From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 10/10] cgroup: implement cgroup_rm_cftypes() Date: Fri, 16 Mar 2012 16:36:03 -0700 Message-ID: <1331940963-15756-11-git-send-email-tj@kernel.org> References: <1331940963-15756-1-git-send-email-tj@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=W1ACw+kuVbib5jnQl9XSED/vYiuVz4Y2eehHGMyR1mI=; b=qq3woiv89cuOt0HpU5mdmyW5rQziV/zCv0Avg3fguUfIUHvP6wBGSmUow4BLfnH3uO QuqPSa03IRORttqct58rigaEGMkskb1xhxX3vgak2xe2xslLKzXJyF1Sqsgfi0BMIwO1 hyo89KjG111fs9bYXConsLr3EN147JnDYyT27kTtyosW+eGKBrlZHo9AofUBIl5GIKNn EbK25BtTQO/NmflXe9fgE0mwEzjTeK8aXRRqqodUNlFBk/ugGBBYcGmI9mmj5v7D1qDi 9LKEGem1t+wtGaCur2ujU3Y6s/x2HnSmnMLaFub9zG9LGZE/tJgwLYc7yuBKzseKtgYt 4/Ug== In-Reply-To: <1331940963-15756-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org, lizf-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Tejun Heo , fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.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 caeaafc..4f3a68b 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -415,6 +415,7 @@ 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 c0c61b9..cf7b298 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2698,17 +2698,20 @@ 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; } } @@ -2732,7 +2735,7 @@ 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); @@ -2758,7 +2761,7 @@ 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); @@ -2796,13 +2799,44 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts) cgroup_cfts_prepare(); 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 after + * subsys_initcall 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 * @@ -3794,7 +3828,7 @@ 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; @@ -3806,7 +3840,7 @@ 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