[PATCH v4 3/7] smb/client: handle smb2_set_sparse() failure in non-extending fallocate

[Huiwen He <huiwen.he@linux.dev>]

From: Huiwen He <hehuiwen@kylinos.cn>

A non-extending fallocate on a sparse file can return success while the
requested range still contains holes. This affects FALLOC_FL_ALLOCATE_RANGE
within EOF and FALLOC_FL_KEEP_SIZE when CIFS clears the sparse attribute.
Later writes into the range may still fail.

CIFS emulates these requests by clearing the sparse attribute for the
whole file. However, it ignores failure from smb2_set_sparse() and returns
success unconditionally.

Return the smb2_set_sparse() error. This prevents CIFS from reporting
successful preallocation when the server rejected FSCTL_SET_SPARSE.

Fixes: f16994797ea8 ("cifs: fix incorrect handling of smb2_set_sparse() return in smb3_simple_falloc")
Signed-off-by: Huiwen He <hehuiwen@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 fs/smb/client/smb2ops.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index bbcd4533406c..2017357efac5 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -3786,8 +3786,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
 		}
 	}
 
-	smb2_set_sparse(xid, tcon, cfile, inode, false);
-	rc = 0;
+	rc = smb2_set_sparse(xid, tcon, cfile, inode, false);
 
 out:
 	if (rc)
-- 
2.43.0