dm raid1: support flush
Flush support for dm-raid1.
When it receives an empty barrier, submit it to all the devices via dm-io.
Signed-off-by: Mikulas Patocka <mpatocka@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 cc9dc79..752a29e 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -396,6 +396,8 @@
*/
static sector_t map_sector(struct mirror *m, struct bio *bio)
{
+ if (unlikely(!bio->bi_size))
+ return 0;
return m->offset + (bio->bi_sector - m->ms->ti->begin);
}
@@ -562,7 +564,7 @@
struct dm_io_region io[ms->nr_mirrors], *dest = io;
struct mirror *m;
struct dm_io_request io_req = {
- .bi_rw = WRITE,
+ .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER),
.mem.type = DM_IO_BVEC,
.mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
.notify.fn = write_callback,
@@ -603,6 +605,11 @@
bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
+ if (unlikely(bio_empty_barrier(bio))) {
+ bio_list_add(&sync, bio);
+ continue;
+ }
+
region = dm_rh_bio_to_region(ms->rh, bio);
if (log->type->is_remote_recovering &&
@@ -995,6 +1002,7 @@
ti->private = ms;
ti->split_io = dm_rh_get_region_size(ms->rh);
+ ti->num_flush_requests = 1;
ms->kmirrord_wq = create_singlethread_workqueue("kmirrord");
if (!ms->kmirrord_wq) {
@@ -1122,7 +1130,8 @@
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
- dm_rh_dec(ms->rh, map_context->ll);
+ if (likely(!bio_empty_barrier(bio)))
+ dm_rh_dec(ms->rh, map_context->ll);
return error;
}