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[72.28.8.195]) by smtp.gmail.com with ESMTPSA id y44sm486168qtb.50.2020.11.25.12.20.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Nov 2020 12:20:46 -0800 (PST) Date: Wed, 25 Nov 2020 15:20:23 -0500 From: Tejun Heo To: Christoph Hellwig Message-ID: References: <20201124132751.3747337-1-hch@lst.de> <20201124132751.3747337-26-hch@lst.de> <20201125164515.GB1975@lst.de> MIME-Version: 1.0 In-Reply-To: <20201125164515.GB1975@lst.de> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-loop: dm-devel@redhat.com Cc: Jens Axboe , Jan Kara , Mike Snitzer , Konrad Rzeszutek Wilk , Greg Kroah-Hartman , Jan Kara , Josef Bacik , Coly Li , linux-block@vger.kernel.org, Richard Weinberger , dm-devel@redhat.com, linux-mtd@lists.infradead.org, Johannes Thumshirn , linux-fsdevel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, linux-mm@kvack.org Subject: Re: [dm-devel] [PATCH 25/45] block: reference struct block_device from struct hd_struct X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hello, On Wed, Nov 25, 2020 at 05:45:15PM +0100, Christoph Hellwig wrote: > On Tue, Nov 24, 2020 at 04:18:49PM -0500, Tejun Heo wrote: > > Hello, > > > > Please see lkml.kernel.org/r/X708BTJ5njtbC2z1@mtj.duckdns.org for a few nits > > on the previous version. > > Thanks, I've addressed the mapping_set_gfp mask nit and updated the > commit log. As Jan pointed also pointed out I think we do need the > remove_inode_hash. Agreed. It'd be nice to replace the stale comment. > > Also, would it make sense to separate out lookup_sem removal? I *think* it's > > there to ensure that the same bdev doesn't get associated with old and new > > gendisks at the same time but can't wrap my head around how it works > > exactly. I can see that this may not be needed once the lifetimes of gendisk > > and block_devices are tied together but that may warrant a bit more > > explanation. > > Jan added lookup_sem in commit 56c0908c855afbb to prevent a three way > race between del_gendisk and blkdev_open due to the weird bdev vs > gendisk lifetime rules. None of that can happen with the new lookup > scheme. Understood. I think it'd be worthwhile to note that in the commit log. Thanks. -- tejun -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel