From: Mike Snitzer WRITE SAME bios are not yet handled correctly by device-mapper so disable their use on device-mapper devices by setting max_write_same_sectors to zero. As an example, a ciphertext device is incompatible because the data gets changed according to the location at which it written and so the dm crypt target cannot support it. Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org Cc: Milan Broz Signed-off-by: Alasdair G Kergon --- drivers/md/dm-table.c | 2 ++ 1 file changed, 2 insertions(+) Index: linux/drivers/md/dm-table.c =================================================================== --- linux.orig/drivers/md/dm-table.c +++ linux/drivers/md/dm-table.c @@ -1445,6 +1445,8 @@ void dm_table_set_restrictions(struct dm else queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q); + q->limits.max_write_same_sectors = 0; + dm_table_set_integrity(t); /*