From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 1/3] netcls_cgroup: introduce netcls_mutex Date: Fri, 16 Nov 2012 19:31:00 -0800 Message-ID: <1353123062-23193-2-git-send-email-tj@kernel.org> References: <1353123062-23193-1-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=Dfxad5EOC8QpmpckVoUz2LifNluK/vaEiPwmiHWFqoA=; b=EXzuoqJyWbOlPtUMcxkJcvtKhLyr0T42Y1jhQPe0xFZVCo2lT/iWSqEy1z03ZIH9G8 sg3SvcY51xvjkDFRGpjJacurG5TISOsNCDBvt376A0GCBUceYWufFKVa6qN6xtUmxNVV /gSZHZnzDeDgDYQ4/jv2T2zyLBsC+L0lr652Ix8eg7veEFEsbr9c1Ftn2hGt6KaPTgFg y0+CoK+tbZmhurF/MRkumdtgwYfkYZLqI9BfPdrbSLjSdjpbO6qiDjpqhQ71YrrQxBM1 MgcOjCChAeaObS07vQeQFwbpIUIgYOr1bUoA5J+nr0XyuVCt5eKEQ/UiOdFKwRoqC7ph t4SQ== In-Reply-To: <1353123062-23193-1-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: daniel.wagner-98C5kh4wR6ohFhg+JK9F0w@public.gmane.org, serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org, tgraf-G/eBtMaohhA@public.gmane.org Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org Introduce netcls_mutex to synchronize modifications to cgroup_cls_state. New cgrp now inherits classid from ->css_online() and write_classid() updates classid while holdin netcls_mutex. As write_classid() doesn't propagate new configuration downwards, this currently doesn't make any userland-visible difference, but will help implementing proper hierarchy support. Signed-off-by: Tejun Heo --- net/sched/cls_cgroup.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index 8cdc18e..80a80c4 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -17,11 +17,14 @@ #include #include #include +#include #include #include #include #include +static DEFINE_MUTEX(netcls_mutex); + static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp) { return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id), @@ -42,12 +45,21 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp) if (!cs) return ERR_PTR(-ENOMEM); - if (cgrp->parent) - cs->classid = cgrp_cls_state(cgrp->parent)->classid; - return &cs->css; } +/* @cgrp coming online, inherit the parent's classid */ +static int cgrp_css_online(struct cgroup *cgrp) +{ + if (!cgrp->parent) + return 0; + + mutex_lock(&netcls_mutex); + cgrp_cls_state(cgrp)->classid = cgrp_cls_state(cgrp->parent)->classid; + mutex_unlock(&netcls_mutex); + return 0; +} + static void cgrp_css_free(struct cgroup *cgrp) { kfree(cgrp_cls_state(cgrp)); @@ -60,7 +72,9 @@ static u64 read_classid(struct cgroup *cgrp, struct cftype *cft) static int write_classid(struct cgroup *cgrp, struct cftype *cft, u64 value) { + mutex_lock(&netcls_mutex); cgrp_cls_state(cgrp)->classid = (u32) value; + mutex_unlock(&netcls_mutex); return 0; } @@ -76,6 +90,7 @@ static struct cftype ss_files[] = { struct cgroup_subsys net_cls_subsys = { .name = "net_cls", .css_alloc = cgrp_css_alloc, + .css_online = cgrp_css_online, .css_free = cgrp_css_free, .subsys_id = net_cls_subsys_id, .base_cftypes = ss_files, -- 1.7.11.7