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Commit dc5ed406 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup fixes from Tejun Heo:
 "Two patches to fix fallouts from the kernfs conversion:

  Li's patch to stop leaking cgroup_root refs across multiple mounts and
  the other fixes the 90s hang during shutdown caused by always using
  root's uid/gid for new cgroup dirs and files."

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: newly created dirs and files should be owned by the creator
  cgroup: fix top cgroup refcnt leak
parents 467a9e16 49957f8e

kernel/cgroup.c

+29 −3
Original line number Diff line number Diff line
@@ -1487,6 +1487,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, 
	struct cgroup_sb_opts opts;

	struct dentry *dentry;

	int ret;

	bool new_sb;



	/*

	 * The first time anyone tries to mount a cgroup, enable the list
@@ -1603,8 +1604,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, 
	if (ret)

		return ERR_PTR(ret);



	dentry = kernfs_mount(fs_type, flags, root->kf_root, NULL);

	if (IS_ERR(dentry))

	dentry = kernfs_mount(fs_type, flags, root->kf_root, &new_sb);

	if (IS_ERR(dentry) || !new_sb)

		cgroup_put(&root->cgrp);

	return dentry;

}
@@ -2345,11 +2346,26 @@ static int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent, 
	return ret;

}



/* set uid and gid of cgroup dirs and files to that of the creator */

static int cgroup_kn_set_ugid(struct kernfs_node *kn)

{

	struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,

			       .ia_uid = current_fsuid(),

			       .ia_gid = current_fsgid(), };



	if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&

	    gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))

		return 0;



	return kernfs_setattr(kn, &iattr);

}



static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft)

{

	char name[CGROUP_FILE_NAME_MAX];

	struct kernfs_node *kn;

	struct lock_class_key *key = NULL;

	int ret;



#ifdef CONFIG_DEBUG_LOCK_ALLOC

	key = &cft->lockdep_key;
@@ -2357,7 +2373,13 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft) 
	kn = __kernfs_create_file(cgrp->kn, cgroup_file_name(cgrp, cft, name),

				  cgroup_file_mode(cft), 0, cft->kf_ops, cft,

				  NULL, false, key);

	return PTR_ERR_OR_ZERO(kn);

	if (IS_ERR(kn))

		return PTR_ERR(kn);



	ret = cgroup_kn_set_ugid(kn);

	if (ret)

		kernfs_remove(kn);

	return ret;

}



/**
@@ -3752,6 +3774,10 @@ static long cgroup_create(struct cgroup *parent, const char *name, 
	 */

	idr_replace(&root->cgroup_idr, cgrp, cgrp->id);



	err = cgroup_kn_set_ugid(kn);

	if (err)

		goto err_destroy;



	err = cgroup_addrm_files(cgrp, cgroup_base_files, true);

	if (err)

		goto err_destroy;