drbd: announce FLUSH/FUA capability to upper layers
Unconditionally announce FLUSH/FUA to upper layers.
If the lower layers on either node do not actually support this,
generic_make_request() will deal with it.
If this causes performance regressions on your setup,
make sure there are no volatile caches involved,
and mount -o nobarrier or equivalent.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 1ee1404..2e0e7fc 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3636,6 +3636,7 @@
q->backing_dev_info.congested_data = mdev;
blk_queue_make_request(q, drbd_make_request);
+ blk_queue_flush(q, REQ_FLUSH | REQ_FUA);
/* Setting the max_hw_sectors to an odd value of 8kibyte here
This triggers a max_bio_size message upon first attach or connect */
blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);