io_uring/rsrc: add empty flag in rsrc_node

Unless a node was flushed by io_rsrc_ref_quiesce(), it'll carry a
resource. Replace ->inline_items with an empty flag, which is
initialised to false and only raised in io_rsrc_ref_quiesce().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/75d384c9d2252e12af73b9cf8a44e1699106aeb1.1681822823.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

io_uring/rsrc.c

@@ -154,7 +154,7 @@ static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
 {
 	struct io_rsrc_data *rsrc_data = ref_node->rsrc_data;
 
-	if (likely(ref_node->inline_items))
+	if (likely(!ref_node->empty))
 		io_rsrc_put_work_one(rsrc_data, &ref_node->item);
 
 	io_rsrc_node_destroy(rsrc_data->ctx, ref_node);
@@ -199,7 +199,7 @@ struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
 	}
 
 	ref_node->rsrc_data = NULL;
-	ref_node->inline_items = 0;
+	ref_node->empty = 0;
 	ref_node->refs = 1;
 	return ref_node;
 }
@@ -218,6 +218,7 @@ __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
 	backup = io_rsrc_node_alloc(ctx);
 	if (!backup)
 		return -ENOMEM;
+	ctx->rsrc_node->empty = true;
 	ctx->rsrc_node->rsrc_data = data;
 	list_add_tail(&ctx->rsrc_node->node, &ctx->rsrc_ref_list);
 	io_put_rsrc_node(ctx, ctx->rsrc_node);
@@ -649,7 +650,6 @@ int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, void *rsrc)
 
 	node->item.rsrc = rsrc;
 	node->item.tag = *tag_slot;
-	node->inline_items = 1;
 	*tag_slot = 0;
 
 	node->rsrc_data = data;

io_uring/rsrc.h

@@ -43,7 +43,7 @@ struct io_rsrc_node {
 		struct io_rsrc_data		*rsrc_data;
 	};
 	int				refs;
-	int				inline_items;
+	bool				empty;
 	struct list_head		node;
 	struct io_rsrc_put		item;
 };