/*
* 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);
}
{
LIST_HEAD(pending);
struct cgroup_subsys *ss = cfts[0].ss;
- struct cgroup *cgrp, *root = &ss->root->top_cgroup;
+ 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;
/* 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;
}
/**
- * cgroup_next_child - find the next child of a given cgroup
- * @pos: the current position (%NULL to initiate traversal)
- * @cgrp: cgroup whose descendants to walk
+ * 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 child of @cgrp and should be called under
- * RCU read lock. The only requirement is that @cgrp and @pos are
- * accessible. The next sibling is guaranteed to be returned regardless of
- * their states.
+ * 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_child(struct cgroup *pos, struct cgroup *cgrp)
+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());
break;
}
- if (&next->sibling != &cgrp->children)
- 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_child);
+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 = cgroup_next_child(NULL, pos);
+ 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_child(pos, pos->parent);
+ 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;
- cgroup_for_each_child(tmp, last)
+ 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 = cgroup_next_child(NULL, pos);
+ 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_child(pos, pos->parent);
+ 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)
/*
* 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_child() to
+ * CGRP_DEAD assertion is depended upon by css_next_child() to
* resume iteration after dropping RCU read lock. See
- * cgroup_next_child() for details.
+ * css_next_child() for details.
*/
set_bit(CGRP_DEAD, &cgrp->flags);
projects / deliverable / linux.git / blobdiff