NFS: Cleanup of NFS read code

Same callback hierarchy inversion as for the NFS write calls. This patch is
not strictly speaking needed by the O_DIRECT code, but avoids confusing
differences between the asynchronous read and write code.

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

1 files changed, 41 insertions, 17 deletions

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index ae3ddd2..2da255f 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -36,8 +36,8 @@
 #define NFSDBG_FACILITY		NFSDBG_PAGECACHE
 
 static int nfs_pagein_one(struct list_head *, struct inode *);
-static void nfs_readpage_result_partial(struct nfs_read_data *, int);
-static void nfs_readpage_result_full(struct nfs_read_data *, int);
+static const struct rpc_call_ops nfs_read_partial_ops;
+static const struct rpc_call_ops nfs_read_full_ops;
 
 static kmem_cache_t *nfs_rdata_cachep;
 mempool_t *nfs_rdata_mempool;
@@ -200,9 +200,11 @@ static void nfs_readpage_release(struct nfs_page *req)
  * Set up the NFS read request struct
  */
 static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
+		const struct rpc_call_ops *call_ops,
 		unsigned int count, unsigned int offset)
 {
 	struct inode		*inode;
+	int flags;
 
 	data->req	  = req;
 	data->inode	  = inode = req->wb_context->dentry->d_inode;
@@ -220,6 +222,9 @@ static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
 	data->res.eof     = 0;
 	nfs_fattr_init(&data->fattr);
 
+	/* 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);
 	NFS_PROTO(inode)->read_setup(data);
 
 	data->task.tk_cookie = (unsigned long)inode;
@@ -307,14 +312,15 @@ static int nfs_pagein_multi(struct list_head *head, struct inode *inode)
 		list_del_init(&data->pages);
 
 		data->pagevec[0] = page;
-		data->complete = nfs_readpage_result_partial;
 
 		if (nbytes > rsize) {
-			nfs_read_rpcsetup(req, data, rsize, offset);
+			nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
+					rsize, offset);
 			offset += rsize;
 			nbytes -= rsize;
 		} else {
-			nfs_read_rpcsetup(req, data, nbytes, offset);
+			nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
+					nbytes, offset);
 			nbytes = 0;
 		}
 		nfs_execute_read(data);
@@ -360,8 +366,7 @@ static int nfs_pagein_one(struct list_head *head, struct inode *inode)
 	}
 	req = nfs_list_entry(data->pages.next);
 
-	data->complete = nfs_readpage_result_full;
-	nfs_read_rpcsetup(req, data, count, 0);
+	nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0);
 
 	nfs_execute_read(data);
 	return 0;
@@ -395,12 +400,15 @@ nfs_pagein_list(struct list_head *head, int rpages)
 /*
  * Handle a read reply that fills part of a page.
  */
-static void nfs_readpage_result_partial(struct nfs_read_data *data, int status)
+static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
 {
+	struct nfs_read_data *data = calldata;
 	struct nfs_page *req = data->req;
 	struct page *page = req->wb_page;
  
-	if (status >= 0) {
+	if (nfs_readpage_result(task, data) != 0)
+		return;
+	if (task->tk_status >= 0) {
 		unsigned int request = data->args.count;
 		unsigned int result = data->res.count;
 
@@ -419,20 +427,28 @@ static void nfs_readpage_result_partial(struct nfs_read_data *data, int status)
 	}
 }
 
+static const struct rpc_call_ops nfs_read_partial_ops = {
+	.rpc_call_done = nfs_readpage_result_partial,
+	.rpc_release = nfs_readdata_release,
+};
+
 /*
  * This is the callback from RPC telling us whether a reply was
  * received or some error occurred (timeout or socket shutdown).
  */
-static void nfs_readpage_result_full(struct nfs_read_data *data, int status)
+static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
 {
+	struct nfs_read_data *data = calldata;
 	unsigned int count = data->res.count;
 
+	if (nfs_readpage_result(task, data) != 0)
+		return;
 	while (!list_empty(&data->pages)) {
 		struct nfs_page *req = nfs_list_entry(data->pages.next);
 		struct page *page = req->wb_page;
 		nfs_list_remove_request(req);
 
-		if (status >= 0) {
+		if (task->tk_status >= 0) {
 			if (count < PAGE_CACHE_SIZE) {
 				if (count < req->wb_bytes)
 					memclear_highpage_flush(page,
@@ -448,19 +464,27 @@ static void nfs_readpage_result_full(struct nfs_read_data *data, int status)
 	}
 }
 
+static const struct rpc_call_ops nfs_read_full_ops = {
+	.rpc_call_done = nfs_readpage_result_full,
+	.rpc_release = nfs_readdata_release,
+};
+
 /*
  * This is the callback from RPC telling us whether a reply was
  * received or some error occurred (timeout or socket shutdown).
  */
-void nfs_readpage_result(struct rpc_task *task, void *calldata)
+int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
 {
-	struct nfs_read_data *data = calldata;
 	struct nfs_readargs *argp = &data->args;
 	struct nfs_readres *resp = &data->res;
-	int status = task->tk_status;
+	int status;
 
 	dprintk("NFS: %4d nfs_readpage_result, (status %d)\n",
-		task->tk_pid, status);
+		task->tk_pid, task->tk_status);
+
+	status = NFS_PROTO(data->inode)->read_done(task, data);
+	if (status != 0)
+		return status;
 
 	nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, resp->count);
 
@@ -474,14 +498,14 @@ void nfs_readpage_result(struct rpc_task *task, void *calldata)
 			argp->pgbase += resp->count;
 			argp->count -= resp->count;
 			rpc_restart_call(task);
-			return;
+			return -EAGAIN;
 		}
 		task->tk_status = -EIO;
 	}
 	spin_lock(&data->inode->i_lock);
 	NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
 	spin_unlock(&data->inode->i_lock);
-	data->complete(data, status);
+	return 0;
 }
 
 /*