Re: [PATCH] ceph: Fix ERR_PTR(0) in ceph_mkdir()

[Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>]

On Wed, 2026-05-20 at 17:54 +0800, Hongling Zeng wrote:
> When mkdir succeeds, ceph_mkdir() sets ret to ERR_PTR(0) which is
> incorrect. It should return NULL instead for success.
> 
> Fixes: 88d5baf69082 ("Change inode_operations.mkdir to return struct dentry *")
> Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
> ---
>  fs/ceph/dir.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index bac9cfb6b982..ab7f7b7016c6 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -1167,7 +1167,7 @@ static struct dentry *ceph_mkdir(struct mnt_idmap *idmap, struct inode *dir,
>  	    !req->r_reply_info.head->is_target &&
>  	    !req->r_reply_info.head->is_dentry)
>  		err = ceph_handle_notrace_create(dir, dentry);
> -	ret = ERR_PTR(err);
> +	ret = err ? ERR_PTR(err) : NULL;
>  out_req:
>  	if (!IS_ERR(ret) && req->r_dentry != dentry)
>  		/* Some other dentry was spliced in */

I think that this modification doesn't make sense. The ERR_PTR(0) returns NULL,
as far as I can understand.

  static inline void * __must_check ERR_PTR(long error)
  {
      return (void *) error;
  }

ERR_PTR(0) evaluates to (void *)0, which is exactly NULL.

Thanks,
Slava.