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>
This commit is contained in:
Mikulas Patocka 2009-06-22 10:12:22 +01:00 committed by Alasdair G Kergon
parent 433bcac564
commit 374bf7e7f6

View file

@ -167,6 +167,7 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
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 +