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, 28 insertions, 0 deletions

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 77966ecb0a2c..86c154bad5db 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -30,6 +30,7 @@
 #include <linux/nfs_fs.h>
 #include "internal.h"
 #include "pnfs.h"
+#include "iostat.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PNFS
 
@@ -880,6 +881,33 @@ pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode)
 }
 
 /*
+ * Call the appropriate parallel I/O subsystem read function.
+ */
+enum pnfs_try_status
+pnfs_try_to_read_data(struct nfs_read_data *rdata,
+                       const struct rpc_call_ops *call_ops)
+{
+        struct inode *inode = rdata->inode;
+        struct nfs_server *nfss = NFS_SERVER(inode);
+        enum pnfs_try_status trypnfs;
+
+        rdata->mds_ops = call_ops;
+
+        dprintk("%s: Reading ino:%lu %u@%llu\n",
+                __func__, inode->i_ino, rdata->args.count, rdata->args.offset);
+
+        trypnfs = nfss->pnfs_curr_ld->read_pagelist(rdata);
+        if (trypnfs == PNFS_NOT_ATTEMPTED) {
+                put_lseg(rdata->lseg);
+                rdata->lseg = NULL;
+        } else {
+                nfs_inc_stats(inode, NFSIOS_PNFS_READ);
+        }
+        dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
+        return trypnfs;
+}
+
+/*
  * Device ID cache. Currently supports one layout type per struct nfs_client.
  * Add layout type to the lookup key to expand to support multiple types.
  */