Re: [PATCH 06/61] 9p: Prefer IS_ERR_OR_NULL over manual NULL check

Dominique Martinet
2026-03-11T08:30:02Z

-most lists...
Hopefully anyone who might care about 9p is on fsdevel.

I second whoever it was who said this should be split and not send all
the patches to everyone...

Philipp Hahn wrote on Tue, Mar 10, 2026 at 12:48:32PM +0100:
> Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
> check.
>
> Change generated with coccinelle.
>
> To: Eric Van Hensbergen <ericvh@kernel.org>
> To: Latchesar Ionkov <lucho@ionkov.net>
> To: Dominique Martinet <asmadeus@codewreck.org>
> To: Christian Schoenebeck <linux_oss@crudebyte.com>
> Cc: v9fs@lists.linux.dev
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Philipp Hahn <phahn-oss@avm.de>
> ---
> fs/9p/fid.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/9p/fid.h b/fs/9p/fid.h
> index 0d6138bee2a3d1ab565ab2d210c0a3f3bf97e4e3..3bb7ef4380e972a2d9ab67eb4aab6cc5bfe2eea7 100644
> --- a/fs/9p/fid.h
> +++ b/fs/9p/fid.h
> @@ -27,7 +27,7 @@ static inline struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
> struct p9_fid *fid, *nfid;
>
> fid = v9fs_fid_lookup(dentry);
> - if (!fid || IS_ERR(fid))
> + if (IS_ERR_OR_NULL(fid))

FWIW v9fs_fid_lookup cannot return NULL -- and all its other callers
only check for IS_ERR() so if there is a corner case that does return
NULL then we have another problem -- so please drop the !fid check
instead.

(not that it matters much... But might as well do it right)

--
Dominique Martinet | Asmadeus