diff options
| -rw-r--r-- | include/linux/cgroup.h | 2 | ||||
| -rw-r--r-- | include/linux/cgroup_subsys.h | 11 | ||||
| -rw-r--r-- | kernel/cgroup.c | 21 |
3 files changed, 27 insertions, 7 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 4afe544d3547..8a111dd42d7a 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -305,6 +305,8 @@ enum { * the flag is not created. * * - blkcg: blk-throttle becomes properly hierarchical. + * + * - debug: disallowed on the default hierarchy. */ CGRP_ROOT_SANE_BEHAVIOR = (1 << 0), diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index 768fe44e19f0..98c4f9b12b03 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -7,10 +7,6 @@ SUBSYS(cpuset) #endif -#if IS_ENABLED(CONFIG_CGROUP_DEBUG) -SUBSYS(debug) -#endif - #if IS_ENABLED(CONFIG_CGROUP_SCHED) SUBSYS(cpu) #endif @@ -50,6 +46,13 @@ SUBSYS(net_prio) #if IS_ENABLED(CONFIG_CGROUP_HUGETLB) SUBSYS(hugetlb) #endif + +/* + * The following subsystems are not supported on the default hierarchy. + */ +#if IS_ENABLED(CONFIG_CGROUP_DEBUG) +SUBSYS(debug) +#endif /* * DO NOT ADD ANY SUBSYSTEM WITHOUT EXPLICIT ACKS FROM CGROUP MAINTAINERS. */ diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 082bb842b11a..a5f75ac4e793 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -148,6 +148,13 @@ struct cgroup_root cgrp_dfl_root; */ static bool cgrp_dfl_root_visible; +/* some controllers are not supported in the default hierarchy */ +static const unsigned int cgrp_dfl_root_inhibit_ss_mask = 0 +#ifdef CONFIG_CGROUP_DEBUG + | (1 << debug_cgrp_id) +#endif + ; + /* The list of hierarchy roots */ static LIST_HEAD(cgroup_roots); @@ -1126,6 +1133,7 @@ static void cgroup_clear_dir(struct cgroup *cgrp, unsigned int subsys_mask) static int rebind_subsystems(struct cgroup_root *dst_root, unsigned int ss_mask) { struct cgroup_subsys *ss; + unsigned int tmp_ss_mask; int ssid, i, ret; lockdep_assert_held(&cgroup_mutex); @@ -1143,7 +1151,12 @@ static int rebind_subsystems(struct cgroup_root *dst_root, unsigned int ss_mask) return -EBUSY; } - ret = cgroup_populate_dir(&dst_root->cgrp, ss_mask); + /* skip creating root files on dfl_root for inhibited subsystems */ + tmp_ss_mask = ss_mask; + if (dst_root == &cgrp_dfl_root) + tmp_ss_mask &= ~cgrp_dfl_root_inhibit_ss_mask; + + ret = cgroup_populate_dir(&dst_root->cgrp, tmp_ss_mask); if (ret) { if (dst_root != &cgrp_dfl_root) return ret; @@ -2426,7 +2439,8 @@ static int cgroup_root_controllers_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - cgroup_print_ss_mask(seq, cgrp->root->subsys_mask); + cgroup_print_ss_mask(seq, cgrp->root->subsys_mask & + ~cgrp_dfl_root_inhibit_ss_mask); return 0; } @@ -2564,7 +2578,8 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, if (tok[0] == '\0') continue; for_each_subsys(ss, ssid) { - if (ss->disabled || strcmp(tok + 1, ss->name)) + if (ss->disabled || strcmp(tok + 1, ss->name) || + ((1 << ss->id) & cgrp_dfl_root_inhibit_ss_mask)) continue; if (*tok == '+') { |