Hi Jens, The only block driver for which the .map_queues() callback can fail is null_blk. Since most blk_mq_map_queues() callers ignore the return value of this function, modify the null_blk driver such that its .map_queues() callback does not fail and change the blk_mq_map_queues() return type into void. Please consider this patch series for the next merge window. Thanks, Bart. Changes compared to v1: - Combined all patches except one into a single patch as requested by Christoph. Bart Van Assche (2): null_blk: Modify the behavior of null_map_queues() block: Change the return type of blk_mq_map_queues() into void block/blk-mq-cpumap.c | 4 +--- block/blk-mq-pci.c | 7 +++---- block/blk-mq-rdma.c | 6 +++--- block/blk-mq-virtio.c | 7 ++++--- block/blk-mq.c | 10 ++++------ drivers/block/null_blk/main.c | 8 ++++---- drivers/block/rnbd/rnbd-clt.c | 4 +--- drivers/block/virtio_blk.c | 4 +--- drivers/nvme/host/fc.c | 3 +-- drivers/nvme/host/pci.c | 4 +--- drivers/nvme/host/rdma.c | 4 +--- drivers/nvme/host/tcp.c | 4 +--- drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 5 +---- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 5 ++--- drivers/scsi/megaraid/megaraid_sas_base.c | 6 ++---- drivers/scsi/mpi3mr/mpi3mr_os.c | 5 +---- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 5 ++--- drivers/scsi/pm8001/pm8001_init.c | 2 +- drivers/scsi/qla2xxx/qla_nvme.c | 6 +----- drivers/scsi/qla2xxx/qla_os.c | 10 ++++------ drivers/scsi/qlogicpti.c | 6 ++---- drivers/scsi/scsi_debug.c | 7 ++----- drivers/scsi/scsi_lib.c | 4 ++-- drivers/scsi/smartpqi/smartpqi_init.c | 6 +++--- drivers/scsi/virtio_scsi.c | 4 ++-- drivers/ufs/core/ufshcd.c | 9 +++------ include/linux/blk-mq-pci.h | 4 ++-- include/linux/blk-mq-rdma.h | 2 +- include/linux/blk-mq-virtio.h | 2 +- include/linux/blk-mq.h | 4 ++-- include/scsi/scsi_host.h | 2 +- 31 files changed, 60 insertions(+), 99 deletions(-)