + } + ret = btrfs_commit_transaction(trans); + if (ret < 0) + btrfs_err(fs_info, + "scrub: failed to commit transaction to fix super block errors: %d", ret); + } return ret; out: scrub_workers_put(fs_info); |