io-wq: cancel unbounded works on io-wq destroy
WARNING: CPU: 5 PID: 227 at fs/io_uring.c:8578 io_ring_exit_work+0xe6/0x470
RIP: 0010:io_ring_exit_work+0xe6/0x470
Call Trace:
process_one_work+0x206/0x400
worker_thread+0x4a/0x3d0
kthread+0x129/0x170
ret_from_fork+0x22/0x30
INFO: task lfs-openat:2359 blocked for more than 245 seconds.
task:lfs-openat state:D stack: 0 pid: 2359 ppid: 1 flags:0x00000004
Call Trace:
...
wait_for_completion+0x8b/0xf0
io_wq_destroy_manager+0x24/0x60
io_wq_put_and_exit+0x18/0x30
io_uring_clean_tctx+0x76/0xa0
__io_uring_files_cancel+0x1b9/0x2e0
do_exit+0xc0/0xb40
...
Even after io-wq destroy has been issued io-wq worker threads will
continue executing all left work items as usual, and may hang waiting
for I/O that won't ever complete (aka unbounded).
[<0>] pipe_read+0x306/0x450
[<0>] io_iter_do_read+0x1e/0x40
[<0>] io_read+0xd5/0x330
[<0>] io_issue_sqe+0xd21/0x18a0
[<0>] io_wq_submit_work+0x6c/0x140
[<0>] io_worker_handle_work+0x17d/0x400
[<0>] io_wqe_worker+0x2c0/0x330
[<0>] ret_from_fork+0x22/0x30
Cancel all unbounded I/O instead of executing them. This changes the
user visible behaviour, but that's inevitable as io-wq is not per task.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/cd4b543154154cba055cf86f351441c2174d7f71.1617842918.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 file changed
