diff options
| author | Mike Snitzer <snitzer@redhat.com> | 2011-05-29 12:52:55 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2011-05-29 12:52:55 +0100 |
| commit | 4c2593270133708698d4b8cea2dab469479ad13b (patch) | |
| tree | f408edef9145b2f9553cbb2142347fc79023c4ff | |
| parent | 139f37f5e14cd883eee2a8a36289f544b5390a44 (diff) | |
dm table: allow targets to support discards internally
Permit a target to support discards regardless of whether or not all its
underlying devices do.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| -rw-r--r-- | drivers/md/dm-table.c | 6 | ||||
| -rw-r--r-- | include/linux/device-mapper.h | 6 |
2 files changed, 11 insertions, 1 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index cb8380c9767f..215e112d153e 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1346,7 +1346,8 @@ bool dm_table_supports_discards(struct dm_table *t) return 0; /* - * Ensure that at least one underlying device supports discards. + * Unless any target used by the table set discards_supported, + * require at least one underlying device to support 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. @@ -1354,6 +1355,9 @@ bool dm_table_supports_discards(struct dm_table *t) while (i < dm_table_get_num_targets(t)) { ti = dm_table_get_target(t, i++); + if (ti->discards_supported) + return 1; + if (ti->type->iterate_devices && ti->type->iterate_devices(ti, device_discard_capable, NULL)) return 1; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 32a4423710f5..4427e0454051 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -191,6 +191,12 @@ struct dm_target { /* Used to provide an error string from the ctr */ char *error; + + /* + * Set if this target needs to receive discards regardless of + * whether or not its underlying devices have support. + */ + unsigned discards_supported:1; }; /* Each target can link one of these into the table */ |