From: Christoph Hellwig Subject: Re: [PATCH-v2 0/5] add support for a lazytime mount option Date: Mon, 24 Nov 2014 01:07:55 -0800 Message-ID: <20141124090755.GA28534@infradead.org> References: <1416675267-2191-1-git-send-email-tytso@mit.edu> 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: <1416675267-2191-1-git-send-email-tytso@mit.edu> Sender: linux-btrfs-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org What's the test coverage for this? xfstest generic/192 tests that atime is persisted over remounts, which we had a bug with when XFS used to have a lazy atime implementation somewhat similar to the proposal. We should have something similar for c/mtime as well. Also a test to ensure timestamps are persisted afer a fsync, although right now I can't imagine how to do that genericly as no other filesystem seems to have an equivaent to XFS_IOC_GOINGDOWN. It seems you also handle i_version updates lazily. although that's not mentioned anywhere. I actually have a clarification request out on the IETF NFSv4 list about the persistance requirements for the change counter but I've not seen an answer to it yet.