nfs: enforce FIFO ordering of operations trying to acquire slot

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

1 files changed, 16 insertions, 2 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index e76427e6346f..0e45075836b2 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -138,8 +138,22 @@ static int nfs41_setup_state_renewal(struct nfs_client *clp)
 static void nfs41_end_drain_session(struct nfs_client *clp,
                 struct nfs4_session *ses)
 {
-        if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state))
-                rpc_wake_up(&ses->fc_slot_table.slot_tbl_waitq);
+        int max_slots;
+
+        if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state)) {
+                spin_lock(&ses->fc_slot_table.slot_tbl_lock);
+                max_slots = ses->fc_slot_table.max_slots;
+                while (max_slots--) {
+                        struct rpc_task *task;
+
+                        task = rpc_wake_up_next(&ses->fc_slot_table.
+                                                slot_tbl_waitq);
+                        if (!task)
+                                break;
+                        rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
+                }
+                spin_unlock(&ses->fc_slot_table.slot_tbl_lock);
+        }
 }
 
 static int nfs41_begin_drain_session(struct nfs_client *clp,