kernel/io_uring: cancel io_uring before task works

For cancelling io_uring requests it needs either to be able to run
currently enqueued task_works or having it shut down by that moment.
Otherwise io_uring_cancel_files() may be waiting for requests that won't
ever complete.

Go with the first way and do cancellations before setting PF_EXITING and
so before putting the task_work infrastructure into a transition state
where task_work_run() would better not be called.

Cc: stable@vger.kernel.org # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-12-30 21:34:16 +00:00 коммит произвёл Jens Axboe
Родитель 1ffc54220c
Коммит b1b6b5a30d
2 изменённых файлов: 2 добавлений и 2 удалений

Просмотреть файл

@ -21,7 +21,6 @@
#include <linux/rcupdate.h>
#include <linux/close_range.h>
#include <net/sock.h>
#include <linux/io_uring.h>
unsigned int sysctl_nr_open __read_mostly = 1024*1024;
unsigned int sysctl_nr_open_min = BITS_PER_LONG;
@ -428,7 +427,6 @@ void exit_files(struct task_struct *tsk)
struct files_struct * files = tsk->files;
if (files) {
io_uring_files_cancel(files);
task_lock(tsk);
tsk->files = NULL;
task_unlock(tsk);

Просмотреть файл

@ -63,6 +63,7 @@
#include <linux/random.h>
#include <linux/rcuwait.h>
#include <linux/compat.h>
#include <linux/io_uring.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
@ -776,6 +777,7 @@ void __noreturn do_exit(long code)
schedule();
}
io_uring_files_cancel(tsk->files);
exit_signals(tsk); /* sets PF_EXITING */
/* sync mm's RSS info before statistics gathering */