io_uring: move dropping of files into separate helper

No functional changes in this patch, prep patch for grabbing references
to the files_struct.
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -5648,6 +5648,20 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	return -EIOCBQUEUED;
 }
 
+static void io_req_drop_files(struct io_kiocb *req)
+{
+	struct io_ring_ctx *ctx = req->ctx;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctx->inflight_lock, flags);
+	list_del(&req->inflight_entry);
+	if (waitqueue_active(&ctx->inflight_wait))
+		wake_up(&ctx->inflight_wait);
+	spin_unlock_irqrestore(&ctx->inflight_lock, flags);
+	req->flags &= ~REQ_F_INFLIGHT;
+	req->work.files = NULL;
+}
+
 static void __io_clean_op(struct io_kiocb *req)
 {
 	struct io_async_ctx *io = req->io;
@@ -5697,17 +5711,8 @@ static void __io_clean_op(struct io_kiocb *req)
 		req->flags &= ~REQ_F_NEED_CLEANUP;
 	}
 
-	if (req->flags & REQ_F_INFLIGHT) {
-		struct io_ring_ctx *ctx = req->ctx;
-		unsigned long flags;
-
-		spin_lock_irqsave(&ctx->inflight_lock, flags);
-		list_del(&req->inflight_entry);
-		if (waitqueue_active(&ctx->inflight_wait))
-			wake_up(&ctx->inflight_wait);
-		spin_unlock_irqrestore(&ctx->inflight_lock, flags);
-		req->flags &= ~REQ_F_INFLIGHT;
-	}
+	if (req->flags & REQ_F_INFLIGHT)
+		io_req_drop_files(req);
 }
 
 static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,