#define dummytop (&rootnode.top_cgroup)
/* This flag indicates whether tasks in the fork and exit paths should
- * take callback_mutex and check for fork/exit handlers to call. This
- * avoids us having to do extra work in the fork/exit path if none of the
- * subsystems need to be called.
+ * check for fork/exit handlers to call. This avoids us having to do
+ * extra work in the fork/exit path if none of the subsystems need to
+ * be called.
*/
static int need_forkexit_callback;
* template: location in which to build the desired set of subsystem
* state objects for the new cgroup group
*/
-
static struct css_set *find_existing_css_set(
struct css_set *oldcg,
struct cgroup *cgrp,
/* Built the set of subsystem state objects that we want to
* see in the new css_set */
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- if (root->subsys_bits & (1ull << i)) {
+ if (root->subsys_bits & (1UL << i)) {
/* Subsystem is in this hierarchy. So we want
* the subsystem state from the new
* cgroup */
* and chains them on tmp through their cgrp_link_list fields. Returns 0 on
* success or a negative error
*/
-
static int allocate_cg_links(int count, struct list_head *tmp)
{
struct cg_cgroup_link *link;
* substituted into the appropriate hierarchy. Must be called with
* cgroup_mutex held
*/
-
static struct css_set *find_css_set(
struct css_set *oldcg, struct cgroup *cgrp)
{
/* Link this cgroup group into the list */
list_add(&res->list, &init_css_set.list);
css_set_count++;
- INIT_LIST_HEAD(&res->tasks);
write_unlock(&css_set_lock);
return res;
* Any task can increment and decrement the count field without lock.
* So in general, code holding cgroup_mutex can't rely on the count
* field not changing. However, if the count goes to zero, then only
- * attach_task() can increment it again. Because a count of zero
+ * cgroup_attach_task() can increment it again. Because a count of zero
* means that no tasks are currently attached, therefore there is no
* way a task attached to that cgroup can fork (the other way to
* increment the count). So code holding cgroup_mutex can safely
* critical pieces of code here. The exception occurs on cgroup_exit(),
* when a task in a notify_on_release cgroup exits. Then cgroup_mutex
* is taken, and if the cgroup count is zero, a usermode call made
- * to /sbin/cgroup_release_agent with the name of the cgroup (path
- * relative to the root of cgroup file system) as the argument.
+ * to the release agent with the name of the cgroup (path relative to
+ * the root of cgroup file system) as the argument.
*
* A cgroup can only be deleted if both its 'count' of using tasks
* is zero, and its list of 'children' cgroups is empty. Since all
* The task_lock() exception
*
* The need for this exception arises from the action of
- * attach_task(), which overwrites one tasks cgroup pointer with
- * another. It does so using cgroup_mutexe, however there are
+ * cgroup_attach_task(), which overwrites one tasks cgroup pointer with
+ * another. It does so using cgroup_mutex, however there are
* several performance critical places that need to reference
* task->cgroup without the expense of grabbing a system global
* mutex. Therefore except as noted below, when dereferencing or, as
- * in attach_task(), modifying a task'ss cgroup pointer we use
+ * in cgroup_attach_task(), modifying a task'ss cgroup pointer we use
* task_lock(), which acts on a spinlock (task->alloc_lock) already in
* the task_struct routinely used for such matters.
*
* P.S. One more locking exception. RCU is used to guard the
- * update of a tasks cgroup pointer by attach_task()
+ * update of a tasks cgroup pointer by cgroup_attach_task()
*/
/**
* cgroup_lock - lock out any changes to cgroup structures
*
*/
-
void cgroup_lock(void)
{
mutex_lock(&cgroup_mutex);
*
* Undo the lock taken in a previous cgroup_lock() call.
*/
-
void cgroup_unlock(void)
{
mutex_unlock(&cgroup_mutex);
* Call subsys's pre_destroy handler.
* This is called before css refcnt check.
*/
-
static void cgroup_call_pre_destroy(struct cgroup *cgrp)
{
struct cgroup_subsys *ss;
return;
}
-
static void cgroup_diput(struct dentry *dentry, struct inode *inode)
{
/* is dentry a directory ? if so, kfree() associated cgroup */
added_bits = final_bits & ~root->actual_subsys_bits;
/* Check that any added subsystems are currently free */
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- unsigned long long bit = 1ull << i;
+ unsigned long bit = 1UL << i;
struct cgroup_subsys *ss = subsys[i];
if (!(bit & added_bits))
continue;
if (!inode)
return -ENOMEM;
- inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_op = &cgroup_dir_inode_operations;
/* directories start off with i_nlink == 2 (for "." entry) */
}
root = kzalloc(sizeof(*root), GFP_KERNEL);
- if (!root)
+ if (!root) {
+ if (opts.release_agent)
+ kfree(opts.release_agent);
return -ENOMEM;
+ }
init_cgroup_root(root);
root->subsys_bits = opts.subsys_bits;
return dentry->d_fsdata;
}
-/*
- * Called with cgroup_mutex held. Writes path of cgroup into buf.
+/**
+ * cgroup_path - generate the path of a cgroup
+ * @cgrp: the cgroup in question
+ * @buf: the buffer to write the path into
+ * @buflen: the length of the buffer
+ *
+ * Called with cgroup_mutex held. Writes path of cgroup into buf.
* Returns 0 on success, -errno on error.
*/
int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
*subsys_id = test_ss->subsys_id;
}
-/*
- * Attach task 'tsk' to cgroup 'cgrp'
+/**
+ * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp'
+ * @cgrp: the cgroup the task is attaching to
+ * @tsk: the task to be attached
*
- * Call holding cgroup_mutex. May take task_lock of
- * the task 'pid' during call.
+ * Call holding cgroup_mutex. May take task_lock of
+ * the task 'tsk' during call.
*/
-static int attach_task(struct cgroup *cgrp, struct task_struct *tsk)
+int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
int retval = 0;
struct cgroup_subsys *ss;
if (pid) {
rcu_read_lock();
- tsk = find_task_by_pid(pid);
+ tsk = find_task_by_vpid(pid);
if (!tsk || tsk->flags & PF_EXITING) {
rcu_read_unlock();
return -ESRCH;
get_task_struct(tsk);
}
- ret = attach_task(cgrp, tsk);
+ ret = cgroup_attach_task(cgrp, tsk);
put_task_struct(tsk);
return ret;
}
/* The various types of files and directories in a cgroup file system */
-
enum cgroup_filetype {
FILE_ROOT,
FILE_DIR,
}
/*
- * cgroup_create_dir - create a directory for an object.
- * cgrp: the cgroup we create the directory for.
- * It must have a valid ->parent field
- * And we are going to fill its ->dentry field.
- * dentry: dentry of the new cgroup
- * mode: mode to set on new directory.
+ * cgroup_create_dir - create a directory for an object.
+ * @cgrp: the cgroup we create the directory for. It must have a valid
+ * ->parent field. And we are going to fill its ->dentry field.
+ * @dentry: dentry of the new cgroup
+ * @mode: mode to set on new directory.
*/
static int cgroup_create_dir(struct cgroup *cgrp, struct dentry *dentry,
int mode)
return 0;
}
-/* Count the number of tasks in a cgroup. */
-
+/**
+ * cgroup_task_count - count the number of tasks in a cgroup.
+ * @cgrp: the cgroup in question
+ *
+ * Return the number of tasks in the cgroup.
+ */
int cgroup_task_count(const struct cgroup *cgrp)
{
int count = 0;
while ((tsk = cgroup_iter_next(cgrp, &it))) {
if (unlikely(n == npids))
break;
- pidarray[n++] = task_pid_nr(tsk);
+ pidarray[n++] = task_pid_vnr(tsk);
}
cgroup_iter_end(cgrp, &it);
return n;
}
/**
- * Build and fill cgroupstats so that taskstats can export it to user
- * space.
- *
+ * cgroupstats_build - build and fill cgroupstats
* @stats: cgroupstats to fill information into
* @dentry: A dentry entry belonging to the cgroup for which stats have
* been requested.
+ *
+ * Build and fill cgroupstats so that taskstats can export it to user
+ * space.
*/
int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
{
}
/*
- * cgroup_create - create a cgroup
- * parent: cgroup that will be parent of the new cgroup.
- * name: name of the new cgroup. Will be strcpy'ed.
- * mode: mode to set on new inode
+ * cgroup_create - create a cgroup
+ * @parent: cgroup that will be parent of the new cgroup
+ * @dentry: dentry of the new cgroup
+ * @mode: mode to set on new inode
*
- * Must be called with the mutex on the parent inode held
+ * Must be called with the mutex on the parent inode held
*/
-
static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
int mode)
{
parent = cgrp->parent;
root = cgrp->root;
sb = root->sb;
+
/*
- * Call pre_destroy handlers of subsys
+ * Call pre_destroy handlers of subsys. Notify subsystems
+ * that rmdir() request comes.
*/
cgroup_call_pre_destroy(cgrp);
- /*
- * Notify subsyses that rmdir() request comes.
- */
if (cgroup_has_css_refs(cgrp)) {
mutex_unlock(&cgroup_mutex);
}
/**
- * cgroup_init_early - initialize cgroups at system boot, and
- * initialize any subsystems that request early init.
+ * cgroup_init_early - cgroup initialization at system boot
+ *
+ * Initialize cgroups at system boot, and initialize any
+ * subsystems that request early init.
*/
int __init cgroup_init_early(void)
{
}
/**
- * cgroup_init - register cgroup filesystem and /proc file, and
- * initialize any subsystems that didn't request early init.
+ * cgroup_init - cgroup initialization
+ *
+ * Register cgroup filesystem and /proc file, and initialize
+ * any subsystems that didn't request early init.
*/
int __init cgroup_init(void)
{
* - Used for /proc/<pid>/cgroup.
* - No need to task_lock(tsk) on this tsk->cgroup reference, as it
* doesn't really matter if tsk->cgroup changes after we read it,
- * and we take cgroup_mutex, keeping attach_task() from changing it
+ * and we take cgroup_mutex, keeping cgroup_attach_task() from changing it
* anyway. No need to check that tsk->cgroup != NULL, thanks to
* the_top_cgroup_hack in cgroup_exit(), which sets an exiting tasks
* cgroup to top_cgroup.
/**
* cgroup_fork - attach newly forked task to its parents cgroup.
- * @tsk: pointer to task_struct of forking parent process.
+ * @child: pointer to task_struct of forking parent process.
*
* Description: A task inherits its parent's cgroup at fork().
*
* A pointer to the shared css_set was automatically copied in
* fork.c by dup_task_struct(). However, we ignore that copy, since
* it was not made under the protection of RCU or cgroup_mutex, so
- * might no longer be a valid cgroup pointer. attach_task() might
+ * might no longer be a valid cgroup pointer. cgroup_attach_task() might
* have already changed current->cgroups, allowing the previously
* referenced cgroup group to be removed and freed.
*
}
/**
- * cgroup_fork_callbacks - called on a new task very soon before
- * adding it to the tasklist. No need to take any locks since no-one
- * can be operating on this task
+ * cgroup_fork_callbacks - run fork callbacks
+ * @child: the new task
+ *
+ * Called on a new task very soon before adding it to the
+ * tasklist. No need to take any locks since no-one can
+ * be operating on this task.
*/
void cgroup_fork_callbacks(struct task_struct *child)
{
}
/**
- * cgroup_post_fork - called on a new task after adding it to the
- * task list. Adds the task to the list running through its css_set
- * if necessary. Has to be after the task is visible on the task list
- * in case we race with the first call to cgroup_iter_start() - to
- * guarantee that the new task ends up on its list. */
+ * cgroup_post_fork - called on a new task after adding it to the task list
+ * @child: the task in question
+ *
+ * Adds the task to the list running through its css_set if necessary.
+ * Has to be after the task is visible on the task list in case we race
+ * with the first call to cgroup_iter_start() - to guarantee that the
+ * new task ends up on its list.
+ */
void cgroup_post_fork(struct task_struct *child)
{
if (use_task_css_set_links) {
/**
* cgroup_exit - detach cgroup from exiting task
* @tsk: pointer to task_struct of exiting process
+ * @run_callback: run exit callbacks?
*
* Description: Detach cgroup from @tsk and release it.
*
* attach us to a different cgroup, decrementing the count on
* the first cgroup that we never incremented. But in this case,
* top_cgroup isn't going away, and either task has PF_EXITING set,
- * which wards off any attach_task() attempts, or task is a failed
- * fork, never visible to attach_task.
- *
+ * which wards off any cgroup_attach_task() attempts, or task is a failed
+ * fork, never visible to cgroup_attach_task.
*/
void cgroup_exit(struct task_struct *tsk, int run_callbacks)
{
}
/**
- * cgroup_clone - duplicate the current cgroup in the hierarchy
- * that the given subsystem is attached to, and move this task into
- * the new child
+ * cgroup_clone - clone the cgroup the given subsystem is attached to
+ * @tsk: the task to be moved
+ * @subsys: the given subsystem
+ *
+ * Duplicate the current cgroup in the hierarchy that the given
+ * subsystem is attached to, and move this task into the new
+ * child.
*/
int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys)
{
}
/* All seems fine. Finish by moving the task into the new cgroup */
- ret = attach_task(child, tsk);
+ ret = cgroup_attach_task(child, tsk);
mutex_unlock(&cgroup_mutex);
out_release:
return ret;
}
-/*
- * See if "cgrp" is a descendant of the current task's cgroup in
- * the appropriate hierarchy
+/**
+ * cgroup_is_descendant - see if @cgrp is a descendant of current task's cgrp
+ * @cgrp: the cgroup in question
+ *
+ * See if @cgrp is a descendant of the current task's cgroup in
+ * the appropriate hierarchy.
*
* If we are sending in dummytop, then presumably we are creating
* the top cgroup in the subsystem.
* release agent task. We don't bother to wait because the caller of
* this routine has no use for the exit status of the release agent
* task, so no sense holding our caller up for that.
- *
*/
-
static void cgroup_release_agent(struct work_struct *work)
{
BUG_ON(work != &release_agent_work);
projects / linux-2.6-omap-h63xx.git / blobdiff