diff options
| -rw-r--r-- | include/linux/cgroup.h | 1 | ||||
| -rw-r--r-- | kernel/cgroup.c | 54 |
2 files changed, 45 insertions, 10 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 87b034ed0c31..028478c6e0c5 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -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); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7d5d1c927d9d..21bba7722350 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -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++) { - err = cgroup_add_file(cgrp, subsys, 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); @@ -2786,13 +2789,44 @@ 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 */ |
