dm table: allow upgrade from bio-based to specialized bio-based variant
In practice this is really only meaningful in the context of the DM
multipath target (which uses dm_table_set_type() to set the type of
device DM should create via its "queue_mode" option).
So this change allows a DM multipath device with "queue_mode bio" to be
upgraded from DM_TYPE_BIO_BASED to DM_TYPE_NVME_BIO_BASED -- iff the
underlying device(s) are NVMe.
DM_TYPE_NVME_BIO_BASED is just a DM core implementation detail that
allows for NVMe-specific optimizations (e.g. use direct_make_request
instead of generic_make_request). If in the future there is no benefit
or need to distinguish NVMe vs not: then it will be removed.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 30b3294..7eb3e2a 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -942,17 +942,12 @@ static int dm_table_determine_type(struct dm_table *t)
if (t->type != DM_TYPE_NONE) {
/* target already set the table's type */
- if (t->type == DM_TYPE_BIO_BASED)
- return 0;
- else if (t->type == DM_TYPE_NVME_BIO_BASED) {
- if (!dm_table_does_not_support_partial_completion(t)) {
- DMERR("nvme bio-based is only possible with devices"
- " that don't support partial completion");
- return -EINVAL;
- }
- /* Fallthru, also verify all devices are blk-mq */
+ if (t->type == DM_TYPE_BIO_BASED) {
+ /* possibly upgrade to a variant of bio-based */
+ goto verify_bio_based;
}
BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
+ BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
goto verify_rq_based;
}
@@ -985,6 +980,7 @@ static int dm_table_determine_type(struct dm_table *t)
}
if (bio_based) {
+verify_bio_based:
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
if (dm_table_supports_dax(t) ||
