From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH] block: get rid of blk_integrity_revalidate() Date: Fri, 21 Apr 2017 14:18:08 -0600 Message-ID: <30a66f64-2785-dc9d-d64a-cb3cf4fc346e@fb.com> References: <1492533800-30627-1-git-send-email-idryomov@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1492533800-30627-1-git-send-email-idryomov@gmail.com> Sender: linux-block-owner@vger.kernel.org To: Ilya Dryomov , "Martin K. Petersen" Cc: Dan Williams , Christoph Hellwig , Mike Snitzer , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, dm-devel@redhat.com, ceph-devel@vger.kernel.org List-Id: dm-devel.ids On 04/18/2017 10:43 AM, Ilya Dryomov wrote: > Commit 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk") > introduced blk_integrity_revalidate(), which seems to assume ownership > of the stable pages flag and unilaterally clears it if no blk_integrity > profile is registered: > > if (bi->profile) > disk->queue->backing_dev_info->capabilities |= > BDI_CAP_STABLE_WRITES; > else > disk->queue->backing_dev_info->capabilities &= > ~BDI_CAP_STABLE_WRITES; > > It's called from revalidate_disk() and rescan_partitions(), making it > impossible to enable stable pages for drivers that support partitions > and don't use blk_integrity: while the call in revalidate_disk() can be > trivially worked around (see zram, which doesn't support partitions and > hence gets away with zram_revalidate_disk()), rescan_partitions() can > be triggered from userspace at any time. This breaks rbd, where the > ceph messenger is responsible for generating/verifying CRCs. > > Since blk_integrity_{un,}register() "must" be used for (un)registering > the integrity profile with the block layer, move BDI_CAP_STABLE_WRITES > setting there. This way drivers that call blk_integrity_register() and > use integrity infrastructure won't interfere with drivers that don't > but still want stable pages. Applied, thanks. -- Jens Axboe