NFSv4.1: generic read

Separate the rpc run portion of nfs_read_rpcsetup into a new function
nfs_initiate_read that is called for normal NFS I/O.

Add a pNFS read_pagelist function that is called instead of nfs_intitate_read
for pNFS reads.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 40 insertions, 25 deletions

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 6dc9eaf00e5c..4127a1c0eec6 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -18,6 +18,8 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfs_fs.h>
 #include <linux/nfs_page.h>
+#include <linux/smp_lock.h>
+#include <linux/module.h>
 
 #include <asm/system.h>
 #include "pnfs.h"
@@ -155,25 +157,20 @@ static void nfs_readpage_release(struct nfs_page *req)
         nfs_release_request(req);
 }
 
-/*
- * Set up the NFS read request struct
- */
-static int 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 pnfs_layout_segment *lseg)
+static int nfs_initiate_read(struct nfs_read_data *data, struct rpc_clnt *clnt,
+                      const struct rpc_call_ops *call_ops)
 {
-        struct inode *inode = req->wb_context->path.dentry->d_inode;
+        struct inode *inode = data->inode;
         int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
         struct rpc_task *task;
         struct rpc_message msg = {
                 .rpc_argp = &data->args,
                 .rpc_resp = &data->res,
-                .rpc_cred = req->wb_context->cred,
+                .rpc_cred = data->cred,
         };
         struct rpc_task_setup task_setup_data = {
                 .task = &data->task,
-                .rpc_client = NFS_CLIENT(inode),
+                .rpc_client = clnt,
                 .rpc_message = &msg,
                 .callback_ops = call_ops,
                 .callback_data = data,
@@ -181,9 +178,37 @@ static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
                 .flags = RPC_TASK_ASYNC | swap_flags,
         };
 
+        /* Set up the initial task struct. */
+        NFS_PROTO(inode)->read_setup(data, &msg);
+
+        dprintk("NFS: %5u initiated read call (req %s/%lld, %u bytes @ "
+                        "offset %llu)\n",
+                        data->task.tk_pid,
+                        inode->i_sb->s_id,
+                        (long long)NFS_FILEID(inode),
+                        data->args.count,
+                        (unsigned long long)data->args.offset);
+
+        task = rpc_run_task(&task_setup_data);
+        if (IS_ERR(task))
+                return PTR_ERR(task);
+        rpc_put_task(task);
+        return 0;
+}
+
+/*
+ * Set up the NFS read request struct
+ */
+static int 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 pnfs_layout_segment *lseg)
+{
+        struct inode *inode = req->wb_context->path.dentry->d_inode;
+
         data->req         = req;
         data->inode       = inode;
-        data->cred        = msg.rpc_cred;
+        data->cred        = req->wb_context->cred;
         data->lseg        = get_lseg(lseg);
 
         data->args.fh     = NFS_FH(inode);
@@ -199,21 +224,11 @@ static int 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. */
-        NFS_PROTO(inode)->read_setup(data, &msg);
-
-        dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
-                        data->task.tk_pid,
-                        inode->i_sb->s_id,
-                        (long long)NFS_FILEID(inode),
-                        count,
-                        (unsigned long long)data->args.offset);
+        if (data->lseg &&
+            (pnfs_try_to_read_data(data, call_ops) == PNFS_ATTEMPTED))
+                return 0;
 
-        task = rpc_run_task(&task_setup_data);
-        if (IS_ERR(task))
-                return PTR_ERR(task);
-        rpc_put_task(task);
-        return 0;
+        return nfs_initiate_read(data, NFS_CLIENT(inode), call_ops);
 }
 
 static void