From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: Re: [PATCH 2/3] block: Add badblock management for gendisks Date: Tue, 24 Nov 2015 14:14:26 -0500 Message-ID: References: <1448066960-20119-1-git-send-email-vishal.l.verma@intel.com> <1448066960-20119-3-git-send-email-vishal.l.verma@intel.com> <1448391837.27481.16.camel@intel.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1448391837.27481.16.camel@intel.com> (Vishal L. Verma's message of "Tue, 24 Nov 2015 19:03:57 +0000") Sender: linux-raid-owner@vger.kernel.org To: "Verma, Vishal L" Cc: "linux-raid@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "linux-block@vger.kernel.org" , "neilb@suse.com" , "axboe@fb.com" , "linux-nvdimm@ml01.01.org" List-Id: linux-raid.ids "Verma, Vishal L" writes: > On Tue, 2015-11-24 at 10:34 -0500, Jeff Moyer wrote: >> Vishal Verma writes: >> >> > NVDIMM devices, which can behave more like DRAM rather than block >> > devices, may develop bad cache lines, or 'poison'. A block device >> > exposed by the pmem driver can then consume poison via a read (or >> > write), and cause a machine check. On platforms without machine >> > check recovery features, this would mean a crash. >> > >> > The block device maintaining a runtime list of all known sectors >> > that >> > have poison can directly avoid this, and also provide a path forward >> > to enable proper handling/recovery for DAX faults on such a device. >> > >> > Use the new badblock management interfaces to add a badblocks list >> > to >> > gendisks. >> >> Because disk_alloc_badblocks can fail, you need to check for a NULL >> disk->bb in all of the utility functions you've defined. >> > > Thanks, Jeff - I'll fix this. I have a handful of other fixes queued up > too, will send out a v2 soon. I'm not sure whether it makes sense to continue without badblock management for the RAID code. I was hoping Neil would comment on that. -Jeff