Events should be removed after rmdir of cgroup directory, but before destroying subsystem state objects. Let's take reference to cgroup directory dentry to do that.
Signed-off-by: Kirill A. Shutemov <[email protected]> Acked-by: KAMEZAWA Hiroyuki <[email protected]> --- include/linux/cgroup.h | 3 --- kernel/cgroup.c | 8 ++++++++ mm/memcontrol.c | 9 --------- 3 files changed, 8 insertions(+), 12 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 64cebfe..1719c75 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -395,9 +395,6 @@ struct cftype { * closes the eventfd or on cgroup removing. * This callback must be implemented, if you want provide * notification functionality. - * - * Be careful. It can be called after destroy(), so you have - * to keep all nesessary data, until all events are removed. */ int (*unregister_event)(struct cgroup *cgrp, struct cftype *cft, struct eventfd_ctx *eventfd); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 46903cb..d142524 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2979,6 +2979,7 @@ static void cgroup_event_remove(struct work_struct *work) eventfd_ctx_put(event->eventfd); kfree(event); + dput(cgrp->dentry); } /* @@ -3099,6 +3100,13 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, goto fail; } + /* + * Events should be removed after rmdir of cgroup directory, but before + * destroying subsystem state objects. Let's take reference to cgroup + * directory dentry to do that. + */ + dget(cgrp->dentry); + spin_lock(&cgrp->event_list_lock); list_add(&event->list, &cgrp->event_list); spin_unlock(&cgrp->event_list_lock); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a443c30..8fe6e7f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3358,12 +3358,6 @@ static int mem_cgroup_register_event(struct cgroup *cgrp, struct cftype *cft, } } - /* - * We need to increment refcnt to be sure that all thresholds - * will be unregistered before calling __mem_cgroup_free() - */ - mem_cgroup_get(memcg); - if (type == _MEM) rcu_assign_pointer(memcg->thresholds, thresholds_new); else @@ -3457,9 +3451,6 @@ assign: /* To be sure that nobody uses thresholds before freeing it */ synchronize_rcu(); - for (i = 0; i < thresholds->size - size; i++) - mem_cgroup_put(memcg); - kfree(thresholds); unlock: mutex_unlock(&memcg->thresholds_lock); -- 1.6.6.2 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
