From: Subject: patch ext4-fix-file-fragmentation-during-large-file-write.patch added to 2.6.27-stable tree Date: Mon, 19 Apr 2010 10:26:50 -0700 Message-ID: <12716980102194@kroah.org> References: <1268699165-17461-11-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Cc: , To: aneesh.kumar@linux.vnet.ibm.com, dev@jaysonking.com, gregkh@suse.de, linux-ext4@vger.kernel.org, tytso@mit.edu Return-path: Received: from kroah.org ([198.145.64.141]:48443 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751890Ab0DSR34 (ORCPT ); Mon, 19 Apr 2010 13:29:56 -0400 In-Reply-To: <1268699165-17461-11-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: This is a note to let you know that we have just queued up the patch titled Subject: ext4: Fix file fragmentation during large file write. to the 2.6.27-stable tree. Its filename is ext4-fix-file-fragmentation-during-large-file-write.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >From tytso@mit.edu Mon Apr 19 10:23:42 2010 From: Aneesh Kumar K.V Date: Mon, 15 Mar 2010 20:26:04 -0400 Subject: ext4: Fix file fragmentation during large file write. To: stable@kernel.org Cc: Ext4 Developers List , "Theodore Ts'o" , "Jayson R. King" , "Aneesh Kumar K.V" Message-ID: <1268699165-17461-11-git-send-email-tytso@mit.edu> From: Aneesh Kumar K.V commit 22208dedbd7626e5fc4339c417f8d24cc21f79d7 upstream. The range_cyclic writeback mode uses the address_space writeback_index as the start index for writeback. With delayed allocation we were updating writeback_index wrongly resulting in highly fragmented file. This patch reduces the number of extents reduced from 4000 to 27 for a 3GB file. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Theodore Ts'o [dev@jaysonking.com: Some changed lines from the original version of this patch were dropped, since they were rolled up with another cherry-picked patch applied to 2.6.27.y earlier.] Signed-off-by: Jayson R. King Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 88 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 55 insertions(+), 33 deletions(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1721,7 +1721,11 @@ static int mpage_da_submit_io(struct mpa pages_skipped = mpd->wbc->pages_skipped; err = mapping->a_ops->writepage(page, mpd->wbc); - if (!err) + if (!err && (pages_skipped == mpd->wbc->pages_skipped)) + /* + * have successfully written the page + * without skipping the same + */ mpd->pages_written++; /* * In error case, we have to continue because @@ -2175,7 +2179,6 @@ static int mpage_da_writepages(struct ad struct writeback_control *wbc, struct mpage_da_data *mpd) { - long to_write; int ret; if (!mpd->get_block) @@ -2190,19 +2193,18 @@ static int mpage_da_writepages(struct ad mpd->pages_written = 0; mpd->retval = 0; - to_write = wbc->nr_to_write; - ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, mpd); - /* * Handle last extent of pages */ if (!mpd->io_done && mpd->next_page != mpd->first_page) { if (mpage_da_map_blocks(mpd) == 0) mpage_da_submit_io(mpd); - } - wbc->nr_to_write = to_write - mpd->pages_written; + mpd->io_done = 1; + ret = MPAGE_DA_EXTENT_TAIL; + } + wbc->nr_to_write -= mpd->pages_written; return ret; } @@ -2447,11 +2449,14 @@ static int ext4_da_writepages_trans_bloc static int ext4_da_writepages(struct address_space *mapping, struct writeback_control *wbc) { + pgoff_t index; + int range_whole = 0; handle_t *handle = NULL; struct mpage_da_data mpd; struct inode *inode = mapping->host; + int no_nrwrite_index_update; + long pages_written = 0, pages_skipped; int needed_blocks, ret = 0, nr_to_writebump = 0; - long to_write, pages_skipped = 0; struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); /* @@ -2485,16 +2490,26 @@ static int ext4_da_writepages(struct add nr_to_writebump = sbi->s_mb_stream_request - wbc->nr_to_write; wbc->nr_to_write = sbi->s_mb_stream_request; } + if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) + range_whole = 1; - - pages_skipped = wbc->pages_skipped; + if (wbc->range_cyclic) + index = mapping->writeback_index; + else + index = wbc->range_start >> PAGE_CACHE_SHIFT; mpd.wbc = wbc; mpd.inode = mapping->host; -restart_loop: - to_write = wbc->nr_to_write; - while (!ret && to_write > 0) { + /* + * we don't want write_cache_pages to update + * nr_to_write and writeback_index + */ + no_nrwrite_index_update = wbc->no_nrwrite_index_update; + wbc->no_nrwrite_index_update = 1; + pages_skipped = wbc->pages_skipped; + + while (!ret && wbc->nr_to_write > 0) { /* * we insert one extent at a time. So we need @@ -2527,46 +2542,53 @@ restart_loop: goto out_writepages; } } - to_write -= wbc->nr_to_write; - mpd.get_block = ext4_da_get_block_write; ret = mpage_da_writepages(mapping, wbc, &mpd); ext4_journal_stop(handle); - if (mpd.retval == -ENOSPC) + if (mpd.retval == -ENOSPC) { + /* commit the transaction which would + * free blocks released in the transaction + * and try again + */ jbd2_journal_force_commit_nested(sbi->s_journal); - - /* reset the retry count */ - if (ret == MPAGE_DA_EXTENT_TAIL) { + wbc->pages_skipped = pages_skipped; + ret = 0; + } else if (ret == MPAGE_DA_EXTENT_TAIL) { /* * got one extent now try with * rest of the pages */ - to_write += wbc->nr_to_write; + pages_written += mpd.pages_written; + wbc->pages_skipped = pages_skipped; ret = 0; - } else if (wbc->nr_to_write) { + } else if (wbc->nr_to_write) /* * There is no more writeout needed * or we requested for a noblocking writeout * and we found the device congested */ - to_write += wbc->nr_to_write; break; - } - wbc->nr_to_write = to_write; - } - - if (!wbc->range_cyclic && (pages_skipped != wbc->pages_skipped)) { - /* We skipped pages in this loop */ - wbc->nr_to_write = to_write + - wbc->pages_skipped - pages_skipped; - wbc->pages_skipped = pages_skipped; - goto restart_loop; } + if (pages_skipped != wbc->pages_skipped) + printk(KERN_EMERG "This should not happen leaving %s " + "with nr_to_write = %ld ret = %d\n", + __func__, wbc->nr_to_write, ret); + + /* Update index */ + index += pages_written; + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) + /* + * set the writeback_index so that range_cyclic + * mode will write it back later + */ + mapping->writeback_index = index; out_writepages: - wbc->nr_to_write = to_write - nr_to_writebump; + if (!no_nrwrite_index_update) + wbc->no_nrwrite_index_update = 0; + wbc->nr_to_write -= nr_to_writebump; return ret; } Patches currently in stable-queue which might be from aneesh.kumar@linux.vnet.ibm.com are queue-2.6.27/ext4-fix-file-fragmentation-during-large-file-write.patch queue-2.6.27/ext4-retry-block-allocation-if-we-have-free-blocks-left.patch queue-2.6.27/vfs-add-no_nrwrite_index_update-writeback-control-flag.patch queue-2.6.27/ext4-retry-block-reservation.patch queue-2.6.27/ext4-invalidate-pages-if-delalloc-block-allocation-fails.patch queue-2.6.27/ext4-use-tag-dirty-lookup-during-mpage_da_submit_io.patch queue-2.6.27/vfs-remove-the-range_cont-writeback-mode.patch queue-2.6.27/ext4-make-sure-all-the-block-allocation-paths-reserve-blocks.patch queue-2.6.27/ext4-implement-range_cyclic-in-ext4_da_writepages-instead-of-write_cache_pages.patch queue-2.6.27/ext4-add-percpu-dirty-block-accounting.patch