From: Theodore Ts'o Subject: [PATCH 2.6.27.y 07/11] ext4: Use tag dirty lookup during mpage_da_submit_io Date: Mon, 15 Mar 2010 20:26:01 -0400 Message-ID: <1268699165-17461-8-git-send-email-tytso@mit.edu> References: <1268699165-17461-1-git-send-email-tytso@mit.edu> Cc: "Jayson R. King" , Ext4 Developers List , "Aneesh Kumar K.V" , Theodore Ts'o To: stable@kernel.org Return-path: Received: from thunk.org ([69.25.196.29]:38644 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932851Ab0CPA0L (ORCPT ); Mon, 15 Mar 2010 20:26:11 -0400 In-Reply-To: <1268699165-17461-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Aneesh Kumar K.V 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 Signed-off-by: Theodore Ts'o --- fs/ext4/inode.c | 30 +++++++++++++----------------- 1 files changed, 13 insertions(+), 17 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 71901ae..a67f837 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1699,17 +1699,23 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd) 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 address_space *mapping, 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 address_space *mapping, 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; } -- 1.6.6.1.1.g974db.dirty