From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: [PATCH 1/6] ext4: cache extent hole in extent status tree for ext4_da_map_blocks() Date: Sun, 23 Nov 2014 00:43:35 -0500 Message-ID: <20141123054335.GA4102@thunk.org> References: <1415961957-21621-1-git-send-email-jack@suse.cz> <1415961957-21621-2-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, Zheng Liu , Zheng Liu , Andreas Dilger To: Jan Kara Return-path: Received: from imap.thunk.org ([74.207.234.97]:45749 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750702AbaKWFnp (ORCPT ); Sun, 23 Nov 2014 00:43:45 -0500 Content-Disposition: inline In-Reply-To: <1415961957-21621-2-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Nov 14, 2014 at 11:45:52AM +0100, Jan Kara wrote: > From: Zheng Liu > > Currently extent status tree doesn't cache extent hole when a write > looks up in extent tree to make sure whether a block has been allocated > or not. In this case, we don't put extent hole in extent cache because > later this extent might be removed and a new delayed extent might be > added back. But it will cause a defect when we do a lot of writes. If > we don't put extent hole in extent cache, the following writes also need > to access extent tree to look at whether or not a block has been > allocated. It brings a cache miss. This commit fixes this defect. > Also if the inode doesn't have any extent, this extent hole will be > cached as well. > > Cc: "Theodore Ts'o" > Cc: Andreas Dilger > Signed-off-by: Zheng Liu > Signed-off-by: Jan Kara This patch (either when applied alone, or as part of the entire patch series) is causing an xfstests regression test failure: FSTYP -- ext4 PLATFORM -- Linux/i686 kvm-xfstests 3.18.0-rc3-00537-g932e3f9 MKFS_OPTIONS -- -q /dev/vdc MOUNT_OPTIONS -- -o acl,user_xattr -o block_validity /dev/vdc /vdc ext4/003 4s ... [00:14:39] [00:14:48] - output mismatch (see /results/results-4k/ext4/003.out.bad) --- tests/ext4/003.out 2014-10-31 10:13:03.000000000 -0400 +++ /results/results-4k/ext4/003.out.bad 2014-11-23 00:14:48.935587897 -0500 @@ -1,3 +1,3 @@ QA output created by 003 -wrote 268435456/268435456 bytes at offset 0 +wrote 241762304/268435456 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) ... (Run 'diff -u tests/ext4/003.out /results/results-4k/ext4/003.out.bad' to see the entire diff) - Ted