Merge branch 'for-3.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup (d030671f) · Commits · 戴 / test

kernel/cgroup.c

+33 −14

Original line number	Diff line number	Diff line
		@@ -1035,6 +1035,11 @@ static void cgroup_get(struct cgroup *cgrp)
		css_get(&cgrp->self);
		}

		static bool cgroup_tryget(struct cgroup *cgrp)
		{
		return css_tryget(&cgrp->self);
		}

		static void cgroup_put(struct cgroup *cgrp)
		{
		css_put(&cgrp->self);
		@@ -1147,7 +1152,8 @@ static struct cgroup cgroup_kn_lock_live(struct kernfs_node kn)
		* protection against removal. Ensure @cgrp stays accessible and
		* break the active_ref protection.
		*/
		cgroup_get(cgrp);
		if (!cgroup_tryget(cgrp))
		return NULL;
		kernfs_break_active_protection(kn);

		mutex_lock(&cgroup_mutex);
		@@ -3271,8 +3277,17 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys ss, struct cftype cfts)
		{
		struct cftype *cft;

		/*
		* If legacy_flies_on_dfl, we want to show the legacy files on the
		* dfl hierarchy but iff the target subsystem hasn't been updated
		* for the dfl hierarchy yet.
		*/
		if (!cgroup_legacy_files_on_dfl \|\|
		ss->dfl_cftypes != ss->legacy_cftypes) {
		for (cft = cfts; cft && cft->name[0] != '\0'; cft++)
		cft->flags \|= __CFTYPE_NOT_ON_DFL;
		}

		return cgroup_add_cftypes(ss, cfts);
		}

		@@ -4387,6 +4402,15 @@ static void css_release_work_fn(struct work_struct *work)
		/* cgroup release path */
		cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
		cgrp->id = -1;

		/*
		* There are two control paths which try to determine
		* cgroup from dentry without going through kernfs -
		* cgroupstats_build() and css_tryget_online_from_dir().
		* Those are supported by RCU protecting clearing of
		* cgrp->kn->priv backpointer.
		*/
		RCU_INIT_POINTER((void __rcu __force *)&cgrp->kn->priv, NULL);
		}

		mutex_unlock(&cgroup_mutex);
		@@ -4543,6 +4567,11 @@ static int cgroup_mkdir(struct kernfs_node parent_kn, const char name,
		struct cftype *base_files;
		int ssid, ret;

		/* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.
		*/
		if (strchr(name, '\n'))
		return -EINVAL;

		parent = cgroup_kn_lock_live(parent_kn);
		if (!parent)
		return -ENODEV;
		@@ -4820,16 +4849,6 @@ static int cgroup_rmdir(struct kernfs_node *kn)

		cgroup_kn_unlock(kn);

		/*
		* There are two control paths which try to determine cgroup from
		* dentry without going through kernfs - cgroupstats_build() and
		* css_tryget_online_from_dir(). Those are supported by RCU
		* protecting clearing of cgrp->kn->priv backpointer, which should
		* happen after all files under it have been removed.
		*/
		if (!ret)
		RCU_INIT_POINTER((void __rcu __force *)&kn->priv, NULL);

		cgroup_put(cgrp);
		return ret;
		}
		@@ -5416,7 +5435,7 @@ struct cgroup_subsys_state css_tryget_online_from_dir(struct dentry dentry,
		/*
		* This path doesn't originate from kernfs and @kn could already
		* have been or be removed at any point. @kn->priv is RCU
		* protected for this access. See cgroup_rmdir() for details.
		* protected for this access. See css_release_work_fn() for details.
		*/
		cgrp = rcu_dereference(kn->priv);
		if (cgrp)

Admin message