Re: [PATCH] common/rc: fix _try_scratch_mount() and _test_mount() when mount fails

[Dave Chinner <david@fromorbit.com>]

On Mon, Apr 11, 2022 at 03:08:38PM +0100, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> After the recent commit 4a7b35d7a76cd9 ("common: allow to run all tests
> on idmapped mounts"), some test that use _try_scratch_mount started to
> fail. For example:
> 
> $ ./check btrfs/131 btrfs/220
> FSTYP         -- btrfs
> PLATFORM      -- Linux/x86_64 debian9 5.17.0-rc8-btrfs-next-114 (...)
> MKFS_OPTIONS  -- /dev/sdc
> MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
> 
> btrfs/131 2s ... - output mismatch (see .../results//btrfs/131.out.bad)
>     --- tests/btrfs/131.out	2020-06-10 19:29:03.818519162 +0100
>     +++ /home/fdmanana/git/hub/xfstests/results//btrfs/131.out.bad (...)
>     @@ -6,8 +6,6 @@
>      Disabling free space cache and enabling free space tree
>      free space tree is enabled
>      Trying to mount without free space tree
>     -mount failed
>     -mount failed
>      Mounting existing free space tree
>      free space tree is enabled
>     ...
>     (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/131.out ...
> btrfs/220 7s ... - output mismatch (see .../results//btrfs/220.out.bad)
>     --- tests/btrfs/220.out	2020-10-16 23:13:46.802162554 +0100
>     +++ /home/fdmanana/git/hub/xfstests/results//btrfs/220.out.bad (...)
>     @@ -1,2 +1,32 @@
>      QA output created by 220
>     +Option fragment=invalid should fail to mount
>     +umount: /home/fdmanana/btrfs-tests/scratch_1: not mounted.
>     +Option nologreplay should fail to mount
>     +umount: /home/fdmanana/btrfs-tests/scratch_1: not mounted.
>     +Option norecovery should fail to mount
>     +umount: /home/fdmanana/btrfs-tests/scratch_1: not mounted.
>     ...
>     (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/220.out ...
> Ran: btrfs/131 btrfs/220
> Failures: btrfs/131 btrfs/220
> Failed 2 of 2 tests
> 
> The reason is that if _try_scratch_mount() fails to mount the filesystem,
> we don't return the failure, instead we call _idmapped_mount(), which
> can succeed and make _try_scratch_mount() return 0 (success). The same
> happens for _test_mount(), however a quick search revealed no tests
> currently relying on the return value of _test_mount().
> 
> So fix that by making _try_scratch_mount() return immediately if it gets
> a mount failure. Also do the same for _test_mount().
> 
> Signed-off-by: Filipe Manana <fdmanana@suse.com>
> ---
>  common/rc | 8 ++++++++
>  1 file changed, 8 insertions(+)

Yup, that fixes the generic/607 failure that I just hit.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

-- 
Dave Chinner
david@fromorbit.com