NFS: Reduce the stack footprint of nfs_follow_remote_path()

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

1 files changed, 12 insertions, 6 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index b4148fc00f9f..fa3111eea29a 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2672,38 +2672,44 @@ out_freepage:
 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
                 const char *export_path, struct vfsmount *mnt_target)
 {
+        struct nameidata *nd = NULL;
         struct mnt_namespace *ns_private;
-        struct nameidata nd;
         struct super_block *s;
         int ret;
 
+        nd = kmalloc(sizeof(*nd), GFP_KERNEL);
+        if (nd == NULL)
+                return -ENOMEM;
+
         ns_private = create_mnt_ns(root_mnt);
         ret = PTR_ERR(ns_private);
         if (IS_ERR(ns_private))
                 goto out_mntput;
 
         ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
-                        export_path, LOOKUP_FOLLOW, &nd);
+                        export_path, LOOKUP_FOLLOW, nd);
 
         put_mnt_ns(ns_private);
 
         if (ret != 0)
                 goto out_err;
 
-        s = nd.path.mnt->mnt_sb;
+        s = nd->path.mnt->mnt_sb;
         atomic_inc(&s->s_active);
         mnt_target->mnt_sb = s;
-        mnt_target->mnt_root = dget(nd.path.dentry);
+        mnt_target->mnt_root = dget(nd->path.dentry);
 
         /* Correct the device pathname */
-        nfs_fix_devname(&nd.path, mnt_target);
+        nfs_fix_devname(&nd->path, mnt_target);
 
-        path_put(&nd.path);
+        path_put(&nd->path);
+        kfree(nd);
         down_write(&s->s_umount);
         return 0;
 out_mntput:
         mntput(root_mnt);
 out_err:
+        kfree(nd);
         return ret;
 }