lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

introduce __block_write_begin

Browse Source 
Split up the block_write_begin implementation - __block_write_begin is a new
trivial wrapper for block_prepare_write that always takes an already
allocated page and can be either called from block_write_begin or filesystem
code that already has a page allocated.  Remove the handling of already
allocated pages from block_write_begin after switching all callers that
do it to __block_write_begin.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Christoph Hellwig
2010-06-04 11:29:57 +02:00
committed by Al Viro
parent f4e420dc42
commit 6e1db88d53
10 changed files with 39 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files

69
fs/buffer.c
View File

@@ -1833,9 +1833,10 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
}
EXPORT_SYMBOL(page_zero_new_buffers);
static int __block_prepare_write(struct inode *inode, struct page *page,
unsigned from, unsigned to, get_block_t *get_block)
int block_prepare_write(struct page *page, unsigned from, unsigned to,
get_block_t *get_block)
{
struct inode *inode = page->mapping->host;
unsigned block_start, block_end;
sector_t block;
int err = 0;
@@ -1908,10 +1909,13 @@ static int __block_prepare_write(struct inode *inode, struct page *page,
if (!buffer_uptodate(*wait_bh))
err = -EIO;
}
if (unlikely(err))
if (unlikely(err)) {
page_zero_new_buffers(page, from, to);
ClearPageUptodate(page);
}
return err;
}
EXPORT_SYMBOL(block_prepare_write);
static int __block_commit_write(struct inode *inode, struct page *page,
unsigned from, unsigned to)
@@ -1948,6 +1952,15 @@ static int __block_commit_write(struct inode *inode, struct page *page,
return 0;
}
int __block_write_begin(struct page *page, loff_t pos, unsigned len,
get_block_t *get_block)
{
unsigned start = pos & (PAGE_CACHE_SIZE - 1);
return block_prepare_write(page, start, start + len, get_block);
}
EXPORT_SYMBOL(__block_write_begin);
/*
* Filesystems implementing the new truncate sequence should use the
* _newtrunc postfix variant which won't incorrectly call vmtruncate.
@@ -1958,41 +1971,22 @@ int block_write_begin_newtrunc(struct file *file, struct address_space *mapping,
struct page **pagep, void **fsdata,
get_block_t *get_block)
{
struct inode *inode = mapping->host;
int status = 0;
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
struct page *page;
pgoff_t index;
unsigned start, end;
int ownpage = 0;
int status;
index = pos >> PAGE_CACHE_SHIFT;
start = pos & (PAGE_CACHE_SIZE - 1);
end = start + len;
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
page = *pagep;
if (page == NULL) {
ownpage = 1;
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page) {
status = -ENOMEM;
goto out;
}
*pagep = page;
} else
BUG_ON(!PageLocked(page));
status = __block_prepare_write(inode, page, start, end, get_block);
status = __block_write_begin(page, pos, len, get_block);
if (unlikely(status)) {
ClearPageUptodate(page);
if (ownpage) {
unlock_page(page);
page_cache_release(page);
*pagep = NULL;
}
unlock_page(page);
page_cache_release(page);
page = NULL;
}
out:
*pagep = page;
return status;
}
EXPORT_SYMBOL(block_write_begin_newtrunc);
@@ -2379,17 +2373,6 @@ out:
}
EXPORT_SYMBOL(cont_write_begin);
int block_prepare_write(struct page *page, unsigned from, unsigned to,
get_block_t *get_block)
{
struct inode *inode = page->mapping->host;
int err = __block_prepare_write(inode, page, from, to, get_block);
if (err)
ClearPageUptodate(page);
return err;
}
EXPORT_SYMBOL(block_prepare_write);
int block_commit_write(struct page *page, unsigned from, unsigned to)
{
struct inode *inode = page->mapping->host;