1 files changed, 24 insertions, 5 deletions

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index e7ce4b3eb0bd..61239a2cb786 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -480,6 +480,23 @@ static const struct dentry_operations rpc_dentry_operations = {
 	.d_delete = rpc_delete_dentry,
 };
 
+/*
+ * Lookup the data. This is trivial - if the dentry didn't already
+ * exist, we know it is negative.
+ */
+static struct dentry *
+rpc_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+	d_add(dentry, NULL);
+	return NULL;
+}
+
+static const struct inode_operations rpc_dir_inode_operations = {
+	.lookup		= rpc_lookup,
+};
+
 static struct inode *
 rpc_get_inode(struct super_block *sb, umode_t mode)
 {
@@ -492,7 +509,7 @@ rpc_get_inode(struct super_block *sb, umode_t mode)
 	switch (mode & S_IFMT) {
 	case S_IFDIR:
 		inode->i_fop = &simple_dir_operations;
-		inode->i_op = &simple_dir_inode_operations;
+		inode->i_op = &rpc_dir_inode_operations;
 		inc_nlink(inode);
 	default:
 		break;
@@ -666,10 +683,8 @@ static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 		if (!dentry)
 			return ERR_PTR(-ENOMEM);
 	}
-	if (dentry->d_inode == NULL) {
-		d_set_d_op(dentry, &rpc_dentry_operations);
+	if (dentry->d_inode == NULL)
 		return dentry;
-	}
 	dput(dentry);
 	return ERR_PTR(-EEXIST);
 }
@@ -1116,6 +1131,7 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 	sb->s_magic = RPCAUTH_GSSMAGIC;
 	sb->s_op = &s_ops;
+	sb->s_d_op = &rpc_dentry_operations;
 	sb->s_time_gran = 1;
 
 	inode = rpc_get_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
@@ -1126,6 +1142,7 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
 		return -ENOMEM;
 	dprintk("RPC:       sending pipefs MOUNT notification for net %p%s\n",
 		net, NET_NAME(net));
+	mutex_lock(&sn->pipefs_sb_lock);
 	sn->pipefs_sb = sb;
 	err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
 					   RPC_PIPEFS_MOUNT,
@@ -1133,6 +1150,7 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto err_depopulate;
 	sb->s_fs_info = get_net(net);
+	mutex_unlock(&sn->pipefs_sb_lock);
 	return 0;
 
 err_depopulate:
@@ -1141,6 +1159,7 @@ err_depopulate:
 					   sb);
 	sn->pipefs_sb = NULL;
 	__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
+	mutex_unlock(&sn->pipefs_sb_lock);
 	return err;
 }
 
@@ -1162,12 +1181,12 @@ static void rpc_kill_sb(struct super_block *sb)
 		goto out;
 	}
 	sn->pipefs_sb = NULL;
-	mutex_unlock(&sn->pipefs_sb_lock);
 	dprintk("RPC:       sending pipefs UMOUNT notification for net %p%s\n",
 		net, NET_NAME(net));
 	blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
 					   RPC_PIPEFS_UMOUNT,
 					   sb);
+	mutex_unlock(&sn->pipefs_sb_lock);
 	put_net(net);
 out:
 	kill_litter_super(sb);