Re: [PATCH v3 3/7] smb/client: mark file sparse before emulating insert range

[hehuiwen <huiwen.he@linux.dev>]

Thanks. I repeated a controlled A/B test with the same kernel tree,
reverting/restoring only this patch.

Without the patch:

./check -d generic/064
FSTYP         -- cifs
PLATFORM      -- Linux/x86_64 localhost 7.2.0-rc6+ #71 SMP 
PREEMPT_DYNAMIC Tue Aug 25 15:38:06 CST 2026
MKFS_OPTIONS  -- //192.168.10.1/scratch_share
MOUNT_OPTIONS -- -o 
username=smbuser,password=Kylin123,vers=3.1.1,mfsymlinks,noperm 
//192.168.10.1/scratch_share /mnt/scratch

generic/064  2s ... QA output created by 064
Extent count after inserts has value of 1
Extent count after inserts is NOT in range 50 .. 53
- output mismatch (see /src/xfstests-dev/results//generic/064.out.bad)
     --- tests/generic/064.out	2026-05-08 16:46:07.377810776 +0800
     +++ /src/xfstests-dev/results//generic/064.out.bad	2026-08-27 
11:11:58.000000000 +0800
     @@ -1,2 +1,3 @@
      QA output created by 064
     -Extent count after inserts is in range
     +Extent count after inserts has value of 1
     +Extent count after inserts is NOT in range 50 .. 53
     ...
     (Run 'diff -u /src/xfstests-dev/tests/generic/064.out 
/src/xfstests-dev/results//generic/064.out.bad'  to see the entire diff)
Ran: generic/064
Failures: generic/064
Failed 1 of 1 tests
---------------------------------------------------------------

With the patch:

./check -d generic/064
FSTYP         -- cifs
PLATFORM      -- Linux/x86_64 localhost 7.2.0-rc6+ #71 SMP 
PREEMPT_DYNAMIC Tue Aug 25 15:38:06 CST 2026
MKFS_OPTIONS  -- //192.168.10.1/scratch_share
MOUNT_OPTIONS -- -o 
username=smbuser,password=Kylin123,vers=3.1.1,mfsymlinks,noperm 
//192.168.10.1/scratch_share /mnt/scratch

generic/064  2s ... QA output created by 064
Extent count after inserts is in range
  2s
Ran: generic/064
Passed all 1 tests

--------------------------------------------------------------
Server configuration:

     Fedora 43
     Samba 4.23.7-2.fc43
     btrfs backing filesystem
     strict allocate = yes

As noted in the v1 cover letter, the Windows Server result is expected: 
aligned 64 KiB and 128 KiB insert ranges are reported as holes, while 
generic/064 uses 4 KiB inserts, which are below the observed
sparse deallocation granularity on Windows.

Thanks,
Huiwen

在 2026/8/27 10:13, Paulo Alcantara 写道:
> Hi Huiwen,
> 
> Huiwen He <huiwen.he@linux.dev> writes:
> 
>> From: Huiwen He <hehuiwen@kylinos.cn>
>>
>> The SMB client emulates FALLOC_FL_INSERT_RANGE with SET_EOF, COPYCHUNK
>> and SET_ZERO_DATA.
>>
>> SET_ZERO_DATA creates a hole only when the file is sparse. On a
>> non-sparse file, it clears the inserted range but leaves its blocks
>> allocated, causing the extent count check in xfstests generic/064 to
>> fail.
>>
>> Fix this by marking the file sparse before modifying it.
>>
>> Tested with xfstests generic/064 against Samba and ksmbd.
> 
> After applying this patch, generic/064 still fails for me against
> samba-4.24.5-1.fc44.x86_64.  Tested it with both btrfs and xfs, and
> 'strict allocate = yes'.  It also fails against Windows Server 2022.
> 
> SECTION       -- smb3
> FSTYP         -- cifs
> PLATFORM      -- Linux/x86_64 fed 7.2.0 #4 SMP PREEMPT_DYNAMIC Wed Aug 26 21:42:48 -03 2026
> MKFS_OPTIONS  -- //192.168.124.43/scratch2
> MOUNT_OPTIONS -- -ousername=testuser,password=foo-321,vers=3.1.1,mfsymlinks,noperm //192.168.124.43/scratch2 /mnt/scratch
> 
> generic/064        - output mismatch (see /root/g/xfstests/results//smb3/generic/064.out.bad)
>      --- tests/generic/064.out   2024-02-15 10:35:04.361833706 -0300
>      +++ /root/g/xfstests/results//smb3/generic/064.out.bad      2026-08-26 21:58:54.469813041 -0300
>      @@ -1,2 +1,3 @@
>       QA output created by 064
>      -Extent count after inserts is in range
>      +Extent count after inserts has value of 1
>      +Extent count after inserts is NOT in range 50 .. 53
>      ...
>      (Run 'diff -u /root/g/xfstests/tests/generic/064.out /root/g/xfstests/results//smb3/generic/064.out.bad'  to see the entire diff)
> Ran: generic/064
> Failures: generic/064
> Failed 1 of 1 tests
> 
> What am I missing?
> 
> Could you please provide details of your server version and settings?
> 
> Thanks.