Commit 7880174e authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/tctx: clean up __io_uring_add_tctx_node() error handling 



Refactor __io_uring_add_tctx_node() so that on error it never leaves
current->io_uring pointing at a half-setup tctx. This moves the
assignment of current->io_uring to the end of the function post any
failure points.

Separate out the node installation into io_tctx_install_node() to
further clean this up.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2c453a42

io_uring/tctx.c

+40 −20
Original line number Diff line number Diff line
@@ -108,10 +108,37 @@ __cold struct io_uring_task *io_uring_alloc_task_context(struct task_struct *tas 
	return tctx;

}



static int io_tctx_install_node(struct io_ring_ctx *ctx,

				struct io_uring_task *tctx)

{

	struct io_tctx_node *node;

	int ret;



	if (xa_load(&tctx->xa, (unsigned long)ctx))

		return 0;



	node = kmalloc_obj(*node);

	if (!node)

		return -ENOMEM;

	node->ctx = ctx;

	node->task = current;



	ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx,

				node, GFP_KERNEL));

	if (ret) {

		kfree(node);

		return ret;

	}



	mutex_lock(&ctx->tctx_lock);

	list_add(&node->ctx_node, &ctx->tctx_list);

	mutex_unlock(&ctx->tctx_lock);

	return 0;

}



int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)

{

	struct io_uring_task *tctx = current->io_uring;

	struct io_tctx_node *node;

	int ret;



	if (unlikely(!tctx)) {
@@ -119,14 +146,13 @@ int __io_uring_add_tctx_node(struct io_ring_ctx *ctx) 
		if (IS_ERR(tctx))

			return PTR_ERR(tctx);



		current->io_uring = tctx;

		if (ctx->int_flags & IO_RING_F_IOWQ_LIMITS_SET) {

			unsigned int limits[2] = { ctx->iowq_limits[0],

						   ctx->iowq_limits[1], };



			ret = io_wq_max_workers(tctx->io_wq, limits);

			if (ret)

				return ret;

				goto err_free;

		}

	}
@@ -137,25 +163,19 @@ int __io_uring_add_tctx_node(struct io_ring_ctx *ctx) 
	 */

	if (tctx->io_wq)

		io_wq_set_exit_on_idle(tctx->io_wq, false);

	if (!xa_load(&tctx->xa, (unsigned long)ctx)) {

		node = kmalloc_obj(*node);

		if (!node)

			return -ENOMEM;

		node->ctx = ctx;

		node->task = current;



		ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx,

					node, GFP_KERNEL));

		if (ret) {

			kfree(node);

			return ret;

	ret = io_tctx_install_node(ctx, tctx);

	if (!ret) {

		current->io_uring = tctx;

		return 0;

	}



		mutex_lock(&ctx->tctx_lock);

		list_add(&node->ctx_node, &ctx->tctx_list);

		mutex_unlock(&ctx->tctx_lock);

	if (!current->io_uring) {

err_free:

		io_wq_put_and_exit(tctx->io_wq);

		percpu_counter_destroy(&tctx->inflight);

		kfree(tctx);

	}

	return 0;

	return ret;

}



int __io_uring_add_tctx_node_from_submit(struct io_ring_ctx *ctx)