[PATCH V10 04/12] io_uring/rsrc: prepare for supporting external 'io_rsrc_node'

[Ming Lei <ming.lei@xxxxxxxxxx>]

Now 'io_rsrc_node' is just one buffer, and it may be provided from
other subsystem, such as the coming group kernel buffer.

So add flag IORING_RSRC_F_NEED_FREE for external 'io_rsrc_node'.

Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
 io_uring/rsrc.c | 12 +++++++-----
 io_uring/rsrc.h | 15 ++++++++++++++-
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index adaae8630932..db5d917081b1 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -123,10 +123,9 @@ struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx, int type)
 	struct io_rsrc_node *node;
 
 	node = kzalloc(sizeof(*node), GFP_KERNEL);
-	if (node) {
-		node->type = type;
-		node->refs = 1;
-	}
+	if (node)
+		io_rsrc_node_init(node, type, IORING_RSRC_F_NEED_FREE);
+
 	return node;
 }
 
@@ -444,6 +443,8 @@ int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
 
 void io_free_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
 {
+	bool need_free = node->flags & IORING_RSRC_F_NEED_FREE;
+
 	lockdep_assert_held(&ctx->uring_lock);
 
 	if (node->tag)
@@ -463,7 +464,8 @@ void io_free_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
 		break;
 	}
 
-	kfree(node);
+	if (need_free)
+		kfree(node);
 }
 
 int io_sqe_files_unregister(struct io_ring_ctx *ctx)
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 7a4668deaa1a..582a69adfdc9 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -10,11 +10,15 @@
 
 enum {
 	IORING_RSRC_FILE		= 0,
-	IORING_RSRC_BUFFER		= 1,
+	IORING_RSRC_BUFFER,
+	__IORING_RSRC_LAST_TYPE,
+
+	IORING_RSRC_F_NEED_FREE		= 1 << 0,
 };
 
 struct io_rsrc_node {
 	unsigned char			type;
+	unsigned char			flags;
 	int				refs;
 
 	u64 tag;
@@ -66,6 +70,15 @@ int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
 int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
 			unsigned int size, unsigned int type);
 
+static inline void io_rsrc_node_init(struct io_rsrc_node *node, int type,
+				     unsigned char flags)
+{
+	WARN_ON_ONCE(type >= __IORING_RSRC_LAST_TYPE);
+
+	node->type = type;
+	node->refs = 1;
+	node->flags = flags;
+}
 static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data,
 						       int index)
 {
-- 
2.47.0