NFS: Ensure that the asynchronous RPC calls complete on nfsiod.

We want to ensure that rpc_call_ops that involve mntput() are run on nfsiod
rather than on rpciod, so that they don't deadlock when the resulting
umount calls rpc_shutdown_client(). Hence we specify that read, write and
commit calls must complete on nfsiod.
Ditto for NFSv4 open, lock, locku and close asynchronous calls.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 7ce0786..b6db833 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -51,6 +51,7 @@
 
 #include "nfs4_fs.h"
 #include "delegation.h"
+#include "internal.h"
 #include "iostat.h"
 
 #define NFSDBG_FACILITY		NFSDBG_PROC
@@ -773,6 +774,7 @@
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_open_confirm_ops,
 		.callback_data = data,
+		.workqueue = nfsiod_workqueue,
 		.flags = RPC_TASK_ASYNC,
 	};
 	int status;
@@ -910,6 +912,7 @@
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_open_ops,
 		.callback_data = data,
+		.workqueue = nfsiod_workqueue,
 		.flags = RPC_TASK_ASYNC,
 	};
 	int status;
@@ -1315,6 +1318,7 @@
 		.rpc_client = server->client,
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_close_ops,
+		.workqueue = nfsiod_workqueue,
 		.flags = RPC_TASK_ASYNC,
 	};
 	int status = -ENOMEM;
@@ -3235,6 +3239,7 @@
 		.rpc_client = NFS_CLIENT(lsp->ls_state->inode),
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_locku_ops,
+		.workqueue = nfsiod_workqueue,
 		.flags = RPC_TASK_ASYNC,
 	};
 
@@ -3419,6 +3424,7 @@
 		.rpc_client = NFS_CLIENT(state->inode),
 		.rpc_message = &msg,
 		.callback_ops = &nfs4_lock_ops,
+		.workqueue = nfsiod_workqueue,
 		.flags = RPC_TASK_ASYNC,
 	};
 	int ret;