From: Christoph Hellwig <hch@xxxxxx>
Split out a drbd_max_peer_bio_size helper for the peer I/O size,
and condense the various checks to a nested min3(..., max())) instead
of using a lot of local variables.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Reviewed-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
Tested-by: Christoph Böhmwalder <christoph.boehmwalder@xxxxxxxxxx>
---
drivers/block/drbd/drbd_nl.c | 84 +++++++++++++++++++++---------------
1 file changed, 49 insertions(+), 35 deletions(-)
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 43747a1aae43..9135001a8e57 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1189,6 +1189,33 @@ static int drbd_check_al_size(struct drbd_device *device, struct disk_conf *dc)
return 0;
}
+static unsigned int drbd_max_peer_bio_size(struct drbd_device *device)
+{
+ /*
+ * We may ignore peer limits if the peer is modern enough. From 8.3.8
+ * onwards the peer can use multiple BIOs for a single peer_request.
+ */
+ if (device->state.conn < C_WF_REPORT_PARAMS)
+ return device->peer_max_bio_size;
+
+ if (first_peer_device(device)->connection->agreed_pro_version < 94)
+ return min(device->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
+
+ /*
+ * Correct old drbd (up to 8.3.7) if it believes it can do more than
+ * 32KiB.
+ */
+ if (first_peer_device(device)->connection->agreed_pro_version == 94)
+ return DRBD_MAX_SIZE_H80_PACKET;
+
+ /*
+ * drbd 8.3.8 onwards, before 8.4.0
+ */
+ if (first_peer_device(device)->connection->agreed_pro_version < 100)
+ return DRBD_MAX_BIO_SIZE_P95;
+ return DRBD_MAX_BIO_SIZE;
+}
+
static void blk_queue_discard_granularity(struct request_queue *q, unsigned int granularity)
{
q->limits.discard_granularity = granularity;
@@ -1303,48 +1330,35 @@ static void drbd_setup_queue_param(struct drbd_device *device, struct drbd_backi
fixup_discard_support(device, q);
}
-void drbd_reconsider_queue_parameters(struct drbd_device *device, struct drbd_backing_dev *bdev, struct o_qlim *o)
+void drbd_reconsider_queue_parameters(struct drbd_device *device,
+ struct drbd_backing_dev *bdev, struct o_qlim *o)
{
- unsigned int now, new, local, peer;
-
- now = queue_max_hw_sectors(device->rq_queue) << 9;
- local = device->local_max_bio_size; /* Eventually last known value, from volatile memory */
- peer = device->peer_max_bio_size; /* Eventually last known value, from meta data */
+ unsigned int now = queue_max_hw_sectors(device->rq_queue) <<
+ SECTOR_SHIFT;
+ unsigned int new;
if (bdev) {
- local = queue_max_hw_sectors(bdev->backing_bdev->bd_disk->queue) << 9;
- device->local_max_bio_size = local;
- }
- local = min(local, DRBD_MAX_BIO_SIZE);
-
- /* We may ignore peer limits if the peer is modern enough.
- Because new from 8.3.8 onwards the peer can use multiple
- BIOs for a single peer_request */
- if (device->state.conn >= C_WF_REPORT_PARAMS) {
- if (first_peer_device(device)->connection->agreed_pro_version < 94)
- peer = min(device->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
- /* Correct old drbd (up to 8.3.7) if it believes it can do more than 32KiB */
- else if (first_peer_device(device)->connection->agreed_pro_version == 94)
- peer = DRBD_MAX_SIZE_H80_PACKET;
- else if (first_peer_device(device)->connection->agreed_pro_version < 100)
- peer = DRBD_MAX_BIO_SIZE_P95; /* drbd 8.3.8 onwards, before 8.4.0 */
- else
- peer = DRBD_MAX_BIO_SIZE;
+ struct request_queue *b = bdev->backing_bdev->bd_disk->queue;
- /* We may later detach and re-attach on a disconnected Primary.
- * Avoid this setting to jump back in that case.
- * We want to store what we know the peer DRBD can handle,
- * not what the peer IO backend can handle. */
- if (peer > device->peer_max_bio_size)
- device->peer_max_bio_size = peer;
+ device->local_max_bio_size =
+ queue_max_hw_sectors(b) << SECTOR_SHIFT;
}
- new = min(local, peer);
- if (device->state.role == R_PRIMARY && new < now)
- drbd_err(device, "ASSERT FAILED new < now; (%u < %u)\n", new, now);
-
- if (new != now)
+ /*
+ * We may later detach and re-attach on a disconnected Primary. Avoid
+ * decreasing the value in this case.
+ *
+ * We want to store what we know the peer DRBD can handle, not what the
+ * peer IO backend can handle.
+ */
+ new = min3(DRBD_MAX_BIO_SIZE, device->local_max_bio_size,
+ max(drbd_max_peer_bio_size(device), device->peer_max_bio_size));
+ if (new != now) {
+ if (device->state.role == R_PRIMARY && new < now)
+ drbd_err(device, "ASSERT FAILED new < now; (%u < %u)\n",
+ new, now);
drbd_info(device, "max BIO size = %u\n", new);
+ }
drbd_setup_queue_param(device, bdev, new, o);
}
--
2.40.1
