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author | Christoph Hellwig <hch@lst.de> | 2010-06-04 11:29:57 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2010-08-09 16:47:32 -0400 |
commit | 6e1db88d536adcbbfe562b2d4b7d6425784fff12 (patch) | |
tree | 8cfcb5a6190722db6249b2e4978f39247975abcf /fs/buffer.c | |
parent | f4e420dc423148fba637af1ab618fa8896dfb2d6 (diff) | |
download | kernel_samsung_crespo-6e1db88d536adcbbfe562b2d4b7d6425784fff12.zip kernel_samsung_crespo-6e1db88d536adcbbfe562b2d4b7d6425784fff12.tar.gz kernel_samsung_crespo-6e1db88d536adcbbfe562b2d4b7d6425784fff12.tar.bz2 |
introduce __block_write_begin
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>
Diffstat (limited to 'fs/buffer.c')
-rw-r--r-- | fs/buffer.c | 69 |
1 files changed, 26 insertions, 43 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 14529ec..c319c49 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -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 = *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)); + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; - 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; |