From: Chris Mason Subject: [PATCH 1/2] Add block_write_full_page_endio for passing endio handler Date: Tue, 14 Apr 2009 16:59:13 -0400 Message-ID: <1239742754.28321.41.camel@think.oraclecorp.com> References: <1239742633.28321.39.camel@think.oraclecorp.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Linus Torvalds , "Theodore Ts'o" , Linux Kernel Developers List , Ext4 Developers List To: Jan Kara Return-path: Received: from rcsinet11.oracle.com ([148.87.113.123]:44484 "EHLO rgminet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751806AbZDNVA1 (ORCPT ); Tue, 14 Apr 2009 17:00:27 -0400 In-Reply-To: <1239742633.28321.39.camel@think.oraclecorp.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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 --- 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 13edf7a..308865b 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -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); @@ -1608,7 +1614,8 @@ 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; @@ -1693,7 +1700,7 @@ 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); } @@ -1746,7 +1753,7 @@ 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 @@ -2672,7 +2679,8 @@ 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); @@ -2830,9 +2838,10 @@ 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); @@ -2841,7 +2850,8 @@ 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); @@ -2864,9 +2874,20 @@ 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) { @@ -3335,9 +3356,11 @@ 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 7b73bb8..16ed028 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);