[PATCH 13/24] pnfs_submit: read path changeover

Fred Isaman
2010-06-08T04:19:47Z

Change readpages path to only call LAYOUTGET once.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
---
fs/nfs/pagelist.c | 2 ++
fs/nfs/pnfs.c | 37 +++++++------------------------------
fs/nfs/pnfs.h | 25 ++++++++++++++++---------
3 files changed, 25 insertions(+), 39 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index ed647b9..c3e5a1f 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -253,6 +253,8 @@ static int nfs_can_coalesce_requests(struct nfs_page *prev,
return 0;
if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
return 0;
+ if (req->wb_lseg != prev->wb_lseg)
+ return 0;
#ifdef CONFIG_NFS_V4_1
if (pgio->pg_test && !pgio->pg_test(pgio, prev, req))
return 0;
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2b5f6fc..692a18e 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1689,7 +1689,7 @@ pnfs_readpages(struct nfs_read_data *rdata)
{
struct nfs_readargs *args = &rdata->args;
struct inode *inode = rdata->inode;
- int numpages, status, pgcount, temp;
+ int numpages, pgcount, temp;
struct nfs_server *nfss = NFS_SERVER(inode);
struct nfs_inode *nfsi = NFS_I(inode);
struct pnfs_layout_segment *lseg;
@@ -1701,19 +1701,8 @@ pnfs_readpages(struct nfs_read_data *rdata)
args->count,
args->offset);

- /* Retrieve and set layout if not allready cached */
- status = _pnfs_update_layout(inode,
- args->context,
- args->count,
- args->offset,
- IOMODE_READ,
- &lseg);
- if (status) {
- dprintk("%s: Updating layout failed (%d), retry with NFS \n",
- __func__, status);
- trypnfs = PNFS_NOT_ATTEMPTED;
- goto out;
- }
+ lseg = rdata->req->wb_lseg;
+ get_lseg(lseg);

/* Determine number of pages. */
pgcount = args->pgbase + args->count;
@@ -1740,7 +1729,6 @@ pnfs_readpages(struct nfs_read_data *rdata)
rdata->pdata.lseg = NULL;
put_lseg(lseg);
}
- out:
dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
return trypnfs;
}
@@ -1749,21 +1737,10 @@ enum pnfs_try_status
_pnfs_try_to_read_data(struct nfs_read_data *data,
const struct rpc_call_ops *call_ops)
{
- struct inode *ino = data->inode;
- struct nfs_server *nfss = NFS_SERVER(ino);
-
- dprintk("--> %s\n", __func__);
- /* Only create an rpc request if utilizing NFSv4 I/O */
- if (!pnfs_enabled_sb(nfss) ||
- !nfss->pnfs_curr_ld->ld_io_ops->read_pagelist) {
- dprintk("<-- %s: not using pnfs\n", __func__);
- return PNFS_NOT_ATTEMPTED;
- } else {
- dprintk("%s: Utilizing pNFS I/O\n", __func__);
- data->pdata.call_ops = call_ops;
- data->pdata.pnfs_error = 0;
- return pnfs_readpages(data);
- }
+ dprintk("%s: Utilizing pNFS I/O\n", __func__);
+ data->pdata.call_ops = call_ops;
+ data->pdata.pnfs_error = 0;
+ return pnfs_readpages(data);
}

enum pnfs_try_status
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 6326ed5..816ebe1 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -94,22 +94,29 @@ static inline int pnfs_enabled_sb(struct nfs_server *nfss)
return nfss->pnfs_curr_ld != NULL;
}

+static inline void _pnfs_clear_lseg_from_pages(struct list_head *head)
+{
+ struct nfs_page *req;
+
+ list_for_each_entry(req, head, wb_list) {
+ put_lseg(req->wb_lseg);
+ req->wb_lseg = NULL;
+ }
+}
+
static inline enum pnfs_try_status
pnfs_try_to_read_data(struct nfs_read_data *data,
const struct rpc_call_ops *call_ops)
{
- struct inode *inode = data->inode;
- struct nfs_server *nfss = NFS_SERVER(inode);
enum pnfs_try_status ret;

- /* FIXME: read_pagelist should probably be mandated */
- if (PNFS_EXISTS_LDIO_OP(nfss, read_pagelist))
- ret = _pnfs_try_to_read_data(data, call_ops);
- else
- ret = PNFS_NOT_ATTEMPTED;
-
+ if (!data->req->wb_lseg)
+ return PNFS_NOT_ATTEMPTED;
+ ret = _pnfs_try_to_read_data(data, call_ops);
if (ret == PNFS_ATTEMPTED)
- nfs_inc_stats(inode, NFSIOS_PNFS_READ);
+ nfs_inc_stats(data->inode, NFSIOS_PNFS_READ);
+ else
+ _pnfs_clear_lseg_from_pages(&data->pages);
return ret;
}

--
1.6.6.1