From 35c80d5f400f68f2eccf3069d1c068e154bde9c9 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 15 Apr 2009 13:22:38 -0400 Subject: [PATCH] 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: Chris Mason Acked-by: Theodore Tso Acked-by: Jan Kara Signed-off-by: Linus Torvalds --- fs/buffer.c | 45 ++++++++++++++++++++++++++++--------- include/linux/buffer_head.h | 3 +++ 2 files changed, 37 insertions(+), 11 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index ff8bb1f2333a..b3e5be7514f5 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -360,7 +360,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) * 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; @@ -438,10 +438,16 @@ static void mark_buffer_async_read(struct buffer_head *bh) set_buffer_async_read(bh); } +void mark_buffer_async_write_endio(struct buffer_head *bh, + bh_end_io_t *handler) +{ + bh->b_end_io = handler; + set_buffer_async_write(bh); +} + void mark_buffer_async_write(struct buffer_head *bh) { - bh->b_end_io = end_buffer_async_write; - set_buffer_async_write(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 @@ static int __block_write_full_page(struct inode *inode, struct page *page, 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 @@ int block_truncate_page(struct address_space *mapping, /* * 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); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 7b73bb8f1970..16ed0284d780 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -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);