Linux-libre 4.8.2-gnupck-4.8.2-gnu

1 files changed, 21 insertions, 1 deletions

diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c
index c1f4c208f..b62973045 100644
--- a/fs/nfs/nfs4session.c
+++ b/fs/nfs/nfs4session.c
@@ -28,6 +28,7 @@ static void nfs4_init_slot_table(struct nfs4_slot_table *tbl, const char *queue)
 	tbl->highest_used_slotid = NFS4_NO_SLOT;
 	spin_lock_init(&tbl->slot_tbl_lock);
 	rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, queue);
+	init_waitqueue_head(&tbl->slot_waitq);
 	init_completion(&tbl->complete);
 }
 
@@ -192,7 +193,8 @@ static int nfs4_slot_get_seqid(struct nfs4_slot_table  *tbl, u32 slotid,
  * RPC call in question is still in flight. This function is mainly
  * intended for use by the callback channel.
  */
-bool nfs4_slot_seqid_in_use(struct nfs4_slot_table *tbl, u32 slotid, u32 seq_nr)
+static bool nfs4_slot_seqid_in_use(struct nfs4_slot_table *tbl,
+		u32 slotid, u32 seq_nr)
 {
 	u32 cur_seq;
 	bool ret = false;
@@ -206,6 +208,24 @@ bool nfs4_slot_seqid_in_use(struct nfs4_slot_table *tbl, u32 slotid, u32 seq_nr)
 }
 
 /*
+ * nfs4_slot_wait_on_seqid - wait until a slot sequence id is complete
+ *
+ * Given a slot table, slot id and sequence number, wait until the
+ * corresponding RPC call completes. This function is mainly
+ * intended for use by the callback channel.
+ */
+int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
+		u32 slotid, u32 seq_nr,
+		unsigned long timeout)
+{
+	if (wait_event_timeout(tbl->slot_waitq,
+			!nfs4_slot_seqid_in_use(tbl, slotid, seq_nr),
+			timeout) == 0)
+		return -ETIMEDOUT;
+	return 0;
+}
+
+/*
  * nfs4_alloc_slot - efficiently look for a free slot
  *
  * nfs4_alloc_slot looks for an unset bit in the used_slots bitmap.