io_uring/rsrc: extract SCM file put helper

SCM file accounting is a slow path and is only used for UNIX files.
Extract a helper out of io_rsrc_file_put() that does the SCM
unaccounting.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/58cc7bffc2ee96bec8c2b89274a51febcbfa5556.1681210788.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/rsrc.c

@@ -832,20 +832,14 @@ int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
 	return 0;
 }
 
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+static __cold void io_rsrc_file_scm_put(struct io_ring_ctx *ctx, struct file *file)
 {
-	struct file *file = prsrc->file;
 #if defined(CONFIG_UNIX)
 	struct sock *sock = ctx->ring_sock->sk;
 	struct sk_buff_head list, *head = &sock->sk_receive_queue;
 	struct sk_buff *skb;
 	int i;
 
-	if (!io_file_need_scm(file)) {
-		fput(file);
-		return;
-	}
-
 	__skb_queue_head_init(&list);
 
 	/*
@@ -895,11 +889,19 @@ static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
 			__skb_queue_tail(head, skb);
 		spin_unlock_irq(&head->lock);
 	}
-#else
-	fput(file);
 #endif
 }
 
+static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
+{
+	struct file *file = prsrc->file;
+
+	if (likely(!io_file_need_scm(file)))
+		fput(file);
+	else
+		io_rsrc_file_scm_put(ctx, file);
+}
+
 int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 			  unsigned nr_args, u64 __user *tags)
 {