From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965130Ab2CUWTe (ORCPT ); Wed, 21 Mar 2012 18:19:34 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:42808 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964971Ab2CUWSO (ORCPT ); Wed, 21 Mar 2012 18:18:14 -0400 From: Tejun Heo To: glommer@parallels.com, lizf@cn.fujitsu.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org Cc: linux-kernel@vger.kernel.org, fweisbec@gmail.com, rni@google.com, ctalbott@google.com, Tejun Heo Subject: [PATCH 12/12] cgroup: implement cgroup_rm_cftypes() Date: Wed, 21 Mar 2012 15:17:45 -0700 Message-Id: <1332368265-21586-13-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: <1332368265-21586-1-git-send-email-tj@kernel.org> References: <1332368265-21586-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Implement cgroup_rm_cftypes() which removes an array of cftypes from a subsystem. It can be called whether the target subsys is attached or not. cgroup core will remove the specified file from all existing cgroups. This will be used to improve sub-subsys modularity and will be helpful for unified hierarchy. Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 1 + kernel/cgroup.c | 54 +++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 45 insertions(+), 10 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index bfe5470..7e523e2 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 67daea9..e87c4c4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2692,17 +2692,20 @@ 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; } } @@ -2726,7 +2729,7 @@ 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); @@ -2752,7 +2755,7 @@ 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); @@ -2788,13 +2791,44 @@ 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 * @@ -3786,7 +3820,7 @@ 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; @@ -3798,7 +3832,7 @@ 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 */ -- 1.7.7.3