dm raid1: support discard

Enable discard support in the DM mirror target.
Also change an existing use of 'bvec' to 'addr' in the union.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 19a59b041c27..c87756eb7a21 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -261,7 +261,7 @@ static int mirror_flush(struct dm_target *ti)
         struct dm_io_request io_req = {
                 .bi_rw = WRITE_FLUSH,
                 .mem.type = DM_IO_KMEM,
-                .mem.ptr.bvec = NULL,
+                .mem.ptr.addr = NULL,
                 .client = ms->io_client,
         };
 
@@ -637,6 +637,12 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
                 .client = ms->io_client,
         };
 
+        if (bio->bi_rw & REQ_DISCARD) {
+                io_req.bi_rw |= REQ_DISCARD;
+                io_req.mem.type = DM_IO_KMEM;
+                io_req.mem.ptr.addr = NULL;
+        }
+
         for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++)
                 map_region(dest++, m, bio);
 
@@ -670,7 +676,8 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
         bio_list_init(&requeue);
 
         while ((bio = bio_list_pop(writes))) {
-                if (bio->bi_rw & REQ_FLUSH) {
+                if ((bio->bi_rw & REQ_FLUSH) ||
+                    (bio->bi_rw & REQ_DISCARD)) {
                         bio_list_add(&sync, bio);
                         continue;
                 }
@@ -1076,6 +1083,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         ti->private = ms;
         ti->split_io = dm_rh_get_region_size(ms->rh);
         ti->num_flush_requests = 1;
+        ti->num_discard_requests = 1;
 
         ms->kmirrord_wq = create_singlethread_workqueue("kmirrord");
         if (!ms->kmirrord_wq) {