Hi, blk-mq may schedule to call queue's complete function on remote CPU via IPI, but never provide any way to synchronize the request's complete fn. In some driver's EH(such as NVMe), hardware queue's resource may be freed & re-allocated. If the completed request's complete fn is run finally after the hardware queue's resource is released, kernel crash will be triggered. Fixes this issue by waitting until completed req's complete fn is run. Thanks, Ming Ming Lei (5): blk-mq: introduce blk_mq_request_completed() blk-mq: introduce blk_mq_tagset_wait_completed_request() nvme: don't abort completed request in nvme_cancel_request nvme: wait until all completed request's complete fn is called blk-mq: remove blk_mq_complete_request_sync block/blk-mq-tag.c | 32 ++++++++++++++++++++++++++++++++ block/blk-mq.c | 13 ++++++------- drivers/nvme/host/core.c | 6 +++++- drivers/nvme/host/pci.c | 2 ++ drivers/nvme/host/rdma.c | 8 ++++++-- drivers/nvme/host/tcp.c | 8 ++++++-- drivers/nvme/target/loop.c | 2 ++ include/linux/blk-mq.h | 3 ++- 8 files changed, 61 insertions(+), 13 deletions(-) Cc: Max Gurtovoy <maxg@xxxxxxxxxxxx> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx> Cc: Keith Busch <keith.busch@xxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> -- 2.20.1
