Commit cf6299b1 authored by Al Viro's avatar Al Viro
Browse files

cgroup: stash cgroup_root reference into cgroup_fs_context 



Note that this reference is *NOT* contributing to refcount of
cgroup_root in question and is valid only until cgroup_do_mount()
returns.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e34a98d5

kernel/cgroup/cgroup-internal.h

+2 −1
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ extern void __init enable_debug_cgroup(void); 
 * The cgroup filesystem superblock creation/mount context.

 */

struct cgroup_fs_context {

	struct cgroup_root	*root;

	unsigned int	flags;			/* CGRP_ROOT_* flags */



	/* cgroup1 bits */
@@ -208,7 +209,7 @@ int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen, 
			  struct cgroup_namespace *ns);



void cgroup_free_root(struct cgroup_root *root);

void init_cgroup_root(struct cgroup_root *root, struct cgroup_fs_context *ctx);

void init_cgroup_root(struct cgroup_fs_context *ctx);

int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask);

int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);

struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags,

kernel/cgroup/cgroup-v1.c

+3 −1
Original line number Diff line number Diff line
@@ -1208,6 +1208,7 @@ int cgroup1_get_tree(struct fs_context *fc) 
		if (root->flags ^ ctx->flags)

			pr_warn("new mount options do not match the existing superblock, will be ignored\n");



		ctx->root = root;

		ret = 0;

		goto out_unlock;

	}
@@ -1234,7 +1235,8 @@ int cgroup1_get_tree(struct fs_context *fc) 
		goto out_unlock;

	}



	init_cgroup_root(root, ctx);

	ctx->root = root;

	init_cgroup_root(ctx);



	ret = cgroup_setup_root(root, ctx->subsys_mask);

	if (ret)

kernel/cgroup/cgroup.c

+5 −2
Original line number Diff line number Diff line
@@ -1915,8 +1915,9 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) 
	INIT_WORK(&cgrp->release_agent_work, cgroup1_release_agent);

}



void init_cgroup_root(struct cgroup_root *root, struct cgroup_fs_context *ctx)

void init_cgroup_root(struct cgroup_fs_context *ctx)

{

	struct cgroup_root *root = ctx->root;

	struct cgroup *cgrp = &root->cgrp;



	INIT_LIST_HEAD(&root->root_list);
@@ -2098,6 +2099,7 @@ static int cgroup_get_tree(struct fs_context *fc) 


	cgrp_dfl_visible = true;

	cgroup_get_live(&cgrp_dfl_root.cgrp);

	ctx->root = &cgrp_dfl_root;



	root = cgroup_do_mount(&cgroup2_fs_type, fc->sb_flags, &cgrp_dfl_root,

					 CGROUP2_SUPER_MAGIC, ns);
@@ -5374,7 +5376,8 @@ int __init cgroup_init_early(void) 
	struct cgroup_subsys *ss;

	int i;



	init_cgroup_root(&cgrp_dfl_root, &ctx);

	ctx.root = &cgrp_dfl_root;

	init_cgroup_root(&ctx);

	cgrp_dfl_root.cgrp.self.flags |= CSS_NO_REF;



	RCU_INIT_POINTER(init_task.cgroups, &init_css_set);