Hi Jens, One of the consequences of the switch to blk-mq is that generic_make_request() calls, a function called by submit_bio(), must be protected by a blk_queue_enter() / blk_queue_exit() pair to avoid that the block-cgroup functions called by generic_make_request() trigger a race condition. This patch series makes the kernel report a warning if that race condition is hit and also adds the necessary protection in submit_bio(). Please consider these patches for kernel v5.4. Thanks, Bart. Bart Van Assche (2): block: Verify whether blk_queue_enter() is used when necessary block: Fix a race condition in submit_bio() block/blk-cgroup.c | 2 ++ block/blk-core.c | 34 +++++++++++++++++++++++++++++++++- include/linux/blk-cgroup.h | 2 ++ include/linux/blkdev.h | 8 ++++++++ 4 files changed, 45 insertions(+), 1 deletion(-) -- 2.22.0.709.g102302147b-goog
