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authorMike Snitzer <snitzer@redhat.com>2010-08-12 04:14:24 +0100
committerAlasdair G Kergon <agk@redhat.com>2010-08-12 04:14:24 +0100
commita79245b3e5669dc203fec63644d988c451fe55d5 (patch)
tree8814720781708a95ac0bd23bb5232aa5ed9337bd /drivers/md
parentc96053b767d494d7c30e2be68097ac9defa9403f (diff)
dm: split discard requests on target boundaries
Update __clone_and_map_discard to loop across all targets in a DM device's table when it processes a discard bio. If a discard crosses a target boundary it must be split accordingly. Update __issue_target_requests and __issue_target_request to allow a cloned discard bio to have a custom start sector and size. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm.c47
1 files changed, 23 insertions, 24 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 561313a7dac..ac384b2a6a3 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1193,7 +1193,7 @@ static struct dm_target_io *alloc_tio(struct clone_info *ci,
}
static void __issue_target_request(struct clone_info *ci, struct dm_target *ti,
- unsigned request_nr)
+ unsigned request_nr, sector_t len)
{
struct dm_target_io *tio = alloc_tio(ci, ti);
struct bio *clone;
@@ -1208,17 +1208,21 @@ static void __issue_target_request(struct clone_info *ci, struct dm_target *ti,
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)
+ 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);
+ __issue_target_request(ci, ti, request_nr, len);
}
static int __clone_and_map_empty_barrier(struct clone_info *ci)
@@ -1227,7 +1231,7 @@ static int __clone_and_map_empty_barrier(struct clone_info *ci)
struct dm_target *ti;
while ((ti = dm_table_get_target(ci->map, target_nr++)))
- __issue_target_requests(ci, ti, ti->num_flush_requests);
+ __issue_target_requests(ci, ti, ti->num_flush_requests, 0);
ci->sector_count = 0;
@@ -1253,32 +1257,27 @@ static void __clone_and_map_simple(struct clone_info *ci, struct dm_target *ti)
static int __clone_and_map_discard(struct clone_info *ci)
{
struct dm_target *ti;
- sector_t max;
+ sector_t len;
- 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.
- */
+ do {
+ ti = dm_table_find_target(ci->map, ci->sector);
+ if (!dm_target_is_valid(ti))
+ return -EIO;
- if (!ti->num_discard_requests)
- return -EOPNOTSUPP;
-
- max = max_io_len(ci->sector, ti);
-
- if (ci->sector_count > max)
/*
- * FIXME: Handle a discard that spans two or more targets.
+ * Even though the device advertised discard support,
+ * reconfiguration might have changed that since the
+ * check was performed.
*/
- return -EOPNOTSUPP;
+ if (!ti->num_discard_requests)
+ return -EOPNOTSUPP;
- __issue_target_requests(ci, ti, ti->num_discard_requests);
+ len = min(ci->sector_count, max_io_len_target_boundary(ci->sector, ti));
- ci->sector_count = 0;
+ __issue_target_requests(ci, ti, ti->num_discard_requests, len);
+
+ ci->sector += len;
+ } while (ci->sector_count -= len);
return 0;
}