From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v4 6/7] dm: Directly disable max_allocate_sectors for now Date: Tue, 21 Jan 2020 07:24:59 -0500 Message-ID: <20200121122458.GA9365@redhat.com> References: <157960325642.108120.13626623438131044304.stgit@localhost.localdomain> <157960337238.108120.18048939587162465175.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <157960337238.108120.18048939587162465175.stgit@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org To: Kirill Tkhai Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, martin.petersen@oracle.com, bob.liu@oracle.com, axboe@kernel.dk, agk@redhat.com, dm-devel@redhat.com, song@kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, Chaitanya.Kulkarni@wdc.com, darrick.wong@oracle.com, ming.lei@redhat.com, osandov@fb.com, jthumshirn@suse.de, minwoo.im.dev@gmail.com, damien.lemoal@wdc.com, andrea.parri@amarulasolutions.com, hare@suse.com, tj@kernel.org, ajay.joshi@wdc.com, sagi@grimberg.me, dsterba@suse.com, bvanassche@acm.org, dhowells@redhat.com, asml.silence@gmail.com List-Id: dm-devel.ids On Tue, Jan 21 2020 at 5:42am -0500, Kirill Tkhai wrote: > Since dm inherits limits from underlining block devices, > this patch directly disables max_allocate_sectors for dm > till full allocation support is implemented. > > This prevents high-level primitives (generic_make_request_checks(), > __blkdev_issue_write_zeroes(), ...) from sending REQ_ALLOCATE > requests. > > Signed-off-by: Kirill Tkhai > --- > drivers/md/dm-table.c | 2 ++ > drivers/md/md.h | 1 + > 2 files changed, 3 insertions(+) You're mixing DM and MD changes in the same patch. But I'm wondering if it might be best to set this default for stacking devices in blk_set_stacking_limits()? And then it is up to each stacking driver to override as needed. Mike