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>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 77966ec..86c154b 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 @@
}
/*
+ * 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.
*/
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 5107d14..585023f 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -45,6 +45,11 @@
struct pnfs_layout_hdr *pls_layout;
};
+enum pnfs_try_status {
+ PNFS_ATTEMPTED = 0,
+ PNFS_NOT_ATTEMPTED = 1,
+};
+
#ifdef CONFIG_NFS_V4_1
#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
@@ -70,6 +75,12 @@
/* test for nfs page cache coalescing */
int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
+
+ /*
+ * Return PNFS_ATTEMPTED to indicate the layout code has attempted
+ * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
+ */
+ enum pnfs_try_status (*read_pagelist) (struct nfs_read_data *nfs_data);
};
struct pnfs_layout_hdr {
@@ -157,6 +168,8 @@
enum pnfs_iomode access_type);
void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
void unset_pnfs_layoutdriver(struct nfs_server *);
+enum pnfs_try_status pnfs_try_to_read_data(struct nfs_read_data *,
+ const struct rpc_call_ops *);
void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *);
int pnfs_layout_process(struct nfs4_layoutget *lgp);
void pnfs_free_lseg_list(struct list_head *tmp_list);
@@ -227,6 +240,13 @@
return NULL;
}
+static inline enum pnfs_try_status
+pnfs_try_to_read_data(struct nfs_read_data *data,
+ const struct rpc_call_ops *call_ops)
+{
+ return PNFS_NOT_ATTEMPTED;
+}
+
static inline bool
pnfs_roc(struct inode *ino)
{
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 6dc9eaf..4127a1c 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"
@@ -155,6 +157,45 @@
nfs_release_request(req);
}
+static int nfs_initiate_read(struct nfs_read_data *data, struct rpc_clnt *clnt,
+ const struct rpc_call_ops *call_ops)
+{
+ 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 = data->cred,
+ };
+ struct rpc_task_setup task_setup_data = {
+ .task = &data->task,
+ .rpc_client = clnt,
+ .rpc_message = &msg,
+ .callback_ops = call_ops,
+ .callback_data = data,
+ .workqueue = nfsiod_workqueue,
+ .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
*/
@@ -164,26 +205,10 @@
struct pnfs_layout_segment *lseg)
{
struct inode *inode = req->wb_context->path.dentry->d_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,
- };
- struct rpc_task_setup task_setup_data = {
- .task = &data->task,
- .rpc_client = NFS_CLIENT(inode),
- .rpc_message = &msg,
- .callback_ops = call_ops,
- .callback_data = data,
- .workqueue = nfsiod_workqueue,
- .flags = RPC_TASK_ASYNC | swap_flags,
- };
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 @@
data->res.eof = 0;
nfs_fattr_init(&data->fattr);
- /* Set up the initial task struct. */
- NFS_PROTO(inode)->read_setup(data, &msg);
+ if (data->lseg &&
+ (pnfs_try_to_read_data(data, call_ops) == PNFS_ATTEMPTED))
+ return 0;
- 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);
-
- 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
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h
index 68b10f5..37a1437 100644
--- a/include/linux/nfs_iostat.h
+++ b/include/linux/nfs_iostat.h
@@ -113,6 +113,7 @@
NFSIOS_SHORTREAD,
NFSIOS_SHORTWRITE,
NFSIOS_DELAY,
+ NFSIOS_PNFS_READ,
__NFSIOS_COUNTSMAX,
};
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 560923e..9d2b9da 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1018,6 +1018,7 @@
struct nfs_readres res;
unsigned long timestamp; /* For lease renewal */
struct pnfs_layout_segment *lseg;
+ const struct rpc_call_ops *mds_ops;
struct page *page_array[NFS_PAGEVEC_SIZE];
};