From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758126AbYGERnU (ORCPT ); Sat, 5 Jul 2008 13:43:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756257AbYGERhL (ORCPT ); Sat, 5 Jul 2008 13:37:11 -0400 Received: from www.church-of-our-saviour.ORG ([69.25.196.31]:33049 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754797AbYGERga (ORCPT ); Sat, 5 Jul 2008 13:36:30 -0400 From: "Theodore Ts'o" To: Ext4 Developers List , Linux Kernel Developers List Cc: "Aneesh Kumar K.V" , Mingming Cao , "Theodore Ts'o" Subject: [PATCH 45/52] mm: Add range_cont mode for writeback Date: Sat, 5 Jul 2008 13:36:11 -0400 Message-Id: <1215279378-30504-46-git-send-email-tytso@mit.edu> X-Mailer: git-send-email 1.5.6.rc3.1.g36b7.dirty In-Reply-To: <1215279378-30504-45-git-send-email-tytso@mit.edu> References: <1215279378-30504-1-git-send-email-tytso@mit.edu> <1215279378-30504-2-git-send-email-tytso@mit.edu> <1215279378-30504-3-git-send-email-tytso@mit.edu> <1215279378-30504-4-git-send-email-tytso@mit.edu> <1215279378-30504-5-git-send-email-tytso@mit.edu> <1215279378-30504-6-git-send-email-tytso@mit.edu> <1215279378-30504-7-git-send-email-tytso@mit.edu> <1215279378-30504-8-git-send-email-tytso@mit.edu> <1215279378-30504-9-git-send-email-tytso@mit.edu> <1215279378-30504-10-git-send-email-tytso@mit.edu> <1215279378-30504-11-git-send-email-tytso@mit.edu> <1215279378-30504-12-git-send-email-tytso@mit.edu> <1215279378-30504-13-git-send-email-tytso@mit.edu> <1215279378-30504-14-git-send-email-tytso@mit.edu> <1215279378-30504-15-git-send-email-tytso@mit.edu> <1215279378-30504-16-git-send-email-tytso@mit.edu> <1215279378-30504-17-git-send-email-tytso@mit.edu> <1215279378-30504-18-git-send-email-tytso@mit.edu> <1215279378-30504-19-git-send-email-tytso@mit.edu> <1215279378-30504-20-git-send-email-tytso@mit.edu> <1215279378-30504-21-git-send-email-tytso@mit.edu> <1215279378-30504-22-git-send-email-tytso@mit.edu> <1215279378-30504-23-git-send-email-tytso@mit.edu> <1215279378-30504-24-git-send-email-tytso@mit.edu> <1215279378-30504-25-git-send-email-tytso@mit.edu> <1215279378-30504-26-git-send-email-tytso@mit.edu> <1215279378-30504-27-git-send-email-tytso@mit.edu> <1215279378-30504-28-git-send-email-tytso@mit.edu> <1215279378-30504-29-git-send-email-tytso@mit.edu> <1215279378-30504-30-git-send-email-tytso@mit.edu> <1215279378-30504-31-git-send-email-tytso@mit.edu> <1215279378-30504-32-git-send-email-tytso@mit.edu> <1215279378-30504-33-git-send-email-tytso@mit.edu> <1215279378-30504-34-git-send-email-tytso@mit.edu> <1215279378-30504-35-git-send-email-tytso@mit.edu> <1215279378-30504-36-git-send-email-tytso@mit.edu> <1215279378-30504-37-git-send-email-tytso@mit.edu> <1215279378-30504-38-git-send-email-tytso@mit.edu> <1215279378-30504-39-git-send-email-tytso@mit.edu> <1215279378-30504-40-git-send-email-tytso@mit.edu> <1215279378-30504-41-git-send-email-tytso@mit.edu> <1215279378-30504-42-git-send-email-tytso@mit.edu> <1215279378-30504-43-git-send-email-tytso@mit.edu> <1215279378-30504-44-git-send-email-tytso@mit.edu> <1215279378-30504-45-git-send-email-tytso@mit.edu> X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@mit.edu X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aneesh Kumar K.V Filesystems like ext4 needs to start a new transaction in the writepages for block allocation. This happens with delayed allocation and there is limit to how many credits we can request from the journal layer. So we call write_cache_pages multiple times with wbc->nr_to_write set to the maximum possible value limitted by the max journal credits available. Add a new mode to writeback that enables us to handle this behaviour. In the new mode we update the wbc->range_start to point to the new offset to be written. Next call to call to write_cache_pages will start writeout from specified range_start offset. In the new mode we also limit writing to the specified wbc->range_end. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Mingming Cao Acked-by: Jan Kara Signed-off-by: "Theodore Ts'o" --- include/linux/writeback.h | 1 + mm/page-writeback.c | 3 +++ 2 files changed, 4 insertions(+), 0 deletions(-) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index f462439..0d8573e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -63,6 +63,7 @@ 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 */ + unsigned range_cont:1; }; /* diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 789b6ad..ded57d5 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -956,6 +956,9 @@ retry: } if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) mapping->writeback_index = index; + + if (wbc->range_cont) + wbc->range_start = index << PAGE_CACHE_SHIFT; return ret; } EXPORT_SYMBOL(write_cache_pages); -- 1.5.6.rc3.1.g36b7.dirty