1 files changed, 22 insertions, 6 deletions

diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
index 42b479b9191f..09404d142d1a 100644
--- a/fs/nfs_common/nfslocalio.c
+++ b/fs/nfs_common/nfslocalio.c
@@ -5,7 +5,7 @@
  */
 
 #include <linux/module.h>
-#include <linux/rculist.h>
+#include <linux/list.h>
 #include <linux/nfslocalio.h>
 #include <net/netns/generic.h>
 
@@ -20,15 +20,27 @@ static DEFINE_SPINLOCK(nfs_uuid_lock);
  */
 static LIST_HEAD(nfs_uuids);
 
-void nfs_uuid_begin(nfs_uuid_t *nfs_uuid)
+void nfs_uuid_init(nfs_uuid_t *nfs_uuid)
 {
 	nfs_uuid->net = NULL;
 	nfs_uuid->dom = NULL;
-	uuid_gen(&nfs_uuid->uuid);
+	INIT_LIST_HEAD(&nfs_uuid->list);
+}
+EXPORT_SYMBOL_GPL(nfs_uuid_init);
 
+bool nfs_uuid_begin(nfs_uuid_t *nfs_uuid)
+{
 	spin_lock(&nfs_uuid_lock);
-	list_add_tail_rcu(&nfs_uuid->list, &nfs_uuids);
+	/* Is this nfs_uuid already in use? */
+	if (!list_empty(&nfs_uuid->list)) {
+		spin_unlock(&nfs_uuid_lock);
+		return false;
+	}
+	uuid_gen(&nfs_uuid->uuid);
+	list_add_tail(&nfs_uuid->list, &nfs_uuids);
 	spin_unlock(&nfs_uuid_lock);
+
+	return true;
 }
 EXPORT_SYMBOL_GPL(nfs_uuid_begin);
 
@@ -36,7 +48,8 @@ void nfs_uuid_end(nfs_uuid_t *nfs_uuid)
 {
 	if (nfs_uuid->net == NULL) {
 		spin_lock(&nfs_uuid_lock);
-		list_del_init(&nfs_uuid->list);
+		if (nfs_uuid->net == NULL)
+			list_del_init(&nfs_uuid->list);
 		spin_unlock(&nfs_uuid_lock);
 	}
 }
@@ -142,8 +155,11 @@ struct nfsd_file *nfs_open_local_fh(nfs_uuid_t *uuid,
 	/* We have an implied reference to net thanks to nfsd_serv_try_get */
 	localio = nfs_to->nfsd_open_local_fh(net, uuid->dom, rpc_clnt,
 					     cred, nfs_fh, fmode);
-	if (IS_ERR(localio))
+	if (IS_ERR(localio)) {
+		rcu_read_lock();
 		nfs_to->nfsd_serv_put(net);
+		rcu_read_unlock();
+	}
 	return localio;
 }
 EXPORT_SYMBOL_GPL(nfs_open_local_fh);