Re: [PATCH v3 0/7] fstests: add tests for btrfs' raid-stripe-tree feature

[Johannes Thumshirn <Johannes.Thumshirn@wdc.com>]

On 05.12.23 20:50, Filipe Manana wrote:
> 
> Just one more thing, and sorry I didn't notice before. All the tests fail
> when running with compression enabled, for example:

Well yeah this is kind of obvious why it happens (now that I see it). 
I'll skip the tests in case of enabled compression.

> Also, they all fail when the free space tree is disabled, like this:
> 
> root 19:45:30 /home/fdmanana/git/hub/xfstests > MKFS_OPTIONS="-O
> ^free-space-tree" ./check btrfs/304
> FSTYP         -- btrfs
> PLATFORM      -- Linux/x86_64 debian0 6.7.0-rc3-btrfs-next-143+ #1 SMP
> PREEMPT_DYNAMIC Mon Dec  4 11:01:37 WET 2023
> MKFS_OPTIONS  -- -O ^free-space-tree /dev/sdb
> MOUNT_OPTIONS -- /dev/sdb /home/fdmanana/btrfs-tests/scratch_1
> 
> btrfs/304 1s ... - output mismatch (see
> /home/fdmanana/git/hub/xfstests/results//btrfs/304.out.bad)
>      --- tests/btrfs/304.out 2023-12-05 19:34:01.040411746 +0000
>      +++ /home/fdmanana/git/hub/xfstests/results//btrfs/304.out.bad
> 2023-12-05 19:45:36.242621419 +0000
>      @@ -15,6 +15,156 @@
>        item 0 key (XXXXXX RAID_STRIPE 4096) itemoff XXXXX itemsize 24
>        encoding: RAID0
>        stripe 0 devid 1 physical XXXXXXXXX
>      + item 1 key (XXXXXX RAID_STRIPE 65536) itemoff XXXXX itemsize 24
>      + encoding: RAID0
>      + stripe 0 devid 1 physical XXXXXXXXX
>      + item 2 key (XXXXXX RAID_STRIPE 65536) itemoff XXXXX itemsize 24
>      ...
>      (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/304.out
> /home/fdmanana/git/hub/xfstests/results//btrfs/304.out.bad'  to see
> the entire diff)
> Ran: btrfs/304
> Failures: btrfs/304
> Failed 1 of 1 tests

OK I'll investigate why this happens.

> 
> And with nodatacow, only one of them fails:
> 
> root 19:46:16 /home/fdmanana/git/hub/xfstests > MOUNT_OPTIONS="-o
> nodatacow" ./check btrfs/304 btrfs/305 btrfs/306 btrfs/307 btrfs/308
> FSTYP         -- btrfs
> PLATFORM      -- Linux/x86_64 debian0 6.7.0-rc3-btrfs-next-143+ #1 SMP
> PREEMPT_DYNAMIC Mon Dec  4 11:01:37 WET 2023
> MKFS_OPTIONS  -- /dev/sdb
> MOUNT_OPTIONS -- -o nodatacow /dev/sdb /home/fdmanana/btrfs-tests/scratch_1
> 
> btrfs/304 1s ...  1s
> btrfs/305 1s ...  1s
> btrfs/306 1s ...  1s
> btrfs/307 1s ...  1s
> btrfs/308 0s ... - output mismatch (see
> /home/fdmanana/git/hub/xfstests/results//btrfs/308.out.bad)
>      --- tests/btrfs/308.out 2023-12-05 19:37:38.379355089 +0000
>      +++ /home/fdmanana/git/hub/xfstests/results//btrfs/308.out.bad
> 2023-12-05 19:46:33.716457540 +0000
>      @@ -28,9 +28,6 @@
>        item 3 key (XXXXXX RAID_STRIPE 32768) itemoff XXXXX itemsize 24
>        encoding: RAID0
>        stripe 0 devid 1 physical XXXXXXXXX
>      - item 4 key (XXXXXX RAID_STRIPE 8192) itemoff XXXXX itemsize 24
>      - encoding: RAID0
>      - stripe 0 devid 1 physical XXXXXXXXX
>       total bytes XXXXXXXX
>      ...
>      (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/308.out
> /home/fdmanana/git/hub/xfstests/results//btrfs/308.out.bad'  to see
> the entire diff)
> Ran: btrfs/304 btrfs/305 btrfs/306 btrfs/307 btrfs/308
> Failures: btrfs/308
> Failed 1 of 5 tests
> 
> For the compression, we can just add a "_require_no_compress".
> We should also skip them when free space tree is not enabled or
> nodatacow is enabled for 308 (don't recall if we already have helpers
> for that).
> 
> Other than that, everything looks good to me.

I'm actually thinking of making RST and nodatacow mutually exclusive, as 
nodatacow re-introduces a risk for a RAID write hole.