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| author | Jens Axboe <axboe@kernel.dk> | 2021-03-09 16:32:13 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-03-10 07:28:43 -0700 |
| commit | e8f98f24549d62cc54bf608c815904a56d4437bc (patch) | |
| tree | a545de836d886a769bd0c68c3df1248e1c15135c | |
| parent | 5199328a0d415b3e372633096b1b92f36b8ac9e5 (diff) | |
| download | linux-e8f98f24549d62cc54bf608c815904a56d4437bc.tar.gz | |
io_uring: always wait for sqd exited when stopping SQPOLL thread
We have a tiny race where io_put_sq_data() calls io_sq_thead_stop() and finds the thread gone, but the thread has indeed not fully exited or called complete() yet. Close it up by always having io_sq_thread_stop() wait on completion of the exit event. Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 6325f32ef6a3..62f998bf2ce8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7079,12 +7079,9 @@ static void io_sq_thread_stop(struct io_sq_data *sqd) if (test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state)) return; down_write(&sqd->rw_lock); - if (!sqd->thread) { - up_write(&sqd->rw_lock); - return; - } set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); - wake_up_process(sqd->thread); + if (sqd->thread) + wake_up_process(sqd->thread); up_write(&sqd->rw_lock); wait_for_completion(&sqd->exited); } @@ -7849,9 +7846,9 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, ret = -EINVAL; if (cpu >= nr_cpu_ids) - goto err; + goto err_sqpoll; if (!cpu_online(cpu)) - goto err; + goto err_sqpoll; sqd->sq_cpu = cpu; } else { @@ -7862,7 +7859,7 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE); if (IS_ERR(tsk)) { ret = PTR_ERR(tsk); - goto err; + goto err_sqpoll; } sqd->thread = tsk; @@ -7881,6 +7878,9 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, err: io_sq_thread_finish(ctx); return ret; +err_sqpoll: + complete(&ctx->sq_data->exited); + goto err; } static inline void __io_unaccount_mem(struct user_struct *user, |