drbd: introduce WRITE_SAME support
We will support WRITE_SAME, if
* all peers support WRITE_SAME (both in kernel and DRBD version),
* all peer devices support WRITE_SAME
* logical_block_size is identical on all peers.
We may at some point introduce a fallback on the receiving side
for devices/kernels that do not support WRITE_SAME,
by open-coding a submit loop. But not yet.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 64e9525..f4ea8d6 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -920,6 +920,31 @@
}
}
+/* communicated if (agreed_features & DRBD_FF_WSAME) */
+void assign_p_sizes_qlim(struct drbd_device *device, struct p_sizes *p, struct request_queue *q)
+{
+ if (q) {
+ p->qlim->physical_block_size = cpu_to_be32(queue_physical_block_size(q));
+ p->qlim->logical_block_size = cpu_to_be32(queue_logical_block_size(q));
+ p->qlim->alignment_offset = cpu_to_be32(queue_alignment_offset(q));
+ p->qlim->io_min = cpu_to_be32(queue_io_min(q));
+ p->qlim->io_opt = cpu_to_be32(queue_io_opt(q));
+ p->qlim->discard_enabled = blk_queue_discard(q);
+ p->qlim->discard_zeroes_data = queue_discard_zeroes_data(q);
+ p->qlim->write_same_capable = !!q->limits.max_write_same_sectors;
+ } else {
+ q = device->rq_queue;
+ p->qlim->physical_block_size = cpu_to_be32(queue_physical_block_size(q));
+ p->qlim->logical_block_size = cpu_to_be32(queue_logical_block_size(q));
+ p->qlim->alignment_offset = 0;
+ p->qlim->io_min = cpu_to_be32(queue_io_min(q));
+ p->qlim->io_opt = cpu_to_be32(queue_io_opt(q));
+ p->qlim->discard_enabled = 0;
+ p->qlim->discard_zeroes_data = 0;
+ p->qlim->write_same_capable = 0;
+ }
+}
+
int drbd_send_sizes(struct drbd_peer_device *peer_device, int trigger_reply, enum dds_flags flags)
{
struct drbd_device *device = peer_device->device;
@@ -928,29 +953,37 @@
sector_t d_size, u_size;
int q_order_type;
unsigned int max_bio_size;
+ unsigned int packet_size;
+ sock = &peer_device->connection->data;
+ p = drbd_prepare_command(peer_device, sock);
+ if (!p)
+ return -EIO;
+
+ packet_size = sizeof(*p);
+ if (peer_device->connection->agreed_features & DRBD_FF_WSAME)
+ packet_size += sizeof(p->qlim[0]);
+
+ memset(p, 0, packet_size);
if (get_ldev_if_state(device, D_NEGOTIATING)) {
- D_ASSERT(device, device->ldev->backing_bdev);
+ struct request_queue *q = bdev_get_queue(device->ldev->backing_bdev);
d_size = drbd_get_max_capacity(device->ldev);
rcu_read_lock();
u_size = rcu_dereference(device->ldev->disk_conf)->disk_size;
rcu_read_unlock();
q_order_type = drbd_queue_order_type(device);
- max_bio_size = queue_max_hw_sectors(device->ldev->backing_bdev->bd_disk->queue) << 9;
+ max_bio_size = queue_max_hw_sectors(q) << 9;
max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE);
+ assign_p_sizes_qlim(device, p, q);
put_ldev(device);
} else {
d_size = 0;
u_size = 0;
q_order_type = QUEUE_ORDERED_NONE;
max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
+ assign_p_sizes_qlim(device, p, NULL);
}
- sock = &peer_device->connection->data;
- p = drbd_prepare_command(peer_device, sock);
- if (!p)
- return -EIO;
-
if (peer_device->connection->agreed_pro_version <= 94)
max_bio_size = min(max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
else if (peer_device->connection->agreed_pro_version < 100)
@@ -962,7 +995,8 @@
p->max_bio_size = cpu_to_be32(max_bio_size);
p->queue_order_type = cpu_to_be16(q_order_type);
p->dds_flags = cpu_to_be16(flags);
- return drbd_send_command(peer_device, sock, P_SIZES, sizeof(*p), NULL, 0);
+
+ return drbd_send_command(peer_device, sock, P_SIZES, packet_size, NULL, 0);
}
/**
@@ -1577,6 +1611,9 @@
? 0 : MSG_MORE);
if (err)
return err;
+ /* REQ_OP_WRITE_SAME has only one segment */
+ if (bio_op(bio) == REQ_OP_WRITE_SAME)
+ break;
}
return 0;
}
@@ -1595,6 +1632,9 @@
bio_iter_last(bvec, iter) ? 0 : MSG_MORE);
if (err)
return err;
+ /* REQ_OP_WRITE_SAME has only one segment */
+ if (bio_op(bio) == REQ_OP_WRITE_SAME)
+ break;
}
return 0;
}
@@ -1626,6 +1666,7 @@
return (bio->bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
(bio->bi_rw & REQ_FUA ? DP_FUA : 0) |
(bio->bi_rw & REQ_PREFLUSH ? DP_FLUSH : 0) |
+ (bio_op(bio) == REQ_OP_WRITE_SAME ? DP_WSAME : 0) |
(bio_op(bio) == REQ_OP_DISCARD ? DP_DISCARD : 0);
else
return bio->bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
@@ -1639,6 +1680,8 @@
struct drbd_device *device = peer_device->device;
struct drbd_socket *sock;
struct p_data *p;
+ struct p_wsame *wsame = NULL;
+ void *digest_out;
unsigned int dp_flags = 0;
int digest_size;
int err;
@@ -1674,12 +1717,29 @@
err = __send_command(peer_device->connection, device->vnr, sock, P_TRIM, sizeof(*t), NULL, 0);
goto out;
}
+ if (dp_flags & DP_WSAME) {
+ /* this will only work if DRBD_FF_WSAME is set AND the
+ * handshake agreed that all nodes and backend devices are
+ * WRITE_SAME capable and agree on logical_block_size */
+ wsame = (struct p_wsame*)p;
+ digest_out = wsame + 1;
+ wsame->size = cpu_to_be32(req->i.size);
+ } else
+ digest_out = p + 1;
/* our digest is still only over the payload.
* TRIM does not carry any payload. */
if (digest_size)
- drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, p + 1);
- err = __send_command(peer_device->connection, device->vnr, sock, P_DATA, sizeof(*p) + digest_size, NULL, req->i.size);
+ drbd_csum_bio(peer_device->connection->integrity_tfm, req->master_bio, digest_out);
+ if (wsame) {
+ err =
+ __send_command(peer_device->connection, device->vnr, sock, P_WSAME,
+ sizeof(*wsame) + digest_size, NULL,
+ bio_iovec(req->master_bio).bv_len);
+ } else
+ err =
+ __send_command(peer_device->connection, device->vnr, sock, P_DATA,
+ sizeof(*p) + digest_size, NULL, req->i.size);
if (!err) {
/* For protocol A, we have to memcpy the payload into
* socket buffers, as we may complete right away
@@ -3660,6 +3720,8 @@
* one PRO_VERSION */
static const char *cmdnames[] = {
[P_DATA] = "Data",
+ [P_WSAME] = "WriteSame",
+ [P_TRIM] = "Trim",
[P_DATA_REPLY] = "DataReply",
[P_RS_DATA_REPLY] = "RSDataReply",
[P_BARRIER] = "Barrier",