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From: NeilBrown <neilb@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 005 of 9] md: Make sure a reshape is started when device switches to read-write.
Date: Mon, 3 Mar 2008 11:17:30 +1100	[thread overview]
Message-ID: <1080303001730.23637@suse.de> (raw)
In-Reply-To: <20080303111240.23302.patches@notabene>


A resync/reshape/recovery thread will refuse to progress when the
array is marked read-only.  So whenever it mark it not read-only, it
is important to wake up thread resync thread.
There is one place we didn't do this.

The problem manifests if the start_ro module parameters is set, and a
raid5 array that is in the middle of a reshape (restripe) is started.
The array will initially be semi-read-only (meaning it acts like it is
readonly until the first write).  So the reshape will not proceed.

On the first write, the array will become read-write, but the reshape
will not be started, and there is no event which will ever restart
that thread.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
 ./drivers/md/md.c |    1 +
 1 file changed, 1 insertion(+)

diff .prev/drivers/md/md.c ./drivers/md/md.c
--- .prev/drivers/md/md.c	2008-02-22 15:46:25.000000000 +1100
+++ ./drivers/md/md.c	2008-02-22 15:46:52.000000000 +1100
@@ -5356,6 +5356,7 @@ void md_write_start(mddev_t *mddev, stru
 		mddev->ro = 0;
 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 		md_wakeup_thread(mddev->thread);
+		md_wakeup_thread(mddev->sync_thread);
 	}
 	atomic_inc(&mddev->writes_pending);
 	if (mddev->in_sync) {

  parent reply	other threads:[~2008-03-03  0:19 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-03  0:16 [PATCH 000 of 9] md: Introduction EXPLAIN PATCH SET HERE NeilBrown
2008-03-03  0:17 ` [PATCH 001 of 9] md: Fix deadlock in md/raid1 and md/raid10 when handling a read error NeilBrown
2008-03-03 15:54   ` Andre Noll
2008-03-04  6:08     ` Neil Brown
2008-03-04 11:29       ` Andre Noll
2008-03-06  3:29         ` Neil Brown
2008-03-06 10:51           ` Andre Noll
2008-03-03  0:17 ` [PATCH 002 of 9] md: Reduce CPU wastage on idle md array with a write-intent bitmap NeilBrown
2008-03-03  0:17 ` [PATCH 003 of 9] md: Guard against possible bad array geometry in v1 metadata NeilBrown
2008-03-03  0:17 ` [PATCH 004 of 9] md: Clean up irregularity with raid autodetect NeilBrown
2008-03-03  0:17 ` NeilBrown [this message]
2008-03-03  0:17 ` [PATCH 006 of 9] md: Lock access to rdev attributes properly NeilBrown
2008-03-03  0:17 ` [PATCH 007 of 9] md: Don't attempt read-balancing for raid10 'far' layouts NeilBrown
2008-03-03  0:17 ` [PATCH 008 of 9] md: Fix possible raid1/raid10 deadlock on read error during resync NeilBrown
2008-03-03  0:18 ` [PATCH 009 of 9] md: The md RAID10 resync thread could cause a md RAID10 array deadlock NeilBrown

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