From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v2 0/2] dm verity: add support for error correction Date: Thu, 3 Dec 2015 18:05:38 -0500 Message-ID: <20151203230538.GB5444@redhat.com> References: <1446688954-29589-1-git-send-email-samitolvanen@google.com> <1449152791-33586-1-git-send-email-samitolvanen@google.com> <20151203195401.GA5444@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20151203195401.GA5444@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Sami Tolvanen Cc: Mikulas Patocka , Mandeep Baines , Will Drewry , Alasdair Kergon , dm-devel@redhat.com, linux-kernel@vger.kernel.org, Kees Cook , Mark Salyzyn List-Id: dm-devel.ids On Thu, Dec 03 2015 at 2:54pm -0500, Mike Snitzer wrote: > On Thu, Dec 03 2015 at 9:26am -0500, > Sami Tolvanen wrote: > > > Changes since v1: > > > > - Added CONFIG_DM_VERITY_FEC and split error correction into > > dm-verity-fec.[ch] to further separate the functionality from the > > rest of dm-verity. Follows the same pattern as dm-uevent. > > > > - Added missing dependencies for REED_SOLOMON to Kconfig. > > > > - Renamed dm-verity.c to dm-verity-target.c to allow an optional > > object to be added. Follows the naming convention of dm-cache and > > dm-era. > > > > - Changed the algorithm to work with one or more small buffers (~4k) > > instead of a single large one. The more buffers we can allocate, > > the faster it will work, but we don't have to preallocate a large > > amount of memory anymore. > > > > - Changed memory allocation to use mempools. v2 preallocates all the > > memory required for each worker thread to guarantee forward > > progress in case of memory pressure. The code attempts to allocate > > more buffers (using GFP_NOIO) and uses them if available. > > > > - Added graceful handling of IO errors, which are now treated as any > > other corruption. > > > > - Rebased against linux-dm/for-next. > > Thanks a lot for these advances, at a high-level it sounds like you've > handled the issues raised as part of v1 review very well. > > I'll review closer now. Goal is to get these changes staged in > linux-next for upstream inclusion during the 4.5 merge window. I took a first pass through your code and pushed the result to this temporary branch here: http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/log/?h=dm-verity-fec As you'll see, I focused primarily on splitting the dm-verity core changes out from the FEC and ignore_zero_blocks changes. Along the way I tweaked some style-nits here or there but the biggest difference between your v2 and what I pushed is captured in this commit: http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/commit/?h=dm-verity-fec&id=cc1339fae225d8cdc8fffeff30f0a9981367d6c0 If you're OK with those changes I'll fold that commit into your main FEC commit. I'll carry on with reviewing your new code (outside of dm-verity core) tomorrow. Mike