drbd: implement REQ_OP_WRITE_ZEROES

It seems like DRBD assumes its on the wire TRIM request always zeroes data.
Use that fact to implement REQ_OP_WRITE_ZEROES.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.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 92c60cb..8e62d9f 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1668,7 +1668,8 @@ static u32 bio_flags_to_wire(struct drbd_connection *connection,
                        (bio->bi_opf & REQ_FUA ? DP_FUA : 0) |
                        (bio->bi_opf & REQ_PREFLUSH ? DP_FLUSH : 0) |
                        (bio_op(bio) == REQ_OP_WRITE_SAME ? DP_WSAME : 0) |
-                       (bio_op(bio) == REQ_OP_DISCARD ? DP_DISCARD : 0);
+                       (bio_op(bio) == REQ_OP_DISCARD ? DP_DISCARD : 0) |
+                       (bio_op(bio) == REQ_OP_WRITE_ZEROES ? DP_DISCARD : 0);
        else
                return bio->bi_opf & REQ_SYNC ? DP_RW_SYNC : 0;
 }

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 908c704..e4516d3 100644 (file)
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1217,10 +1217,12 @@ static void decide_on_discard_support(struct drbd_device *device,
                blk_queue_discard_granularity(q, 512);
                q->limits.max_discard_sectors = drbd_max_discard_sectors(connection);
                queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
+               q->limits.max_write_zeroes_sectors = drbd_max_discard_sectors(connection);
        } else {
                queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
                blk_queue_discard_granularity(q, 0);
                q->limits.max_discard_sectors = 0;
+               q->limits.max_write_zeroes_sectors = 0;
        }
 }
 

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index bc1d296..1b0a2be 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -2285,7 +2285,7 @@ static unsigned long wire_flags_to_bio_flags(u32 dpf)
 static unsigned long wire_flags_to_bio_op(u32 dpf)
 {
        if (dpf & DP_DISCARD)
-               return REQ_OP_DISCARD;
+               return REQ_OP_WRITE_ZEROES;
        else
                return REQ_OP_WRITE;
 }
@@ -2476,7 +2476,7 @@ static int receive_Data(struct drbd_connection *connection, struct packet_info *
        op_flags = wire_flags_to_bio_flags(dp_flags);
        if (pi->cmd == P_TRIM) {
                D_ASSERT(peer_device, peer_req->i.size > 0);
-               D_ASSERT(peer_device, op == REQ_OP_DISCARD);
+               D_ASSERT(peer_device, op == REQ_OP_WRITE_ZEROES);
                D_ASSERT(peer_device, peer_req->pages == NULL);
        } else if (peer_req->pages == NULL) {
                D_ASSERT(device, peer_req->i.size == 0);
@@ -4789,7 +4789,7 @@ static int receive_rs_deallocated(struct drbd_connection *connection, struct pac
 
        if (get_ldev(device)) {
                struct drbd_peer_request *peer_req;
-               const int op = REQ_OP_DISCARD;
+               const int op = REQ_OP_WRITE_ZEROES;
 
                peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER, sector,
                                               size, 0, GFP_NOIO);

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 6da9ea8..b5730e1 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -59,6 +59,7 @@ static struct drbd_request *drbd_req_new(struct drbd_device *device, struct bio
        drbd_req_make_private_bio(req, bio_src);
        req->rq_state = (bio_data_dir(bio_src) == WRITE ? RQ_WRITE : 0)
                      | (bio_op(bio_src) == REQ_OP_WRITE_SAME ? RQ_WSAME : 0)
+                     | (bio_op(bio_src) == REQ_OP_WRITE_ZEROES ? RQ_UNMAP : 0)
                      | (bio_op(bio_src) == REQ_OP_DISCARD ? RQ_UNMAP : 0);
        req->device = device;
        req->master_bio = bio_src;
@@ -1180,7 +1181,8 @@ drbd_submit_req_private_bio(struct drbd_request *req)
        if (get_ldev(device)) {
                if (drbd_insert_fault(device, type))
                        bio_io_error(bio);
-               else if (bio_op(bio) == REQ_OP_DISCARD)
+               else if (bio_op(bio) == REQ_OP_WRITE_ZEROES ||
+                        bio_op(bio) == REQ_OP_DISCARD)
                        drbd_process_discard_req(req);
                else
                        generic_make_request(bio);
@@ -1234,7 +1236,8 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long
        _drbd_start_io_acct(device, req);
 
        /* process discards always from our submitter thread */
-       if (bio_op(bio) & REQ_OP_DISCARD)
+       if ((bio_op(bio) & REQ_OP_WRITE_ZEROES) ||
+           (bio_op(bio) & REQ_OP_DISCARD))
                goto queue_for_submitter_thread;
 
        if (rw == WRITE && req->private_bio && req->i.size

diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 3bff33f..1afcb4e 100644 (file)
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -174,7 +174,8 @@ void drbd_peer_request_endio(struct bio *bio)
        struct drbd_peer_request *peer_req = bio->bi_private;
        struct drbd_device *device = peer_req->peer_device->device;
        bool is_write = bio_data_dir(bio) == WRITE;
-       bool is_discard = !!(bio_op(bio) == REQ_OP_DISCARD);
+       bool is_discard = bio_op(bio) == REQ_OP_WRITE_ZEROES ||
+                         bio_op(bio) == REQ_OP_DISCARD;
 
        if (bio->bi_error && __ratelimit(&drbd_ratelimit_state))
                drbd_warn(device, "%s: error=%d s=%llus\n",
@@ -249,6 +250,7 @@ void drbd_request_endio(struct bio *bio)
        /* to avoid recursion in __req_mod */
        if (unlikely(bio->bi_error)) {
                switch (bio_op(bio)) {
+               case REQ_OP_WRITE_ZEROES:
                case REQ_OP_DISCARD:
                        if (bio->bi_error == -EOPNOTSUPP)
                                what = DISCARD_COMPLETED_NOTSUPP;