dm_complete_request(clone, error);
}
-static sector_t max_io_len(struct mapped_device *md,
- sector_t sector, struct dm_target *ti)
+/*
+ * Return maximum size of I/O possible at the supplied sector up to the current
+ * target boundary.
+ */
+static sector_t max_io_len_target_boundary(sector_t sector, struct dm_target *ti)
+{
+ sector_t target_offset = dm_target_offset(ti, sector);
+
+ return ti->len - target_offset;
+}
+
+static sector_t max_io_len(sector_t sector, struct dm_target *ti)
{
- sector_t offset = sector - ti->begin;
- sector_t len = ti->len - offset;
+ sector_t len = max_io_len_target_boundary(sector, ti);
/*
* Does the target need to split even further ?
*/
if (ti->split_io) {
sector_t boundary;
+ sector_t offset = dm_target_offset(ti, sector);
boundary = ((offset + ti->split_io) & ~(ti->split_io - 1))
- offset;
if (len > boundary)
return tio;
}
-static void __flush_target(struct clone_info *ci, struct dm_target *ti,
- unsigned request_nr)
+static void __issue_target_request(struct clone_info *ci, struct dm_target *ti,
+ unsigned request_nr, sector_t len)
{
struct dm_target_io *tio = alloc_tio(ci, ti);
struct bio *clone;
tio->info.target_request_nr = request_nr;
- clone = bio_alloc_bioset(GFP_NOIO, 0, ci->md->bs);
+ /*
+ * Discard requests require the bio's inline iovecs be initialized.
+ * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush
+ * and discard, so no need for concern about wasted bvec allocations.
+ */
+ clone = bio_alloc_bioset(GFP_NOIO, ci->bio->bi_max_vecs, ci->md->bs);
__bio_clone(clone, ci->bio);
clone->bi_destructor = dm_bio_destructor;
+ if (len) {
+ clone->bi_sector = ci->sector;
+ clone->bi_size = to_bytes(len);
+ }
__map_bio(ti, clone, tio);
}
+static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
+ unsigned num_requests, sector_t len)
+{
+ unsigned request_nr;
+
+ for (request_nr = 0; request_nr < num_requests; request_nr++)
+ __issue_target_request(ci, ti, request_nr, len);
+}
+
static int __clone_and_map_empty_barrier(struct clone_info *ci)
{
- unsigned target_nr = 0, request_nr;
+ unsigned target_nr = 0;
struct dm_target *ti;
while ((ti = dm_table_get_target(ci->map, target_nr++)))
- for (request_nr = 0; request_nr < ti->num_flush_requests;
- request_nr++)
- __flush_target(ci, ti, request_nr);
+ __issue_target_requests(ci, ti, ti->num_flush_requests, 0);
+
+ ci->sector_count = 0;
+
+ 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 len;
+
+ do {
+ 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;
+
+ len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
+
+ __issue_target_requests(ci, ti, ti->num_discard_requests, len);
+
+ ci->sector += len;
+ } while (ci->sector_count -= len);
return 0;
}
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);
+ max = max_io_len(ci->sector, 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) {
/*
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);
if (!dm_target_is_valid(ti))
return -EIO;
- max = max_io_len(ci->md, ci->sector, ti);
-
- tio = alloc_tio(ci, ti);
+ max = max_io_len(ci->sector, 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);
/*
* Find maximum amount of I/O that won't need splitting
*/
- max_sectors = min(max_io_len(md, bvm->bi_sector, ti),
+ max_sectors = min(max_io_len(bvm->bi_sector, ti),
(sector_t) BIO_MAX_SECTORS);
max_size = (max_sectors << SECTOR_SHIFT) - bvm->bi_size;
if (max_size < 0)
git.openpandora.org / pandora-kernel.git / blobdiff