This is a note to let you know that I've just added the patch titled
md: fix calculation of stacking limits on level change.
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-fix-calculation-of-stacking-limits-on-level-change.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 02e5f5c0a0f726e66e3d8506ea1691e344277969 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@xxxxxxx>
Date: Thu, 14 Nov 2013 15:16:15 +1100
Subject: md: fix calculation of stacking limits on level change.
From: NeilBrown <neilb@xxxxxxx>
commit 02e5f5c0a0f726e66e3d8506ea1691e344277969 upstream.
The various ->run routines of md personalities assume that the 'queue'
has been initialised by the blk_set_stacking_limits() call in
md_alloc().
However when the level is changed (by level_store()) the ->run routine
for the new level is called for an array which has already had the
stacking limits modified. This can result in incorrect final
settings.
So call blk_set_stacking_limits() before ->run in level_store().
A specific consequence of this bug is that it causes
discard_granularity to be set incorrectly when reshaping a RAID4 to a
RAID0.
This is suitable for any -stable kernel since 3.3 in which
blk_set_stacking_limits() was introduced.
Reported-and-tested-by: "Baldysiak, Pawel" <pawel.baldysiak@xxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3620,6 +3620,7 @@ level_store(struct mddev *mddev, const c
mddev->in_sync = 1;
del_timer_sync(&mddev->safemode_timer);
}
+ blk_set_stacking_limits(&mddev->queue->limits);
pers->run(mddev);
set_bit(MD_CHANGE_DEVS, &mddev->flags);
mddev_resume(mddev);
Patches currently in stable-queue which might be from neilb@xxxxxxx are
queue-3.12/md-raid5-before-freeing-old-multi-thread-worker-it-should-flush-them.patch
queue-3.12/md-fix-calculation-of-stacking-limits-on-level-change.patch
queue-3.12/raid5-use-slow_path-to-release-stripe-when-mddev-thread-is-null.patch
queue-3.12/md-test-mddev-flags-more-safely-in-md_check_recovery.patch
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