From: Pavel Begunkov <[email protected]>
To: Jens Axboe <[email protected]>, [email protected]
Subject: [PATCH 3/3] io_uring: fix cancellation hangs
Date: Sun, 20 Dec 2020 13:21:45 +0000 [thread overview]
Message-ID: <f06b936c1a537828f4055a3673d05e82c846d77c.1608469706.git.asml.silence@gmail.com> (raw)
In-Reply-To: <[email protected]>
We may enter files cancellation with requests that we want to cancel and
that are currently enqueued as task_work. However, before that happens
do_exit() sets PF_EXITING, disabling io_run_task_work() and so locking
up cancellation.
Also, if run between setting PF_EXITING and exit_task_work(), as the
case exit_files() and so io_uring cancellation, task_work_add() might
actually enqueue more task works.
Signed-off-by: Pavel Begunkov <[email protected]>
---
fs/io_uring.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 30edf47a8f1a..941fe9b64fd9 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2357,12 +2357,6 @@ static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
static inline bool io_run_task_work(void)
{
- /*
- * Not safe to run on exiting task, and the task_work handling will
- * not add work to such a task.
- */
- if (unlikely(current->flags & PF_EXITING))
- return false;
if (current->task_works) {
__set_current_state(TASK_RUNNING);
task_work_run();
--
2.24.0
next prev parent reply other threads:[~2020-12-20 13:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-20 13:21 [PATCH 0/3] task/files cancellation fixes Pavel Begunkov
2020-12-20 13:21 ` [PATCH 1/3] io_uring: always progress task_work on task cancel Pavel Begunkov
2020-12-20 13:21 ` [PATCH 2/3] io_uring: end waiting before task cancel attempts Pavel Begunkov
2020-12-20 13:21 ` Pavel Begunkov [this message]
2020-12-20 18:01 ` [PATCH 0/3] task/files cancellation fixes Pavel Begunkov
2020-12-20 18:05 ` Jens Axboe
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