Currently, cftypes added by cgroup_add_cftypes() are used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through.
cgroup_subsys will grow two separate cftype addition functions and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch adds cgroup_add_legacy_cftypes() which currently is a simple wrapper around cgroup_add_cftypes() and replaces all cgroup_add_cftypes() usages with it. While at it, this patch drops a completely spurious return from __hugetlb_cgroup_file_init(). This patch doesn't introduce any functional differences. Signed-off-by: Tejun Heo <[email protected]> Acked-by: Neil Horman <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Aneesh Kumar K.V <[email protected]> --- block/blk-cgroup.c | 3 ++- include/linux/cgroup.h | 2 +- kernel/cgroup.c | 7 ++++++- mm/hugetlb_cgroup.c | 5 ++--- mm/memcontrol.c | 3 ++- net/ipv4/tcp_memcontrol.c | 2 +- 6 files changed, 14 insertions(+), 8 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 5cfbc72..2541cf0 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1124,7 +1124,8 @@ int __init blkcg_policy_register(struct blkcg_policy *pol) /* everything is in place, add intf files for the new policy */ if (pol->cftypes) - WARN_ON(cgroup_add_cftypes(&blkio_cgrp_subsys, pol->cftypes)); + WARN_ON(cgroup_add_legacy_cftypes(&blkio_cgrp_subsys, + pol->cftypes)); ret = 0; out_unlock: mutex_unlock(&blkcg_pol_mutex); diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index a6e9c2e..f5f0fee 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -590,7 +590,7 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp) char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen); -int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); +int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); int cgroup_rm_cftypes(struct cftype *cfts); bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 6496a83..c275aa4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3170,7 +3170,7 @@ int cgroup_rm_cftypes(struct cftype *cfts) * function currently returns 0 as long as @cfts registration is successful * even if some file creation attempts on existing cgroups fail. */ -int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) +static int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) { int ret; @@ -3195,6 +3195,11 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) return ret; } +int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) +{ + return cgroup_add_cftypes(ss, cfts); +} + /** * cgroup_task_count - count the number of tasks in a cgroup. * @cgrp: the cgroup in question diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 493f758..9aae6f4 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -358,9 +358,8 @@ static void __init __hugetlb_cgroup_file_init(int idx) cft = &h->cgroup_files[4]; memset(cft, 0, sizeof(*cft)); - WARN_ON(cgroup_add_cftypes(&hugetlb_cgrp_subsys, h->cgroup_files)); - - return; + WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys, + h->cgroup_files)); } void __init hugetlb_cgroup_file_init(void) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8331f27..b6b3c6f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7065,7 +7065,8 @@ __setup("swapaccount=", enable_swap_account); static void __init memsw_file_init(void) { - WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys, memsw_cgroup_files)); + WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, + memsw_cgroup_files)); } static void __init enable_swap_cgroup(void) diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c index f7a2ec3..3af5226 100644 --- a/net/ipv4/tcp_memcontrol.c +++ b/net/ipv4/tcp_memcontrol.c @@ -222,7 +222,7 @@ static struct cftype tcp_files[] = { static int __init tcp_memcontrol_init(void) { - WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys, tcp_files)); + WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, tcp_files)); return 0; } __initcall(tcp_memcontrol_init); -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
