This is a note to let you know that I've just added the patch titled
io_uring: unpark SQPOLL thread for cancelation
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-unpark-sqpoll-thread-for-cancelation.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Mar 10 01:03:15 PM CET 2021
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Wed, 10 Mar 2021 11:30:39 +0000
Subject: io_uring: unpark SQPOLL thread for cancelation
To: stable@xxxxxxxxxxxxxxx
Cc: Jens Axboe <axboe@xxxxxxxxx>, syzbot+695b03d82fa8e4901b06@xxxxxxxxxxxxxxxxxxxxxxxxx
Message-ID: <165b3785cd6e17ffea1e53dfab027b6f89684dde.1615375332.git.asml.silence@xxxxxxxxx>
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
commit 34343786ecc5ff493ca4d1f873b4386759ba52ee upstream
We park SQPOLL task before going into io_uring_cancel_files(), so the
task won't run task_works including those that might be important for
the cancellation passes. In this case it's io_poll_remove_one(), which
frees requests via io_put_req_deferred().
Unpark it for while waiting, it's ok as we disable submissions
beforehand, so no new requests will be generated.
INFO: task syz-executor893:8493 blocked for more than 143 seconds.
Call Trace:
context_switch kernel/sched/core.c:4327 [inline]
__schedule+0x90c/0x21a0 kernel/sched/core.c:5078
schedule+0xcf/0x270 kernel/sched/core.c:5157
io_uring_cancel_files fs/io_uring.c:8912 [inline]
io_uring_cancel_task_requests+0xe70/0x11a0 fs/io_uring.c:8979
__io_uring_files_cancel+0x110/0x1b0 fs/io_uring.c:9067
io_uring_files_cancel include/linux/io_uring.h:51 [inline]
do_exit+0x2fe/0x2ae0 kernel/exit.c:780
do_group_exit+0x125/0x310 kernel/exit.c:922
__do_sys_exit_group kernel/exit.c:933 [inline]
__se_sys_exit_group kernel/exit.c:931 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Cc: stable@xxxxxxxxxxxxxxx # 5.5+
Reported-by: syzbot+695b03d82fa8e4901b06@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8955,11 +8955,16 @@ static void io_uring_cancel_files(struct
break;
io_uring_try_cancel_requests(ctx, task, files);
+
+ if (ctx->sq_data)
+ io_sq_thread_unpark(ctx->sq_data);
prepare_to_wait(&task->io_uring->wait, &wait,
TASK_UNINTERRUPTIBLE);
if (inflight == io_uring_count_inflight(ctx, task, files))
schedule();
finish_wait(&task->io_uring->wait, &wait);
+ if (ctx->sq_data)
+ io_sq_thread_park(ctx->sq_data);
}
}
Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are
queue-5.11/io_uring-io-wq-kill-off-now-unused-io_wq_work_no_cancel.patch
queue-5.11/io_uring-get-rid-of-intermediate-ioring_op_close-stage.patch
queue-5.11/io_uring-fix-inconsistent-lock-state.patch
queue-5.11/fs-provide-locked-helper-variant-of-close_fd_get_file.patch
queue-5.11/io_uring-io-wq-return-2-step-work-swap-scheme.patch
queue-5.11/io_uring-deduplicate-core-cancellations-sequence.patch
queue-5.11/io_uring-unpark-sqpoll-thread-for-cancelation.patch
queue-5.11/io_uring-don-t-take-uring_lock-during-iowq-cancel.patch
queue-5.11/io_uring-deduplicate-failing-task_work_add.patch
