Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756686Ab3IYAUl (ORCPT ); Tue, 24 Sep 2013 20:20:41 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39616 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756611Ab3IYAUb (ORCPT ); Tue, 24 Sep 2013 20:20:31 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , "Theodore Tso" Subject: [ 061/117] ext4: move test whether extent to map can be extended to one place Date: Tue, 24 Sep 2013 17:18:47 -0700 Message-Id: <20130925001747.521451488@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20130925001740.833541979@linuxfoundation.org> References: <20130925001740.833541979@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3789 Lines: 114 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 09930042a2e94cf8ee79d22943915612c1e4ba51 upstream. Currently the logic whether the current buffer can be added to an extent of buffers to map is split between mpage_add_bh_to_extent() and add_page_bufs_to_extent(). Move the whole logic to mpage_add_bh_to_extent() which makes things a bit more straightforward and make following i_size fixes easier. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 49 +++++++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 20 deletions(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1904,34 +1904,48 @@ static int ext4_writepage(struct page *p * * @mpd - extent of blocks * @lblk - logical number of the block in the file - * @b_state - b_state of the buffer head added + * @bh - buffer head we want to add to the extent * - * the function is used to collect contig. blocks in same state + * The function is used to collect contig. blocks in the same state. If the + * buffer doesn't require mapping for writeback and we haven't started the + * extent of buffers to map yet, the function returns 'true' immediately - the + * caller can write the buffer right away. Otherwise the function returns true + * if the block has been added to the extent, false if the block couldn't be + * added. */ -static int mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, - unsigned long b_state) +static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, + struct buffer_head *bh) { struct ext4_map_blocks *map = &mpd->map; - /* Don't go larger than mballoc is willing to allocate */ - if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN) - return 0; + /* Buffer that doesn't need mapping for writeback? */ + if (!buffer_dirty(bh) || !buffer_mapped(bh) || + (!buffer_delay(bh) && !buffer_unwritten(bh))) { + /* So far no extent to map => we write the buffer right away */ + if (map->m_len == 0) + return true; + return false; + } /* First block in the extent? */ if (map->m_len == 0) { map->m_lblk = lblk; map->m_len = 1; - map->m_flags = b_state & BH_FLAGS; - return 1; + map->m_flags = bh->b_state & BH_FLAGS; + return true; } + /* Don't go larger than mballoc is willing to allocate */ + if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN) + return false; + /* Can we merge the block to our big extent? */ if (lblk == map->m_lblk + map->m_len && - (b_state & BH_FLAGS) == map->m_flags) { + (bh->b_state & BH_FLAGS) == map->m_flags) { map->m_len++; - return 1; + return true; } - return 0; + return false; } static bool add_page_bufs_to_extent(struct mpage_da_data *mpd, @@ -1946,18 +1960,13 @@ static bool add_page_bufs_to_extent(stru do { BUG_ON(buffer_locked(bh)); - if (!buffer_dirty(bh) || !buffer_mapped(bh) || - (!buffer_delay(bh) && !buffer_unwritten(bh)) || - lblk >= blocks) { + if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) { /* Found extent to map? */ if (mpd->map.m_len) return false; - if (lblk >= blocks) - return true; - continue; + /* Everything mapped so far and we hit EOF */ + return true; } - if (!mpage_add_bh_to_extent(mpd, lblk, bh->b_state)) - return false; } while (lblk++, (bh = bh->b_this_page) != head); return true; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/