NFS: Fix following referral mount points with different security

I create a new proc_lookup_mountpoint() to use when submounting an NFS
v4 share.  This function returns an rpc_clnt to use for performing an
fs_locations() call on a referral's mountpoint.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 34 insertions, 10 deletions

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 1807866bb3ab..b9a593d056b3 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -200,6 +200,22 @@ out_shutdown:
 out:
         return err;
 }
+
+static struct rpc_clnt *nfs_lookup_mountpoint(struct inode *dir,
+                                              struct qstr *name,
+                                              struct nfs_fh *fh,
+                                              struct nfs_fattr *fattr)
+{
+        int err;
+
+        if (NFS_PROTO(dir)->version == 4)
+                return nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
+
+        err = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, name, fh, fattr);
+        if (err)
+                return ERR_PTR(err);
+        return rpc_clone_client(NFS_SERVER(dir)->client);
+}
 #else /* CONFIG_NFS_V4 */
 static inline int nfs_lookup_with_sec(struct nfs_server *server,
                                       struct dentry *parent, struct dentry *dentry,
@@ -209,6 +225,17 @@ static inline int nfs_lookup_with_sec(struct nfs_server *server,
 {
         return -EPERM;
 }
+
+static inline struct rpc_clnt *nfs_lookup_mountpoint(struct inode *dir,
+                                                     struct qstr *name,
+                                                     struct nfs_fh *fh,
+                                                     struct nfs_fattr *fattr)
+{
+        int err = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, name, fh, fattr);
+        if (err)
+                return ERR_PTR(err);
+        return rpc_clone_client(NFS_SERVER(dir)->client);
+}
 #endif /* CONFIG_NFS_V4 */
 
 /*
@@ -226,11 +253,10 @@ static inline int nfs_lookup_with_sec(struct nfs_server *server,
 struct vfsmount *nfs_d_automount(struct path *path)
 {
         struct vfsmount *mnt;
-        struct nfs_server *server = NFS_SERVER(path->dentry->d_inode);
         struct dentry *parent;
         struct nfs_fh *fh = NULL;
         struct nfs_fattr *fattr = NULL;
-        int err;
+        struct rpc_clnt *client;
         rpc_authflavor_t flavor = RPC_AUTH_UNIX;
 
         dprintk("--> nfs_d_automount()\n");
@@ -249,21 +275,19 @@ struct vfsmount *nfs_d_automount(struct path *path)
 
         /* Look it up again to get its attributes */
         parent = dget_parent(path->dentry);
-        err = server->nfs_client->rpc_ops->lookup(server->client, parent->d_inode,
-                                                  &path->dentry->d_name,
-                                                  fh, fattr);
-        if (err == -EPERM && NFS_PROTO(parent->d_inode)->secinfo != NULL)
-                err = nfs_lookup_with_sec(server, parent, path->dentry, path, fh, fattr, &flavor);
+        client = nfs_lookup_mountpoint(parent->d_inode, &path->dentry->d_name, fh, fattr);
         dput(parent);
-        if (err != 0) {
-                mnt = ERR_PTR(err);
+        if (IS_ERR(client)) {
+                mnt = ERR_CAST(client);
                 goto out;
         }
 
         if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
-                mnt = nfs_do_refmount(path->dentry);
+                mnt = nfs_do_refmount(client, path->dentry);
         else
                 mnt = nfs_do_submount(path->dentry, fh, fattr, flavor);
+        rpc_shutdown_client(client);
+
         if (IS_ERR(mnt))
                 goto out;