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Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c153
1 files changed, 77 insertions, 76 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1051c1f69674..8f296b83b6a3 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -96,16 +96,19 @@ static DEFINE_MUTEX(cgroup_root_mutex);
*/
#define SUBSYS(_x) [_x ## _subsys_id] = &_x ## _subsys,
#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
-static struct cgroup_subsys *subsys[CGROUP_SUBSYS_COUNT] = {
+static struct cgroup_subsys *cgroup_subsys[CGROUP_SUBSYS_COUNT] = {
#include <linux/cgroup_subsys.h>
};
/*
- * The "rootnode" hierarchy is the "dummy hierarchy", reserved for the
- * subsystems that are otherwise unattached - it never has more than a
- * single cgroup, and all tasks are part of that cgroup.
+ * The dummy hierarchy, reserved for the subsystems that are otherwise
+ * unattached - it never has more than a single cgroup, and all tasks are
+ * part of that cgroup.
*/
-static struct cgroupfs_root rootnode;
+static struct cgroupfs_root cgroup_dummy_root;
+
+/* dummy_top is a shorthand for the dummy hierarchy's top cgroup */
+static struct cgroup * const cgroup_dummy_top = &cgroup_dummy_root.top_cgroup;
/*
* cgroupfs file entry, pointed to from leaf dentry->d_fsdata.
@@ -183,8 +186,8 @@ struct cgroup_event {
/* The list of hierarchy roots */
-static LIST_HEAD(roots);
-static int root_count;
+static LIST_HEAD(cgroup_roots);
+static int cgroup_root_count;
/*
* Hierarchy ID allocation and mapping. It follows the same exclusion
@@ -193,9 +196,6 @@ static int root_count;
*/
static DEFINE_IDR(cgroup_hierarchy_idr);
-/* dummytop is a shorthand for the dummy hierarchy's top cgroup */
-#define dummytop (&rootnode.top_cgroup)
-
static struct cgroup_name root_cgroup_name = { .name = "/" };
/*
@@ -268,7 +268,7 @@ list_for_each_entry(_ss, &_root->subsys_list, sibling)
/* for_each_active_root() allows you to iterate across the active hierarchies */
#define for_each_active_root(_root) \
-list_for_each_entry(_root, &roots, root_list)
+list_for_each_entry(_root, &cgroup_roots, root_list)
static inline struct cgroup *__d_cgrp(struct dentry *dentry)
{
@@ -650,7 +650,7 @@ static struct css_set *find_css_set(struct css_set *old_cset,
return NULL;
/* Allocate all the cgrp_cset_link objects that we'll need */
- if (allocate_cgrp_cset_links(root_count, &tmp_links) < 0) {
+ if (allocate_cgrp_cset_links(cgroup_root_count, &tmp_links) < 0) {
kfree(cset);
return NULL;
}
@@ -1000,7 +1000,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
/* Check that any added subsystems are currently free */
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
unsigned long bit = 1UL << i;
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
if (!(bit & added_mask))
continue;
/*
@@ -1009,7 +1009,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
* ensure that subsystems won't disappear once selected.
*/
BUG_ON(ss == NULL);
- if (ss->root != &rootnode) {
+ if (ss->root != &cgroup_dummy_root) {
/* Subsystem isn't free */
return -EBUSY;
}
@@ -1024,15 +1024,15 @@ static int rebind_subsystems(struct cgroupfs_root *root,
/* Process each subsystem */
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
unsigned long bit = 1UL << i;
if (bit & added_mask) {
/* We're binding this subsystem to this hierarchy */
BUG_ON(ss == NULL);
BUG_ON(cgrp->subsys[i]);
- BUG_ON(!dummytop->subsys[i]);
- BUG_ON(dummytop->subsys[i]->cgroup != dummytop);
- cgrp->subsys[i] = dummytop->subsys[i];
+ BUG_ON(!cgroup_dummy_top->subsys[i]);
+ BUG_ON(cgroup_dummy_top->subsys[i]->cgroup != cgroup_dummy_top);
+ cgrp->subsys[i] = cgroup_dummy_top->subsys[i];
cgrp->subsys[i]->cgroup = cgrp;
list_move(&ss->sibling, &root->subsys_list);
ss->root = root;
@@ -1042,14 +1042,14 @@ static int rebind_subsystems(struct cgroupfs_root *root,
} else if (bit & removed_mask) {
/* We're removing this subsystem */
BUG_ON(ss == NULL);
- BUG_ON(cgrp->subsys[i] != dummytop->subsys[i]);
+ BUG_ON(cgrp->subsys[i] != cgroup_dummy_top->subsys[i]);
BUG_ON(cgrp->subsys[i]->cgroup != cgrp);
if (ss->bind)
- ss->bind(dummytop);
- dummytop->subsys[i]->cgroup = dummytop;
+ ss->bind(cgroup_dummy_top);
+ cgroup_dummy_top->subsys[i]->cgroup = cgroup_dummy_top;
cgrp->subsys[i] = NULL;
- subsys[i]->root = &rootnode;
- list_move(&ss->sibling, &rootnode.subsys_list);
+ cgroup_subsys[i]->root = &cgroup_dummy_root;
+ list_move(&ss->sibling, &cgroup_dummy_root.subsys_list);
/* subsystem is now free - drop reference on module */
module_put(ss->module);
} else if (bit & final_subsys_mask) {
@@ -1112,10 +1112,10 @@ struct cgroup_sb_opts {
};
/*
- * Convert a hierarchy specifier into a bitmask of subsystems and flags. Call
- * with cgroup_mutex held to protect the subsys[] array. This function takes
- * refcounts on subsystems to be used, unless it returns error, in which case
- * no refcounts are taken.
+ * Convert a hierarchy specifier into a bitmask of subsystems and
+ * flags. Call with cgroup_mutex held to protect the cgroup_subsys[]
+ * array. This function takes refcounts on subsystems to be used, unless it
+ * returns error, in which case no refcounts are taken.
*/
static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
{
@@ -1201,7 +1201,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
}
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
if (ss == NULL)
continue;
if (strcmp(token, ss->name))
@@ -1228,7 +1228,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
*/
if (all_ss || (!one_ss && !opts->none && !opts->name)) {
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
if (ss == NULL)
continue;
if (ss->disabled)
@@ -1284,7 +1284,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
if (!(bit & opts->subsys_mask))
continue;
- if (!try_module_get(subsys[i]->module)) {
+ if (!try_module_get(cgroup_subsys[i]->module)) {
module_pin_failed = true;
break;
}
@@ -1301,7 +1301,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
if (!(bit & opts->subsys_mask))
continue;
- module_put(subsys[i]->module);
+ module_put(cgroup_subsys[i]->module);
}
return -ENOENT;
}
@@ -1317,7 +1317,7 @@ static void drop_parsed_module_refcounts(unsigned long subsys_mask)
if (!(bit & subsys_mask))
continue;
- module_put(subsys[i]->module);
+ module_put(cgroup_subsys[i]->module);
}
}
@@ -1648,8 +1648,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
/* EBUSY should be the only error here */
BUG_ON(ret);
- list_add(&root->root_list, &roots);
- root_count++;
+ list_add(&root->root_list, &cgroup_roots);
+ cgroup_root_count++;
sb->s_root->d_fsdata = root_cgrp;
root->top_cgroup.dentry = sb->s_root;
@@ -1746,7 +1746,7 @@ static void cgroup_kill_sb(struct super_block *sb) {
if (!list_empty(&root->root_list)) {
list_del(&root->root_list);
- root_count--;
+ cgroup_root_count--;
}
cgroup_exit_root_id(root);
@@ -2807,7 +2807,7 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
u64 update_before;
/* %NULL @cfts indicates abort and don't bother if @ss isn't attached */
- if (!cfts || ss->root == &rootnode ||
+ if (!cfts || ss->root == &cgroup_dummy_root ||
!atomic_inc_not_zero(&sb->s_active)) {
mutex_unlock(&cgroup_mutex);
return;
@@ -4186,7 +4186,7 @@ static void init_cgroup_css(struct cgroup_subsys_state *css,
css->cgroup = cgrp;
css->flags = 0;
css->id = NULL;
- if (cgrp == dummytop)
+ if (cgrp == cgroup_dummy_top)
css->flags |= CSS_ROOT;
BUG_ON(cgrp->subsys[ss->subsys_id]);
cgrp->subsys[ss->subsys_id] = css;
@@ -4615,12 +4615,12 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
cgroup_init_cftsets(ss);
/* Create the top cgroup state for this subsystem */
- list_add(&ss->sibling, &rootnode.subsys_list);
- ss->root = &rootnode;
- css = ss->css_alloc(dummytop);
+ list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
+ ss->root = &cgroup_dummy_root;
+ css = ss->css_alloc(cgroup_dummy_top);
/* We don't handle early failures gracefully */
BUG_ON(IS_ERR(css));
- init_cgroup_css(css, ss, dummytop);
+ init_cgroup_css(css, ss, cgroup_dummy_top);
/* Update the init_css_set to contain a subsys
* pointer to this state - since the subsystem is
@@ -4635,7 +4635,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
* need to invoke fork callbacks here. */
BUG_ON(!list_empty(&init_task.tasks));
- BUG_ON(online_css(ss, dummytop));
+ BUG_ON(online_css(ss, cgroup_dummy_top));
mutex_unlock(&cgroup_mutex);
@@ -4681,7 +4681,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
*/
if (ss->module == NULL) {
/* a sanity check */
- BUG_ON(subsys[ss->subsys_id] != ss);
+ BUG_ON(cgroup_subsys[ss->subsys_id] != ss);
return 0;
}
@@ -4689,26 +4689,26 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
cgroup_init_cftsets(ss);
mutex_lock(&cgroup_mutex);
- subsys[ss->subsys_id] = ss;
+ cgroup_subsys[ss->subsys_id] = ss;
/*
* no ss->css_alloc seems to need anything important in the ss
- * struct, so this can happen first (i.e. before the rootnode
+ * struct, so this can happen first (i.e. before the dummy root
* attachment).
*/
- css = ss->css_alloc(dummytop);
+ css = ss->css_alloc(cgroup_dummy_top);
if (IS_ERR(css)) {
- /* failure case - need to deassign the subsys[] slot. */
- subsys[ss->subsys_id] = NULL;
+ /* failure case - need to deassign the cgroup_subsys[] slot. */
+ cgroup_subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
return PTR_ERR(css);
}
- list_add(&ss->sibling, &rootnode.subsys_list);
- ss->root = &rootnode;
+ list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
+ ss->root = &cgroup_dummy_root;
/* our new subsystem will be attached to the dummy hierarchy. */
- init_cgroup_css(css, ss, dummytop);
+ init_cgroup_css(css, ss, cgroup_dummy_top);
/* init_idr must be after init_cgroup_css because it sets css->id. */
if (ss->use_id) {
ret = cgroup_init_idr(ss, css);
@@ -4739,7 +4739,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
}
write_unlock(&css_set_lock);
- ret = online_css(ss, dummytop);
+ ret = online_css(ss, cgroup_dummy_top);
if (ret)
goto err_unload;
@@ -4774,27 +4774,28 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
* try_module_get in parse_cgroupfs_options should ensure that it
* doesn't start being used while we're killing it off.
*/
- BUG_ON(ss->root != &rootnode);
+ BUG_ON(ss->root != &cgroup_dummy_root);
mutex_lock(&cgroup_mutex);
- offline_css(ss, dummytop);
+ offline_css(ss, cgroup_dummy_top);
if (ss->use_id)
idr_destroy(&ss->idr);
/* deassign the subsys_id */
- subsys[ss->subsys_id] = NULL;
+ cgroup_subsys[ss->subsys_id] = NULL;
- /* remove subsystem from rootnode's list of subsystems */
+ /* remove subsystem from the dummy root's list of subsystems */
list_del_init(&ss->sibling);
/*
- * disentangle the css from all css_sets attached to the dummytop. as
- * in loading, we need to pay our respects to the hashtable gods.
+ * disentangle the css from all css_sets attached to the dummy
+ * top. as in loading, we need to pay our respects to the hashtable
+ * gods.
*/
write_lock(&css_set_lock);
- list_for_each_entry(link, &dummytop->cset_links, cset_link) {
+ list_for_each_entry(link, &cgroup_dummy_top->cset_links, cset_link) {
struct css_set *cset = link->cset;
unsigned long key;
@@ -4806,13 +4807,13 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
write_unlock(&css_set_lock);
/*
- * remove subsystem's css from the dummytop and free it - need to
- * free before marking as null because ss->css_free needs the
- * cgrp->subsys pointer to find their state. note that this also
- * takes care of freeing the css_id.
+ * remove subsystem's css from the cgroup_dummy_top and free it -
+ * need to free before marking as null because ss->css_free needs
+ * the cgrp->subsys pointer to find their state. note that this
+ * also takes care of freeing the css_id.
*/
- ss->css_free(dummytop);
- dummytop->subsys[ss->subsys_id] = NULL;
+ ss->css_free(cgroup_dummy_top);
+ cgroup_dummy_top->subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
}
@@ -4832,17 +4833,17 @@ int __init cgroup_init_early(void)
INIT_LIST_HEAD(&init_css_set.tasks);
INIT_HLIST_NODE(&init_css_set.hlist);
css_set_count = 1;
- init_cgroup_root(&rootnode);
- root_count = 1;
+ init_cgroup_root(&cgroup_dummy_root);
+ cgroup_root_count = 1;
init_task.cgroups = &init_css_set;
init_cgrp_cset_link.cset = &init_css_set;
- init_cgrp_cset_link.cgrp = dummytop;
- list_add(&init_cgrp_cset_link.cset_link, &rootnode.top_cgroup.cset_links);
+ init_cgrp_cset_link.cgrp = cgroup_dummy_top;
+ list_add(&init_cgrp_cset_link.cset_link, &cgroup_dummy_top->cset_links);
list_add(&init_cgrp_cset_link.cgrp_link, &init_css_set.cgrp_links);
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
/* at bootup time, we don't worry about modular subsystems */
if (!ss || ss->module)
@@ -4881,7 +4882,7 @@ int __init cgroup_init(void)
return err;
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
/* at bootup time, we don't worry about modular subsystems */
if (!ss || ss->module)
@@ -4900,7 +4901,7 @@ int __init cgroup_init(void)
mutex_lock(&cgroup_mutex);
mutex_lock(&cgroup_root_mutex);
- BUG_ON(cgroup_init_root_id(&rootnode));
+ BUG_ON(cgroup_init_root_id(&cgroup_dummy_root));
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
@@ -5004,7 +5005,7 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
*/
mutex_lock(&cgroup_mutex);
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
if (ss == NULL)
continue;
seq_printf(m, "%s\t%d\t%d\t%d\n",
@@ -5101,7 +5102,7 @@ void cgroup_post_fork(struct task_struct *child)
* can't touch that.
*/
for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
if (ss->fork)
ss->fork(child);
@@ -5172,7 +5173,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
* subsystems, see cgroup_post_fork() for details.
*/
for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
if (ss->exit) {
struct cgroup *old_cgrp =
@@ -5291,7 +5292,7 @@ static int __init cgroup_disable(char *str)
if (!*token)
continue;
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- struct cgroup_subsys *ss = subsys[i];
+ struct cgroup_subsys *ss = cgroup_subsys[i];
/*
* cgroup_disable, being at boot time, can't