Do have_submounts(), shrink_dcache_parent() and d_drop() atomically.
check_submounts_and_drop() can deal with negative dentries and
non-directories as well.
Non-directories can also be mounted on.  And just like directories we don't
want these to disappear with invalidation.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
        if (inode && S_ISDIR(inode->i_mode)) {
                /* Purge readdir caches. */
                nfs_zap_caches(inode);
-               /* If we have submounts, don't unhash ! */
-               if (have_submounts(dentry))
-                       goto out_valid;
                if (dentry->d_flags & DCACHE_DISCONNECTED)
                        goto out_valid;
-               shrink_dcache_parent(dentry);
        }
-       d_drop(dentry);
+       /* If we have submounts, don't unhash ! */
+       if (check_submounts_and_drop(dentry) != 0)
+               goto out_valid;
+
        dput(parent);
        dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
                        __func__, dentry->d_parent->d_name.name,