From: Subject: patch vfs-add-no_nrwrite_index_update-writeback-control-flag.patch added to 2.6.27-stable tree Date: Mon, 19 Apr 2010 10:27:06 -0700 Message-ID: <12716980263125@kroah.org> References: <1268699165-17461-10-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]:48496 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752446Ab0DSRaF (ORCPT ); Mon, 19 Apr 2010 13:30:05 -0400 In-Reply-To: <1268699165-17461-10-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: vfs: Add no_nrwrite_index_update writeback control flag to the 2.6.27-stable tree. Its filename is vfs-add-no_nrwrite_index_update-writeback-control-flag.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 10:23:14 2010 From: Aneesh Kumar K.V Date: Mon, 15 Mar 2010 20:26:03 -0400 Subject: vfs: Add no_nrwrite_index_update writeback control flag To: stable@kernel.org Cc: linux-fsdevel@vger.kernel.org, Ext4 Developers List , "Theodore Ts'o" , "Jayson R. King" , "Aneesh Kumar K.V" Message-ID: <1268699165-17461-10-git-send-email-tytso@mit.edu> From: Aneesh Kumar K.V commit 17bc6c30cf6bfffd816bdc53682dd46fc34a2cf4 upstream. If no_nrwrite_index_update is set we don't update nr_to_write and address space writeback_index in write_cache_pages. This change enables a file system to skip these updates in write_cache_pages and do them in the writepages() callback. This patch will be followed by an ext4 patch that make use of these new flags. Signed-off-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" CC: linux-fsdevel@vger.kernel.org [dev@jaysonking.com: Modified the patch to account for subsequent changes in mainline being cherry-picked earlier for 2.6.27.y.] Signed-off-by: Jayson R. King Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- include/linux/writeback.h | 9 +++++++++ mm/page-writeback.c | 14 +++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-) --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -62,6 +62,15 @@ struct writeback_control { unsigned for_writepages:1; /* This is a writepages() call */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned more_io:1; /* more io to be dispatched */ + /* + * write_cache_pages() won't update wbc->nr_to_write and + * mapping->writeback_index if no_nrwrite_index_update + * is set. write_cache_pages() may write more than we + * requested and we want to make sure nr_to_write and + * writeback_index are updated in a consistent manner + * so we use a single control to update them + */ + unsigned no_nrwrite_index_update:1; }; /* --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -878,6 +878,7 @@ int write_cache_pages(struct address_spa pgoff_t done_index; int cycled; int range_whole = 0; + long nr_to_write = wbc->nr_to_write; if (wbc->nonblocking && bdi_write_congested(bdi)) { wbc->encountered_congestion = 1; @@ -985,9 +986,9 @@ continue_unlock: } } - if (wbc->nr_to_write > 0) { - wbc->nr_to_write--; - if (wbc->nr_to_write == 0 && + if (nr_to_write > 0) { + nr_to_write--; + if (nr_to_write == 0 && wbc->sync_mode == WB_SYNC_NONE) { /* * We stop writing back only if we are @@ -1024,8 +1025,11 @@ continue_unlock: end = writeback_index - 1; goto retry; } - if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) - mapping->writeback_index = done_index; + if (!wbc->no_nrwrite_index_update) { + if (wbc->range_cyclic || (range_whole && nr_to_write > 0)) + mapping->writeback_index = done_index; + wbc->nr_to_write = nr_to_write; + } 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