smb/client: mark file sparse before emulating insert range

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.

This patch produces the expected sparse extents in xfstests generic/064
only when the server-reported block size is compatible with the server's
deallocation granularity.

For ksmbd, the reported block size follows the backing filesystem,
and the test passes. For Samba, the test passes with a block size
matching the backend granularity, for example, 4 KiB on Btrfs, but not
with the default 1 KiB value. For Windows Server 2022, 4 KiB inserts do
not generate holes, while aligned inserts of 64 KiB or larger do.

Fixes: 7fe6fe95b936 ("cifs: add FALLOC_FL_INSERT_RANGE support")
Signed-off-by: Huiwen He <hehuiwen@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>

0 files changed, 0 insertions, 0 deletions