Commit 25156198 authored Mar 04, 2008 by NeilBrown Committed by Linus Torvalds Mar 04, 2008

md: make sure a reshape is started when device switches to read-write

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent d0fae18f

drivers/md/md.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -5356,6 +5356,7 @@ void md_write_start(mddev_t mddev, struct bio bi)
		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) {

Admin message