Commit f9432480 authored by Chen Ridong's avatar Chen Ridong
Browse files

cgroup: add cgroup_root_ext to keep kabi 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IA7HMV



--------------------------------

Commit 1e8c422d6363 ("[Backport] cgroup: Make operations on the cgroup
root_list RCU safe") added rcu member to struct cgroup_root, which broke
KABI. To keep KABI, add cgroup_root_ext.

Fixes: 1e8c422d6363 ("[Backport] cgroup: Make operations on the cgroup root_list RCU safe")
Signed-off-by: default avatarChen Ridong <chenridong@huawei.com>
parent a9af292d

include/linux/cgroup-defs.h

+12 −4
Original line number Diff line number Diff line
@@ -526,10 +526,6 @@ struct cgroup_root { 
	/* Unique id for this hierarchy. */

	int hierarchy_id;



	/* A list running through the active hierarchies */

	struct list_head root_list;

	struct rcu_head rcu;	/* Must be near the top */



	/* The root cgroup.  Root is destroyed on its release. */

	struct cgroup cgrp;
@@ -542,6 +538,9 @@ struct cgroup_root { 
	/* Wait while cgroups are being destroyed */

	wait_queue_head_t wait;



	/* A list running through the active hierarchies */

	struct list_head root_list;



	/* Hierarchy-specific flags */

	unsigned int flags;
@@ -557,6 +556,15 @@ struct cgroup_root { 
	KABI_RESERVE(4)

};



/*

 * To keep kabi uncharged, add cgroup_root_ext, add rcu_head to make operations

 * on the cgroup root_list RCU safe

 */

struct cgroup_root_ext {

	struct rcu_head rcu;    /* Must be near the top */

	struct cgroup_root root;

};



/*

 * struct cftype: handler definitions for cgroup control files

 *

kernel/cgroup/cgroup-v1.c

+4 −2
Original line number Diff line number Diff line
@@ -1145,6 +1145,7 @@ static int cgroup1_root_to_use(struct fs_context *fc) 
{

	struct cgroup_fs_context *ctx = cgroup_fc2context(fc);

	struct cgroup_root *root;

	struct cgroup_root_ext *root_ext;

	struct cgroup_subsys *ss;

	int i, ret;
@@ -1217,10 +1218,11 @@ static int cgroup1_root_to_use(struct fs_context *fc) 
	if (ctx->ns != &init_cgroup_ns)

		return -EPERM;



	root = kzalloc(sizeof(*root), GFP_KERNEL);

	if (!root)

	root_ext = kzalloc(sizeof(struct cgroup_root_ext), GFP_KERNEL);

	if (!root_ext)

		return -ENOMEM;



	root = &root_ext->root;

	ctx->root = root;

	init_cgroup_root(ctx);

kernel/cgroup/cgroup.c

+4 −1
Original line number Diff line number Diff line
@@ -1303,7 +1303,10 @@ static void cgroup_exit_root_id(struct cgroup_root *root) 


void cgroup_free_root(struct cgroup_root *root)

{

	kfree_rcu(root, rcu);

	struct cgroup_root_ext *root_ext;



	root_ext = container_of(root, struct cgroup_root_ext, root);

	kfree_rcu(root_ext, rcu);

}



static void cgroup_destroy_root(struct cgroup_root *root)