From: Ross Zwisler Subject: Re: [fstests PATCH v3] generic: add test for DAX MAP_SYNC support Date: Thu, 16 Nov 2017 15:59:47 -0700 Message-ID: <20171116225947.GA23070@linux.intel.com> References: <20171025204704.3382-1-ross.zwisler@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ross Zwisler , Josef Bacik , Eryu Guan , fstests , linux-kernel , Alasdair Kergon , Dan Williams , Dave Chinner , Jan Kara , Mike Snitzer , Shaohua Li , dm-devel@redhat.com, linux-nvdimm@lists.01.org, linux-raid@vger.kernel.org, linux-fsdevel , Ext4 , linux-xfs , Christoph Hellwig To: Amir Goldstein Return-path: Received: from mga11.intel.com ([192.55.52.93]:17787 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751685AbdKPW7s (ORCPT ); Thu, 16 Nov 2017 17:59:48 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Oct 26, 2017 at 07:59:39AM +0300, Amir Goldstein wrote: > On Wed, Oct 25, 2017 at 11:47 PM, Ross Zwisler > wrote: > > Add a test that exercises DAX's new MAP_SYNC flag. > > > > This test creates a file and writes to it via an mmap(), but never syncs > > via fsync/msync. This process is tracked via dm-log-writes, then replayed. > > > > If MAP_SYNC is working the dm-log-writes replay will show the test file > > with 1MiB of on-media block allocations. This is because each allocating > > page fault included an implicit metadata sync. If MAP_SYNC isn't working > > (which you can test by fiddling with the parameters to mmap()) the file > > will be smaller or missing entirely. > > > > Note that dm-log-writes doesn't track the data that we write via the > > mmap(), so we can't do any data integrity checking. We can only verify > > that the metadata writes for the page faults happened. > > > > Signed-off-by: Ross Zwisler > > > > --- > > > > Changes since v2: > > - Fixed _require_log_writes() so that DAX will be disallowed if the > > version of the dm-log-writes target is older than v1.1.0. (Amir) > > It seems like your kernel patch bumped the version to 1.0.1... Ah, yep, that's the version number that I submitted but Mike changed it to v1.1.0 in his tree. Here's the patch that was merged for v4.15-rc1: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers?id=98d82f48f1983ceef5c8d2f6c87bfee2918790ee > > > > --- > > .gitignore | 1 + > > common/dmlogwrites | 4 ++- > > common/rc | 6 ++-- > > src/Makefile | 3 +- > > src/t_map_sync.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++ > > tests/generic/466 | 76 ++++++++++++++++++++++++++++++++++++++++++ > > tests/generic/466.out | 3 ++ > > tests/generic/group | 1 + > > 8 files changed, 182 insertions(+), 4 deletions(-) > > create mode 100644 src/t_map_sync.c > > create mode 100755 tests/generic/466 > > create mode 100644 tests/generic/466.out > > > > diff --git a/.gitignore b/.gitignore > > index 2014c08..9fc0695 100644 > > --- a/.gitignore > > +++ b/.gitignore > > @@ -119,6 +119,7 @@ > > /src/t_getcwd > > /src/t_holes > > /src/t_immutable > > +/src/t_map_sync > > /src/t_mmap_cow_race > > /src/t_mmap_dio > > /src/t_mmap_fallocate > > diff --git a/common/dmlogwrites b/common/dmlogwrites > > index 247c744..71d008d 100644 > > --- a/common/dmlogwrites > > +++ b/common/dmlogwrites > > @@ -23,8 +23,10 @@ _require_log_writes() > > [ -z "$LOGWRITES_DEV" -o ! -b "$LOGWRITES_DEV" ] && \ > > _notrun "This test requires a valid \$LOGWRITES_DEV" > > > > - _exclude_scratch_mount_option dax > > _require_dm_target log-writes > > + if [[ ${DMTARGET_VER[0]} == 1 && ${DMTARGET_VER[1]} < 1 ]]; then > > + _exclude_scratch_mount_option dax > > + fi > > IMO, this would be better as: > > local z=0 > _scratch_has_mount_option dax && z=1 > _require_dm_target log-writes 1 0 $z > > Or something like that Yep, this is nicer. Fixed. Thanks for the review.