From: Tejun Heo Date: Sat, 29 Jun 2013 00:07:30 +0000 (-0700) Subject: cgroup: move number_of_cgroups test out of rebind_subsystems() into cgroup_remount() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f172e67cf9d842bc646d0f66792e38435a334b1e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git cgroup: move number_of_cgroups test out of rebind_subsystems() into cgroup_remount() rebind_subsystems() currently fails if the hierarchy has any !root cgroups; however, on the planned unified hierarchy, rebind_subsystems() will be used while populated. Move the test to cgroup_remount(), which is the only place the test is necessary anyway. As it's impossible for the other two callers of rebind_subsystems() to have populated hierarchy, this doesn't make any behavior changes. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 4ec8d2da94d1..c108d3d1ea30 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1021,13 +1021,6 @@ static int rebind_subsystems(struct cgroupfs_root *root, } } - /* Currently we don't handle adding/removing subsystems when - * any child cgroups exist. This is theoretically supportable - * but involves complex error handling, so it's being left until - * later */ - if (root->number_of_cgroups > 1) - return -EBUSY; - ret = cgroup_populate_dir(cgrp, added_mask); if (ret) return ret; @@ -1373,6 +1366,12 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) goto out_unlock; } + /* remounting is not allowed for populated hierarchies */ + if (root->number_of_cgroups > 1) { + ret = -EBUSY; + goto out_unlock; + } + ret = rebind_subsystems(root, added_mask, removed_mask); if (ret) goto out_unlock;