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NFS: Cleanup: add common helper nfs_page_length()

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Clean up a lot of ad-hoc page length calculations in fs/nfs/write.c

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2006-12-05 00:35:38 -05:00
parent 277459d2e2
commit 49a70f2786
3 changed files with 31 additions and 63 deletions
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18
fs/nfs/internal.h
View File

@ -217,3 +217,21 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
sb->s_maxbytes = MAX_LFS_FILESIZE;
}
/*
* Determine the number of bytes of data the page contains
*/
static inline
unsigned int nfs_page_length(struct page *page)
{
loff_t i_size = i_size_read(page->mapping->host);
if (i_size > 0) {
pgoff_t end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
if (page->index < end_index)
return PAGE_CACHE_SIZE;
if (page->index == end_index)
return ((i_size - 1) & ~PAGE_CACHE_MASK) + 1;
}
return 0;
}

21
fs/nfs/read.c
View File

@ -30,6 +30,7 @@
#include <asm/system.h>
#include "internal.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
@ -83,22 +84,6 @@ void nfs_readdata_release(void *data)
nfs_readdata_free(data);
}
static
unsigned int nfs_page_length(struct inode *inode, struct page *page)
{
loff_t i_size = i_size_read(inode);
unsigned long idx;
if (i_size <= 0)
return 0;
idx = (i_size - 1) >> PAGE_CACHE_SHIFT;
if (page->index > idx)
return 0;
if (page->index != idx)
return PAGE_CACHE_SIZE;
return 1 + ((i_size - 1) & (PAGE_CACHE_SIZE - 1));
}
static
int nfs_return_empty_page(struct page *page)
{
@ -231,7 +216,7 @@ static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
struct nfs_page *new;
unsigned int len;
len = nfs_page_length(inode, page);
len = nfs_page_length(page);
if (len == 0)
return nfs_return_empty_page(page);
new = nfs_create_request(ctx, inode, page, 0, len);
@ -667,7 +652,7 @@ readpage_async_filler(void *data, struct page *page)
unsigned int len;
nfs_wb_page(inode, page);
len = nfs_page_length(inode, page);
len = nfs_page_length(page);
if (len == 0)
return nfs_return_empty_page(page);
new = nfs_create_request(desc->ctx, inode, page, 0, len);

55
fs/nfs/write.c
View File

@ -63,6 +63,7 @@
#include <linux/smp_lock.h>
#include "delegation.h"
#include "internal.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
@ -199,30 +200,15 @@ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int c
*/
static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count)
{
loff_t end_offs;
if (PageUptodate(page))
return;
if (base != 0)
return;
if (count == PAGE_CACHE_SIZE) {
SetPageUptodate(page);
if (count != nfs_page_length(page))
return;
}
end_offs = i_size_read(page->mapping->host) - 1;
if (end_offs < 0)
return;
/* Is this the last page? */
if (page->index != (unsigned long)(end_offs >> PAGE_CACHE_SHIFT))
return;
/* This is the last page: set PG_uptodate if we cover the entire
* extent of the data, then zero the rest of the page.
*/
if (count == (unsigned int)(end_offs & (PAGE_CACHE_SIZE - 1)) + 1) {
if (count != PAGE_CACHE_SIZE)
memclear_highpage_flush(page, count, PAGE_CACHE_SIZE - count);
SetPageUptodate(page);
}
SetPageUptodate(page);
}
/*
@ -330,9 +316,7 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct nfs_open_context *ctx;
struct inode *inode = page->mapping->host;
unsigned long end_index;
unsigned offset = PAGE_CACHE_SIZE;
loff_t i_size = i_size_read(inode);
unsigned offset;
int inode_referenced = 0;
int priority = wb_priority(wbc);
int err;
@ -350,22 +334,15 @@ int nfs_writepage(struct page *page, struct writeback_control *wbc)
*/
if (igrab(inode) != 0)
inode_referenced = 1;
end_index = i_size >> PAGE_CACHE_SHIFT;
/* Ensure we've flushed out any previous writes */
nfs_wb_page_priority(inode, page, priority);
/* easy case */
if (page->index < end_index)
goto do_it;
/* things got complicated... */
offset = i_size & (PAGE_CACHE_SIZE-1);
/* OK, are we completely out? */
err = 0; /* potential race with truncate - ignore */
if (page->index >= end_index+1 || !offset)
err = 0;
offset = nfs_page_length(page);
if (!offset)
goto out;
do_it:
ctx = nfs_find_open_context(inode, NULL, FMODE_WRITE);
if (ctx == NULL) {
err = -EBADF;
@ -826,20 +803,8 @@ int nfs_updatepage(struct file *file, struct page *page,
* fragmenting write requests.
*/
if (PageUptodate(page) && inode->i_flock == NULL && !(file->f_mode & O_SYNC)) {
loff_t end_offs = i_size_read(inode) - 1;
unsigned long end_index = end_offs >> PAGE_CACHE_SHIFT;
count += offset;
count = max(count + offset, nfs_page_length(page));
offset = 0;
if (unlikely(end_offs < 0)) {
/* Do nothing */
} else if (page->index == end_index) {
unsigned int pglen;
pglen = (unsigned int)(end_offs & (PAGE_CACHE_SIZE-1)) + 1;
if (count < pglen)
count = pglen;
} else if (page->index < end_index)
count = PAGE_CACHE_SIZE;
}
/*