From: NeilBrown Date: Thu, 14 Nov 2013 04:16:15 +0000 (+1100) Subject: md: fix calculation of stacking limits on level change. X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=8e43aac1ec86b5955ecf396395f6fd8b4be42157;p=linux-edison.git md: fix calculation of stacking limits on level change. 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" Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/md/md.c b/drivers/md/md.c index d78f1fffab0..2290b95009d 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3619,6 +3619,7 @@ 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);