Re: [PATCH 2/6] nfsd: release path refs on follow_down() error

[Al Viro]

On Sun, May 31, 2026 at 08:06:59AM -0400, Jeff Layton wrote:


> Fix by calling path_put(&path) before the goto out in the err < 0
> arm so the entry-time refs are released on all follow_down() error
> returns.

Might be better to unify all those path_put()...  Something like this,
perhaps?

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index eafdf7b7890f..bdcd78f49112 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -141,13 +141,13 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
 	if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
 	    nfsd_mountpoint(dentry, exp) == 2) {
 		/* This is only a mountpoint in some other namespace */
-		path_put(&path);
 		goto out;
 	}
 
 	exp2 = rqst_exp_get_by_name(rqstp, &path);
 	if (IS_ERR(exp2)) {
 		err = PTR_ERR(exp2);
+		exp2 = NULL;
 		/*
 		 * We normally allow NFS clients to continue
 		 * "underneath" a mountpoint that is not exported.
@@ -157,10 +157,7 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
 		 */
 		if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
 			err = 0;
-		path_put(&path);
-		goto out;
-	}
-	if (nfsd_v4client(rqstp) ||
+	} else if (nfsd_v4client(rqstp) ||
 		(exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
 		/* successfully crossed mount point */
 		/*
@@ -174,9 +171,10 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
 		*expp = exp2;
 		exp2 = exp;
 	}
-	path_put(&path);
-	exp_put(exp2);
 out:
+	path_put(&path);
+	if (exp2)
+		exp_put(exp2);
 	return err;
 }