From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 7 Feb 2025 08:59:11 +0000 (+0100)
Subject: radix-tree: purge node allocation override hooks
X-Git-Tag: 4.20.0-rc4~2
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=1275093a96fed45057db241b3aa6e191d9dcf596;p=xen.git

radix-tree: purge node allocation override hooks

These were needed by TMEM only, which is long gone. The Linux original
doesn't have such either. This effectively reverts one of the "Other
changes" from 8dc6738dbb3c ("Update radix-tree.[ch] from upstream Linux
to gain RCU awareness").

Positive side effect: Two cf_check go away.

While there also convert xmalloc()+memset() to xzalloc(). (Don't convert
to xvzalloc(), as that would require touching the freeing side, too.)

Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
---

diff --git a/xen/common/radix-tree.c b/xen/common/radix-tree.c
index fb283a9d52..063ff1e69d 100644
--- a/xen/common/radix-tree.c
+++ b/xen/common/radix-tree.c
@@ -53,12 +53,6 @@ struct rcu_node {
 	struct rcu_head rcu_head;
 };
 
-static struct radix_tree_node *cf_check rcu_node_alloc(void *arg)
-{
-	struct rcu_node *rcu_node = xmalloc(struct rcu_node);
-	return rcu_node ? &rcu_node->node : NULL;
-}
-
 static void cf_check _rcu_node_free(struct rcu_head *head)
 {
 	struct rcu_node *rcu_node =
@@ -66,26 +60,20 @@ static void cf_check _rcu_node_free(struct rcu_head *head)
 	xfree(rcu_node);
 }
 
-static void cf_check rcu_node_free(struct radix_tree_node *node, void *arg)
-{
-	struct rcu_node *rcu_node = container_of(node, struct rcu_node, node);
-	call_rcu(&rcu_node->rcu_head, _rcu_node_free);
-}
-
 static struct radix_tree_node *radix_tree_node_alloc(
 	struct radix_tree_root *root)
 {
-	struct radix_tree_node *ret;
-	ret = root->node_alloc(root->node_alloc_free_arg);
-	if (ret)
-		memset(ret, 0, sizeof(*ret));
-	return ret;
+	struct rcu_node *rcu_node = xzalloc(struct rcu_node);
+
+	return rcu_node ? &rcu_node->node : NULL;
 }
 
 static void radix_tree_node_free(
 	struct radix_tree_root *root, struct radix_tree_node *node)
 {
-	root->node_free(node, root->node_alloc_free_arg);
+	struct rcu_node *rcu_node = container_of(node, struct rcu_node, node);
+
+	call_rcu(&rcu_node->rcu_head, _rcu_node_free);
 }
 
 /*
@@ -718,19 +706,6 @@ void radix_tree_destroy(
 void radix_tree_init(struct radix_tree_root *root)
 {
 	memset(root, 0, sizeof(*root));
-	root->node_alloc = rcu_node_alloc;
-	root->node_free = rcu_node_free;
-}
-
-void radix_tree_set_alloc_callbacks(
-	struct radix_tree_root *root,
-	radix_tree_alloc_fn_t *node_alloc,
-	radix_tree_free_fn_t *node_free,
-	void *node_alloc_free_arg)
-{
-	root->node_alloc = node_alloc;
-	root->node_free = node_free;
-	root->node_alloc_free_arg = node_alloc_free_arg;
 }
 
 static __init unsigned long __maxindex(unsigned int height)
diff --git a/xen/include/xen/radix-tree.h b/xen/include/xen/radix-tree.h
index 58c40312e6..9d5ffae3eb 100644
--- a/xen/include/xen/radix-tree.h
+++ b/xen/include/xen/radix-tree.h
@@ -66,11 +66,6 @@ typedef void radix_tree_free_fn_t(struct radix_tree_node *, void *);
 struct radix_tree_root {
 	unsigned int		height;
 	struct radix_tree_node	__rcu *rnode;
-
-	/* Allow to specify custom node alloc/dealloc routines. */
-	radix_tree_alloc_fn_t *node_alloc;
-	radix_tree_free_fn_t *node_free;
-	void *node_alloc_free_arg;
 };
 
 /*
@@ -78,11 +73,6 @@ struct radix_tree_root {
  */
 
 void radix_tree_init(struct radix_tree_root *root);
-void radix_tree_set_alloc_callbacks(
-	struct radix_tree_root *root,
-	radix_tree_alloc_fn_t *node_alloc,
-	radix_tree_free_fn_t *node_free,
-	void *node_alloc_free_arg);
 
 void radix_tree_destroy(
 	struct radix_tree_root *root,