The code to stack blk-mq drivers is only used by dm-multipath, and will preferably stay that way. Make it optional and only selected by device mapper, so that the buildbots more easily catch abuses like the one that slipped in in the ufs driver in the last merged window. Another positive side effects is that kernel builds without device mapper shrink a little bit as well. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- block/Kconfig | 3 +++ block/blk-mq.c | 2 ++ drivers/md/Kconfig | 1 + 3 files changed, 6 insertions(+) diff --git a/block/Kconfig b/block/Kconfig index 205f8d01c6952..168b873eb666d 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -230,6 +230,9 @@ config BLK_PM config BLOCK_HOLDER_DEPRECATED bool +config BLK_MQ_STACKING + bool + source "block/Kconfig.iosched" endif # BLOCK diff --git a/block/blk-mq.c b/block/blk-mq.c index 6c59ffe765fde..db62d34afb637 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2840,6 +2840,7 @@ void blk_mq_submit_bio(struct bio *bio) blk_mq_try_issue_directly(rq->mq_hctx, rq)); } +#ifdef CONFIG_BLK_MQ_STACKING /** * blk_cloned_rq_check_limits - Helper function to check a cloned request * for the new queue limits @@ -3017,6 +3018,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, return -ENOMEM; } EXPORT_SYMBOL_GPL(blk_rq_prep_clone); +#endif /* CONFIG_BLK_MQ_STACKING */ /* * Steal bios from a request and add them to a bio list. diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index b5ea378e66cb1..998a5cfdbc4e9 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -204,6 +204,7 @@ config BLK_DEV_DM tristate "Device mapper support" select BLOCK_HOLDER_DEPRECATED if SYSFS select BLK_DEV_DM_BUILTIN + select BLK_MQ_STACKING depends on DAX || DAX=n help Device-mapper is a low level volume manager. It works by allowing -- 2.30.2