From: Dave Chinner Subject: Re: [PATCH 3/4] vfs: don't let the dirty time inodes get more than a day stale Date: Wed, 26 Nov 2014 10:48:51 +1100 Message-ID: <20141125234851.GB9561@dastard> References: <1416599964-21892-1-git-send-email-tytso@mit.edu> <1416599964-21892-4-git-send-email-tytso@mit.edu> <20141125015332.GE27262@dastard> <20141125044508.GG31339@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, Ext4 Developers List , xfs@oss.sgi.com, linux-btrfs@vger.kernel.org To: Theodore Ts'o Return-path: Content-Disposition: inline In-Reply-To: <20141125044508.GG31339@thunk.org> Sender: linux-btrfs-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon, Nov 24, 2014 at 11:45:08PM -0500, Theodore Ts'o wrote: > On Tue, Nov 25, 2014 at 12:53:32PM +1100, Dave Chinner wrote: > > On Fri, Nov 21, 2014 at 02:59:23PM -0500, Theodore Ts'o wrote: > > > Guarantee that the on-disk timestamps will be no more than 24 hours > > > stale. > > > > > > Signed-off-by: Theodore Ts'o > > > > If we put these inodes on the dirty inode list with at writeback > > time of 24 hours, this is completely unnecessary. > > What do you mean by "a writeback time of 24 hours"? Do you mean > creating a new field in the inode which specifies when the writeback > should happen? No. > I still worry about the dirty inode list getting > somewhat long large in the strictatime && lazytime case, and the inode > bloat nazi's coming after us for adding a new field to struct inode > structure. Use another pure inode time dirty list, and move the inode to the existing dirty list when it gets marked I_DIRTY. > Or do you mean trying to abuse the dirtied_when field in some way? No abuse necessary at all. Just a different inode_dirtied_after() check is requires if the inode is on the time dirty list in move_expired_inodes(). Cheers, Dave. -- Dave Chinner david@fromorbit.com