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 void kill_css(struct cgroup_subsys_state *css);
static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
bool is_add);
-static void cgroup_pidlist_destroy_all(struct cgroup *cgrp);
/* IDR wrappers which synchronize using cgroup_idr_lock */
static int cgroup_idr_alloc(struct idr *idr, void *ptr, int start, int end,
return false;
}
-static int cgroup_is_releasable(const struct cgroup *cgrp)
-{
- const int bits =
- (1 << CGRP_RELEASABLE) |
- (1 << CGRP_NOTIFY_ON_RELEASE);
- return (cgrp->flags & bits) == bits;
-}
-
static int notify_on_release(const struct cgroup *cgrp)
{
return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
; \
else
-/* the list of cgroups eligible for automatic release. Protected by
- * release_list_lock */
-static LIST_HEAD(release_list);
-static DEFINE_RAW_SPINLOCK(release_list_lock);
static void cgroup_release_agent(struct work_struct *work);
-static DECLARE_WORK(release_agent_work, cgroup_release_agent);
static void check_for_release(struct cgroup *cgrp);
/*
return key;
}
-static void put_css_set_locked(struct css_set *cset, bool taskexit)
+static void put_css_set_locked(struct css_set *cset)
{
struct cgrp_cset_link *link, *tmp_link;
struct cgroup_subsys *ss;
/* @cgrp can't go away while we're holding css_set_rwsem */
if (list_empty(&cgrp->cset_links)) {
cgroup_update_populated(cgrp, false);
- if (notify_on_release(cgrp)) {
- if (taskexit)
- set_bit(CGRP_RELEASABLE, &cgrp->flags);
- check_for_release(cgrp);
- }
+ check_for_release(cgrp);
}
kfree(link);
kfree_rcu(cset, rcu_head);
}
-static void put_css_set(struct css_set *cset, bool taskexit)
+static void put_css_set(struct css_set *cset)
{
/*
* Ensure that the refcount doesn't hit zero while any readers
return;
down_write(&css_set_rwsem);
- put_css_set_locked(cset, taskexit);
+ put_css_set_locked(cset);
up_write(&css_set_rwsem);
}
* knows that the cgroup won't be removed, as cgroup_rmdir()
* needs that mutex.
*
- * The fork and exit callbacks cgroup_fork() and cgroup_exit(), don't
- * (usually) take cgroup_mutex. These are the two most performance
- * 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 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
* tasks in the system use _some_ cgroup, and since there is always at
INIT_LIST_HEAD(&cgrp->self.sibling);
INIT_LIST_HEAD(&cgrp->self.children);
INIT_LIST_HEAD(&cgrp->cset_links);
- INIT_LIST_HEAD(&cgrp->release_list);
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
cgrp->self.cgroup = cgrp;
INIT_LIST_HEAD(&cgrp->e_csets[ssid]);
init_waitqueue_head(&cgrp->offline_waitq);
+ INIT_WORK(&cgrp->release_agent_work, cgroup_release_agent);
}
static void init_cgroup_root(struct cgroup_root *root,
goto out;
root_cgrp->id = ret;
- ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release);
+ ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release, 0,
+ GFP_KERNEL);
if (ret)
goto out;
* task. As trading it for new_cset is protected by cgroup_mutex,
* we're safe to drop it here; it will be freed under RCU.
*/
- set_bit(CGRP_RELEASABLE, &old_cgrp->flags);
- put_css_set_locked(old_cset, false);
+ put_css_set_locked(old_cset);
}
/**
cset->mg_src_cgrp = NULL;
cset->mg_dst_cset = NULL;
list_del_init(&cset->mg_preload_node);
- put_css_set_locked(cset, false);
+ put_css_set_locked(cset);
}
up_write(&css_set_rwsem);
}
if (src_cset == dst_cset) {
src_cset->mg_src_cgrp = NULL;
list_del_init(&src_cset->mg_preload_node);
- put_css_set(src_cset, false);
- put_css_set(dst_cset, false);
+ put_css_set(src_cset);
+ put_css_set(dst_cset);
continue;
}
if (list_empty(&dst_cset->mg_preload_node))
list_add(&dst_cset->mg_preload_node, &csets);
else
- put_css_set(dst_cset, false);
+ put_css_set(dst_cset);
}
list_splice_tail(&csets, preloaded_csets);
static int cgroup_write_notify_on_release(struct cgroup_subsys_state *css,
struct cftype *cft, u64 val)
{
- clear_bit(CGRP_RELEASABLE, &css->cgroup->flags);
if (val)
set_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
else
/* cgroup free path */
atomic_dec(&cgrp->root->nr_cgrps);
cgroup_pidlist_destroy_all(cgrp);
+ cancel_work_sync(&cgrp->release_agent_work);
if (cgroup_parent(cgrp)) {
/*
init_and_link_css(css, ss, cgrp);
- err = percpu_ref_init(&css->refcnt, css_release);
+ err = percpu_ref_init(&css->refcnt, css_release, 0, GFP_KERNEL);
if (err)
goto err_free_css;
goto out_unlock;
}
- ret = percpu_ref_init(&cgrp->self.refcnt, css_release);
+ ret = percpu_ref_init(&cgrp->self.refcnt, css_release, 0, GFP_KERNEL);
if (ret)
goto out_free_cgrp;
for_each_css(css, ssid, cgrp)
kill_css(css);
- /* CSS_ONLINE is clear, remove from ->release_list for the last time */
- raw_spin_lock(&release_list_lock);
- if (!list_empty(&cgrp->release_list))
- list_del_init(&cgrp->release_list);
- raw_spin_unlock(&release_list_lock);
-
/*
* Remove @cgrp directory along with the base files. @cgrp has an
* extra ref on its kn.
*/
kernfs_remove(cgrp->kn);
- set_bit(CGRP_RELEASABLE, &cgroup_parent(cgrp)->flags);
check_for_release(cgroup_parent(cgrp));
/* put the base reference */
cgrp = cgroup_kn_lock_live(kn);
if (!cgrp)
return 0;
- cgroup_get(cgrp); /* for @kn->priv clearing */
ret = cgroup_destroy_locked(cgrp);
cgroup_kn_unlock(kn);
-
- cgroup_put(cgrp);
return ret;
}
* - Print task's cgroup paths into seq_file, one line for each hierarchy
* - Used for /proc/<pid>/cgroup.
*/
-
-/* TODO: Use a proper seq_file iterator */
-int proc_cgroup_show(struct seq_file *m, void *v)
+int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *tsk)
{
- struct pid *pid;
- struct task_struct *tsk;
char *buf, *path;
int retval;
struct cgroup_root *root;
if (!buf)
goto out;
- retval = -ESRCH;
- pid = m->private;
- tsk = get_pid_task(pid, PIDTYPE_PID);
- if (!tsk)
- goto out_free;
-
- retval = 0;
-
mutex_lock(&cgroup_mutex);
down_read(&css_set_rwsem);
seq_putc(m, '\n');
}
+ retval = 0;
out_unlock:
up_read(&css_set_rwsem);
mutex_unlock(&cgroup_mutex);
- put_task_struct(tsk);
-out_free:
kfree(buf);
out:
return retval;
int i;
/*
- * This may race against cgroup_enable_task_cg_links(). As that
+ * This may race against cgroup_enable_task_cg_lists(). As that
* function sets use_task_css_set_links before grabbing
* tasklist_lock and we just went through tasklist_lock to add
* @child, it's guaranteed that either we see the set
* when implementing operations which need to migrate all tasks of
* a cgroup to another.
*
- * Note that if we lose to cgroup_enable_task_cg_links(), @child
+ * Note that if we lose to cgroup_enable_task_cg_lists(), @child
* will remain in init_css_set. This is safe because all tasks are
* in the init_css_set before cg_links is enabled and there's no
* operation which transfers all tasks out of init_css_set.
}
if (put_cset)
- put_css_set(cset, true);
+ put_css_set(cset);
}
static void check_for_release(struct cgroup *cgrp)
{
- if (cgroup_is_releasable(cgrp) && list_empty(&cgrp->cset_links) &&
- !css_has_online_children(&cgrp->self)) {
- /*
- * Control Group is currently removeable. If it's not
- * already queued for a userspace notification, queue
- * it now
- */
- int need_schedule_work = 0;
-
- raw_spin_lock(&release_list_lock);
- if (!cgroup_is_dead(cgrp) &&
- list_empty(&cgrp->release_list)) {
- list_add(&cgrp->release_list, &release_list);
- need_schedule_work = 1;
- }
- raw_spin_unlock(&release_list_lock);
- if (need_schedule_work)
- schedule_work(&release_agent_work);
- }
+ if (notify_on_release(cgrp) && !cgroup_has_tasks(cgrp) &&
+ !css_has_online_children(&cgrp->self) && !cgroup_is_dead(cgrp))
+ schedule_work(&cgrp->release_agent_work);
}
/*
*/
static void cgroup_release_agent(struct work_struct *work)
{
- BUG_ON(work != &release_agent_work);
+ struct cgroup *cgrp =
+ container_of(work, struct cgroup, release_agent_work);
+ char *pathbuf = NULL, *agentbuf = NULL, *path;
+ char *argv[3], *envp[3];
+
mutex_lock(&cgroup_mutex);
- raw_spin_lock(&release_list_lock);
- while (!list_empty(&release_list)) {
- char *argv[3], *envp[3];
- int i;
- char *pathbuf = NULL, *agentbuf = NULL, *path;
- struct cgroup *cgrp = list_entry(release_list.next,
- struct cgroup,
- release_list);
- list_del_init(&cgrp->release_list);
- raw_spin_unlock(&release_list_lock);
- pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
- if (!pathbuf)
- goto continue_free;
- path = cgroup_path(cgrp, pathbuf, PATH_MAX);
- if (!path)
- goto continue_free;
- agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
- if (!agentbuf)
- goto continue_free;
-
- i = 0;
- argv[i++] = agentbuf;
- argv[i++] = path;
- argv[i] = NULL;
-
- i = 0;
- /* minimal command environment */
- envp[i++] = "HOME=/";
- envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
- envp[i] = NULL;
-
- /* Drop the lock while we invoke the usermode helper,
- * since the exec could involve hitting disk and hence
- * be a slow process */
- mutex_unlock(&cgroup_mutex);
- call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
- mutex_lock(&cgroup_mutex);
- continue_free:
- kfree(pathbuf);
- kfree(agentbuf);
- raw_spin_lock(&release_list_lock);
- }
- raw_spin_unlock(&release_list_lock);
+
+ pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
+ agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
+ if (!pathbuf || !agentbuf)
+ goto out;
+
+ path = cgroup_path(cgrp, pathbuf, PATH_MAX);
+ if (!path)
+ goto out;
+
+ argv[0] = agentbuf;
+ argv[1] = path;
+ argv[2] = NULL;
+
+ /* minimal command environment */
+ envp[0] = "HOME=/";
+ envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+ envp[2] = NULL;
+
+ mutex_unlock(&cgroup_mutex);
+ call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
+ goto out_free;
+out:
mutex_unlock(&cgroup_mutex);
+out_free:
+ kfree(agentbuf);
+ kfree(pathbuf);
}
static int __init cgroup_disable(char *str)
static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
- return test_bit(CGRP_RELEASABLE, &css->cgroup->flags);
+ return (!cgroup_has_tasks(css->cgroup) &&
+ !css_has_online_children(&css->cgroup->self));
}
static struct cftype debug_files[] = {
git.samba.org / sfrench / cifs-2.6.git / blobdiff