From: "Jayson R. King" Subject: [07/11] ext4: Use tag dirty lookup during mpage_da_submit_io Date: Sat, 27 Feb 2010 00:33:00 -0600 Message-ID: <4B88BC9C.50502@jaysonking.com> References: <4B88BA1B.4050500@jaysonking.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Aneesh Kumar K.V" , Mingming Cao , Theodore Ts'o , linux-ext4@vger.kernel.org, Andrew Morton , Jayson King To: LKML , Stable team , Greg Kroah-Hartman Return-path: Received: from bosmailout15.eigbox.net ([66.96.187.15]:33922 "EHLO bosmailout15.eigbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967850Ab0B0HWq (ORCPT ); Sat, 27 Feb 2010 02:22:46 -0500 In-Reply-To: <4B88BA1B.4050500@jaysonking.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Aneesh Kumar K.V Date: Tue Oct 14 09:20:19 2008 -0400 Subject: ext4: Use tag dirty lookup during mpage_da_submit_io commit af6f029d3836eb7264cd3fbb13a6baf0e5fdb5ea upstream. This enables us to drop the range_cont writeback mode use from ext4_da_writepages. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Jayson R. King --- fs/ext4/inode.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-) diff -urNp linux-2.6.27.orig/fs/ext4/inode.c linux-2.6.27/fs/ext4/inode.c --- linux-2.6.27.orig/fs/ext4/inode.c 2010-02-26 14:24:53.269252744 -0600 +++ linux-2.6.27/fs/ext4/inode.c 2010-02-26 14:25:01.277252724 -0600 @@ -1699,17 +1699,23 @@ static int mpage_da_submit_io(struct mpa pagevec_init(&pvec, 0); while (index <= end) { - nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); + /* + * We can use PAGECACHE_TAG_DIRTY lookup here because + * even though we have cleared the dirty flag on the page + * We still keep the page in the radix tree with tag + * PAGECACHE_TAG_DIRTY. See clear_page_dirty_for_io. + * The PAGECACHE_TAG_DIRTY is cleared in set_page_writeback + * which is called via the below writepage callback. + */ + nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, + PAGECACHE_TAG_DIRTY, + min(end - index, + (pgoff_t)PAGEVEC_SIZE-1) + 1); if (nr_pages == 0) break; for (i = 0; i < nr_pages; i++) { struct page *page = pvec.pages[i]; - index = page->index; - if (index > end) - break; - index++; - BUG_ON(!PageLocked(page)); BUG_ON(PageWriteback(page)); @@ -2442,7 +2448,6 @@ static int ext4_da_writepages(struct add struct writeback_control *wbc) { handle_t *handle = NULL; - loff_t range_start = 0; struct mpage_da_data mpd; struct inode *inode = mapping->host; int needed_blocks, ret = 0, nr_to_writebump = 0; @@ -2481,14 +2486,7 @@ static int ext4_da_writepages(struct add wbc->nr_to_write = sbi->s_mb_stream_request; } - if (!wbc->range_cyclic) - /* - * If range_cyclic is not set force range_cont - * and save the old writeback_index - */ - wbc->range_cont = 1; - range_start = wbc->range_start; pages_skipped = wbc->pages_skipped; mpd.wbc = wbc; @@ -2559,9 +2557,8 @@ restart_loop: wbc->nr_to_write = to_write; } - if (wbc->range_cont && (pages_skipped != wbc->pages_skipped)) { + if (!wbc->range_cyclic && (pages_skipped != wbc->pages_skipped)) { /* We skipped pages in this loop */ - wbc->range_start = range_start; wbc->nr_to_write = to_write + wbc->pages_skipped - pages_skipped; wbc->pages_skipped = pages_skipped; @@ -2570,7 +2567,6 @@ restart_loop: out_writepages: wbc->nr_to_write = to_write - nr_to_writebump; - wbc->range_start = range_start; return ret; }