drbd: zero-out partial unaligned discards on local backend

[linux] / drivers / block / drbd / drbd_req.c

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 74903ab..355cf10 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1156,6 +1156,16 @@ static int drbd_process_write_request(struct drbd_request *req)
        return remote;
 }
 
+static void drbd_process_discard_req(struct drbd_request *req)
+{
+       int err = drbd_issue_discard_or_zero_out(req->device,
+                               req->i.sector, req->i.size >> 9, true);
+
+       if (err)
+               req->private_bio->bi_error = -EIO;
+       bio_endio(req->private_bio);
+}
+
 static void
 drbd_submit_req_private_bio(struct drbd_request *req)
 {
@@ -1176,6 +1186,8 @@ drbd_submit_req_private_bio(struct drbd_request *req)
                                    : rw == READ  ? DRBD_FAULT_DT_RD
                                    :               DRBD_FAULT_DT_RA))
                        bio_io_error(bio);
+               else if (bio_op(bio) == REQ_OP_DISCARD)
+                       drbd_process_discard_req(req);
                else
                        generic_make_request(bio);
                put_ldev(device);
@@ -1227,18 +1239,23 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long
        /* Update disk stats */
        _drbd_start_io_acct(device, req);
 
+       /* process discards always from our submitter thread */
+       if (bio_op(bio) & REQ_OP_DISCARD)
+               goto queue_for_submitter_thread;
+
        if (rw == WRITE && req->private_bio && req->i.size
        && !test_bit(AL_SUSPENDED, &device->flags)) {
-               if (!drbd_al_begin_io_fastpath(device, &req->i)) {
-                       atomic_inc(&device->ap_actlog_cnt);
-                       drbd_queue_write(device, req);
-                       return NULL;
-               }
+               if (!drbd_al_begin_io_fastpath(device, &req->i))
+                       goto queue_for_submitter_thread;
                req->rq_state |= RQ_IN_ACT_LOG;
                req->in_actlog_jif = jiffies;
        }
-
        return req;
+
+ queue_for_submitter_thread:
+       atomic_inc(&device->ap_actlog_cnt);
+       drbd_queue_write(device, req);
+       return NULL;
 }
 
 static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request *req)