| From | Luis Henriques <> | Subject | [PATCH 3.5 55/90] md: fix calculation of stacking limits on level change. | Date | Thu, 5 Dec 2013 17:35:37 +0000 |
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3.5.7.27 -stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown <neilb@suse.de>
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@intel.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/md/md.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/md/md.c b/drivers/md/md.c index 5f5e10e..84f0f19 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3681,6 +3681,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len) 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); -- 1.8.3.2
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