Allows the net_cls cgroup subsystem to be compiled as a module From: Ben Blum This patch modifies net/sched/cls_cgroup.c to allow the net_cls subsystem to be optionally compiled as a module instead of builtin. The cgroup_subsys struct is moved around a bit to allow the subsys_id to be either declared as a compile-time constant by the cgroup_subsys.h include in cgroup.h, or, if it's a module, initialized within the struct by cgroup_load_subsys. Signed-off-by: Ben Blum --- net/sched/Kconfig | 2 +- net/sched/cls_cgroup.c | 37 ++++++++++++++++++++++++++++--------- 2 files changed, 29 insertions(+), 10 deletions(-) diff --git a/net/sched/Kconfig b/net/sched/Kconfig index 929218a..8489951 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -328,7 +328,7 @@ config NET_CLS_FLOW module will be called cls_flow. config NET_CLS_CGROUP - bool "Control Group Classifier" + tristate "Control Group Classifier" select NET_CLS depends on CGROUPS ---help--- diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index e4877ca..df9723b 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -24,6 +24,25 @@ struct cgroup_cls_state u32 classid; }; +static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss, + struct cgroup *cgrp); +static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp); +static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp); + +struct cgroup_subsys net_cls_subsys = { + .name = "net_cls", + .create = cgrp_create, + .destroy = cgrp_destroy, + .populate = cgrp_populate, +#ifdef CONFIG_NET_CLS_CGROUP + .subsys_id = net_cls_subsys_id, +#else +#define net_cls_subsys_id net_cls_subsys.subsys_id +#endif + .module = THIS_MODULE, +}; + + static inline struct cgroup_cls_state *cgrp_cls_state(struct cgroup *cgrp) { return container_of(cgroup_subsys_state(cgrp, net_cls_subsys_id), @@ -79,14 +98,6 @@ static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files)); } -struct cgroup_subsys net_cls_subsys = { - .name = "net_cls", - .create = cgrp_create, - .destroy = cgrp_destroy, - .populate = cgrp_populate, - .subsys_id = net_cls_subsys_id, -}; - struct cls_cgroup_head { u32 handle; @@ -277,12 +288,20 @@ static struct tcf_proto_ops cls_cgroup_ops __read_mostly = { static int __init init_cgroup_cls(void) { - return register_tcf_proto_ops(&cls_cgroup_ops); + int ret = register_tcf_proto_ops(&cls_cgroup_ops); + if (ret) + return ret; + ret = cgroup_load_subsys(&net_cls_subsys); + if (ret) + unregister_tcf_proto_ops(&cls_cgroup_ops); + return ret; } static void __exit exit_cgroup_cls(void) { unregister_tcf_proto_ops(&cls_cgroup_ops); + /* TODO: unload subsystem. for now, the try_module_get in load_subsys + * prevents us from getting here. */ } module_init(init_cgroup_cls); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/