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>

diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 19a59b041c277a4e83b739011031572bf135109f..c87756eb7a2149e7b1773a7b22f35914d40eeee7 100644 (file)
--- 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) {