diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index aad41f0..7dc8788 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -149,12 +149,14 @@ struct cgroup_root cgrp_dfl_root;
*/
static bool cgrp_dfl_root_visible;
+/*
+ * Set by the boot param of the same name and makes subsystems with NULL
+ * ->dfl_files to use ->legacy_files on the default hierarchy.
+ */
+static bool cgroup_legacy_files_on_dfl;
+
/* 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
- ;
+static unsigned int cgrp_dfl_root_inhibit_ss_mask;
/* The list of hierarchy roots */
@@ -180,13 +182,15 @@ static u64 css_serial_nr_next = 1;
*/
static int need_forkexit_callback __read_mostly;
-static struct cftype cgroup_base_files[];
+static struct cftype cgroup_dfl_base_files[];
+static struct cftype cgroup_legacy_base_files[];
static void cgroup_put(struct cgroup *cgrp);
static int rebind_subsystems(struct cgroup_root *dst_root,
unsigned int ss_mask);
static int cgroup_destroy_locked(struct cgroup *cgrp);
-static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss);
+static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
+ bool visible);
static void css_release(struct percpu_ref *ref);
static void kill_css(struct cgroup_subsys_state *css);
static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
@@ -1037,6 +1041,58 @@ static void cgroup_put(struct cgroup *cgrp)
}
/**
+ * cgroup_refresh_child_subsys_mask - update child_subsys_mask
+ * @cgrp: the target cgroup
+ *
+ * On the default hierarchy, a subsystem may request other subsystems to be
+ * enabled together through its ->depends_on mask. In such cases, more
+ * subsystems than specified in "cgroup.subtree_control" may be enabled.
+ *
+ * This function determines which subsystems need to be enabled given the
+ * current @cgrp->subtree_control and records it in
+ * @cgrp->child_subsys_mask. The resulting mask is always a superset of
+ * @cgrp->subtree_control and follows the usual hierarchy rules.
+ */
+static void cgroup_refresh_child_subsys_mask(struct cgroup *cgrp)
+{
+ struct cgroup *parent = cgroup_parent(cgrp);
+ unsigned int cur_ss_mask = cgrp->subtree_control;
+ struct cgroup_subsys *ss;
+ int ssid;
+
+ lockdep_assert_held(&cgroup_mutex);
+
+ if (!cgroup_on_dfl(cgrp)) {
+ cgrp->child_subsys_mask = cur_ss_mask;
+ return;
+ }
+
+ while (true) {
+ unsigned int new_ss_mask = cur_ss_mask;
+
+ for_each_subsys(ss, ssid)
+ if (cur_ss_mask & (1 << ssid))
+ new_ss_mask |= ss->depends_on;
+
+ /*
+ * Mask out subsystems which aren't available. This can
+ * happen only if some depended-upon subsystems were bound
+ * to non-default hierarchies.
+ */
+ if (parent)
+ new_ss_mask &= parent->child_subsys_mask;
+ else
+ new_ss_mask &= cgrp->root->subsys_mask;
+
+ if (new_ss_mask == cur_ss_mask)
+ break;
+ cur_ss_mask = new_ss_mask;
+ }
+
+ cgrp->child_subsys_mask = cur_ss_mask;
+}
+
+/**
* cgroup_kn_unlock - unlocking helper for cgroup kernfs methods
* @kn: the kernfs_node being serviced
*
@@ -1208,12 +1264,15 @@ 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);
@@ -1233,8 +1292,6 @@ static int cgroup_show_options(struct seq_file *seq,
for_each_subsys(ss, ssid)
if (root->subsys_mask & (1 << ssid))
seq_printf(seq, ",%s", ss->name);
- if (root->flags & CGRP_ROOT_SANE_BEHAVIOR)
- seq_puts(seq, ",sane_behavior");
if (root->flags & CGRP_ROOT_NOPREFIX)
seq_puts(seq, ",noprefix");
if (root->flags & CGRP_ROOT_XATTR)
@@ -1268,6 +1325,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
bool all_ss = false, one_ss = false;
unsigned int mask = -1U;
struct cgroup_subsys *ss;
+ int nr_opts = 0;
int i;
#ifdef CONFIG_CPUSETS
@@ -1277,6 +1335,8 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
memset(opts, 0, sizeof(*opts));
while ((token = strsep(&o, ",")) != NULL) {
+ nr_opts++;
+
if (!*token)
return -EINVAL;
if (!strcmp(token, "none")) {
@@ -1361,37 +1421,33 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
return -ENOENT;
}
- /* Consistency checks */
-
if (opts->flags & CGRP_ROOT_SANE_BEHAVIOR) {
pr_warn("sane_behavior: this is still under development and its behaviors will change, proceed at your own risk\n");
-
- if ((opts->flags & (CGRP_ROOT_NOPREFIX | CGRP_ROOT_XATTR)) ||
- opts->cpuset_clone_children || opts->release_agent ||
- opts->name) {
- pr_err("sane_behavior: noprefix, xattr, clone_children, release_agent and name are not allowed\n");
+ if (nr_opts != 1) {
+ pr_err("sane_behavior: no other mount options allowed\n");
return -EINVAL;
}
- } else {
- /*
- * If the 'all' option was specified select all the
- * subsystems, otherwise if 'none', 'name=' and a subsystem
- * name options were not specified, let's default to 'all'
- */
- if (all_ss || (!one_ss && !opts->none && !opts->name))
- for_each_subsys(ss, i)
- if (!ss->disabled)
- opts->subsys_mask |= (1 << i);
-
- /*
- * We either have to specify by name or by subsystems. (So
- * all empty hierarchies must have a name).
- */
- if (!opts->subsys_mask && !opts->name)
- return -EINVAL;
+ return 0;
}
/*
+ * If the 'all' option was specified select all the subsystems,
+ * otherwise if 'none', 'name=' and a subsystem name options were
+ * not specified, let's default to 'all'
+ */
+ if (all_ss || (!one_ss && !opts->none && !opts->name))
+ for_each_subsys(ss, i)
+ if (!ss->disabled)
+ opts->subsys_mask |= (1 << i);
+
+ /*
+ * We either have to specify by name or by subsystems. (So all
+ * empty hierarchies must have a name).
+ */
+ if (!opts->subsys_mask && !opts->name)
+ return -EINVAL;
+
+ /*
* Option noprefix was introduced just for backward compatibility
* with the old cpuset, so we allow noprefix only if mounting just
* the cpuset subsystem.
@@ -1399,7 +1455,6 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
return -EINVAL;
-
/* Can't specify "none" and some subsystems */
if (opts->subsys_mask && opts->none)
return -EINVAL;
@@ -1414,8 +1469,8 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
struct cgroup_sb_opts opts;
unsigned int added_mask, removed_mask;
- if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) {
- pr_err("sane_behavior: remount is not allowed\n");
+ if (root == &cgrp_dfl_root) {
+ pr_err("remount is not allowed\n");
return -EINVAL;
}
@@ -1434,11 +1489,10 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
removed_mask = root->subsys_mask & ~opts.subsys_mask;
/* Don't allow flags or name to change at remount */
- if (((opts.flags ^ root->flags) & CGRP_ROOT_OPTION_MASK) ||
+ if ((opts.flags ^ root->flags) ||
(opts.name && strcmp(opts.name, root->name))) {
pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
- opts.flags & CGRP_ROOT_OPTION_MASK, opts.name ?: "",
- root->flags & CGRP_ROOT_OPTION_MASK, root->name);
+ opts.flags, opts.name ?: "", root->flags, root->name);
ret = -EINVAL;
goto out_unlock;
}
@@ -1563,6 +1617,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned int ss_mask)
{
LIST_HEAD(tmp_links);
struct cgroup *root_cgrp = &root->cgrp;
+ struct cftype *base_files;
struct css_set *cset;