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| author | Pavel Begunkov <asml.silence@gmail.com> | 2020-07-24 20:07:21 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-07-24 12:51:33 -0600 |
| commit | 4ae6dbd683860b9edc254ea8acf5e04b5ae242e5 (patch) | |
| tree | 8e92fab9956b4ede6cc6751f6c5a543da8877f52 /fs | |
| parent | d5e16d8e23825304c6a9945116cc6b6f8d51f28c (diff) | |
| download | lwn-4ae6dbd683860b9edc254ea8acf5e04b5ae242e5.tar.gz lwn-4ae6dbd683860b9edc254ea8acf5e04b5ae242e5.zip | |
io_uring: fix lockup in io_fail_links()
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: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io_uring.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 98e8079e67e7..493e5047e67c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4199,10 +4199,9 @@ static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt) hash_del(&req->hash_node); io_poll_complete(req, req->result, 0); - req->flags |= REQ_F_COMP_LOCKED; - io_put_req_find_next(req, nxt); spin_unlock_irq(&ctx->completion_lock); + io_put_req_find_next(req, nxt); io_cqring_ev_posted(ctx); } |