NFS: Cleanup of NFS write code in preparation for asynchronous o_direct

This patch inverts the callback hierarchy for NFS write calls.

Instead of having the NFSv2/v3/v4-specific code set up the RPC callback
ops, we allow the original caller to do so. This allows for more
flexibility w.r.t. how to set up and tear down the nfs_write_data
structure while still allowing the NFSv3/v4 code to perform error
handling.

The greater flexibility is needed by the asynchronous O_DIRECT code, which
wants to be able to hold on to the original nfs_write_data structures after
the WRITE RPC call has completed in order to be able to replay them if the
COMMIT call determines that the server has rebooted.

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

1 files changed, 13 insertions, 41 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index f1ff4fa6cce5..ef4dc315ecc2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2388,32 +2388,23 @@ nfs4_proc_read_setup(struct nfs_read_data *data)
 	rpc_call_setup(task, &msg, 0);
 }
 
-static void nfs4_write_done(struct rpc_task *task, void *calldata)
+static int nfs4_write_done(struct rpc_task *task, struct nfs_write_data *data)
 {
-	struct nfs_write_data *data = calldata;
 	struct inode *inode = data->inode;
 	
 	if (nfs4_async_handle_error(task, NFS_SERVER(inode)) == -EAGAIN) {
 		rpc_restart_call(task);
-		return;
+		return -EAGAIN;
 	}
 	if (task->tk_status >= 0) {
 		renew_lease(NFS_SERVER(inode), data->timestamp);
 		nfs_post_op_update_inode(inode, data->res.fattr);
 	}
-	/* Call back common NFS writeback processing */
-	nfs_writeback_done(task, calldata);
+	return 0;
 }
 
-static const struct rpc_call_ops nfs4_write_ops = {
-	.rpc_call_done = nfs4_write_done,
-	.rpc_release = nfs_writedata_release,
-};
-
-static void
-nfs4_proc_write_setup(struct nfs_write_data *data, int how)
+static void nfs4_proc_write_setup(struct nfs_write_data *data, int how)
 {
-	struct rpc_task	*task = &data->task;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_WRITE],
 		.rpc_argp = &data->args,
@@ -2423,7 +2414,6 @@ nfs4_proc_write_setup(struct nfs_write_data *data, int how)
 	struct inode *inode = data->inode;
 	struct nfs_server *server = NFS_SERVER(inode);
 	int stable;
-	int flags;
 	
 	if (how & FLUSH_STABLE) {
 		if (!NFS_I(inode)->ncommit)
@@ -2438,57 +2428,37 @@ nfs4_proc_write_setup(struct nfs_write_data *data, int how)
 
 	data->timestamp   = jiffies;
 
-	/* Set the initial flags for the task.  */
-	flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
-
 	/* Finalize the task. */
-	rpc_init_task(task, NFS_CLIENT(inode), flags, &nfs4_write_ops, data);
-	rpc_call_setup(task, &msg, 0);
+	rpc_call_setup(&data->task, &msg, 0);
 }
 
-static void nfs4_commit_done(struct rpc_task *task, void *calldata)
+static int nfs4_commit_done(struct rpc_task *task, struct nfs_write_data *data)
 {
-	struct nfs_write_data *data = calldata;
 	struct inode *inode = data->inode;
 	
 	if (nfs4_async_handle_error(task, NFS_SERVER(inode)) == -EAGAIN) {
 		rpc_restart_call(task);
-		return;
+		return -EAGAIN;
 	}
 	if (task->tk_status >= 0)
 		nfs_post_op_update_inode(inode, data->res.fattr);
-	/* Call back common NFS writeback processing */
-	nfs_commit_done(task, calldata);
+	return 0;
 }
 
-static const struct rpc_call_ops nfs4_commit_ops = {
-	.rpc_call_done = nfs4_commit_done,
-	.rpc_release = nfs_commit_release,
-};
-
-static void
-nfs4_proc_commit_setup(struct nfs_write_data *data, int how)
+static void nfs4_proc_commit_setup(struct nfs_write_data *data, int how)
 {
-	struct rpc_task	*task = &data->task;
 	struct rpc_message msg = {
 		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COMMIT],
 		.rpc_argp = &data->args,
 		.rpc_resp = &data->res,
 		.rpc_cred = data->cred,
 	};	
-	struct inode *inode = data->inode;
-	struct nfs_server *server = NFS_SERVER(inode);
-	int flags;
+	struct nfs_server *server = NFS_SERVER(data->inode);
 	
 	data->args.bitmask = server->attr_bitmask;
 	data->res.server = server;
 
-	/* Set the initial flags for the task.  */
-	flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
-
-	/* Finalize the task. */
-	rpc_init_task(task, NFS_CLIENT(inode), flags, &nfs4_commit_ops, data);
-	rpc_call_setup(task, &msg, 0);	
+	rpc_call_setup(&data->task, &msg, 0);
 }
 
 /*
@@ -3648,7 +3618,9 @@ struct nfs_rpc_ops	nfs_v4_clientops = {
 	.decode_dirent	= nfs4_decode_dirent,
 	.read_setup	= nfs4_proc_read_setup,
 	.write_setup	= nfs4_proc_write_setup,
+	.write_done	= nfs4_write_done,
 	.commit_setup	= nfs4_proc_commit_setup,
+	.commit_done	= nfs4_commit_done,
 	.file_open      = nfs_open,
 	.file_release   = nfs_release,
 	.lock		= nfs4_proc_lock,