Hi Jens, current blk_submit_bio can call into the bio splitting code without q_usage_counter held, which can lead to inconsistent limits beeing applied for drivers that change the limits at runtime. The first patch in the series is a small comment and naming cleanup, and the second one ensures we always hold q_usage_counter before even entering blk_mq_submit_bio. Diffstat: blk-core.c | 14 +++++++++----- blk-mq.c | 59 ++++++++++++++++++++++++++++------------------------------- blk-mq.h | 2 +- 3 files changed, 38 insertions(+), 37 deletions(-)