io_uring: inline io_cqring_mark_overflow()

There is only one user of it and the name is misleading, get rid of it
by inlining. By the way make overflow_flush's return value deduction
simpler.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1708,15 +1708,6 @@ static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
 		eventfd_signal(ctx->cq_ev_fd, 1);
 }
 
-static void io_cqring_mark_overflow(struct io_ring_ctx *ctx)
-{
-	if (list_empty(&ctx->cq_overflow_list)) {
-		clear_bit(0, &ctx->sq_check_overflow);
-		clear_bit(0, &ctx->cq_check_overflow);
-		ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
-	}
-}
-
 /* Returns true if there are no backlogged entries after the flush */
 static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
 				     struct task_struct *tsk,
@@ -1726,13 +1717,13 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
 	struct io_kiocb *req, *tmp;
 	struct io_uring_cqe *cqe;
 	unsigned long flags;
+	bool all_flushed;
 	LIST_HEAD(list);
 
 	if (!force && __io_cqring_events(ctx) == rings->cq_ring_entries)
 		return false;
 
 	spin_lock_irqsave(&ctx->completion_lock, flags);
-	cqe = NULL;
 	list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) {
 		if (!io_match_task(req, tsk, files))
 			continue;
@@ -1753,9 +1744,14 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
 		}
 	}
 
-	io_commit_cqring(ctx);
-	io_cqring_mark_overflow(ctx);
+	all_flushed = list_empty(&ctx->cq_overflow_list);
+	if (all_flushed) {
+		clear_bit(0, &ctx->sq_check_overflow);
+		clear_bit(0, &ctx->cq_check_overflow);
+		ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
+	}
 
+	io_commit_cqring(ctx);
 	spin_unlock_irqrestore(&ctx->completion_lock, flags);
 	io_cqring_ev_posted(ctx);
 
@@ -1765,7 +1761,7 @@ static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
 		io_put_req(req);
 	}
 
-	return cqe != NULL;
+	return all_flushed;
 }
 
 static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)