From: Ross Zwisler Subject: Re: [fstests PATCH v2] generic: add test for DAX MAP_SYNC support Date: Wed, 25 Oct 2017 11:12:24 -0600 Message-ID: <20171025171224.GA12331@linux.intel.com> References: <20171020052943.15104-1-ross.zwisler@linux.intel.com> <20171020212556.30816-1-ross.zwisler@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-xfs , Jan Kara , Eryu Guan , Mike Snitzer , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Josef Bacik , Dave Chinner , linux-kernel , fstests , linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Christoph Hellwig , linux-fsdevel , Ext4 , Shaohua Li , Alasdair Kergon To: Amir Goldstein Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org On Wed, Oct 25, 2017 at 03:19:22PM +0300, Amir Goldstein wrote: > On Sun, Oct 22, 2017 at 9:56 AM, Amir Goldstein wrote: > > On Sat, Oct 21, 2017 at 12:25 AM, 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 v1: > >> - Addressed review feedback from Amir. Thank you for the review! > > > > Looks good. > > > >> > >> --- > >> .gitignore | 1 + > >> common/dmlogwrites | 1 - > >> src/Makefile | 3 +- > >> src/t_map_sync.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++ > >> tests/generic/466 | 76 ++++++++++++++++++++++++++++++++++++++++++ > >> tests/generic/466.out | 3 ++ > >> tests/generic/group | 1 + > >> 7 files changed, 175 insertions(+), 2 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..5b57df9 100644 > >> --- a/common/dmlogwrites > >> +++ b/common/dmlogwrites > >> @@ -23,7 +23,6 @@ _require_log_writes() > >> [ -z "$LOGWRITES_DEV" -o ! -b "$LOGWRITES_DEV" ] && \ > >> _notrun "This test requires a valid \$LOGWRITES_DEV" > >> > >> - _exclude_scratch_mount_option dax > > Wait. It this really ok to relax no dax from _require_log_writes()? > Shouldn't you check log-write target version or something to verify > that log-writes+dax is really supported? > I think you should. Ah, yep, that makes sense. I'll update for v3.