linux/io_uring/tctx.h

// SPDX-License-Identifier: GPL-2.0

#include <linux/llist.h>

/*
 * Arbitrary limit, can be raised if need be
 */
#define IO_RINGFD_REG_MAX 16

struct io_uring_task {
	/* submission side */
	int				cached_refs;
	const struct io_ring_ctx 	*last;
	struct io_wq			*io_wq;
	struct file			*registered_rings[IO_RINGFD_REG_MAX];

	struct xarray			xa;
	struct wait_queue_head		wait;
	atomic_t			in_idle;
	atomic_t			inflight_tracked;
	struct percpu_counter		inflight;

	struct { /* task_work */
		struct llist_head	task_list;
		struct callback_head	task_work;
	} ____cacheline_aligned_in_smp;
};

struct io_tctx_node {
	struct list_head	ctx_node;
	struct task_struct	*task;
	struct io_ring_ctx	*ctx;
};

int io_uring_alloc_task_context(struct task_struct *task,
				struct io_ring_ctx *ctx);
void io_uring_del_tctx_node(unsigned long index);
int __io_uring_add_tctx_node(struct io_ring_ctx *ctx, bool submitter);
void io_uring_clean_tctx(struct io_uring_task *tctx);

void io_uring_unreg_ringfd(void);
int io_ringfd_register(struct io_ring_ctx *ctx, void __user *__arg,
		       unsigned nr_args);
int io_ringfd_unregister(struct io_ring_ctx *ctx, void __user *__arg,
			 unsigned nr_args);

/*
 * Note that this task has used io_uring. We use it for cancelation purposes.
 */
static inline int io_uring_add_tctx_node(struct io_ring_ctx *ctx)
{
	struct io_uring_task *tctx = current->io_uring;

	if (likely(tctx && tctx->last == ctx))
		return 0;
	return __io_uring_add_tctx_node(ctx, true);
}