+static void sanitize_disk_conf(struct drbd_device *device, struct disk_conf *disk_conf,
+ struct drbd_backing_dev *nbc)
+{
+ struct request_queue * const q = nbc->backing_bdev->bd_disk->queue;
+
+ if (disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
+ disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
+ if (disk_conf->al_extents > drbd_al_extents_max(nbc))
+ disk_conf->al_extents = drbd_al_extents_max(nbc);
+
+ if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data) {
+ disk_conf->rs_discard_granularity = 0; /* disable feature */
+ drbd_info(device, "rs_discard_granularity feature disabled\n");
+ }
+
+ if (disk_conf->rs_discard_granularity) {
+ int orig_value = disk_conf->rs_discard_granularity;
+ int remainder;
+
+ if (q->limits.discard_granularity > disk_conf->rs_discard_granularity)
+ disk_conf->rs_discard_granularity = q->limits.discard_granularity;
+
+ remainder = disk_conf->rs_discard_granularity % q->limits.discard_granularity;
+ disk_conf->rs_discard_granularity += remainder;
+
+ if (disk_conf->rs_discard_granularity > q->limits.max_discard_sectors << 9)
+ disk_conf->rs_discard_granularity = q->limits.max_discard_sectors << 9;
+
+ if (disk_conf->rs_discard_granularity != orig_value)
+ drbd_info(device, "rs_discard_granularity changed to %d\n",
+ disk_conf->rs_discard_granularity);
+ }
+}
+