static void cgroup_offline_fn(struct work_struct *work);
static int cgroup_destroy_locked(struct cgroup *cgrp);
-static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
- struct cftype cfts[], bool is_add);
+static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
+ bool is_add);
/* convenient tests for these bits */
static inline bool cgroup_is_dead(const struct cgroup *cgrp)
/*
* Release the subsystem state objects.
*/
- for_each_root_subsys(cgrp->root, ss)
- ss->css_free(cgrp);
+ for_each_root_subsys(cgrp->root, ss) {
+ struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
+ ss->css_free(css);
+ }
cgrp->root->number_of_cgroups--;
mutex_unlock(&cgroup_mutex);
if (!test_bit(i, &subsys_mask))
continue;
list_for_each_entry(set, &ss->cftsets, node)
- cgroup_addrm_files(cgrp, NULL, set->cfts, false);
+ cgroup_addrm_files(cgrp, set->cfts, false);
}
}
list_move(&ss->sibling, &root->subsys_list);
ss->root = root;
if (ss->bind)
- ss->bind(cgrp);
+ ss->bind(cgrp->subsys[i]);
/* refcount was already taken, and we're keeping it */
root->subsys_mask |= bit;
BUG_ON(cgrp->subsys[i]->cgroup != cgrp);
if (ss->bind)
- ss->bind(cgroup_dummy_top);
+ ss->bind(cgroup_dummy_top->subsys[i]);
cgroup_dummy_top->subsys[i]->cgroup = cgroup_dummy_top;
cgrp->subsys[i] = NULL;
cgroup_subsys[i]->root = &cgroup_dummy_root;
INIT_LIST_HEAD(&cgrp->release_list);
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
+ cgrp->dummy_css.cgroup = cgrp;
INIT_LIST_HEAD(&cgrp->event_list);
spin_lock_init(&cgrp->event_list_lock);
simple_xattrs_init(&cgrp->xattrs);
*/
cred = override_creds(&init_cred);
- ret = cgroup_addrm_files(root_cgrp, NULL, cgroup_base_files, true);
+ ret = cgroup_addrm_files(root_cgrp, cgroup_base_files, true);
if (ret)
goto rm_base_files;
rm_base_files:
free_cgrp_cset_links(&tmp_links);
- cgroup_addrm_files(&root->top_cgroup, NULL, cgroup_base_files, false);
+ cgroup_addrm_files(&root->top_cgroup, cgroup_base_files, false);
revert_creds(cred);
unlock_drop:
cgroup_exit_root_id(root);
* step 1: check that we can legitimately attach to the cgroup.
*/
for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
if (ss->can_attach) {
- retval = ss->can_attach(cgrp, &tset);
+ retval = ss->can_attach(css, &tset);
if (retval) {
failed_ss = ss;
goto out_cancel_attach;
* step 4: do subsystem attach callbacks.
*/
for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
if (ss->attach)
- ss->attach(cgrp, &tset);
+ ss->attach(css, &tset);
}
/*
out_cancel_attach:
if (retval) {
for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
if (ss == failed_ss)
break;
if (ss->cancel_attach)
- ss->cancel_attach(cgrp, &tset);
+ ss->cancel_attach(css, &tset);
}
}
out_free_group_list:
}
EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
-static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid)
+static int cgroup_tasks_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 pid)
{
- return attach_task_by_pid(cgrp, pid, false);
+ return attach_task_by_pid(css->cgroup, pid, false);
}
-static int cgroup_procs_write(struct cgroup *cgrp, struct cftype *cft, u64 tgid)
+static int cgroup_procs_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 tgid)
{
- return attach_task_by_pid(cgrp, tgid, true);
+ return attach_task_by_pid(css->cgroup, tgid, true);
}
-static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+static int cgroup_release_agent_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, const char *buffer)
{
- BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+ BUILD_BUG_ON(sizeof(css->cgroup->root->release_agent_path) < PATH_MAX);
if (strlen(buffer) >= PATH_MAX)
return -EINVAL;
- if (!cgroup_lock_live_group(cgrp))
+ if (!cgroup_lock_live_group(css->cgroup))
return -ENODEV;
mutex_lock(&cgroup_root_mutex);
- strcpy(cgrp->root->release_agent_path, buffer);
+ strcpy(css->cgroup->root->release_agent_path, buffer);
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
return 0;
}
-static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft,
- struct seq_file *seq)
+static int cgroup_release_agent_show(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *seq)
{
+ struct cgroup *cgrp = css->cgroup;
+
if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
seq_puts(seq, cgrp->root->release_agent_path);
return 0;
}
-static int cgroup_sane_behavior_show(struct cgroup *cgrp, struct cftype *cft,
- struct seq_file *seq)
+static int cgroup_sane_behavior_show(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *seq)
{
- seq_printf(seq, "%d\n", cgroup_sane_behavior(cgrp));
+ seq_printf(seq, "%d\n", cgroup_sane_behavior(css->cgroup));
return 0;
}
+/* return the css for the given cgroup file */
+static struct cgroup_subsys_state *cgroup_file_css(struct cfent *cfe)
+{
+ struct cftype *cft = cfe->type;
+ struct cgroup *cgrp = __d_cgrp(cfe->dentry->d_parent);
+
+ if (cft->ss)
+ return cgrp->subsys[cft->ss->subsys_id];
+ return &cgrp->dummy_css;
+}
+
/* A buffer size big enough for numbers or short strings */
#define CGROUP_LOCAL_BUFFER_SIZE 64
-static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
+static ssize_t cgroup_write_X64(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ const char __user *userbuf, size_t nbytes,
+ loff_t *unused_ppos)
{
char buffer[CGROUP_LOCAL_BUFFER_SIZE];
int retval = 0;
u64 val = simple_strtoull(strstrip(buffer), &end, 0);
if (*end)
return -EINVAL;
- retval = cft->write_u64(cgrp, cft, val);
+ retval = cft->write_u64(css, cft, val);
} else {
s64 val = simple_strtoll(strstrip(buffer), &end, 0);
if (*end)
return -EINVAL;
- retval = cft->write_s64(cgrp, cft, val);
+ retval = cft->write_s64(css, cft, val);
}
if (!retval)
retval = nbytes;
return retval;
}
-static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
+static ssize_t cgroup_write_string(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ const char __user *userbuf, size_t nbytes,
+ loff_t *unused_ppos)
{
char local_buffer[CGROUP_LOCAL_BUFFER_SIZE];
int retval = 0;
}
buffer[nbytes] = 0; /* nul-terminate */
- retval = cft->write_string(cgrp, cft, strstrip(buffer));
+ retval = cft->write_string(css, cft, strstrip(buffer));
if (!retval)
retval = nbytes;
out:
}
static ssize_t cgroup_file_write(struct file *file, const char __user *buf,
- size_t nbytes, loff_t *ppos)
+ size_t nbytes, loff_t *ppos)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
struct cftype *cft = __d_cft(file->f_dentry);
- struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
+ struct cgroup_subsys_state *css = cgroup_file_css(cfe);
- if (cgroup_is_dead(cgrp))
- return -ENODEV;
if (cft->write)
- return cft->write(cgrp, cft, file, buf, nbytes, ppos);
+ return cft->write(css, cft, file, buf, nbytes, ppos);
if (cft->write_u64 || cft->write_s64)
- return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_write_X64(css, cft, file, buf, nbytes, ppos);
if (cft->write_string)
- return cgroup_write_string(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_write_string(css, cft, file, buf, nbytes, ppos);
if (cft->trigger) {
- int ret = cft->trigger(cgrp, (unsigned int)cft->private);
+ int ret = cft->trigger(css, (unsigned int)cft->private);
return ret ? ret : nbytes;
}
return -EINVAL;
}
-static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
+static ssize_t cgroup_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ char __user *buf, size_t nbytes, loff_t *ppos)
{
char tmp[CGROUP_LOCAL_BUFFER_SIZE];
- u64 val = cft->read_u64(cgrp, cft);
+ u64 val = cft->read_u64(css, cft);
int len = sprintf(tmp, "%llu\n", (unsigned long long) val);
return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
}
-static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
+static ssize_t cgroup_read_s64(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ char __user *buf, size_t nbytes, loff_t *ppos)
{
char tmp[CGROUP_LOCAL_BUFFER_SIZE];
- s64 val = cft->read_s64(cgrp, cft);
+ s64 val = cft->read_s64(css, cft);
int len = sprintf(tmp, "%lld\n", (long long) val);
return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
}
static ssize_t cgroup_file_read(struct file *file, char __user *buf,
- size_t nbytes, loff_t *ppos)
+ size_t nbytes, loff_t *ppos)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
struct cftype *cft = __d_cft(file->f_dentry);
- struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
-
- if (cgroup_is_dead(cgrp))
- return -ENODEV;
+ struct cgroup_subsys_state *css = cgroup_file_css(cfe);
if (cft->read)
- return cft->read(cgrp, cft, file, buf, nbytes, ppos);
+ return cft->read(css, cft, file, buf, nbytes, ppos);
if (cft->read_u64)
- return cgroup_read_u64(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_read_u64(css, cft, file, buf, nbytes, ppos);
if (cft->read_s64)
- return cgroup_read_s64(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_read_s64(css, cft, file, buf, nbytes, ppos);
return -EINVAL;
}
{
struct cfent *cfe = m->private;
struct cftype *cft = cfe->type;
- struct cgroup *cgrp = __d_cgrp(cfe->dentry->d_parent);
+ struct cgroup_subsys_state *css = cgroup_file_css(cfe);
if (cft->read_map) {
struct cgroup_map_cb cb = {
.fill = cgroup_map_add,
.state = m,
};
- return cft->read_map(cgrp, cft, &cb);
+ return cft->read_map(css, cft, &cb);
}
- return cft->read_seq_string(cgrp, cft, m);
+ return cft->read_seq_string(css, cft, m);
}
static const struct file_operations cgroup_seqfile_operations = {
static int cgroup_file_open(struct inode *inode, struct file *file)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
+ struct cftype *cft = __d_cft(file->f_dentry);
+ struct cgroup_subsys_state *css = cgroup_file_css(cfe);
int err;
- struct cfent *cfe;
- struct cftype *cft;
err = generic_file_open(inode, file);
if (err)
return err;
- cfe = __d_cfe(file->f_dentry);
- cft = cfe->type;
+
+ /*
+ * If the file belongs to a subsystem, pin the css. Will be
+ * unpinned either on open failure or release. This ensures that
+ * @css stays alive for all file operations.
+ */
+ if (css->ss && !css_tryget(css))
+ return -ENODEV;
if (cft->read_map || cft->read_seq_string) {
file->f_op = &cgroup_seqfile_operations;
err = cft->open(inode, file);
}
+ if (css->ss && err)
+ css_put(css);
return err;
}
static int cgroup_file_release(struct inode *inode, struct file *file)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
struct cftype *cft = __d_cft(file->f_dentry);
+ struct cgroup_subsys_state *css = cgroup_file_css(cfe);
+ int ret = 0;
+
if (cft->release)
- return cft->release(inode, file);
- return 0;
+ ret = cft->release(inode, file);
+ if (css->ss)
+ css_put(css);
+ return ret;
}
/*
return mode;
}
-static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
- struct cftype *cft)
+static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft)
{
struct dentry *dir = cgrp->dentry;
struct cgroup *parent = __d_cgrp(dir);
umode_t mode;
char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 };
- if (subsys && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) {
- strcpy(name, subsys->name);
+ if (cft->ss && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) {
+ strcpy(name, cft->ss->name);
strcat(name, ".");
}
strcat(name, cft->name);
/**
* cgroup_addrm_files - add or remove files to a cgroup directory
* @cgrp: the target cgroup
- * @subsys: the subsystem of files to be added
* @cfts: array of cftypes to be added
* @is_add: whether to add or remove
*
* Depending on @is_add, add or remove files defined by @cfts on @cgrp.
- * All @cfts should belong to @subsys. For removals, this function never
- * fails. If addition fails, this function doesn't remove files already
- * added. The caller is responsible for cleaning up.
+ * For removals, this function never fails. If addition fails, this
+ * function doesn't remove files already added. The caller is responsible
+ * for cleaning up.
*/
-static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
- struct cftype cfts[], bool is_add)
+static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
+ bool is_add)
{
struct cftype *cft;
int ret;
continue;
if (is_add) {
- ret = cgroup_add_file(cgrp, subsys, cft);
+ ret = cgroup_add_file(cgrp, cft);
if (ret) {
pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n",
cft->name, ret);
/*
* Thanks to the entanglement with vfs inode locking, we can't walk
* the existing cgroups under cgroup_mutex and create files.
- * Instead, we use cgroup_for_each_descendant_pre() and drop RCU
- * read lock before calling cgroup_addrm_files().
+ * Instead, we use css_for_each_descendant_pre() and drop RCU read
+ * lock before calling cgroup_addrm_files().
*/
mutex_lock(&cgroup_mutex);
}
-static int cgroup_cfts_commit(struct cgroup_subsys *ss,
- struct cftype *cfts, bool is_add)
+static int cgroup_cfts_commit(struct cftype *cfts, bool is_add)
__releases(&cgroup_mutex)
{
LIST_HEAD(pending);
- struct cgroup *cgrp, *root = &ss->root->top_cgroup;
+ struct cgroup_subsys *ss = cfts[0].ss;
+ struct cgroup *root = &ss->root->top_cgroup;
struct super_block *sb = ss->root->sb;
struct dentry *prev = NULL;
struct inode *inode;
+ struct cgroup_subsys_state *css;
u64 update_before;
int ret = 0;
inode = root->dentry->d_inode;
mutex_lock(&inode->i_mutex);
mutex_lock(&cgroup_mutex);
- ret = cgroup_addrm_files(root, ss, cfts, is_add);
+ ret = cgroup_addrm_files(root, cfts, is_add);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&inode->i_mutex);
/* add/rm files for all cgroups created before */
rcu_read_lock();
- cgroup_for_each_descendant_pre(cgrp, root) {
+ css_for_each_descendant_pre(css, cgroup_css(root, ss->subsys_id)) {
+ struct cgroup *cgrp = css->cgroup;
+
if (cgroup_is_dead(cgrp))
continue;
mutex_lock(&inode->i_mutex);
mutex_lock(&cgroup_mutex);
if (cgrp->serial_nr < update_before && !cgroup_is_dead(cgrp))
- ret = cgroup_addrm_files(cgrp, ss, cfts, is_add);
+ ret = cgroup_addrm_files(cgrp, cfts, is_add);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&inode->i_mutex);
int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
{
struct cftype_set *set;
+ struct cftype *cft;
int ret;
set = kzalloc(sizeof(*set), GFP_KERNEL);
if (!set)
return -ENOMEM;
+ for (cft = cfts; cft->name[0] != '\0'; cft++)
+ cft->ss = ss;
+
cgroup_cfts_prepare();
set->cfts = cfts;
list_add_tail(&set->node, &ss->cftsets);
- ret = cgroup_cfts_commit(ss, cfts, true);
+ ret = cgroup_cfts_commit(cfts, true);
if (ret)
- cgroup_rm_cftypes(ss, cfts);
+ cgroup_rm_cftypes(cfts);
return ret;
}
EXPORT_SYMBOL_GPL(cgroup_add_cftypes);
/**
* cgroup_rm_cftypes - remove an array of cftypes from a subsystem
- * @ss: target cgroup subsystem
* @cfts: zero-length name terminated array of cftypes
*
- * Unregister @cfts from @ss. Files described by @cfts are removed from
- * all existing cgroups to which @ss is attached and all future cgroups
- * won't have them either. This function can be called anytime whether @ss
- * is attached or not.
+ * Unregister @cfts. Files described by @cfts are removed from all
+ * existing cgroups and all future cgroups won't have them either. This
+ * function can be called anytime whether @cfts' subsys is attached or not.
*
* Returns 0 on successful unregistration, -ENOENT if @cfts is not
- * registered with @ss.
+ * registered.
*/
-int cgroup_rm_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
+int cgroup_rm_cftypes(struct cftype *cfts)
{
struct cftype_set *set;
+ if (!cfts || !cfts[0].ss)
+ return -ENOENT;
+
cgroup_cfts_prepare();
- list_for_each_entry(set, &ss->cftsets, node) {
+ list_for_each_entry(set, &cfts[0].ss->cftsets, node) {
if (set->cfts == cfts) {
list_del(&set->node);
kfree(set);
- cgroup_cfts_commit(ss, cfts, false);
+ cgroup_cfts_commit(cfts, false);
return 0;
}
}
- cgroup_cfts_commit(ss, NULL, false);
+ cgroup_cfts_commit(NULL, false);
return -ENOENT;
}
}
/**
- * cgroup_next_sibling - find the next sibling of a given cgroup
- * @pos: the current cgroup
+ * css_next_child - find the next child of a given css
+ * @pos_css: the current position (%NULL to initiate traversal)
+ * @parent_css: css whose children to walk
*
- * This function returns the next sibling of @pos and should be called
- * under RCU read lock. The only requirement is that @pos is accessible.
- * The next sibling is guaranteed to be returned regardless of @pos's
- * state.
+ * This function returns the next child of @parent_css and should be called
+ * under RCU read lock. The only requirement is that @parent_css and
+ * @pos_css are accessible. The next sibling is guaranteed to be returned
+ * regardless of their states.
*/
-struct cgroup *cgroup_next_sibling(struct cgroup *pos)
+struct cgroup_subsys_state *
+css_next_child(struct cgroup_subsys_state *pos_css,
+ struct cgroup_subsys_state *parent_css)
{
+ struct cgroup *pos = pos_css ? pos_css->cgroup : NULL;
+ struct cgroup *cgrp = parent_css->cgroup;
struct cgroup *next;
WARN_ON_ONCE(!rcu_read_lock_held());
* safe to dereference from this RCU critical section. If
* ->sibling.next is inaccessible, cgroup_is_dead() is guaranteed
* to be visible as %true here.
+ *
+ * If @pos is dead, its next pointer can't be dereferenced;
+ * however, as each cgroup is given a monotonically increasing
+ * unique serial number and always appended to the sibling list,
+ * the next one can be found by walking the parent's children until
+ * we see a cgroup with higher serial number than @pos's. While
+ * this path can be slower, it's taken only when either the current
+ * cgroup is removed or iteration and removal race.
*/
- if (likely(!cgroup_is_dead(pos))) {
+ if (!pos) {
+ next = list_entry_rcu(cgrp->children.next, struct cgroup, sibling);
+ } else if (likely(!cgroup_is_dead(pos))) {
next = list_entry_rcu(pos->sibling.next, struct cgroup, sibling);
- if (&next->sibling != &pos->parent->children)
- return next;
- return NULL;
+ } else {
+ list_for_each_entry_rcu(next, &cgrp->children, sibling)
+ if (next->serial_nr > pos->serial_nr)
+ break;
}
- /*
- * Can't dereference the next pointer. Each cgroup is given a
- * monotonically increasing unique serial number and always
- * appended to the sibling list, so the next one can be found by
- * walking the parent's children until we see a cgroup with higher
- * serial number than @pos's.
- *
- * While this path can be slow, it's taken only when either the
- * current cgroup is removed or iteration and removal race.
- */
- list_for_each_entry_rcu(next, &pos->parent->children, sibling)
- if (next->serial_nr > pos->serial_nr)
- return next;
- return NULL;
+ if (&next->sibling == &cgrp->children)
+ return NULL;
+
+ if (parent_css->ss)
+ return cgroup_css(next, parent_css->ss->subsys_id);
+ else
+ return &next->dummy_css;
}
-EXPORT_SYMBOL_GPL(cgroup_next_sibling);
+EXPORT_SYMBOL_GPL(css_next_child);
/**
- * cgroup_next_descendant_pre - find the next descendant for pre-order walk
+ * css_next_descendant_pre - find the next descendant for pre-order walk
* @pos: the current position (%NULL to initiate traversal)
- * @cgroup: cgroup whose descendants to walk
+ * @root: css whose descendants to walk
*
- * To be used by cgroup_for_each_descendant_pre(). Find the next
- * descendant to visit for pre-order traversal of @cgroup's descendants.
+ * To be used by css_for_each_descendant_pre(). Find the next descendant
+ * to visit for pre-order traversal of @root's descendants.
*
* While this function requires RCU read locking, it doesn't require the
* whole traversal to be contained in a single RCU critical section. This
* function will return the correct next descendant as long as both @pos
- * and @cgroup are accessible and @pos is a descendant of @cgroup.
+ * and @root are accessible and @pos is a descendant of @root.
*/
-struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos,
- struct cgroup *cgroup)
+struct cgroup_subsys_state *
+css_next_descendant_pre(struct cgroup_subsys_state *pos,
+ struct cgroup_subsys_state *root)
{
- struct cgroup *next;
+ struct cgroup_subsys_state *next;
WARN_ON_ONCE(!rcu_read_lock_held());
- /* if first iteration, pretend we just visited @cgroup */
+ /* if first iteration, pretend we just visited @root */
if (!pos)
- pos = cgroup;
+ pos = root;
/* visit the first child if exists */
- next = list_first_or_null_rcu(&pos->children, struct cgroup, sibling);
+ next = css_next_child(NULL, pos);
if (next)
return next;
/* no child, visit my or the closest ancestor's next sibling */
- while (pos != cgroup) {
- next = cgroup_next_sibling(pos);
+ while (pos != root) {
+ next = css_next_child(pos, css_parent(pos));
if (next)
return next;
- pos = pos->parent;
+ pos = css_parent(pos);
}
return NULL;
}
-EXPORT_SYMBOL_GPL(cgroup_next_descendant_pre);
+EXPORT_SYMBOL_GPL(css_next_descendant_pre);
/**
- * cgroup_rightmost_descendant - return the rightmost descendant of a cgroup
- * @pos: cgroup of interest
+ * css_rightmost_descendant - return the rightmost descendant of a css
+ * @pos: css of interest
*
- * Return the rightmost descendant of @pos. If there's no descendant,
- * @pos is returned. This can be used during pre-order traversal to skip
+ * Return the rightmost descendant of @pos. If there's no descendant, @pos
+ * is returned. This can be used during pre-order traversal to skip
* subtree of @pos.
*
* While this function requires RCU read locking, it doesn't require the
* function will return the correct rightmost descendant as long as @pos is
* accessible.
*/
-struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos)
+struct cgroup_subsys_state *
+css_rightmost_descendant(struct cgroup_subsys_state *pos)
{
- struct cgroup *last, *tmp;
+ struct cgroup_subsys_state *last, *tmp;
WARN_ON_ONCE(!rcu_read_lock_held());
last = pos;
/* ->prev isn't RCU safe, walk ->next till the end */
pos = NULL;
- list_for_each_entry_rcu(tmp, &last->children, sibling)
+ css_for_each_child(tmp, last)
pos = tmp;
} while (pos);
return last;
}
-EXPORT_SYMBOL_GPL(cgroup_rightmost_descendant);
+EXPORT_SYMBOL_GPL(css_rightmost_descendant);
-static struct cgroup *cgroup_leftmost_descendant(struct cgroup *pos)
+static struct cgroup_subsys_state *
+css_leftmost_descendant(struct cgroup_subsys_state *pos)
{
- struct cgroup *last;
+ struct cgroup_subsys_state *last;
do {
last = pos;
- pos = list_first_or_null_rcu(&pos->children, struct cgroup,
- sibling);
+ pos = css_next_child(NULL, pos);
} while (pos);
return last;
}
/**
- * cgroup_next_descendant_post - find the next descendant for post-order walk
+ * css_next_descendant_post - find the next descendant for post-order walk
* @pos: the current position (%NULL to initiate traversal)
- * @cgroup: cgroup whose descendants to walk
+ * @root: css whose descendants to walk
*
- * To be used by cgroup_for_each_descendant_post(). Find the next
- * descendant to visit for post-order traversal of @cgroup's descendants.
+ * To be used by css_for_each_descendant_post(). Find the next descendant
+ * to visit for post-order traversal of @root's descendants.
*
* While this function requires RCU read locking, it doesn't require the
* whole traversal to be contained in a single RCU critical section. This
* function will return the correct next descendant as long as both @pos
* and @cgroup are accessible and @pos is a descendant of @cgroup.
*/
-struct cgroup *cgroup_next_descendant_post(struct cgroup *pos,
- struct cgroup *cgroup)
+struct cgroup_subsys_state *
+css_next_descendant_post(struct cgroup_subsys_state *pos,
+ struct cgroup_subsys_state *root)
{
- struct cgroup *next;
+ struct cgroup_subsys_state *next;
WARN_ON_ONCE(!rcu_read_lock_held());
/* if first iteration, visit the leftmost descendant */
if (!pos) {
- next = cgroup_leftmost_descendant(cgroup);
- return next != cgroup ? next : NULL;
+ next = css_leftmost_descendant(root);
+ return next != root ? next : NULL;
}
/* if there's an unvisited sibling, visit its leftmost descendant */
- next = cgroup_next_sibling(pos);
+ next = css_next_child(pos, css_parent(pos));
if (next)
- return cgroup_leftmost_descendant(next);
+ return css_leftmost_descendant(next);
/* no sibling left, visit parent */
- next = pos->parent;
- return next != cgroup ? next : NULL;
+ next = css_parent(pos);
+ return next != root ? next : NULL;
}
-EXPORT_SYMBOL_GPL(cgroup_next_descendant_post);
+EXPORT_SYMBOL_GPL(css_next_descendant_post);
void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it)
__acquires(css_set_lock)
return cgroup_pidlist_open(file, CGROUP_FILE_PROCS);
}
-static u64 cgroup_read_notify_on_release(struct cgroup *cgrp,
- struct cftype *cft)
+static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return notify_on_release(cgrp);
+ return notify_on_release(css->cgroup);
}
-static int cgroup_write_notify_on_release(struct cgroup *cgrp,
- struct cftype *cft,
- u64 val)
+static int cgroup_write_notify_on_release(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
{
- clear_bit(CGRP_RELEASABLE, &cgrp->flags);
+ clear_bit(CGRP_RELEASABLE, &css->cgroup->flags);
if (val)
- set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
+ set_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
else
- clear_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
+ clear_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
return 0;
}
* Input must be in format '<event_fd> <control_fd> <args>'.
* Interpretation of args is defined by control file implementation.
*/
-static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+static int cgroup_write_event_control(struct cgroup_subsys_state *css,
+ struct cftype *cft, const char *buffer)
{
+ struct cgroup *cgrp = css->cgroup;
struct cgroup_event *event;
struct cgroup *cgrp_cfile;
unsigned int efd, cfd;
return ret;
}
-static u64 cgroup_clone_children_read(struct cgroup *cgrp,
- struct cftype *cft)
+static u64 cgroup_clone_children_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
+ return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
}
-static int cgroup_clone_children_write(struct cgroup *cgrp,
- struct cftype *cft,
- u64 val)
+static int cgroup_clone_children_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
{
if (val)
- set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
+ set_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
else
- clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
+ clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
return 0;
}
continue;
list_for_each_entry(set, &ss->cftsets, node) {
- ret = cgroup_addrm_files(cgrp, ss, set->cfts, true);
+ ret = cgroup_addrm_files(cgrp, set->cfts, true);
if (ret < 0)
goto err;
}
/* invoke ->css_online() on a new CSS and mark it online if successful */
static int online_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
{
+ struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
int ret = 0;
lockdep_assert_held(&cgroup_mutex);
if (ss->css_online)
- ret = ss->css_online(cgrp);
+ ret = ss->css_online(css);
if (!ret)
- cgrp->subsys[ss->subsys_id]->flags |= CSS_ONLINE;
+ css->flags |= CSS_ONLINE;
return ret;
}
return;
if (ss->css_offline)
- ss->css_offline(cgrp);
+ ss->css_offline(css);
- cgrp->subsys[ss->subsys_id]->flags &= ~CSS_ONLINE;
+ css->flags &= ~CSS_ONLINE;
}
/*
for_each_root_subsys(root, ss) {
struct cgroup_subsys_state *css;
- css = ss->css_alloc(cgrp);
+ css = ss->css_alloc(parent->subsys[ss->subsys_id]);
if (IS_ERR(css)) {
err = PTR_ERR(css);
goto err_free_all;
err = percpu_ref_init(&css->refcnt, css_release);
if (err) {
- ss->css_free(cgrp);
+ ss->css_free(css);
goto err_free_all;
}
idr_replace(&root->cgroup_idr, cgrp, cgrp->id);
- err = cgroup_addrm_files(cgrp, NULL, cgroup_base_files, true);
+ err = cgroup_addrm_files(cgrp, cgroup_base_files, true);
if (err)
goto err_destroy;
if (css) {
percpu_ref_cancel_init(&css->refcnt);
- ss->css_free(cgrp);
+ ss->css_free(css);
}
}
mutex_unlock(&cgroup_mutex);
/*
* Mark @cgrp dead. This prevents further task migration and child
* creation by disabling cgroup_lock_live_group(). Note that
- * CGRP_DEAD assertion is depended upon by cgroup_next_sibling() to
+ * CGRP_DEAD assertion is depended upon by css_next_child() to
* resume iteration after dropping RCU read lock. See
- * cgroup_next_sibling() for details.
+ * css_next_child() for details.
*/
set_bit(CGRP_DEAD, &cgrp->flags);
* but we aren't quite done with @cgrp yet, so hold onto it.
*/
cgroup_clear_dir(cgrp, cgrp->root->subsys_mask);
- cgroup_addrm_files(cgrp, NULL, cgroup_base_files, false);
+ cgroup_addrm_files(cgrp, cgroup_base_files, false);
dget(d);
cgroup_d_remove_dir(d);
* deregistration.
*/
if (ss->base_cftypes) {
+ struct cftype *cft;
+
+ for (cft = ss->base_cftypes; cft->name[0] != '\0'; cft++)
+ cft->ss = ss;
+
ss->base_cftset.cfts = ss->base_cftypes;
list_add_tail(&ss->base_cftset.node, &ss->cftsets);
}
/* Create the top cgroup state for this subsystem */
list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
ss->root = &cgroup_dummy_root;
- css = ss->css_alloc(cgroup_dummy_top);
+ css = ss->css_alloc(cgroup_dummy_top->subsys[ss->subsys_id]);
/* We don't handle early failures gracefully */
BUG_ON(IS_ERR(css));
init_cgroup_css(css, ss, cgroup_dummy_top);
* struct, so this can happen first (i.e. before the dummy root
* attachment).
*/
- css = ss->css_alloc(cgroup_dummy_top);
+ css = ss->css_alloc(cgroup_dummy_top->subsys[ss->subsys_id]);
if (IS_ERR(css)) {
/* failure case - need to deassign the cgroup_subsys[] slot. */
cgroup_subsys[ss->subsys_id] = NULL;
* the cgrp->subsys pointer to find their state. note that this
* also takes care of freeing the css_id.
*/
- ss->css_free(cgroup_dummy_top);
+ ss->css_free(cgroup_dummy_top->subsys[ss->subsys_id]);
cgroup_dummy_top->subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
*/
for_each_builtin_subsys(ss, i) {
if (ss->exit) {
- struct cgroup *old_cgrp = cset->subsys[i]->cgroup;
- struct cgroup *cgrp = task_cgroup(tsk, i);
+ struct cgroup_subsys_state *old_css = cset->subsys[i];
+ struct cgroup_subsys_state *css = task_css(tsk, i);
- ss->exit(cgrp, old_cgrp, tsk);
+ ss->exit(css, old_css, tsk);
}
}
}
}
#ifdef CONFIG_CGROUP_DEBUG
-static struct cgroup_subsys_state *debug_css_alloc(struct cgroup *cgrp)
+static struct cgroup_subsys_state *
+debug_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
return css;
}
-static void debug_css_free(struct cgroup *cgrp)
+static void debug_css_free(struct cgroup_subsys_state *css)
{
- kfree(cgrp->subsys[debug_subsys_id]);
+ kfree(css);
}
-static u64 debug_taskcount_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 debug_taskcount_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return cgroup_task_count(cgrp);
+ return cgroup_task_count(css->cgroup);
}
-static u64 current_css_set_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 current_css_set_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
return (u64)(unsigned long)current->cgroups;
}
-static u64 current_css_set_refcount_read(struct cgroup *cgrp,
+static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css,
struct cftype *cft)
{
u64 count;
return count;
}
-static int current_css_set_cg_links_read(struct cgroup *cgrp,
+static int current_css_set_cg_links_read(struct cgroup_subsys_state *css,
struct cftype *cft,
struct seq_file *seq)
{
}
#define MAX_TASKS_SHOWN_PER_CSS 25
-static int cgroup_css_links_read(struct cgroup *cgrp,
- struct cftype *cft,
- struct seq_file *seq)
+static int cgroup_css_links_read(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *seq)
{
struct cgrp_cset_link *link;
read_lock(&css_set_lock);
- list_for_each_entry(link, &cgrp->cset_links, cset_link) {
+ list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
struct css_set *cset = link->cset;
struct task_struct *task;
int count = 0;
return 0;
}
-static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
- return test_bit(CGRP_RELEASABLE, &cgrp->flags);
+ return test_bit(CGRP_RELEASABLE, &css->cgroup->flags);
}
static struct cftype debug_files[] = {
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