dm: use common __issue_target_request for flush and discard support
Rename __flush_target to __issue_target_request now that it is used to
issue both flush and discard requests.
Introduce __issue_target_requests as a convenient wrapper to
__issue_target_request 'num_flush_requests' or 'num_discard_requests'
times per target.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 44aba29..3dd846e 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1182,30 +1182,42 @@
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)
{
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;
__map_bio(ti, clone, tio);
}
+static void __issue_target_requests(struct clone_info *ci, struct dm_target *ti,
+ unsigned num_requests)
+{
+ unsigned request_nr;
+
+ for (request_nr = 0; request_nr < num_requests; request_nr++)
+ __issue_target_request(ci, ti, request_nr);
+}
+
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);
ci->sector_count = 0;
@@ -1254,7 +1266,9 @@
*/
return -EOPNOTSUPP;
- __clone_and_map_simple(ci, ti);
+ __issue_target_requests(ci, ti, ti->num_discard_requests);
+
+ ci->sector_count = 0;
return 0;
}
