From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: dm: era: use do_div for 64-bit division Date: Tue, 11 Mar 2014 08:59:54 -0400 Message-ID: <20140311125954.GA9752@redhat.com> References: <3014967.i7OXqBNQ5E@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <3014967.i7OXqBNQ5E@wuerfel> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: dm-devel@redhat.com, Alasdair Kergon , Joe Thornber , linux-kernel@vger.kernel.org List-Id: dm-devel.ids On Tue, Mar 11 2014 at 4:31am -0400, Arnd Bergmann wrote: > Commit 983043be0c1de "dm era: support non power-of-2 blocksize" > introduced the use of sector_div to divide a variable of type > dm_block_t by an integer. This fails on 32-bit machines when > CONFIG_LBDAF is not set, because that assumes that the first > argument is a 32-bit number. > > To allow building this driver in all configurations, we either > have to cast the dm_block_t to sector_t or use do_div(), which > always takes a 64-bit argument. This patch uses the second > approach in order to cope with theoretical configurations where > dm_block_t contains a number that does not fit into sector_t. Thanks for taking the time to look into this. But the first approach was used on Friday (and is adequate considering we're starting with the bio's bi_sector). The new commit id is 1c5a63b138638d08f4dc65ed48d3d5d3bad1b08b. The moral of the story is: don't make a mistake on Thursday because that last linux-next of the week will plague you for the next 5 days. I was hoping for relief with Monday's linux-next build but alas... ;)