cgroup: implement cgroup_rm_cftypes() (79578621) · Commits · 戴 / test

include/linux/cgroup.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -406,6 +406,7 @@ struct cgroup_scanner {
		};

		int cgroup_add_cftypes(struct cgroup_subsys ss, const struct cftype cfts);
		int cgroup_rm_cftypes(struct cgroup_subsys ss, const struct cftype cfts);

		int cgroup_is_removed(const struct cgroup *cgrp);

kernel/cgroup.c

+44 −10

Original line number	Diff line number	Diff line
		@@ -2690,17 +2690,20 @@ out:
		return error;
		}

		static int cgroup_add_files(struct cgroup cgrp, struct cgroup_subsys subsys,
		const struct cftype cfts[])
		static int cgroup_addrm_files(struct cgroup cgrp, struct cgroup_subsys subsys,
		const struct cftype cfts[], bool is_add)
		{
		const struct cftype *cft;
		int err, ret = 0;

		for (cft = cfts; cft->name[0] != '\0'; cft++) {
		if (is_add)
		err = cgroup_add_file(cgrp, subsys, cft);
		else
		err = cgroup_rm_file(cgrp, cft);
		if (err) {
		pr_warning("cgroup_add_files: failed to create %s, err=%d\n",
		cft->name, err);
		pr_warning("cgroup_addrm_files: failed to %s %s, err=%d\n",
		is_add ? "add" : "remove", cft->name, err);
		ret = err;
		}
		}
		@@ -2724,7 +2727,7 @@ static void cgroup_cfts_prepare(void)
		}

		static void cgroup_cfts_commit(struct cgroup_subsys *ss,
		const struct cftype *cfts)
		const struct cftype *cfts, bool is_add)
		__releases(&cgroup_mutex) __releases(&cgroup_cft_mutex)
		{
		LIST_HEAD(pending);
		@@ -2750,7 +2753,7 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
		mutex_lock(&inode->i_mutex);
		mutex_lock(&cgroup_mutex);
		if (!cgroup_is_removed(cgrp))
		cgroup_add_files(cgrp, ss, cfts);
		cgroup_addrm_files(cgrp, ss, cfts, is_add);
		mutex_unlock(&cgroup_mutex);
		mutex_unlock(&inode->i_mutex);

		@@ -2786,12 +2789,43 @@ int cgroup_add_cftypes(struct cgroup_subsys ss, const struct cftype cfts)
		cgroup_cfts_prepare();
		set->cfts = cfts;
		list_add_tail(&set->node, &ss->cftsets);
		cgroup_cfts_commit(ss, cfts);
		cgroup_cfts_commit(ss, cfts, true);

		return 0;
		}
		EXPORT_SYMBOL_GPL(cgroup_add_cftypes);

		/**
		* cgroup_rm_cftypes - remove an array of cftypes from a subsystem
		* @ss: target cgroup subsystem
		* @cfts: zero-length name terminated array of cftypes
		*
		* Unregister @cfts from @ss. Files described by @cfts are removed from
		* all existing cgroups to which @ss is attached and all future cgroups
		* won't have them either. This function can be called anytime whether @ss
		* is attached or not.
		*
		* Returns 0 on successful unregistration, -ENOENT if @cfts is not
		* registered with @ss.
		*/
		int cgroup_rm_cftypes(struct cgroup_subsys ss, const struct cftype cfts)
		{
		struct cftype_set *set;

		cgroup_cfts_prepare();

		list_for_each_entry(set, &ss->cftsets, node) {
		if (set->cfts == cfts) {
		list_del_init(&set->node);
		cgroup_cfts_commit(ss, cfts, false);
		return 0;
		}
		}

		cgroup_cfts_commit(ss, NULL, false);
		return -ENOENT;
		}

		/**
		* cgroup_task_count - count the number of tasks in a cgroup.
		* @cgrp: the cgroup in question
		@@ -3784,7 +3818,7 @@ static int cgroup_populate_dir(struct cgroup *cgrp)
		int err;
		struct cgroup_subsys *ss;

		err = cgroup_add_files(cgrp, NULL, files);
		err = cgroup_addrm_files(cgrp, NULL, files, true);
		if (err < 0)
		return err;

		@@ -3796,7 +3830,7 @@ static int cgroup_populate_dir(struct cgroup *cgrp)
		return err;

		list_for_each_entry(set, &ss->cftsets, node)
		cgroup_add_files(cgrp, ss, set->cfts);
		cgroup_addrm_files(cgrp, ss, set->cfts, true);
		}

		/* This cgroup is ready now */

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