Merge tag 'nfs-for-3.8-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:

 - Error reporting in nfs_xdev_mount incorrectly maps all errors to
   ENOMEM

 - Fix an NFSv4 refcounting issue

 - Fix a mount failure when the server reboots during NFSv4 trunking
   discovery

 - NFSv4.1 mounts may need to run the lease recovery thread.

 - Don't silently fail setattr() requests on mountpoints

 - Fix a SUNRPC socket/transport livelock and priority queue issue

 - We must handle NFS4ERR_DELAY when resetting the NFSv4.1 session.

* tag 'nfs-for-3.8-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4.1: Handle NFS4ERR_DELAY when resetting the NFSv4.1 session
  SUNRPC: When changing the queue priority, ensure that we change the owner
  NFS: Don't silently fail setattr() requests on mountpoints
  NFSv4.1: Ensure that nfs41_walk_client_list() does start lease recovery
  NFSv4: Fix NFSv4 trunking discovery
  NFSv4: Fix NFSv4 reference counting for trunked sessions
  NFS: Fix error reporting in nfs_xdev_mount

1 files changed, 17 insertions, 1 deletions

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index bfa31714581..fb20f25ddec 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -98,9 +98,25 @@ __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
 	list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list);
 }
 
+static void rpc_rotate_queue_owner(struct rpc_wait_queue *queue)
+{
+	struct list_head *q = &queue->tasks[queue->priority];
+	struct rpc_task *task;
+
+	if (!list_empty(q)) {
+		task = list_first_entry(q, struct rpc_task, u.tk_wait.list);
+		if (task->tk_owner == queue->owner)
+			list_move_tail(&task->u.tk_wait.list, q);
+	}
+}
+
 static void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
 {
-	queue->priority = priority;
+	if (queue->priority != priority) {
+		/* Fairness: rotate the list when changing priority */
+		rpc_rotate_queue_owner(queue);
+		queue->priority = priority;
+	}
 }
 
 static void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)