drbd: always use_bmbv, ignore setting

Now that the peer may handle multi-bio EEs,
we can ignore the peer's limit,
and concentrate on the limits of the local IO stack.

This is safe accross drbd protocol versions,
as our queue_max_sectors() will be adjusted accordingly.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

3 files changed, 6 insertions, 5 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 28ef76bd5230..f20336bc59c8 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -704,9 +704,6 @@ void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int max_seg_s) __mu
         struct request_queue * const b = mdev->ldev->backing_bdev->bd_disk->queue;
         int max_segments = mdev->ldev->dc.max_bio_bvecs;
 
-        if (b->merge_bvec_fn && !mdev->ldev->dc.use_bmbv)
-                max_seg_s = PAGE_SIZE;
-
         max_seg_s = min(queue_max_sectors(b) * queue_logical_block_size(b), max_seg_s);
 
         blk_queue_max_hw_sectors(q, max_seg_s >> 9);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 388a3e8bb0d0..a04ec01ab3ce 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3011,7 +3011,11 @@ static int receive_sizes(struct drbd_conf *mdev, struct p_header *h)
                         ldsc = 1;
                 }
 
-                max_seg_s = be32_to_cpu(p->max_segment_size);
+                if (mdev->agreed_pro_version < 94)
+                        max_seg_s = be32_to_cpu(p->max_segment_size);
+                else /* drbd 8.3.8 onwards */
+                        max_seg_s = DRBD_MAX_SEGMENT_SIZE;
+
                 if (max_seg_s != queue_max_segment_size(mdev->rq_queue))
                         drbd_setup_queue_param(mdev, max_seg_s);
 
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index d8d9bbfca3b8..343e0e6dd532 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1110,7 +1110,7 @@ int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct
         } else if (limit && get_ldev(mdev)) {
                 struct request_queue * const b =
                         mdev->ldev->backing_bdev->bd_disk->queue;
-                if (b->merge_bvec_fn && mdev->ldev->dc.use_bmbv) {
+                if (b->merge_bvec_fn) {
                         backing_limit = b->merge_bvec_fn(b, bvm, bvec);
                         limit = min(limit, backing_limit);
                 }