dm: stripe support flush
Flush support for the stripe target.
This sets ti->num_flush_requests to the number of stripes and
remaps individual flush requests to the appropriate stripe devices.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 41569bc..c64fe82 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -167,6 +167,7 @@
sc->stripes = stripes;
sc->stripe_width = width;
ti->split_io = chunk_size;
+ ti->num_flush_requests = stripes;
sc->chunk_mask = ((sector_t) chunk_size) - 1;
for (sc->chunk_shift = 0; chunk_size; sc->chunk_shift++)
@@ -211,10 +212,18 @@
union map_info *map_context)
{
struct stripe_c *sc = (struct stripe_c *) ti->private;
+ sector_t offset, chunk;
+ uint32_t stripe;
- sector_t offset = bio->bi_sector - ti->begin;
- sector_t chunk = offset >> sc->chunk_shift;
- uint32_t stripe = sector_div(chunk, sc->stripes);
+ if (unlikely(bio_empty_barrier(bio))) {
+ BUG_ON(map_context->flush_request >= sc->stripes);
+ bio->bi_bdev = sc->stripe[map_context->flush_request].dev->bdev;
+ return DM_MAPIO_REMAPPED;
+ }
+
+ offset = bio->bi_sector - ti->begin;
+ chunk = offset >> sc->chunk_shift;
+ stripe = sector_div(chunk, sc->stripes);
bio->bi_bdev = sc->stripe[stripe].dev->bdev;
bio->bi_sector = sc->stripe[stripe].physical_start +