From c934edadcc7a64e399942ae34b912939057a77a7 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 5 Mar 2018 15:26:06 -0500 Subject: [PATCH] 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 --- drivers/md/dm-table.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) 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) || -- 2.7.4