Commit 7b76ec11fec40203836b488496d2df082d5b2022
Committed by
Alasdair G Kergon
Alasdair G Kergon
1 parent
a79245b3e5
Exists in
master
and in
7 other branches
dm stripe: support discards
The DM core will submit a discard bio to the stripe target for each stripe in a striped DM device. The stripe target will determine stripe-specific portions of the supplied bio to be remapped into individual (at most 'num_discard_requests' extents). If a given stripe-specific discard bio doesn't touch a particular stripe the bio will be dropped. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Showing 1 changed file with 39 additions and 0 deletions Side-by-side Diff
drivers/md/dm-stripe.c
| ... | ... | @@ -176,6 +176,7 @@ |
| 176 | 176 | |
| 177 | 177 | ti->split_io = chunk_size; |
| 178 | 178 | ti->num_flush_requests = stripes; |
| 179 | + ti->num_discard_requests = stripes; | |
| 179 | 180 | |
| 180 | 181 | sc->chunk_shift = ffs(chunk_size) - 1; |
| 181 | 182 | sc->chunk_mask = ((sector_t) chunk_size) - 1; |
| ... | ... | @@ -230,6 +231,39 @@ |
| 230 | 231 | *result = (chunk << sc->chunk_shift) | (offset & sc->chunk_mask); |
| 231 | 232 | } |
| 232 | 233 | |
| 234 | +static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector, | |
| 235 | + uint32_t target_stripe, sector_t *result) | |
| 236 | +{ | |
| 237 | + uint32_t stripe; | |
| 238 | + | |
| 239 | + stripe_map_sector(sc, sector, &stripe, result); | |
| 240 | + if (stripe == target_stripe) | |
| 241 | + return; | |
| 242 | + *result &= ~sc->chunk_mask; /* round down */ | |
| 243 | + if (target_stripe < stripe) | |
| 244 | + *result += sc->chunk_mask + 1; /* next chunk */ | |
| 245 | +} | |
| 246 | + | |
| 247 | +static int stripe_map_discard(struct stripe_c *sc, struct bio *bio, | |
| 248 | + uint32_t target_stripe) | |
| 249 | +{ | |
| 250 | + sector_t begin, end; | |
| 251 | + | |
| 252 | + stripe_map_range_sector(sc, bio->bi_sector, target_stripe, &begin); | |
| 253 | + stripe_map_range_sector(sc, bio->bi_sector + bio_sectors(bio), | |
| 254 | + target_stripe, &end); | |
| 255 | + if (begin < end) { | |
| 256 | + bio->bi_bdev = sc->stripe[target_stripe].dev->bdev; | |
| 257 | + bio->bi_sector = begin + sc->stripe[target_stripe].physical_start; | |
| 258 | + bio->bi_size = to_bytes(end - begin); | |
| 259 | + return DM_MAPIO_REMAPPED; | |
| 260 | + } else { | |
| 261 | + /* The range doesn't map to the target stripe */ | |
| 262 | + bio_endio(bio, 0); | |
| 263 | + return DM_MAPIO_SUBMITTED; | |
| 264 | + } | |
| 265 | +} | |
| 266 | + | |
| 233 | 267 | static int stripe_map(struct dm_target *ti, struct bio *bio, |
| 234 | 268 | union map_info *map_context) |
| 235 | 269 | { |
| ... | ... | @@ -242,6 +276,11 @@ |
| 242 | 276 | BUG_ON(target_request_nr >= sc->stripes); |
| 243 | 277 | bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev; |
| 244 | 278 | return DM_MAPIO_REMAPPED; |
| 279 | + } | |
| 280 | + if (unlikely(bio->bi_rw & REQ_DISCARD)) { | |
| 281 | + target_request_nr = map_context->target_request_nr; | |
| 282 | + BUG_ON(target_request_nr >= sc->stripes); | |
| 283 | + return stripe_map_discard(sc, bio, target_request_nr); | |
| 245 | 284 | } |
| 246 | 285 | |
| 247 | 286 | stripe_map_sector(sc, bio->bi_sector, &stripe, &bio->bi_sector); |