Merge branch 'for-4.5-ancestor-test' of... (17749398) · Commits · e / devices / android_kernel_fairphone_FP3

fs/kernfs/dir.c

+46 −0

Original line number	Original line	Diff line number	Diff line
	@@ -694,6 +694,29 @@ static struct kernfs_node kernfs_find_ns(struct kernfs_node parent,
	return NULL;		return NULL;
	}		}

			static struct kernfs_node kernfs_walk_ns(struct kernfs_node parent,
			const unsigned char *path,
			const void *ns)
			{
			static char path_buf[PATH_MAX]; /* protected by kernfs_mutex */
			size_t len = strlcpy(path_buf, path, PATH_MAX);
			char *p = path_buf;
			char *name;

			lockdep_assert_held(&kernfs_mutex);

			if (len >= PATH_MAX)
			return NULL;

			while ((name = strsep(&p, "/")) && parent) {
			if (*name == '\0')
			continue;
			parent = kernfs_find_ns(parent, name, ns);
			}

			return parent;
			}

	/**		/**
	* kernfs_find_and_get_ns - find and get kernfs_node with the given name		* kernfs_find_and_get_ns - find and get kernfs_node with the given name
	* @parent: kernfs_node to search under		* @parent: kernfs_node to search under
	@@ -718,6 +741,29 @@ struct kernfs_node kernfs_find_and_get_ns(struct kernfs_node parent,
	}		}
	EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns);		EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns);

			/**
			* kernfs_walk_and_get_ns - find and get kernfs_node with the given path
			* @parent: kernfs_node to search under
			* @path: path to look for
			* @ns: the namespace tag to use
			*
			* Look for kernfs_node with path @path under @parent and get a reference
			* if found. This function may sleep and returns pointer to the found
			* kernfs_node on success, %NULL on failure.
			*/
			struct kernfs_node kernfs_walk_and_get_ns(struct kernfs_node parent,
			const char path, const void ns)
			{
			struct kernfs_node *kn;

			mutex_lock(&kernfs_mutex);
			kn = kernfs_walk_ns(parent, path, ns);
			kernfs_get(kn);
			mutex_unlock(&kernfs_mutex);

			return kn;
			}

	/**		/**
	* kernfs_create_root - create a new kernfs hierarchy		* kernfs_create_root - create a new kernfs hierarchy
	* @scops: optional syscall operations for the hierarchy		* @scops: optional syscall operations for the hierarchy

include/linux/cgroup-defs.h

+14 −0

Original line number	Original line	Diff line number	Diff line
	@@ -224,6 +224,14 @@ struct cgroup {
	*/		*/
	int id;		int id;

			/*
			* The depth this cgroup is at. The root is at depth zero and each
			* step down the hierarchy increments the level. This along with
			* ancestor_ids[] can determine whether a given cgroup is a
			* descendant of another without traversing the hierarchy.
			*/
			int level;

	/*		/*
	* Each non-empty css_set associated with this cgroup contributes		* Each non-empty css_set associated with this cgroup contributes
	* one to populated_cnt. All children with non-zero popuplated_cnt		* one to populated_cnt. All children with non-zero popuplated_cnt
	@@ -279,6 +287,9 @@ struct cgroup {

	/* used to schedule release agent */		/* used to schedule release agent */
	struct work_struct release_agent_work;		struct work_struct release_agent_work;

			/* ids of the ancestors at each level including self */
			int ancestor_ids[];
	};		};

	/*		/*
	@@ -298,6 +309,9 @@ struct cgroup_root {
	/* The root cgroup. Root is destroyed on its release. */		/* The root cgroup. Root is destroyed on its release. */
	struct cgroup cgrp;		struct cgroup cgrp;

			/* for cgrp->ancestor_ids[0] */
			int cgrp_ancestor_id_storage;

	/* Number of cgroups in the hierarchy, used only for /proc/cgroups */		/* Number of cgroups in the hierarchy, used only for /proc/cgroups */
	atomic_t nr_cgrps;		atomic_t nr_cgrps;

include/linux/cgroup.h

+24 −1

Original line number	Original line	Diff line number	Diff line
	@@ -81,7 +81,8 @@ struct cgroup_subsys_state cgroup_get_e_css(struct cgroup cgroup,
	struct cgroup_subsys_state css_tryget_online_from_dir(struct dentry dentry,		struct cgroup_subsys_state css_tryget_online_from_dir(struct dentry dentry,
	struct cgroup_subsys *ss);		struct cgroup_subsys *ss);

	bool cgroup_is_descendant(struct cgroup cgrp, struct cgroup ancestor);		struct cgroup cgroup_get_from_path(const char path);

	int cgroup_attach_task_all(struct task_struct from, struct task_struct );		int cgroup_attach_task_all(struct task_struct from, struct task_struct );
	int cgroup_transfer_tasks(struct cgroup to, struct cgroup from);		int cgroup_transfer_tasks(struct cgroup to, struct cgroup from);

	@@ -361,6 +362,11 @@ static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
	percpu_ref_put_many(&css->refcnt, n);		percpu_ref_put_many(&css->refcnt, n);
	}		}

			static inline void cgroup_put(struct cgroup *cgrp)
			{
			css_put(&cgrp->self);
			}

	/**		/**
	* task_css_set_check - obtain a task's css_set with extra access conditions		* task_css_set_check - obtain a task's css_set with extra access conditions
	* @task: the task to obtain css_set for		* @task: the task to obtain css_set for
	@@ -468,6 +474,23 @@ static inline struct cgroup task_cgroup(struct task_struct task,
	return task_css(task, subsys_id)->cgroup;		return task_css(task, subsys_id)->cgroup;
	}		}

			/**
			* cgroup_is_descendant - test ancestry
			* @cgrp: the cgroup to be tested
			* @ancestor: possible ancestor of @cgrp
			*
			* Test whether @cgrp is a descendant of @ancestor. It also returns %true
			* if @cgrp == @ancestor. This function is safe to call as long as @cgrp
			* and @ancestor are accessible.
			*/
			static inline bool cgroup_is_descendant(struct cgroup *cgrp,
			struct cgroup *ancestor)
			{
			if (cgrp->root != ancestor->root \|\| cgrp->level < ancestor->level)
			return false;
			return cgrp->ancestor_ids[ancestor->level] == ancestor->id;
			}

	/* no synchronization, the result can only be used as a hint */		/* no synchronization, the result can only be used as a hint */
	static inline bool cgroup_is_populated(struct cgroup *cgrp)		static inline bool cgroup_is_populated(struct cgroup *cgrp)
	{		{

include/linux/kernfs.h

+12 −0

Original line number	Original line	Diff line number	Diff line
	@@ -274,6 +274,8 @@ void pr_cont_kernfs_path(struct kernfs_node *kn);
	struct kernfs_node kernfs_get_parent(struct kernfs_node kn);		struct kernfs_node kernfs_get_parent(struct kernfs_node kn);
	struct kernfs_node kernfs_find_and_get_ns(struct kernfs_node parent,		struct kernfs_node kernfs_find_and_get_ns(struct kernfs_node parent,
	const char name, const void ns);		const char name, const void ns);
			struct kernfs_node kernfs_walk_and_get_ns(struct kernfs_node parent,
			const char path, const void ns);
	void kernfs_get(struct kernfs_node *kn);		void kernfs_get(struct kernfs_node *kn);
	void kernfs_put(struct kernfs_node *kn);		void kernfs_put(struct kernfs_node *kn);

	@@ -350,6 +352,10 @@ static inline struct kernfs_node *
	kernfs_find_and_get_ns(struct kernfs_node parent, const char name,		kernfs_find_and_get_ns(struct kernfs_node parent, const char name,
	const void *ns)		const void *ns)
	{ return NULL; }		{ return NULL; }
			static inline struct kernfs_node *
			kernfs_walk_and_get_ns(struct kernfs_node parent, const char path,
			const void *ns)
			{ return NULL; }

	static inline void kernfs_get(struct kernfs_node *kn) { }		static inline void kernfs_get(struct kernfs_node *kn) { }
	static inline void kernfs_put(struct kernfs_node *kn) { }		static inline void kernfs_put(struct kernfs_node *kn) { }
	@@ -430,6 +436,12 @@ kernfs_find_and_get(struct kernfs_node kn, const char name)
	return kernfs_find_and_get_ns(kn, name, NULL);		return kernfs_find_and_get_ns(kn, name, NULL);
	}		}

			static inline struct kernfs_node *
			kernfs_walk_and_get(struct kernfs_node kn, const char path)
			{
			return kernfs_walk_and_get_ns(kn, path, NULL);
			}

	static inline struct kernfs_node *		static inline struct kernfs_node *
	kernfs_create_dir(struct kernfs_node parent, const char name, umode_t mode,		kernfs_create_dir(struct kernfs_node parent, const char name, umode_t mode,
	void *priv)		void *priv)

kernel/cgroup.c

+44 −27

Original line number	Original line	Diff line number	Diff line
	@@ -441,11 +441,6 @@ static bool cgroup_tryget(struct cgroup *cgrp)
	return css_tryget(&cgrp->self);		return css_tryget(&cgrp->self);
	}		}

	static void cgroup_put(struct cgroup *cgrp)
	{
	css_put(&cgrp->self);
	}

	struct cgroup_subsys_state of_css(struct kernfs_open_file of)		struct cgroup_subsys_state of_css(struct kernfs_open_file of)
	{		{
	struct cgroup *cgrp = of->kn->parent->priv;		struct cgroup *cgrp = of->kn->parent->priv;
	@@ -466,25 +461,6 @@ struct cgroup_subsys_state of_css(struct kernfs_open_file of)
	}		}
	EXPORT_SYMBOL_GPL(of_css);		EXPORT_SYMBOL_GPL(of_css);

	/**
	* cgroup_is_descendant - test ancestry
	* @cgrp: the cgroup to be tested
	* @ancestor: possible ancestor of @cgrp
	*
	* Test whether @cgrp is a descendant of @ancestor. It also returns %true
	* if @cgrp == @ancestor. This function is safe to call as long as @cgrp
	* and @ancestor are accessible.
	*/
	bool cgroup_is_descendant(struct cgroup cgrp, struct cgroup ancestor)
	{
	while (cgrp) {
	if (cgrp == ancestor)
	return true;
	cgrp = cgroup_parent(cgrp);
	}
	return false;
	}

	static int notify_on_release(const struct cgroup *cgrp)		static int notify_on_release(const struct cgroup *cgrp)
	{		{
	return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);		return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
	@@ -1912,6 +1888,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned long ss_mask)
	if (ret < 0)		if (ret < 0)
	goto out;		goto out;
	root_cgrp->id = ret;		root_cgrp->id = ret;
			root_cgrp->ancestor_ids[0] = ret;

	ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release, 0,		ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release, 0,
	GFP_KERNEL);		GFP_KERNEL);
	@@ -4901,11 +4878,11 @@ static int create_css(struct cgroup cgrp, struct cgroup_subsys ss,
	static int cgroup_mkdir(struct kernfs_node parent_kn, const char name,		static int cgroup_mkdir(struct kernfs_node parent_kn, const char name,
	umode_t mode)		umode_t mode)
	{		{
	struct cgroup parent, cgrp;		struct cgroup parent, cgrp, *tcgrp;
	struct cgroup_root *root;		struct cgroup_root *root;
	struct cgroup_subsys *ss;		struct cgroup_subsys *ss;
	struct kernfs_node *kn;		struct kernfs_node *kn;
	int ssid, ret;		int level, ssid, ret;

	/* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.		/* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.
	*/		*/
	@@ -4916,9 +4893,11 @@ static int cgroup_mkdir(struct kernfs_node parent_kn, const char name,
	if (!parent)		if (!parent)
	return -ENODEV;		return -ENODEV;
	root = parent->root;		root = parent->root;
			level = parent->level + 1;

	/* allocate the cgroup and its ID, 0 is reserved for the root */		/* allocate the cgroup and its ID, 0 is reserved for the root */
	cgrp = kzalloc(sizeof(*cgrp), GFP_KERNEL);		cgrp = kzalloc(sizeof(*cgrp) +
			sizeof(cgrp->ancestor_ids[0]) * (level + 1), GFP_KERNEL);
	if (!cgrp) {		if (!cgrp) {
	ret = -ENOMEM;		ret = -ENOMEM;
	goto out_unlock;		goto out_unlock;
	@@ -4942,6 +4921,10 @@ static int cgroup_mkdir(struct kernfs_node parent_kn, const char name,

	cgrp->self.parent = &parent->self;		cgrp->self.parent = &parent->self;
	cgrp->root = root;		cgrp->root = root;
			cgrp->level = level;

			for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp))
			cgrp->ancestor_ids[tcgrp->level] = tcgrp->id;

	if (notify_on_release(parent))		if (notify_on_release(parent))
	set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);		set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
	@@ -5805,6 +5788,40 @@ struct cgroup_subsys_state css_from_id(int id, struct cgroup_subsys ss)
	return id > 0 ? idr_find(&ss->css_idr, id) : NULL;		return id > 0 ? idr_find(&ss->css_idr, id) : NULL;
	}		}

			/**
			* cgroup_get_from_path - lookup and get a cgroup from its default hierarchy path
			* @path: path on the default hierarchy
			*
			* Find the cgroup at @path on the default hierarchy, increment its
			* reference count and return it. Returns pointer to the found cgroup on
			* success, ERR_PTR(-ENOENT) if @path doens't exist and ERR_PTR(-ENOTDIR)
			* if @path points to a non-directory.
			*/
			struct cgroup cgroup_get_from_path(const char path)
			{
			struct kernfs_node *kn;
			struct cgroup *cgrp;

			mutex_lock(&cgroup_mutex);

			kn = kernfs_walk_and_get(cgrp_dfl_root.cgrp.kn, path);
			if (kn) {
			if (kernfs_type(kn) == KERNFS_DIR) {
			cgrp = kn->priv;
			cgroup_get(cgrp);
			} else {
			cgrp = ERR_PTR(-ENOTDIR);
			}
			kernfs_put(kn);
			} else {
			cgrp = ERR_PTR(-ENOENT);
			}

			mutex_unlock(&cgroup_mutex);
			return cgrp;
			}
			EXPORT_SYMBOL_GPL(cgroup_get_from_path);

	#ifdef CONFIG_CGROUP_DEBUG		#ifdef CONFIG_CGROUP_DEBUG
	static struct cgroup_subsys_state *		static struct cgroup_subsys_state *
	debug_css_alloc(struct cgroup_subsys_state *parent_css)		debug_css_alloc(struct cgroup_subsys_state *parent_css)