Commit 1b00764f authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: cancel reqs of all iowq's on ring exit 



io_ring_exit_work() have to cancel all requests, including those staying
in io-wq, however it tries only cancellation of current tctx, which is
NULL. If we've got task==NULL, use the ctx-to-tctx map to go over all
tctx/io-wq and try cancellations on them.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b5bb3a24

fs/io_uring.c

+39 −3
Original line number Diff line number Diff line
@@ -8688,19 +8688,55 @@ static void io_cancel_defer_files(struct io_ring_ctx *ctx, 
	}

}



static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)

{

	struct io_kiocb *req = container_of(work, struct io_kiocb, work);



	return req->ctx == data;

}



static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)

{

	struct io_tctx_node *node;

	enum io_wq_cancel cret;

	bool ret = false;



	mutex_lock(&ctx->uring_lock);

	list_for_each_entry(node, &ctx->tctx_list, ctx_node) {

		struct io_uring_task *tctx = node->task->io_uring;



		/*

		 * io_wq will stay alive while we hold uring_lock, because it's

		 * killed after ctx nodes, which requires to take the lock.

		 */

		if (!tctx || !tctx->io_wq)

			continue;

		cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true);

		ret |= (cret != IO_WQ_CANCEL_NOTFOUND);

	}

	mutex_unlock(&ctx->uring_lock);



	return ret;

}



static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,

					 struct task_struct *task,

					 struct files_struct *files)

{

	struct io_task_cancel cancel = { .task = task, .files = files, };

	struct task_struct *tctx_task = task ?: current;

	struct io_uring_task *tctx = tctx_task->io_uring;

	struct io_uring_task *tctx = task ? task->io_uring : NULL;



	while (1) {

		enum io_wq_cancel cret;

		bool ret = false;



		if (tctx && tctx->io_wq) {

		if (!task) {

			ret |= io_uring_try_cancel_iowq(ctx);

		} else if (tctx && tctx->io_wq) {

			/*

			 * Cancels requests of all rings, not only @ctx, but

			 * it's fine as the task is in exit/exec.

			 */

			cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb,

					       &cancel, true);

			ret |= (cret != IO_WQ_CANCEL_NOTFOUND);