Re: [PATCH] btrfs: return -EIO on error in btree_write_cache_pages

From: Eric Sandeen <esandeen@redhat.com>
To: Josef Bacik <josef@toxicpanda.com>,
	linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH] btrfs: return -EIO on error in btree_write_cache_pages
Date: Fri, 10 Jul 2020 07:50:15 -0700	[thread overview]
Message-ID: <2666ea17-def0-7a5b-7af9-646a9edf03cf@redhat.com> (raw)
In-Reply-To: <20200710140619.2366724-1-josef@toxicpanda.com>

On 7/10/20 9:06 AM, Josef Bacik wrote:
> Eric reported seeing this message while running generic/475
> 
> BTRFS: error (device dm-3) in btrfs_sync_log:3084: errno=-117 Filesystem corrupted
> 
> This ret came from btrfs_write_marked_extents().  If we get an aborted
> transaction via an -EIO somewhere, we'll see it in
> btree_write_cache_pages() and return -EUCLEAN, which we spit out as
> "Filesystem corrupted".  Except we shouldn't be returning -EUCLEAN here,
> we need to be returning -EIO.  -EUCLEAN is reserved for actual
> corruption, not IO errors.

Is BTRFS_FS_STATE_ERROR only set for IO errors, or could it also be
set for an actual corruption state?

> Reported-by: Eric Sandeen <esandeen@redhat.com>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  fs/btrfs/extent_io.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index a76b7da91aa6..6f0dd15729cc 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -4122,7 +4122,7 @@ int btree_write_cache_pages(struct address_space *mapping,
>  	if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
>  		ret = flush_write_bio(&epd);
>  	} else {
> -		ret = -EUCLEAN;
> +		ret = -EIO;
>  		end_write_bio(&epd, ret);
>  	}
>  	return ret;
> 