NFS: Add an iocounter wait function for async RPC tasks
By sleeping on a new NFS Unlock-On-Close waitqueue, rpc tasks may wait for
a lock context's iocounter to reach zero. The rpc waitqueue is only woken
when the open_context has the NFS_CONTEXT_UNLOCK flag set in order to
mitigate spurious wake-ups for any iocounter reaching zero.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 1b29915..9aa044e 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -76,6 +76,7 @@
#define NFS_CONTEXT_ERROR_WRITE (0)
#define NFS_CONTEXT_RESEND_WRITES (1)
#define NFS_CONTEXT_BAD (2)
+#define NFS_CONTEXT_UNLOCK (3)
int error;
struct list_head list;