From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 4/6] md: don't export log device Date: Tue, 13 Oct 2015 05:07:19 -0700 Message-ID: <20151013120719.GA9734@infradead.org> References: <7aecea0895b46e28c2b8a876a83da10d7f30d7f1.1443973492.git.shli@fb.com> <87pp0q6s1i.fsf@notabene.neil.brown.name> <20151008031644.GA3063621@devbig084.prn1.facebook.com> <87bnca6lli.fsf@notabene.neil.brown.name> <20151008043121.GA3189627@devbig084.prn1.facebook.com> <8737xl7v5l.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <8737xl7v5l.fsf@notabene.neil.brown.name> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Shaohua Li , linux-raid@vger.kernel.org, Kernel-team@fb.com, songliubraving@fb.com, hch@infradead.org, dan.j.williams@intel.com List-Id: linux-raid.ids On Thu, Oct 08, 2015 at 05:04:54PM +1100, Neil Brown wrote: > Having two disks with ->raid_disk==0 does seem a little weird, but we do > already have that in some cases. > When you have a hot-replace going, both the original and the replacement > have the same ->raid_disk numbers. They can be distinguished by the > Replacement flag. > I'm suggesting the same (sort of) for journals, and distinguish by the > Journal flag. > > I did quick audit and just found setup_conf, run() and md_update_sb(). > If you could do an audit to that would be good. I'd be surprised if you > find many more places where Journal needs to be tested with ->raid_disk. Overloading positive numbers for the journal disk sounds like a bad idea to me as it will cause a lot of confusion. I'd rather assign specific negative values to special roles outside the actual rate. This will require an initial audit, but give us nicely understandable rules later on.