From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2DE492C81 for ; Wed, 24 Nov 2021 06:36:15 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id C659668AFE; Wed, 24 Nov 2021 07:36:05 +0100 (CET) Date: Wed, 24 Nov 2021 07:36:05 +0100 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Christoph Hellwig , Dan Williams , Mike Snitzer , Ira Weiny , dm-devel@redhat.com, linux-xfs@vger.kernel.org, nvdimm@lists.linux.dev, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH 06/29] dax: move the partition alignment check into fs_dax_get_by_bdev Message-ID: <20211124063605.GA6889@lst.de> References: <20211109083309.584081-1-hch@lst.de> <20211109083309.584081-7-hch@lst.de> <20211123222555.GE266024@magnolia> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211123222555.GE266024@magnolia> User-Agent: Mutt/1.5.17 (2007-11-01) On Tue, Nov 23, 2021 at 02:25:55PM -0800, Darrick J. Wong wrote: > > + if ((get_start_sect(bdev) * SECTOR_SIZE) % PAGE_SIZE || > > + (bdev_nr_sectors(bdev) * SECTOR_SIZE) % PAGE_SIZE) { > > Do we have to be careful about 64-bit division here, or do we not > support DAX on 32-bit? I can't find anything in the Kconfig limiting DAX to 32-bit. But then again the existing code has divisions like this, so the compiler is probably smart enough to turn them into shifts. > > + pr_info("%pg: error: unaligned partition for dax\n", bdev); > > I also wonder if this should be ratelimited...? This happens once (or maybe three times for XFS with rt and log devices) at mount time, so I see no need for a ratelimit.