From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o123WfEm151097 for ; Mon, 1 Feb 2010 21:32:51 -0600 Received: from mail-ew0-f227.google.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id ABF1A1C97ADE for ; Mon, 1 Feb 2010 19:33:20 -0800 (PST) Received: from mail-ew0-f227.google.com (mail-ew0-f227.google.com [209.85.219.227]) by cuda.sgi.com with ESMTP id mH24HTzrbIMnKiVN for ; Mon, 01 Feb 2010 19:33:20 -0800 (PST) Received: by ewy27 with SMTP id 27so955584ewy.18 for ; Mon, 01 Feb 2010 19:33:19 -0800 (PST) From: Edward Shishkin Subject: [patch 0/7] per-bdi flushing model improvements. reiser4 Date: Tue, 2 Feb 2010 02:55:46 +0100 MIME-Version: 1.0 Message-Id: <201002020255.46920.edward.shishkin@gmail.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Andrew Morton , ReiserFS Development List Cc: linux-fsdevel@vger.kernel.org, jens.axboe@oracle.com, linux-kernel@vger.kernel.org, xfs@oss.sgi.com Hello. Andrew Morton wrote: > reiser4 is currently disabled in -mm (via reiser4-disable.patch) > because recent changes to fs/fs/writeback.c wrecked the build. I fixed > it about ten times as the underlying code was churning, then gave up. It > would be nice if you take a look at that sometime please. > > I have taken a look at fs/fs-writeback.c and found that per-superblock flushing interface is eliminated. However migrating to per-bdi flushing model doesn't necessarily means that such interface doesn't exist or is not needed anymore. Flushing in accordance with the scheme "data-inode- data-inode-..." would be very suboptimal for reiser4. Also xfs people were unhappy with such flushing model: http://article.gmane.org/gmane.linux.file-systems/30153 Moreover, current stuff doesn't look fine. Why do we pin/unpin superblock for every inode? It would be more reasonable to pin it for the whole group of inodes and call a flushing handler for them. The patch 4 introduces such handler writeback_sb_inodes (which resembles dropped sync_sb_inodes, the difference is that the newer version doesn't flush necessarily all inodes of the superblock). Please, consider pushing this patch to mainline. The patch 5 adds a super operation .writeback_inodes (former .sync_inodes) which allows a file system to make optimizations. It can happen that reiser4 will flush a bit more inodes then generic implementation suggests. "a bit more" doesn't mean "all dirty inodes of the superblock" (see a comment about atoms in the header of patch 6). Finally, some file systems have its own means for periodical writeout of dirty data. Since b_io contains inodes of many superblocks we need to evict our inodes back to dirty list when flushing is going on with for_kupdate flag installed. The new library function writeback_skip_sb_inodes() provides such possibility. Please, apply. Thanks, Edward. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs