• Pavel Begunkov's avatar
    io_uring: fix lockup in io_fail_links() · 4ae6dbd6
    Pavel Begunkov authored
    io_fail_links() doesn't consider REQ_F_COMP_LOCKED leading to nested
    spin_lock(completion_lock) and lockup.
    
    [  197.680409] rcu: INFO: rcu_preempt detected expedited stalls on
    	CPUs/tasks: { 6-... } 18239 jiffies s: 1421 root: 0x40/.
    [  197.680411] rcu: blocking rcu_node structures:
    [  197.680412] Task dump for CPU 6:
    [  197.680413] link-timeout    R  running task        0  1669
    	1 0x8000008a
    [  197.680414] Call Trace:
    [  197.680420]  ? io_req_find_next+0xa0/0x200
    [  197.680422]  ? io_put_req_find_next+0x2a/0x50
    [  197.680423]  ? io_poll_task_func+0xcf/0x140
    [  197.680425]  ? task_work_run+0x67/0xa0
    [  197.680426]  ? do_exit+0x35d/0xb70
    [  197.680429]  ? syscall_trace_enter+0x187/0x2c0
    [  197.680430]  ? do_group_exit+0x43/0xa0
    [  197.680448]  ? __x64_sys_exit_group+0x18/0x20
    [  197.680450]  ? do_syscall_64+0x52/0xa0
    [  197.680452]  ? entry_SYSCALL_64_after_hwframe+0x44/0xa9
    Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
    4ae6dbd6
io_uring.c 196 KB