Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:
 "Nothing too interesting.  Just a handful of cleanup patches"

* 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "cgroup: remove redundant variable in cgroup_mount()"
  cgroup: remove redundant variable in cgroup_mount()
  cgroup: fix missing unlock in cgroup_release_agent()
  cgroup: remove CGRP_RELEASABLE flag
  perf/cgroup: Remove perf_put_cgroup()
  cgroup: remove redundant check in cgroup_ino()
  cpuset: simplify proc_cpuset_show()
  cgroup: simplify proc_cgroup_show()
  cgroup: use a per-cgroup work for release agent
  cgroup: remove bogus comments
  cgroup: remove redundant code in cgroup_rmdir()
  cgroup: remove some useless forward declarations
  cgroup: fix a typo in comment.
This commit is contained in:
Linus Torvalds 2014-10-10 07:24:40 -04:00
commit b211e9d7c8
7 changed files with 68 additions and 202 deletions

View File

@ -376,37 +376,6 @@ static const struct file_operations proc_lstats_operations = {
#endif
#ifdef CONFIG_CGROUPS
static int cgroup_open(struct inode *inode, struct file *file)
{
struct pid *pid = PROC_I(inode)->pid;
return single_open(file, proc_cgroup_show, pid);
}
static const struct file_operations proc_cgroup_operations = {
.open = cgroup_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif
#ifdef CONFIG_PROC_PID_CPUSET
static int cpuset_open(struct inode *inode, struct file *file)
{
struct pid *pid = PROC_I(inode)->pid;
return single_open(file, proc_cpuset_show, pid);
}
static const struct file_operations proc_cpuset_operations = {
.open = cpuset_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif
static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
@ -2579,10 +2548,10 @@ static const struct pid_entry tgid_base_stuff[] = {
REG("latency", S_IRUGO, proc_lstats_operations),
#endif
#ifdef CONFIG_PROC_PID_CPUSET
REG("cpuset", S_IRUGO, proc_cpuset_operations),
ONE("cpuset", S_IRUGO, proc_cpuset_show),
#endif
#ifdef CONFIG_CGROUPS
REG("cgroup", S_IRUGO, proc_cgroup_operations),
ONE("cgroup", S_IRUGO, proc_cgroup_show),
#endif
ONE("oom_score", S_IRUGO, proc_oom_score),
REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),
@ -2925,10 +2894,10 @@ static const struct pid_entry tid_base_stuff[] = {
REG("latency", S_IRUGO, proc_lstats_operations),
#endif
#ifdef CONFIG_PROC_PID_CPUSET
REG("cpuset", S_IRUGO, proc_cpuset_operations),
ONE("cpuset", S_IRUGO, proc_cpuset_show),
#endif
#ifdef CONFIG_CGROUPS
REG("cgroup", S_IRUGO, proc_cgroup_operations),
ONE("cgroup", S_IRUGO, proc_cgroup_show),
#endif
ONE("oom_score", S_IRUGO, proc_oom_score),
REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations),

View File

@ -27,7 +27,6 @@
struct cgroup_root;
struct cgroup_subsys;
struct inode;
struct cgroup;
extern int cgroup_init_early(void);
@ -38,7 +37,8 @@ extern void cgroup_exit(struct task_struct *p);
extern int cgroupstats_build(struct cgroupstats *stats,
struct dentry *dentry);
extern int proc_cgroup_show(struct seq_file *, void *);
extern int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk);
/* define the enumeration of all cgroup subsystems */
#define SUBSYS(_x) _x ## _cgrp_id,
@ -161,11 +161,6 @@ static inline void css_put(struct cgroup_subsys_state *css)
/* bits in struct cgroup flags field */
enum {
/*
* Control Group has previously had a child cgroup or a task,
* but no longer (only if CGRP_NOTIFY_ON_RELEASE is set)
*/
CGRP_RELEASABLE,
/* Control Group requires release notifications to userspace */
CGRP_NOTIFY_ON_RELEASE,
/*
@ -234,13 +229,6 @@ struct cgroup {
*/
struct list_head e_csets[CGROUP_SUBSYS_COUNT];
/*
* Linked list running through all cgroups that can
* potentially be reaped by the release agent. Protected by
* release_list_lock
*/
struct list_head release_list;
/*
* list of pidlists, up to two for each namespace (one for procs, one
* for tasks); created on demand.
@ -250,6 +238,9 @@ struct cgroup {
/* used to wait for offlining of csses */
wait_queue_head_t offline_waitq;
/* used to schedule release agent */
struct work_struct release_agent_work;
};
#define MAX_CGROUP_ROOT_NAMELEN 64
@ -536,13 +527,10 @@ static inline bool cgroup_has_tasks(struct cgroup *cgrp)
return !list_empty(&cgrp->cset_links);
}
/* returns ino associated with a cgroup, 0 indicates unmounted root */
/* returns ino associated with a cgroup */
static inline ino_t cgroup_ino(struct cgroup *cgrp)
{
if (cgrp->kn)
return cgrp->kn->ino;
else
return 0;
return cgrp->kn->ino;
}
/* cft/css accessors for cftype->write() operation */

View File

@ -86,7 +86,8 @@ extern void __cpuset_memory_pressure_bump(void);
extern void cpuset_task_status_allowed(struct seq_file *m,
struct task_struct *task);
extern int proc_cpuset_show(struct seq_file *, void *);
extern int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *tsk);
extern int cpuset_mem_spread_node(void);
extern int cpuset_slab_spread_node(void);

View File

@ -185,7 +185,6 @@ static int need_forkexit_callback __read_mostly;
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);
@ -195,7 +194,6 @@ static void css_release(struct percpu_ref *ref);
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,
@ -331,14 +329,6 @@ bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor)
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);
@ -394,12 +384,7 @@ static int notify_on_release(const struct cgroup *cgrp)
; \
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);
/*
@ -498,7 +483,7 @@ static unsigned long css_set_hash(struct cgroup_subsys_state *css[])
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;
@ -524,11 +509,7 @@ static void put_css_set_locked(struct css_set *cset, bool taskexit)
/* @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);
@ -537,7 +518,7 @@ static void put_css_set_locked(struct css_set *cset, bool taskexit)
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
@ -548,7 +529,7 @@ static void put_css_set(struct css_set *cset, bool taskexit)
return;
down_write(&css_set_rwsem);
put_css_set_locked(cset, taskexit);
put_css_set_locked(cset);
up_write(&css_set_rwsem);
}
@ -969,14 +950,6 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task,
* 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
@ -1587,7 +1560,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
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;
@ -1597,6 +1569,7 @@ static void init_cgroup_housekeeping(struct 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,
@ -2052,8 +2025,7 @@ static void cgroup_task_migrate(struct cgroup *old_cgrp,
* 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);
}
/**
@ -2074,7 +2046,7 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
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);
}
@ -2168,8 +2140,8 @@ static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp,
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;
}
@ -2178,7 +2150,7 @@ static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp,
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);
@ -4173,7 +4145,6 @@ static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
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
@ -4351,6 +4322,7 @@ static void css_free_work_fn(struct work_struct *work)
/* 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)) {
/*
@ -4813,19 +4785,12 @@ static int cgroup_destroy_locked(struct cgroup *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 */
@ -4842,13 +4807,10 @@ static int cgroup_rmdir(struct kernfs_node *kn)
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;
}
@ -5052,12 +5014,9 @@ core_initcall(cgroup_wq_init);
* - 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;
@ -5067,14 +5026,6 @@ int proc_cgroup_show(struct seq_file *m, void *v)
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);
@ -5104,11 +5055,10 @@ int proc_cgroup_show(struct seq_file *m, void *v)
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;
@ -5179,7 +5129,7 @@ void cgroup_post_fork(struct task_struct *child)
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
@ -5194,7 +5144,7 @@ void cgroup_post_fork(struct task_struct *child)
* 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.
@ -5278,30 +5228,14 @@ void cgroup_exit(struct task_struct *tsk)
}
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);
}
/*
@ -5329,52 +5263,39 @@ static void check_for_release(struct cgroup *cgrp)
*/
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;
pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
if (!pathbuf || !agentbuf)
goto out;
i = 0;
/* minimal command environment */
envp[i++] = "HOME=/";
envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
envp[i] = NULL;
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;
/* 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);
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)
@ -5562,7 +5483,8 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v)
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[] = {

View File

@ -2730,10 +2730,9 @@ void __cpuset_memory_pressure_bump(void)
* and we take cpuset_mutex, keeping cpuset_attach() from changing it
* anyway.
*/
int proc_cpuset_show(struct seq_file *m, void *unused_v)
int proc_cpuset_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, *p;
struct cgroup_subsys_state *css;
int retval;
@ -2743,24 +2742,16 @@ int proc_cpuset_show(struct seq_file *m, void *unused_v)
if (!buf)
goto out;
retval = -ESRCH;
pid = m->private;
tsk = get_pid_task(pid, PIDTYPE_PID);
if (!tsk)
goto out_free;
retval = -ENAMETOOLONG;
rcu_read_lock();
css = task_css(tsk, cpuset_cgrp_id);
p = cgroup_path(css->cgroup, buf, PATH_MAX);
rcu_read_unlock();
if (!p)
goto out_put_task;
goto out_free;
seq_puts(m, p);
seq_putc(m, '\n');
retval = 0;
out_put_task:
put_task_struct(tsk);
out_free:
kfree(buf);
out:

View File

@ -392,14 +392,9 @@ perf_cgroup_match(struct perf_event *event)
event->cgrp->css.cgroup);
}
static inline void perf_put_cgroup(struct perf_event *event)
{
css_put(&event->cgrp->css);
}
static inline void perf_detach_cgroup(struct perf_event *event)
{
perf_put_cgroup(event);
css_put(&event->cgrp->css);
event->cgrp = NULL;
}

View File

@ -148,7 +148,7 @@ static int hwpoison_filter_task(struct page *p)
ino = cgroup_ino(css->cgroup);
css_put(css);
if (!ino || ino != hwpoison_filter_memcg)
if (ino != hwpoison_filter_memcg)
return -EINVAL;
return 0;