From: Ian Kent <ikent@redhat.com>
Date: Tue, 1 Dec 2009 17:07:37 -0500
Subject: [nfs] nfsiod: ensure the asynchronous RPC calls complete
Message-id: <20091201170736.12228.97886.stgit@zeus.themaw.net>
Patchwork-id: 21574
O-Subject: [RHEL 5.4 PATCH 4/5] NFS: Ensure that the asynchronous RPC calls
	complete on nfsiod (bz489931)
Bugzilla: 489931
RH-Acked-by: Jeff Layton <jlayton@redhat.com>

From: Trond Myklebust <Trond.Myklebust@netapp.com>

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/direct.c b/fs/nfs/direct.c
index 2cb97fb..fbcf17d 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -54,6 +54,7 @@
 #include <asm/uaccess.h>
 #include <asm/atomic.h>
 
+#include "internal.h"
 #include "iostat.h"
 
 #define NFSDBG_FACILITY		NFSDBG_VFS
@@ -315,8 +316,8 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned lo
 		data->res.eof = 0;
 		data->res.count = bytes;
 
-		rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
-				&nfs_read_direct_ops, data);
+		rpc_init_task_wq(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
+				 &nfs_read_direct_ops, data, nfsiod_workqueue);
 		NFS_PROTO(inode)->read_setup(data);
 
 		data->task.tk_cookie = (unsigned long) inode;
@@ -415,8 +416,8 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
 		 * Reuse data->task; data->args should not have changed
 		 * since the original request was sent.
 		 */
-		rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
-				&nfs_write_direct_ops, data);
+		rpc_init_task_wq(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
+				&nfs_write_direct_ops, data, nfsiod_workqueue);
 		NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE);
 
 		data->task.tk_priority = RPC_PRIORITY_NORMAL;
@@ -480,8 +481,8 @@ static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
 	data->res.fattr = &data->fattr;
 	data->res.verf = &data->verf;
 
-	rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC,
-				&nfs_commit_direct_ops, data);
+	rpc_init_task_wq(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC,
+				&nfs_commit_direct_ops, data, nfsiod_workqueue);
 	NFS_PROTO(data->inode)->commit_setup(data, 0);
 
 	data->task.tk_priority = RPC_PRIORITY_NORMAL;
@@ -655,8 +656,8 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned l
 		data->res.count = bytes;
 		data->res.verf = &data->verf;
 
-		rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
-				&nfs_write_direct_ops, data);
+		rpc_init_task_wq(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
+				 &nfs_write_direct_ops, data, nfsiod_workqueue);
 		NFS_PROTO(inode)->write_setup(data, sync);
 
 		data->task.tk_priority = RPC_PRIORITY_NORMAL;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 572af58..bc6d415 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
@@ -302,7 +303,8 @@ static int nfs4_call_async(struct rpc_clnt *clnt,
 {
 	struct rpc_task *task;
 
-	if (!(task = rpc_new_task(clnt, RPC_TASK_ASYNC, tk_ops, calldata)))
+	if (!(task = rpc_new_task_wq(clnt, RPC_TASK_ASYNC, tk_ops, calldata,
+				     nfsiod_workqueue)))
 		return -ENOMEM;
 	rpc_execute(task);
 	return 0;
@@ -630,7 +632,8 @@ static int _nfs4_proc_open_confirm(struct nfs4_opendata *data)
 	 * want to ensure that it takes the 'error' code path.
 	 */
 	data->rpc_status = -ENOMEM;
-	task = rpc_run_task(server->client, RPC_TASK_ASYNC, &nfs4_open_confirm_ops, data);
+	task = rpc_run_task_wq(server->client, RPC_TASK_ASYNC,
+			       &nfs4_open_confirm_ops, data, nfsiod_workqueue);
 	if (IS_ERR(task))
 		return PTR_ERR(task);
 	status = nfs4_wait_for_completion_rpc_task(task);
@@ -736,7 +739,8 @@ static int _nfs4_proc_open(struct nfs4_opendata *data)
 	 * want to ensure that it takes the 'error' code path.
 	 */
 	data->rpc_status = -ENOMEM;
-	task = rpc_run_task(server->client, RPC_TASK_ASYNC, &nfs4_open_ops, data);
+	task = rpc_run_task_wq(server->client, RPC_TASK_ASYNC, &nfs4_open_ops,
+				data, nfsiod_workqueue);
 	if (IS_ERR(task))
 		return PTR_ERR(task);
 	status = nfs4_wait_for_completion_rpc_task(task);
@@ -3324,7 +3328,7 @@ static struct rpc_task *nfs4_do_unlck(struct file_lock *fl,
 		return ERR_PTR(-ENOMEM);
 	}
 
-	return rpc_run_task(NFS_CLIENT(lsp->ls_state->inode), RPC_TASK_ASYNC, &nfs4_locku_ops, data);
+	return rpc_run_task_wq(NFS_CLIENT(lsp->ls_state->inode), RPC_TASK_ASYNC, &nfs4_locku_ops, data, nfsiod_workqueue);
 }
 
 static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)
@@ -3503,8 +3507,8 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *f
 		data->arg.block = 1;
 	if (reclaim != 0)
 		data->arg.reclaim = 1;
-	task = rpc_run_task(NFS_CLIENT(state->inode), RPC_TASK_ASYNC,
-			&nfs4_lock_ops, data);
+	task = rpc_run_task_wq(NFS_CLIENT(state->inode), RPC_TASK_ASYNC,
+			&nfs4_lock_ops, data, nfsiod_workqueue);
 	if (IS_ERR(task))
 		return PTR_ERR(task);
 	ret = nfs4_wait_for_completion_rpc_task(task);
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 57fd698..768a20c 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -300,7 +300,8 @@ static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
 
 	/* Set up the initial task struct. */
 	flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
-	rpc_init_task(&data->task, NFS_CLIENT(inode), flags, call_ops, data);
+	rpc_init_task_wq(&data->task, NFS_CLIENT(inode), flags, call_ops, data,
+			 nfsiod_workqueue);
 	NFS_PROTO(inode)->read_setup(data);
 
 	data->task.tk_cookie = (unsigned long)inode;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f683476..1de7756 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -996,7 +996,8 @@ static void nfs_write_rpcsetup(struct nfs_page *req,
 
 	/* Set up the initial task struct.  */
 	flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
-	rpc_init_task(&data->task, NFS_CLIENT(inode), flags, call_ops, data);
+	rpc_init_task_wq(&data->task, NFS_CLIENT(inode), flags, call_ops, data,
+			 nfsiod_workqueue);
 	NFS_PROTO(inode)->write_setup(data, how);
 
 	data->task.tk_priority = flush_task_priority(how);
@@ -1397,7 +1398,7 @@ static void nfs_commit_rpcsetup(struct list_head *head,
 
 	/* Set up the initial task struct.  */
 	flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
-	rpc_init_task(&data->task, NFS_CLIENT(inode), flags, &nfs_commit_ops, data);
+	rpc_init_task_wq(&data->task, NFS_CLIENT(inode), flags, &nfs_commit_ops, data, nfsiod_workqueue);
 	NFS_PROTO(inode)->commit_setup(data, how);
 
 	data->task.tk_priority = flush_task_priority(how);