This is a note to let you know that I've just added the patch titled md/raid5: Compare apples to apples (or sectors to sectors) to the 4.5-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-raid5-compare-apples-to-apples-or-sectors-to-sectors.patch and it can be found in the queue-4.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e7597e69dec59b65c5525db1626b9d34afdfa678 Mon Sep 17 00:00:00 2001 From: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> Date: Tue, 16 Feb 2016 16:44:24 -0500 Subject: md/raid5: Compare apples to apples (or sectors to sectors) From: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> 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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/raid5.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7014,8 +7014,8 @@ static int raid5_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 Patches currently in stable-queue which might be from Jes.Sorensen@xxxxxxxxxx are queue-4.5/md-raid5-compare-apples-to-apples-or-sectors-to-sectors.patch -- 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