From: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit e7597e69dec59b65c5525db1626b9d34afdfa678 upstream. 'max_discard_sectors' is in sectors, while 'stripe' is in bytes. This fixes the problem where DISCARD would get disabled on some larger RAID5 configurations (6 or more drives in my testing), while it worked as expected with smaller configurations. Fixes: 620125f2bf8 ("MD: raid5 trim support") Signed-off-by: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> Signed-off-by: Shaohua Li <shli@xxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- drivers/md/raid5.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4881851c4b42..9fbc77c6e132 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5985,8 +5985,8 @@ static int run(struct mddev *mddev) } if (discard_supported && - mddev->queue->limits.max_discard_sectors >= stripe && - mddev->queue->limits.discard_granularity >= stripe) + mddev->queue->limits.max_discard_sectors >= (stripe >> 9) && + mddev->queue->limits.discard_granularity >= stripe) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); else -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html