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ext4: remove vestiges of nobh support

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The nobh option was only supported for writeback mode, but given that all
write paths actually create buffer heads it effectively was a no-op already.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Christoph Hellwig 2010-06-14 14:42:49 -04:00 • committed by Theodore Ts'o
parent 5a0790c2c4
commit 206f7ab4f4
4 changed files with 15 additions and 44 deletions
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27
fs/ext4/inode.c
View file

@ -2553,18 +2553,16 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
/*
* This function is used as a standard get_block_t calback function
* when there is no desire to allocate any blocks. It is used as a
* callback function for block_prepare_write(), nobh_writepage(), and
* block_write_full_page(). These functions should only try to map a
* single block at a time.
* callback function for block_prepare_write() and block_write_full_page().
* These functions should only try to map a single block at a time.
*
* Since this function doesn't do block allocations even if the caller
* requests it by passing in create=1, it is critically important that
* any caller checks to make sure that any buffer heads are returned
* by this function are either all already mapped or marked for
* delayed allocation before calling nobh_writepage() or
* block_write_full_page(). Otherwise, b_blocknr could be left
* unitialized, and the page write functions will be taken by
* surprise.
* delayed allocation before calling block_write_full_page(). Otherwise,
* b_blocknr could be left unitialized, and the page write functions will
* be taken by surprise.
*/
static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
@ -2749,9 +2747,7 @@ static int ext4_writepage(struct page *page,
return __ext4_journalled_writepage(page, len);
}
if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
ret = nobh_writepage(page, noalloc_get_block_write, wbc);
else if (page_bufs && buffer_uninit(page_bufs)) {
if (page_bufs && buffer_uninit(page_bufs)) {
ext4_set_bh_endio(page_bufs, inode);
ret = block_write_full_page_endio(page, noalloc_get_block_write,
wbc, ext4_end_io_buffer_write);
@ -4125,17 +4121,6 @@ int ext4_block_truncate_page(handle_t *handle,
length = blocksize - (offset & (blocksize - 1));
iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
/*
* For "nobh" option, we can only work if we don't need to
* read-in the page - otherwise we create buffers to do the IO.
*/
if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
ext4_should_writeback_data(inode) && PageUptodate(page)) {
zero_user(page, offset, length);
set_page_dirty(page);
goto unlock;
}
if (!page_has_buffers(page))
create_empty_buffers(page, blocksize, 0);