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| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-04-08 01:54:42 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-04-08 13:33:17 -0600 |
| commit | c60eb049f4a19ddddcd3ee97a9c79ab8066a6a03 (patch) | |
| tree | 925912804184a6403646e2cee326046d43e1aece /fs/io-wq.c | |
| parent | 9728463737db027557e8ba315cbbca6b81122c04 (diff) | |
| download | lwn-c60eb049f4a19ddddcd3ee97a9c79ab8066a6a03.tar.gz lwn-c60eb049f4a19ddddcd3ee97a9c79ab8066a6a03.zip | |
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>
Diffstat (limited to 'fs/io-wq.c')
| -rw-r--r-- | fs/io-wq.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c index 433c4d3c3c1c..4eba531bea5a 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -415,6 +415,7 @@ static void io_worker_handle_work(struct io_worker *worker) { struct io_wqe *wqe = worker->wqe; struct io_wq *wq = wqe->wq; + bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state); do { struct io_wq_work *work; @@ -444,6 +445,9 @@ get_next: unsigned int hash = io_get_work_hash(work); next_hashed = wq_next_work(work); + + if (unlikely(do_kill) && (work->flags & IO_WQ_WORK_UNBOUND)) + work->flags |= IO_WQ_WORK_CANCEL; wq->do_work(work); io_assign_current_work(worker, NULL); |