Commit 73b25d3b authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: deduplicate SCM accounting 



Merge io_sqe_file_register() and io_sqe_file_register(). The only
real difference left between them is from where we get an skb.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dddda3039c71fcbec24b3465cbe8c7e7ae7bb0e8.1649334991.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e390510a

fs/io_uring.c

+40 −67
Original line number Diff line number Diff line
@@ -8601,7 +8601,6 @@ static struct io_sq_data *io_get_sq_data(struct io_uring_params *p, 
	return sqd;

}



#if defined(CONFIG_UNIX)

/*

 * Ensure the UNIX gc is aware of our file set, so we are certain that

 * the io_uring can be safely unregistered on process exit, even if we have
@@ -8609,12 +8608,31 @@ static struct io_sq_data *io_get_sq_data(struct io_uring_params *p, 
 * files because otherwise they can't form a loop and so are not interesting

 * for GC.

 */

static int __io_sqe_files_scm(struct io_ring_ctx *ctx, struct file *file)

static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file)

{

#if defined(CONFIG_UNIX)

	struct sock *sk = ctx->ring_sock->sk;

	struct sk_buff_head *head = &sk->sk_receive_queue;

	struct scm_fp_list *fpl;

	struct sk_buff *skb;



	if (likely(!io_file_need_scm(file)))

		return 0;



	/*

	 * See if we can merge this file into an existing skb SCM_RIGHTS

	 * file set. If there's no room, fall back to allocating a new skb

	 * and filling it in.

	 */

	spin_lock_irq(&head->lock);

	skb = skb_peek(head);

	if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)

		__skb_unlink(skb, head);

	else

		skb = NULL;

	spin_unlock_irq(&head->lock);



	if (!skb) {

		fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);

		if (!fpl)

			return -ENOMEM;
@@ -8625,22 +8643,24 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, struct file *file) 
			return -ENOMEM;

		}



	skb->sk = sk;



		fpl->user = get_uid(current_user());

	fpl->fp[0] = get_file(file);

	unix_inflight(fpl->user, file);



		fpl->max = SCM_MAX_FD;

	fpl->count = 1;

		fpl->count = 0;



		UNIXCB(skb).fp = fpl;

		skb->sk = sk;

		skb->destructor = unix_destruct_scm;

		refcount_add(skb->truesize, &sk->sk_wmem_alloc);

	skb_queue_head(&sk->sk_receive_queue, skb);

	}



	fpl = UNIXCB(skb).fp;

	fpl->fp[fpl->count++] = get_file(file);

	unix_inflight(fpl->user, file);

	skb_queue_head(head, skb);

	fput(file);

#endif

	return 0;

}

#endif



static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)

{
@@ -8760,8 +8780,6 @@ static void io_rsrc_put_work(struct work_struct *work) 
	}

}



static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file);



static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,

				 unsigned nr_args, u64 __user *tags)

{
@@ -8839,51 +8857,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, 
	return ret;

}



static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file)

{

#if defined(CONFIG_UNIX)

	struct sock *sock = ctx->ring_sock->sk;

	struct sk_buff_head *head = &sock->sk_receive_queue;

	struct sk_buff *skb;



	if (!io_file_need_scm(file))

		return 0;



	/*

	 * See if we can merge this file into an existing skb SCM_RIGHTS

	 * file set. If there's no room, fall back to allocating a new skb

	 * and filling it in.

	 */

	spin_lock_irq(&head->lock);

	skb = skb_peek(head);

	if (skb) {

		struct scm_fp_list *fpl = UNIXCB(skb).fp;



		if (fpl->count < SCM_MAX_FD) {

			__skb_unlink(skb, head);

			spin_unlock_irq(&head->lock);

			fpl->fp[fpl->count] = get_file(file);

			unix_inflight(fpl->user, fpl->fp[fpl->count]);

			fpl->count++;

			spin_lock_irq(&head->lock);

			__skb_queue_head(head, skb);

		} else {

			skb = NULL;

		}

	}

	spin_unlock_irq(&head->lock);



	if (skb) {

		fput(file);

		return 0;

	}



	return __io_sqe_files_scm(ctx, file);

#else

	return 0;

#endif

}



static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx,

				 struct io_rsrc_node *node, void *rsrc)

{