Re: [PATCH v2 3/3] smb/client: fix nlink of an overwritten open file

> This patch fixes xfstests generic/035 when mounted with `posix` option.

generic/035 passes to Samba with posix mount option without the patch.
Any idea why this patch was needed for ksmbd but not for Samba

On Tue, Aug 4, 2026 at 7:34 AM ChenXiaoSong
<[email protected]> wrote:
>
> From: ChenXiaoSong <[email protected]>
>
> Reproducer:
>
>   1. server: systemctl start ksmbd
>   2. client: mount with `posix` option
>      mount -t cifs -o posix //${server_ip}/export /mnt
>   3. client: touch /mnt/file1 /mnt/file2
>   4. client: C program: int fd = open("/mnt/file2", O_RDONLY);
>   5. client: C program: rename("/mnt/file1", "/mnt/file2");
>   6. client: C program: struct stat stbuf; fstat(fd, &stbuf);
>                         stbuf.st_nlink is 1, should be 0
>
> This patch fixes xfstests generic/035 when mounted with `posix` option.
>
> Signed-off-by: ChenXiaoSong <[email protected]>
> ---
>  fs/smb/client/inode.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
> index 0afff761aab9..0b6273ce01a8 100644
> --- a/fs/smb/client/inode.c
> +++ b/fs/smb/client/inode.c
> @@ -2648,11 +2648,8 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
>         if (d_really_is_positive(target_dentry)) {
>                 if (!rc) {
>                         struct inode *inode = d_inode(target_dentry);
> -                       /*
> -                        * Samba and ksmbd servers allow renaming a target
> -                        * directory that is open, so make sure to update
> -                        * ->i_nlink and then mark it as delete pending.
> -                        */
> +
> +                       /* Update the target link count after rename. */
>                         if (S_ISDIR(inode->i_mode)) {
>                                 drop_cached_dir_by_name(xid, tcon, to_name, cifs_sb);
>                                 spin_lock(&inode->i_lock);
> @@ -2663,6 +2660,10 @@ cifs_rename2(struct mnt_idmap *idmap, struct inode *source_dir,
>                                 CIFS_I(inode)->time = 0; /* force reval */
>                                 inode_set_ctime_current(inode);
>                                 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
> +                       } else {
> +                               cifs_mark_open_handles_for_deleted_file(inode, to_name);
> +                               cifs_drop_nlink(inode);
> +                               inode_set_ctime_current(inode);
>                         }
>                 } else if (rc == -EACCES || rc == -EEXIST) {
>                         /*
> --
> 2.54.0
>


-- 
Thanks,

Steve