Re: [PATCH v2] sunrpc: Fix error checking for d_hash_and_lookup()

[Jiri Pirko]

Mon, Aug 26, 2024 at 01:25:09PM CEST, yanzhen@xxxxxxxx wrote:
>The d_hash_and_lookup() function returns either an error pointer or NULL.
>
>It might be more appropriate to check error using IS_ERR_OR_NULL().
>
>Fixes: b7ade38165ca ("sunrpc: fixed rollback in rpc_gssd_dummy_populate()")

That certainly does not look correct.


>Signed-off-by: Yan Zhen <yanzhen@xxxxxxxx>
>---
>
>Changes in v2:
>- Providing a "fixes" tag blaming the commit.
>
> net/sunrpc/rpc_pipe.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
>index 910a5d850d04..fd03dd46b1f2 100644
>--- a/net/sunrpc/rpc_pipe.c
>+++ b/net/sunrpc/rpc_pipe.c
>@@ -1306,7 +1306,7 @@ rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
> 
> 	/* We should never get this far if "gssd" doesn't exist */
> 	gssd_dentry = d_hash_and_lookup(root, &q);
>-	if (!gssd_dentry)
>+	if (IS_ERR_OR_NULL(gssd_dentry))
> 		return ERR_PTR(-ENOENT);
> 
> 	ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
>@@ -1318,7 +1318,7 @@ rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
> 	q.name = gssd_dummy_clnt_dir[0].name;
> 	q.len = strlen(gssd_dummy_clnt_dir[0].name);
> 	clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
>-	if (!clnt_dentry) {
>+	if (IS_ERR_OR_NULL(clnt_dentry)) {
> 		__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
> 		pipe_dentry = ERR_PTR(-ENOENT);
> 		goto out;
>-- 
>2.34.1
>
>