From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH] imsm: FIX: Do not write check-point '0' Date: Mon, 2 May 2011 16:12:23 +1000 Message-ID: <20110502161223.68f11b4d@notabene.brown> References: <20110429142921.12605.54696.stgit@gklab-128-013.igk.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110429142921.12605.54696.stgit@gklab-128-013.igk.intel.com> Sender: linux-raid-owner@vger.kernel.org To: Adam Kwolek Cc: linux-raid@vger.kernel.org, dan.j.williams@intel.com, ed.ciechanowski@intel.com, wojciech.neubauer@intel.com List-Id: linux-raid.ids On Fri, 29 Apr 2011 16:29:21 +0200 Adam Kwolek wrote: > When 2 arrays are configured in container and arrays are reassembled during > rebuild or initialization, checkpoint for one array can be reset. It depends > on arrays assembly order. > > Scenario: > 1. Create 2 arrays (e.g. raid5) > 2. Add spare to container > 3. Degrade arrays /rebuild starts on array #1 and continues to n%/ > 4. Reassembly arrays > 5. Rebuild starts on array #2 /because of assembly order/ from 0% > 6. On first checkpoint stored for array #2 (non 0 value), checkpoint > for array #1 is cleared /it is delayed rebuild in md, so progress is 0/ > 7. Rebuild on #1 starts from n% /it was configured before checkpoint > was cleared/. > > Any next reassembly during rebuild of #2 array (after p.6) causes > checkpoint information lost for array #1. > > Solution is not store checkpoint for progress == 0. > Checkpoint is set to 0 when rebuild/initialization starts. > > Note: Please apply this patch on master branch. > > Signed-off-by: Adam Kwolek > --- Applied, thanks. NeilBrown > > super-intel.c | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/super-intel.c b/super-intel.c > index 83135a6..0956c92 100644 > --- a/super-intel.c > +++ b/super-intel.c > @@ -5479,6 +5479,7 @@ mark_checkpoint: > * curr_migr_unit needs updating > */ > if (units32 == units && > + units32 != 0 && > __le32_to_cpu(dev->vol.curr_migr_unit) != units32) { > dprintf("imsm: mark checkpoint (%u)\n", units32); > dev->vol.curr_migr_unit = __cpu_to_le32(units32); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html