Commit 4c259327 authored by Mike Snitzer's avatar Mike Snitzer Committed by Alasdair G Kergon

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: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 139f37f5
...@@ -1346,7 +1346,8 @@ bool dm_table_supports_discards(struct dm_table *t) ...@@ -1346,7 +1346,8 @@ bool dm_table_supports_discards(struct dm_table *t)
return 0; 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 * t->devices includes internal dm devices such as mirror logs
* so we need to use iterate_devices here, which targets * so we need to use iterate_devices here, which targets
* supporting discard must provide. * supporting discard must provide.
...@@ -1354,6 +1355,9 @@ bool dm_table_supports_discards(struct dm_table *t) ...@@ -1354,6 +1355,9 @@ bool dm_table_supports_discards(struct dm_table *t)
while (i < dm_table_get_num_targets(t)) { while (i < dm_table_get_num_targets(t)) {
ti = dm_table_get_target(t, i++); ti = dm_table_get_target(t, i++);
if (ti->discards_supported)
return 1;
if (ti->type->iterate_devices && if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti, device_discard_capable, NULL)) ti->type->iterate_devices(ti, device_discard_capable, NULL))
return 1; return 1;
......
...@@ -191,6 +191,12 @@ struct dm_target { ...@@ -191,6 +191,12 @@ struct dm_target {
/* Used to provide an error string from the ctr */ /* Used to provide an error string from the ctr */
char *error; 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 */ /* Each target can link one of these into the table */
......
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