NFS: create common nfs_pgio_header for both read and write

In order to avoid duplicating all the data in nfs_read_data whenever we
split it up into multiple RPC calls (either due to a short read result
or due to rsize < PAGE_SIZE), we split out the bits that are the same
per RPC call into a separate "header" structure.

The goal this patch moves towards is to have a single header
refcounted by several rpc_data structures.  Thus, want to always refer
from rpc_data to the header, and not the other way.  This patch comes
close to that ideal, but the directio code currently needs some
special casing, isolated in the nfs_direct_[read_write]hdr_release()
functions.  This will be dealt with in a future patch.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Fred Isaman
2012-04-20 14:47:44 -04:00
committed by Trond Myklebust
parent b554284976
commit cd841605f7
14 changed files with 376 additions and 278 deletions

View File

@@ -440,11 +440,12 @@ static void _read_done(struct ore_io_state *ios, void *private)
int objio_read_pagelist(struct nfs_read_data *rdata)
{
struct nfs_pgio_header *hdr = rdata->header;
struct objio_state *objios;
int ret;
ret = objio_alloc_io_state(NFS_I(rdata->inode)->layout, true,
rdata->lseg, rdata->args.pages, rdata->args.pgbase,
ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, true,
hdr->lseg, rdata->args.pages, rdata->args.pgbase,
rdata->args.offset, rdata->args.count, rdata,
GFP_KERNEL, &objios);
if (unlikely(ret))
@@ -483,12 +484,12 @@ static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
{
struct objio_state *objios = priv;
struct nfs_write_data *wdata = objios->oir.rpcdata;
struct address_space *mapping = wdata->header->inode->i_mapping;
pgoff_t index = offset / PAGE_SIZE;
struct page *page = find_get_page(wdata->inode->i_mapping, index);
struct page *page = find_get_page(mapping, index);
if (!page) {
page = find_or_create_page(wdata->inode->i_mapping,
index, GFP_NOFS);
page = find_or_create_page(mapping, index, GFP_NOFS);
if (unlikely(!page)) {
dprintk("%s: grab_cache_page Failed index=0x%lx\n",
__func__, index);
@@ -518,11 +519,12 @@ static const struct _ore_r4w_op _r4w_op = {
int objio_write_pagelist(struct nfs_write_data *wdata, int how)
{
struct nfs_pgio_header *hdr = wdata->header;
struct objio_state *objios;
int ret;
ret = objio_alloc_io_state(NFS_I(wdata->inode)->layout, false,
wdata->lseg, wdata->args.pages, wdata->args.pgbase,
ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, false,
hdr->lseg, wdata->args.pages, wdata->args.pgbase,
wdata->args.offset, wdata->args.count, wdata, GFP_NOFS,
&objios);
if (unlikely(ret))