diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/dm-linear.c | 1 | ||||
| -rw-r--r-- | drivers/md/dm-table.c | 44 | ||||
| -rw-r--r-- | drivers/md/dm.c | 65 | ||||
| -rw-r--r-- | drivers/md/dm.h | 1 |
4 files changed, 99 insertions, 12 deletions
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index 9200dbf..f043b5f 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -53,6 +53,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv) } ti->num_flush_requests = 1; + ti->num_discard_requests = 1; ti->private = lc; return 0; diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index bc60ef7..f9fc07d 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -54,6 +54,8 @@ struct dm_table { sector_t *highs; struct dm_target *targets; + unsigned discards_supported:1; + /* * Indicates the rw permissions for the new logical * device. This should be a combination of FMODE_READ @@ -203,6 +205,7 @@ int dm_table_create(struct dm_table **result, fmode_t mode, INIT_LIST_HEAD(&t->devices); atomic_set(&t->holders, 0); + t->discards_supported = 1; if (!num_targets) num_targets = KEYS_PER_NODE; @@ -770,6 +773,9 @@ int dm_table_add_target(struct dm_table *t, const char *type, t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; + if (!tgt->num_discard_requests) + t->discards_supported = 0; + return 0; bad: @@ -1135,6 +1141,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, else queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); + if (!dm_table_supports_discards(t)) + queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q); + else + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); + dm_table_set_integrity(t); /* @@ -1281,6 +1292,39 @@ struct mapped_device *dm_table_get_md(struct dm_table *t) return t->md; } +static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + + return q && blk_queue_discard(q); +} + +bool dm_table_supports_discards(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i = 0; + + if (!t->discards_supported) + return 0; + + /* + * Ensure that at least one underlying device supports discards. + * t->devices includes internal dm devices such as mirror logs + * so we need to use iterate_devices here, which targets + * supporting discard must provide. + */ + while (i < dm_table_get_num_targets(t)) { + ti = dm_table_get_target(t, i++); + + if (ti->type->iterate_devices && + ti->type->iterate_devices(ti, device_discard_capable, NULL)) + return 1; + } + + return 0; +} + EXPORT_SYMBOL(dm_vcalloc); EXPORT_SYMBOL(dm_get_device); EXPORT_SYMBOL(dm_put_device); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 0d47101..44aba29 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1212,6 +1212,53 @@ static int __clone_and_map_empty_barrier(struct clone_info *ci) return 0; } +/* + * Perform all io with a single clone. + */ +static void __clone_and_map_simple(struct clone_info *ci, struct dm_target *ti) +{ + struct bio *clone, *bio = ci->bio; + struct dm_target_io *tio; + + tio = alloc_tio(ci, ti); + clone = clone_bio(bio, ci->sector, ci->idx, + bio->bi_vcnt - ci->idx, ci->sector_count, + ci->md->bs); + __map_bio(ti, clone, tio); + ci->sector_count = 0; +} + +static int __clone_and_map_discard(struct clone_info *ci) +{ + struct dm_target *ti; + sector_t max; + + ti = dm_table_find_target(ci->map, ci->sector); + if (!dm_target_is_valid(ti)) + return -EIO; + + /* + * Even though the device advertised discard support, + * reconfiguration might have changed that since the + * check was performed. + */ + + if (!ti->num_discard_requests) + return -EOPNOTSUPP; + + max = max_io_len(ci->md, ci->sector, ti); + + if (ci->sector_count > max) + /* + * FIXME: Handle a discard that spans two or more targets. + */ + return -EOPNOTSUPP; + + __clone_and_map_simple(ci, ti); + + return 0; +} + static int __clone_and_map(struct clone_info *ci) { struct bio *clone, *bio = ci->bio; @@ -1222,27 +1269,21 @@ static int __clone_and_map(struct clone_info *ci) if (unlikely(bio_empty_barrier(bio))) return __clone_and_map_empty_barrier(ci); + if (unlikely(bio->bi_rw & REQ_DISCARD)) + return __clone_and_map_discard(ci); + ti = dm_table_find_target(ci->map, ci->sector); if (!dm_target_is_valid(ti)) return -EIO; max = max_io_len(ci->md, ci->sector, ti); - /* - * Allocate a target io object. - */ - tio = alloc_tio(ci, ti); - if (ci->sector_count <= max) { /* * Optimise for the simple case where we can do all of * the remaining io with a single clone. */ - clone = clone_bio(bio, ci->sector, ci->idx, - bio->bi_vcnt - ci->idx, ci->sector_count, - ci->md->bs); - __map_bio(ti, clone, tio); - ci->sector_count = 0; + __clone_and_map_simple(ci, ti); } else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) { /* @@ -1263,6 +1304,7 @@ static int __clone_and_map(struct clone_info *ci) len += bv_len; } + tio = alloc_tio(ci, ti); clone = clone_bio(bio, ci->sector, ci->idx, i - ci->idx, len, ci->md->bs); __map_bio(ti, clone, tio); @@ -1286,12 +1328,11 @@ static int __clone_and_map(struct clone_info *ci) return -EIO; max = max_io_len(ci->md, ci->sector, ti); - - tio = alloc_tio(ci, ti); } len = min(remaining, max); + tio = alloc_tio(ci, ti); clone = split_bvec(bio, ci->sector, ci->idx, bv->bv_offset + offset, len, ci->md->bs); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 0d7b374..0c2dd5f 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -61,6 +61,7 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits); int dm_table_any_busy_target(struct dm_table *t); unsigned dm_table_get_type(struct dm_table *t); bool dm_table_request_based(struct dm_table *t); +bool dm_table_supports_discards(struct dm_table *t); int dm_table_alloc_md_mempools(struct dm_table *t); void dm_table_free_md_mempools(struct dm_table *t); struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); |