diff options
| -rw-r--r-- | include/linux/cgroup.h | 8 | ||||
| -rw-r--r-- | kernel/cgroup.c | 46 |
2 files changed, 36 insertions, 18 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 8a111dd42d7a..8d52c8e5b510 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -203,7 +203,13 @@ struct cgroup { struct kernfs_node *kn; /* cgroup kernfs entry */ struct kernfs_node *populated_kn; /* kn for "cgroup.subtree_populated" */ - /* the bitmask of subsystems enabled on the child cgroups */ + /* + * The bitmask of subsystems enabled on the child cgroups. + * ->subtree_control is the one configured through + * "cgroup.subtree_control" while ->child_subsys_mask is the + * effective one which may have more subsystems enabled. + */ + unsigned int subtree_control; unsigned int child_subsys_mask; /* Private pointers for each registered subsystem */ diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a46d7e2012b4..14a9d88eacf9 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1036,6 +1036,11 @@ static void cgroup_put(struct cgroup *cgrp) css_put(&cgrp->self); } +static void cgroup_refresh_child_subsys_mask(struct cgroup *cgrp) +{ + cgrp->child_subsys_mask = cgrp->subtree_control; +} + /** * cgroup_kn_unlock - unlocking helper for cgroup kernfs methods * @kn: the kernfs_node being serviced @@ -1208,12 +1213,15 @@ static int rebind_subsystems(struct cgroup_root *dst_root, unsigned int ss_mask) up_write(&css_set_rwsem); src_root->subsys_mask &= ~(1 << ssid); - src_root->cgrp.child_subsys_mask &= ~(1 << ssid); + src_root->cgrp.subtree_control &= ~(1 << ssid); + cgroup_refresh_child_subsys_mask(&src_root->cgrp); /* default hierarchy doesn't enable controllers by default */ dst_root->subsys_mask |= 1 << ssid; - if (dst_root != &cgrp_dfl_root) - dst_root->cgrp.child_subsys_mask |= 1 << ssid; + if (dst_root != &cgrp_dfl_root) { + dst_root->cgrp.subtree_control |= 1 << ssid; + cgroup_refresh_child_subsys_mask(&dst_root->cgrp); + } if (ss->bind) ss->bind(css); @@ -2454,7 +2462,7 @@ static int cgroup_controllers_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - cgroup_print_ss_mask(seq, cgroup_parent(cgrp)->child_subsys_mask); + cgroup_print_ss_mask(seq, cgroup_parent(cgrp)->subtree_control); return 0; } @@ -2463,7 +2471,7 @@ static int cgroup_subtree_control_show(struct seq_file *seq, void *v) { struct cgroup *cgrp = seq_css(seq)->cgroup; - cgroup_print_ss_mask(seq, cgrp->child_subsys_mask); + cgroup_print_ss_mask(seq, cgrp->subtree_control); return 0; } @@ -2608,7 +2616,7 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, for_each_subsys(ss, ssid) { if (enable & (1 << ssid)) { - if (cgrp->child_subsys_mask & (1 << ssid)) { + if (cgrp->subtree_control & (1 << ssid)) { enable &= ~(1 << ssid); continue; } @@ -2616,7 +2624,7 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, /* unavailable or not enabled on the parent? */ if (!(cgrp_dfl_root.subsys_mask & (1 << ssid)) || (cgroup_parent(cgrp) && - !(cgroup_parent(cgrp)->child_subsys_mask & (1 << ssid)))) { + !(cgroup_parent(cgrp)->subtree_control & (1 << ssid)))) { ret = -ENOENT; goto out_unlock; } @@ -2644,14 +2652,14 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, return restart_syscall(); } } else if (disable & (1 << ssid)) { - if (!(cgrp->child_subsys_mask & (1 << ssid))) { + if (!(cgrp->subtree_control & (1 << ssid))) { disable &= ~(1 << ssid); continue; } /* a child has it enabled? */ cgroup_for_each_live_child(child, cgrp) { - if (child->child_subsys_mask & (1 << ssid)) { + if (child->subtree_control & (1 << ssid)) { ret = -EBUSY; goto out_unlock; } @@ -2665,7 +2673,7 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, } /* - * Except for the root, child_subsys_mask must be zero for a cgroup + * Except for the root, subtree_control must be zero for a cgroup * with tasks so that child cgroups don't compete against tasks. */ if (enable && cgroup_parent(cgrp) && !list_empty(&cgrp->cset_links)) { @@ -2673,8 +2681,9 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, goto out_unlock; } - cgrp->child_subsys_mask |= enable; - cgrp->child_subsys_mask &= ~disable; + cgrp->subtree_control |= enable; + cgrp->subtree_control &= ~disable; + cgroup_refresh_child_subsys_mask(cgrp); /* create new csses */ for_each_subsys(ss, ssid) { @@ -2713,8 +2722,9 @@ out_unlock: return ret ?: nbytes; err_undo_css: - cgrp->child_subsys_mask &= ~enable; - cgrp->child_subsys_mask |= disable; + cgrp->subtree_control &= ~enable; + cgrp->subtree_control |= disable; + cgroup_refresh_child_subsys_mask(cgrp); for_each_subsys(ss, ssid) { if (!(enable & (1 << ssid))) @@ -4428,10 +4438,12 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, /* * On the default hierarchy, a child doesn't automatically inherit - * child_subsys_mask from the parent. Each is configured manually. + * subtree_control from the parent. Each is configured manually. */ - if (!cgroup_on_dfl(cgrp)) - cgrp->child_subsys_mask = parent->child_subsys_mask; + if (!cgroup_on_dfl(cgrp)) { + cgrp->subtree_control = parent->subtree_control; + cgroup_refresh_child_subsys_mask(cgrp); + } kernfs_activate(kn); |