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 ae3ddd24cf8f..2da255f0247f 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;
 }
 
 /*