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| author | Jens Axboe <axboe@kernel.dk> | 2020-09-13 14:38:30 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-09-14 10:22:15 -0600 |
| commit | 6200b0ae4ea28a4bfd8eb434e33e6201b7a6a282 (patch) | |
| tree | 030f91c1bd13d622e75f8b0f7b58bc141aeb15c5 | |
| parent | 87ceb6a6b81eca000911403446d4c6043b4e4f82 (diff) | |
| download | linux-6200b0ae4ea28a4bfd8eb434e33e6201b7a6a282.tar.bz2 | |
io_uring: don't run task work on an exiting task
This isn't safe, and isn't needed either. We are guaranteed that any
work we queue is on a live task (and will be run), or it goes to
our backup io-wq threads if the task is exiting.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 01756a131be6..a29c8913b1f0 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1753,6 +1753,9 @@ static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb, struct io_ring_ctx *ctx = req->ctx; int ret, notify; + if (tsk->flags & PF_EXITING) + return -ESRCH; + /* * SQPOLL kernel thread doesn't need notification, just a wakeup. For * all other cases, use TWA_SIGNAL unconditionally to ensure we're @@ -2012,6 +2015,12 @@ 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(); @@ -8184,6 +8193,8 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, /* cancel this request, or head link requests */ io_attempt_cancel(ctx, cancel_req); io_put_req(cancel_req); + /* cancellations _may_ trigger task work */ + io_run_task_work(); schedule(); finish_wait(&ctx->inflight_wait, &wait); } |