From: Pavel Tikhomirov <ptikhomi...@virtuozzo.com> It is likely a leftover from __cgroup_path where it protects cgrp->name in cgroup_get_ve_root there is nothing rcu_dereferenced, also in cgroup_is_descendant there is no rcu for cgrp->parent.
https://jira.sw.ru/browse/PSBM-69678 Signed-off-by: Pavel Tikhomirov <ptikhomi...@virtuozzo.com> Reviewed-by: Andrey Ryabinin <aryabi...@virtuozzo.com> eshatokhin@: It seems, the actual fix for PSBM-69678 was ported to VZ8 as a part of 90c47968843b3 "ve/cgroups: Introduce subgroups_limit control" and 90368f957e01b "ve/sched/stat: Introduce functions to calculate vcpustat data". Only "f8168436b4eb ve/cgroup: remove rcu_read_lock from cgroup_get_ve_root" was skipped, so here it is. cgroup_get_ve_root1() does not dereference RCU-protected pointers, cgroup_parent() does not do that do that either, so rcu_read_lock/unlock are not needed. Done in the scope of https://jira.sw.ru/browse/PSBM-127794. Signed-off-by: Evgenii Shatokhin <eshatok...@virtuozzo.com> --- kernel/cgroup/cgroup.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 779a71bdbaef..23b8b3ffe50f 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2087,7 +2087,6 @@ struct cgroup *cgroup_get_ve_root1(struct cgroup *cgrp) { struct cgroup *ve_root = NULL; - rcu_read_lock(); do { if (test_bit(CGRP_VE_ROOT, &cgrp->flags)) { ve_root = cgrp; @@ -2095,7 +2094,6 @@ struct cgroup *cgroup_get_ve_root1(struct cgroup *cgrp) } cgrp = cgroup_parent(cgrp); } while (cgrp); - rcu_read_unlock(); return ve_root; } -- 2.29.0 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
