[PATCH] fstests: re-add btrfs/125 into auto group

[PATCH] fstests: re-add btrfs/125 into auto group

[Qu Wenruo]

Test case btrfs/125 previous has a very random pass/fail ratio.

This is due to the fact that previously btrfs RAID56 recovery path will
always trust the cached data.

Thus if there is some operation reading part/all of the full stripe,
that full stripe can be cached, making later recovery to generate bad
data.

As the cached data can be stale (intentionally caused by the test case).

Upstream commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage
compatible") incidentally disable all the cache re-use for btrfs RAID56,
thus make btrfs/125 to always pass.

Although we will later re-enable the cache behavior for btrfs RAID56, we
will not let recovery path to use any cache at all, thus this will give
us the best things from both worlds, making btrfs/125 to pass
consistently, while still enable cache for regular read/write.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 tests/btrfs/125 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/btrfs/125 b/tests/btrfs/125
index b58f2aa282bd..ced812cd921a 100755
--- a/tests/btrfs/125
+++ b/tests/btrfs/125
@@ -22,7 +22,7 @@
 # Verify if all three checkpoints match
 #
 . ./common/preamble
-_begin_fstest replace volume balance
+_begin_fstest auto replace volume balance
 
 # Override the default cleanup function.
 _cleanup()
-- 
2.36.1

Re: [PATCH] fstests: re-add btrfs/125 into auto group

[Filipe Manana]

On Wed, Jun 08, 2022 at 03:20:21PM +0800, Qu Wenruo wrote:
> Test case btrfs/125 previous has a very random pass/fail ratio.
> 
> This is due to the fact that previously btrfs RAID56 recovery path will
> always trust the cached data.
> 
> Thus if there is some operation reading part/all of the full stripe,
> that full stripe can be cached, making later recovery to generate bad
> data.
> 
> As the cached data can be stale (intentionally caused by the test case).
> 
> Upstream commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage
> compatible") incidentally disable all the cache re-use for btrfs RAID56,
> thus make btrfs/125 to always pass.
> 
> Although we will later re-enable the cache behavior for btrfs RAID56, we
> will not let recovery path to use any cache at all, thus this will give
> us the best things from both worlds, making btrfs/125 to pass
> consistently, while still enable cache for regular read/write.

The test has failed very often, and that's due to known problem with
degraded rw mounts and partial stripe writes [1].

I just ran it again, and the problem is obviously still there, as nothing
changed regarding that problem:

root 10:18:07 /home/fdmanana/git/hub/xfstests (for-next)> ./check btrfs/125
FSTYP         -- btrfs
PLATFORM      -- Linux/x86_64 debian9 5.18.0-btrfs-next-119 #1 SMP PREEMPT_DYNAMIC Sat May 28 20:28:23 WEST 2022
MKFS_OPTIONS  -- /dev/sdb
MOUNT_OPTIONS -- /dev/sdb /home/fdmanana/btrfs-tests/scratch_1

btrfs/125 5s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/125.out.bad)
    --- tests/btrfs/125.out	2020-06-10 19:29:03.818519162 +0100
    +++ /home/fdmanana/git/hub/xfstests/results//btrfs/125.out.bad	2022-06-08 10:18:13.521948910 +0100
    @@ -3,5 +3,15 @@
     Write data with degraded mount
     
     Mount normal and balance
    +ERROR: error during balancing '/home/fdmanana/btrfs-tests/scratch_1': Input/output error
    +There may be more info in syslog - try dmesg | tail
    +md5sum: /home/fdmanana/btrfs-tests/scratch_1/tf2: Input/output error
     
    ...
    (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/125.out /home/fdmanana/git/hub/xfstests/results//btrfs/125.out.bad'  to see the entire diff)
Ran: btrfs/125
Failures: btrfs/125
Failed 1 of 1 tests

root 10:18:17 /home/fdmanana/git/hub/xfstests (for-next)> dmesg
[777880.530807] run fstests btrfs/125 at 2022-06-08 10:18:09
[777881.341004] BTRFS: device fsid fc182050-867d-42b3-8b70-7a717d5d8c10 devid 1 transid 6 /dev/sdb scanned by mkfs.btrfs (3174370)
[777881.343023] BTRFS: device fsid fc182050-867d-42b3-8b70-7a717d5d8c10 devid 2 transid 6 /dev/sdd scanned by mkfs.btrfs (3174370)
[777881.343156] BTRFS: device fsid fc182050-867d-42b3-8b70-7a717d5d8c10 devid 3 transid 6 /dev/sde scanned by mkfs.btrfs (3174370)
[777881.360352] BTRFS info (device sdb): flagging fs with big metadata feature
[777881.360356] BTRFS info (device sdb): using free space tree
[777881.360357] BTRFS info (device sdb): has skinny extents
[777881.365900] BTRFS info (device sdb): checking UUID tree
[777881.459545] BTRFS: device fsid fc182050-867d-42b3-8b70-7a717d5d8c10 devid 2 transid 8 /dev/sdd scanned by mount (3174418)
[777881.459637] BTRFS: device fsid fc182050-867d-42b3-8b70-7a717d5d8c10 devid 1 transid 8 /dev/sdb scanned by mount (3174418)
[777881.460202] BTRFS info (device sdb): flagging fs with big metadata feature
[777881.460204] BTRFS info (device sdb): allowing degraded mounts
[777881.460206] BTRFS info (device sdb): using free space tree
[777881.460206] BTRFS info (device sdb): has skinny extents
[777881.466293] BTRFS warning (device sdb): devid 3 uuid a9540970-da42-44f8-9e62-30e6fdf013af is missing
[777881.466568] BTRFS warning (device sdb): devid 3 uuid a9540970-da42-44f8-9e62-30e6fdf013af is missing
[777881.923840] BTRFS: device fsid 57e10060-7318-4cd3-8e2d-4c3e481b1dab devid 1 transid 16797 /dev/sda scanned by btrfs (3174443)
[777881.939421] BTRFS info (device sdb): flagging fs with big metadata feature
[777881.939425] BTRFS info (device sdb): using free space tree
[777881.939426] BTRFS info (device sdb): has skinny extents
[777881.959199] BTRFS info (device sdb): balance: start -d -m -s
[777881.959348] BTRFS info (device sdb): relocating block group 754581504 flags data|raid5
[777882.352088] verify_parent_transid: 787 callbacks suppressed
[777882.352092] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.352327] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.352481] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.352692] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.352844] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.353066] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.353241] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.353567] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.353760] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.353982] BTRFS error (device sdb): parent transid verify failed on 38993920 wanted 9 found 5
[777882.455036] BTRFS info (device sdb): balance: ended with status: -5
[777882.456202] BTRFS: error (device sdb: state A) in do_free_extent_accounting:2864: errno=-5 IO failure

So I don't think it should be added to the auto group.
Thanks.

[1] https://lore.kernel.org/linux-btrfs/CAL3q7H4oa70DUhOFE7kot62KjxcbvvZKxu62VfLpAcmgsinBFw@mail.gmail.com/
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  tests/btrfs/125 | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/btrfs/125 b/tests/btrfs/125
> index b58f2aa282bd..ced812cd921a 100755
> --- a/tests/btrfs/125
> +++ b/tests/btrfs/125
> @@ -22,7 +22,7 @@
>  # Verify if all three checkpoints match
>  #
>  . ./common/preamble
> -_begin_fstest replace volume balance
> +_begin_fstest auto replace volume balance
>  
>  # Override the default cleanup function.
>  _cleanup()
> -- 
> 2.36.1
>