Commit 35c80d5f authored by Chris Mason's avatar Chris Mason Committed by Linus Torvalds
Browse files

Add block_write_full_page_endio for passing endio handler 



block_write_full_page doesn't allow the caller to control what happens
when the IO is over.  This adds a new call named block_write_full_page_endio
so the buffer head end_io handler can be provided by the caller.

This will be used by the ext3 data=guarded mode to do i_size updates in
a workqueue based end_io handler.  end_buffer_async_write is also
exported so it can be called to do the dirty work of managing page
writeback for the higher level end_io handler.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
Acked-by: default avatarTheodore Tso <tytso@mit.edu>
Acked-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f6995585

fs/buffer.c

+34 −11
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ still_busy: 
 * Completion handler for block_write_full_page() - pages which are unlocked

 * during I/O, and which have PageWriteback cleared upon I/O completion.

 */

static void end_buffer_async_write(struct buffer_head *bh, int uptodate)

void end_buffer_async_write(struct buffer_head *bh, int uptodate)

{

	char b[BDEVNAME_SIZE];

	unsigned long flags;
@@ -438,11 +438,17 @@ static void mark_buffer_async_read(struct buffer_head *bh) 
	set_buffer_async_read(bh);

}



void mark_buffer_async_write(struct buffer_head *bh)

void mark_buffer_async_write_endio(struct buffer_head *bh,

				   bh_end_io_t *handler)

{

	bh->b_end_io = end_buffer_async_write;

	bh->b_end_io = handler;

	set_buffer_async_write(bh);

}



void mark_buffer_async_write(struct buffer_head *bh)

{

	mark_buffer_async_write_endio(bh, end_buffer_async_write);

}

EXPORT_SYMBOL(mark_buffer_async_write);
@@ -1615,7 +1621,8 @@ EXPORT_SYMBOL(unmap_underlying_metadata); 
 * unplugging the device queue.

 */

static int __block_write_full_page(struct inode *inode, struct page *page,

			get_block_t *get_block, struct writeback_control *wbc)

			get_block_t *get_block, struct writeback_control *wbc,

			bh_end_io_t *handler)

{

	int err;

	sector_t block;
@@ -1700,7 +1707,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, 
			continue;

		}

		if (test_clear_buffer_dirty(bh)) {

			mark_buffer_async_write(bh);

			mark_buffer_async_write_endio(bh, handler);

		} else {

			unlock_buffer(bh);

		}
@@ -1753,7 +1760,7 @@ recover: 
		if (buffer_mapped(bh) && buffer_dirty(bh) &&

		    !buffer_delay(bh)) {

			lock_buffer(bh);

			mark_buffer_async_write(bh);

			mark_buffer_async_write_endio(bh, handler);

		} else {

			/*

			 * The buffer may have been set dirty during
@@ -2679,7 +2686,8 @@ int nobh_writepage(struct page *page, get_block_t *get_block, 
out:

	ret = mpage_writepage(page, get_block, wbc);

	if (ret == -EAGAIN)

		ret = __block_write_full_page(inode, page, get_block, wbc);

		ret = __block_write_full_page(inode, page, get_block, wbc,

					      end_buffer_async_write);

	return ret;

}

EXPORT_SYMBOL(nobh_writepage);
@@ -2837,9 +2845,10 @@ out: 


/*

 * The generic ->writepage function for buffer-backed address_spaces

 * this form passes in the end_io handler used to finish the IO.

 */

int block_write_full_page(struct page *page, get_block_t *get_block,

			struct writeback_control *wbc)

int block_write_full_page_endio(struct page *page, get_block_t *get_block,

			struct writeback_control *wbc, bh_end_io_t *handler)

{

	struct inode * const inode = page->mapping->host;

	loff_t i_size = i_size_read(inode);
@@ -2848,7 +2857,8 @@ int block_write_full_page(struct page *page, get_block_t *get_block, 


	/* Is the page fully inside i_size? */

	if (page->index < end_index)

		return __block_write_full_page(inode, page, get_block, wbc);

		return __block_write_full_page(inode, page, get_block, wbc,

					       handler);



	/* Is the page fully outside i_size? (truncate in progress) */

	offset = i_size & (PAGE_CACHE_SIZE-1);
@@ -2871,9 +2881,20 @@ int block_write_full_page(struct page *page, get_block_t *get_block, 
	 * writes to that region are not written out to the file."

	 */

	zero_user_segment(page, offset, PAGE_CACHE_SIZE);

	return __block_write_full_page(inode, page, get_block, wbc);

	return __block_write_full_page(inode, page, get_block, wbc, handler);

}



/*

 * The generic ->writepage function for buffer-backed address_spaces

 */

int block_write_full_page(struct page *page, get_block_t *get_block,

			struct writeback_control *wbc)

{

	return block_write_full_page_endio(page, get_block, wbc,

					   end_buffer_async_write);

}





sector_t generic_block_bmap(struct address_space *mapping, sector_t block,

			    get_block_t *get_block)

{
@@ -3342,9 +3363,11 @@ EXPORT_SYMBOL(block_read_full_page); 
EXPORT_SYMBOL(block_sync_page);

EXPORT_SYMBOL(block_truncate_page);

EXPORT_SYMBOL(block_write_full_page);

EXPORT_SYMBOL(block_write_full_page_endio);

EXPORT_SYMBOL(cont_write_begin);

EXPORT_SYMBOL(end_buffer_read_sync);

EXPORT_SYMBOL(end_buffer_write_sync);

EXPORT_SYMBOL(end_buffer_async_write);

EXPORT_SYMBOL(file_fsync);

EXPORT_SYMBOL(generic_block_bmap);

EXPORT_SYMBOL(generic_cont_expand_simple);

include/linux/buffer_head.h

+3 −0
Original line number Diff line number Diff line
@@ -155,6 +155,7 @@ void create_empty_buffers(struct page *, unsigned long, 
			unsigned long b_state);

void end_buffer_read_sync(struct buffer_head *bh, int uptodate);

void end_buffer_write_sync(struct buffer_head *bh, int uptodate);

void end_buffer_async_write(struct buffer_head *bh, int uptodate);



/* Things to do with buffers at mapping->private_list */

void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
@@ -197,6 +198,8 @@ extern int buffer_heads_over_limit; 
void block_invalidatepage(struct page *page, unsigned long offset);

int block_write_full_page(struct page *page, get_block_t *get_block,

				struct writeback_control *wbc);

int block_write_full_page_endio(struct page *page, get_block_t *get_block,

			struct writeback_control *wbc, bh_end_io_t *handler);

int block_read_full_page(struct page*, get_block_t*);

int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,

				unsigned long from);

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