diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 49da55c1528a..8c2a000cf3f5 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1698,6 +1698,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) } ti->num_flush_requests = 1; + ti->discard_zeroes_data_unsupported = 1; + return 0; bad: diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 322669807077..bc04518e9d8b 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1283,6 +1283,22 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned flush) return 0; } +static bool dm_table_discard_zeroes_data(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i = 0; + + /* Ensure that all targets supports discard_zeroes_data. */ + while (i < dm_table_get_num_targets(t)) { + ti = dm_table_get_target(t, i++); + + if (ti->discard_zeroes_data_unsupported) + return 0; + } + + return 1; +} + void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1305,6 +1321,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } blk_queue_flush(q, flush); + if (!dm_table_discard_zeroes_data(t)) + q->limits.discard_zeroes_data = 0; + dm_table_set_integrity(t); /* diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 3fa1f3d90ce0..99e3e50b5c57 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -197,6 +197,11 @@ struct dm_target { * whether or not its underlying devices have support. */ unsigned discards_supported:1; + + /* + * Set if this target does not return zeroes on discarded blocks. + */ + unsigned discard_zeroes_data_unsupported:1; }; /* Each target can link one of these into the table */