ensure q_usage_counter is held over bio splits

Christoph Hellwig
2024-01-11T13:57:11Z

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(-)