To make it bindable, we need to thaw all processes when unbinding the freezer subsystem from a cgroup hierarchy.
Signed-off-by: Li Zefan <[email protected]> --- include/linux/cgroup.h | 3 ++- kernel/cgroup.c | 22 ++++++++++++++++++++-- kernel/cgroup_freezer.c | 19 +++++++++++++++++-- 3 files changed, 39 insertions(+), 5 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 49369ff..1e4e1df 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -478,7 +478,8 @@ struct cgroup_subsys { int (*populate)(struct cgroup_subsys *ss, struct cgroup *cgrp); void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp); - void (*bind)(struct cgroup_subsys *ss, struct cgroup *root); + void (*bind)(struct cgroup_subsys *ss, struct cgroup *cgrp, + bool unbind); int subsys_id; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 6364bb5..12c1f7c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1105,6 +1105,22 @@ static int hierarchy_populate_dir(struct cgroup *cgrp, void *data) return 0; } +static int hierarchy_subsys_bind(struct cgroup *cgrp, void *data) +{ + struct cgroup_subsys *ss = data; + + ss->bind(ss, cgrp, false); + return 0; +} + +static int hierarchy_subsys_unbind(struct cgroup *cgrp, void *data) +{ + struct cgroup_subsys *ss = data;; + + ss->bind(ss, cgrp, true); + return 0; +} + /* * Call with cgroup_mutex held. Drops reference counts on modules, including * any duplicate ones that parse_cgroupfs_options took. If this function @@ -1172,7 +1188,8 @@ static int rebind_subsystems(struct cgroupfs_root *root, list_move(&ss->sibling, &root->subsys_list); ss->root = root; if (ss->bind) - ss->bind(ss, cgrp); + cgroup_walk_hierarchy(hierarchy_subsys_bind, + ss, cgrp); mutex_unlock(&ss->hierarchy_mutex); /* refcount was already taken, and we're keeping it */ } else if (bit & removed_bits) { @@ -1180,7 +1197,8 @@ static int rebind_subsystems(struct cgroupfs_root *root, BUG_ON(ss == NULL); mutex_lock(&ss->hierarchy_mutex); if (ss->bind) - ss->bind(ss, dummytop); + cgroup_walk_hierarchy(hierarchy_subsys_unbind, + ss, cgrp); subsys[i]->root = &rootnode; list_move(&ss->sibling, &rootnode.subsys_list); mutex_unlock(&ss->hierarchy_mutex); diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index e7bebb7..de13ce4 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -383,6 +383,21 @@ static int freezer_populate(struct cgroup_subsys *ss, struct cgroup *cgroup) return cgroup_add_files(cgroup, ss, files, ARRAY_SIZE(files)); } +/* + * Thaw all processes before unbinding the freezer subsysem from + * cgroup hierarchy. + * */ +static void freezer_bind(struct cgroup_subsys *ss, struct cgroup *cgrp, + bool unbind) +{ + struct freezer *freezer = cgroup_freezer(cgrp); + + if (!unbind) + return; + + unfreeze_cgroup(cgrp, freezer); +} + struct cgroup_subsys freezer_subsys = { .name = "freezer", .create = freezer_create, @@ -390,7 +405,7 @@ struct cgroup_subsys freezer_subsys = { .populate = freezer_populate, .subsys_id = freezer_subsys_id, .can_attach = freezer_can_attach, - .attach = NULL, .fork = freezer_fork, - .exit = NULL, + .bind = freezer_bind, + .can_bind = 1, }; -- 1.7.0.1 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
