dm: clear all discard attributes in queue_limits when discards are disabled

Otherwise, it can happen that the QUEUE_FLAG_DISCARD isn't set but the
various discard attributes (which get exposed via sysfs) may be set.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 6f1ec12c287cd8d71f3b46ea55a964e4955f2c43..3acf8f56eb648a89e280ac2ba2dbe2589bec0b42 100644 (file)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1801,9 +1801,15 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
         */
        q->limits = *limits;
 
-       if (!dm_table_supports_discards(t))
+       if (!dm_table_supports_discards(t)) {
                queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
-       else
+               /* Must also clear discard limits... */
+               q->limits.max_discard_sectors = 0;
+               q->limits.max_hw_discard_sectors = 0;
+               q->limits.discard_granularity = 0;
+               q->limits.discard_alignment = 0;
+               q->limits.discard_misaligned = 0;
+       } else
                queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 
        if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {