
static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
{
	struct io_sq_data *sq = NULL;
	bool has_lock;
	int i;

	/*
	 * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
	 * since fdinfo case grabs it in the opposite direction of normal use
	 * cases. If we fail to get the lock, we just don't iterate any
	 * structures that could be going away outside the io_uring mutex.
	 */
	has_lock = mutex_trylock(&ctx->uring_lock);

	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
		sq = ctx->sq_data;
		if (!sq->thread)
			sq = NULL;
	}

	seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
	seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
		struct file *f = *io_fixed_file_slot(ctx->file_data, i);

		if (f)
			seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
		else
			seq_printf(m, "%5u: <none>\n", i);
	}
	seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
	for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
		struct io_mapped_ubuf *buf = &ctx->user_bufs[i];

		seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
						(unsigned int) buf->len);
	}
	if (has_lock && !idr_is_empty(&ctx->personality_idr)) {
		seq_printf(m, "Personalities:\n");
		idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
	}
	seq_printf(m, "PollList:\n");
	spin_lock_irq(&ctx->completion_lock);
	for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
		struct hlist_head *list = &ctx->cancel_hash[i];
		struct io_kiocb *req;

		hlist_for_each_entry(req, list, hash_node)
			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
					req->task->task_works != NULL);
	}
	spin_unlock_irq(&ctx->completion_lock);
	if (has_lock)
		mutex_unlock(&ctx->uring_lock);

static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
{
	struct io_sq_data *sq = NULL;
	bool has_lock;
	int i;

	 
	has_lock = mutex_trylock(&ctx->uring_lock);

	if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
		sq = ctx->sq_data;
		if (!sq->thread)
			sq = NULL;
	}

	seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
	seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
	seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
	for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
		struct file *f = *io_fixed_file_slot(ctx->file_data, i);

		if (f)
			seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
		else
			seq_printf(m, "%5u: <none>\n", i);
	}
	seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
	for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
		struct io_mapped_ubuf *buf = &ctx->user_bufs[i];

		seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
						(unsigned int) buf->len);
	}
	if (has_lock && !idr_is_empty(&ctx->personality_idr)) {
		seq_printf(m, "Personalities:\n");
		idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
	}
	seq_printf(m, "PollList:\n");
	spin_lock_irq(&ctx->completion_lock);
	for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
		struct hlist_head *list = &ctx->cancel_hash[i];
		struct io_kiocb *req;

		hlist_for_each_entry(req, list, hash_node)
			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
					req->task->task_works != NULL);
	}
	spin_unlock_irq(&ctx->completion_lock);
	if (has_lock)
		mutex_unlock(&ctx->uring_lock);