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Commit b211e9d7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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.
parents d9428f09 e756c7b6

fs/proc/base.c

+4 −35
Original line number Diff line number Diff line
@@ -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),

include/linux/cgroup.h

+7 −19
Original line number Diff line number Diff line
@@ -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;

}



/* cft/css accessors for cftype->write() operation */

include/linux/cpuset.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

kernel/cgroup.c

+53 −131
Original line number Diff line number Diff line
@@ -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;
@@ -524,12 +509,8 @@ 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);

		}

		}



		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);

	mutex_lock(&cgroup_mutex);

	raw_spin_lock(&release_list_lock);

	while (!list_empty(&release_list)) {

		char *argv[3], *envp[3];

		int i;

	struct cgroup *cgrp =

		container_of(work, struct cgroup, release_agent_work);

	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);

	char *argv[3], *envp[3];



	mutex_lock(&cgroup_mutex);



	pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);

		if (!pathbuf)

			goto continue_free;

	agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);

	if (!pathbuf || !agentbuf)

		goto out;



	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;

		goto out;



		i = 0;

		argv[i++] = agentbuf;

		argv[i++] = path;

		argv[i] = NULL;

	argv[0] = agentbuf;

	argv[1] = path;

	argv[2] = NULL;



		i = 0;

	/* minimal command environment */

		envp[i++] = "HOME=/";

		envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";

		envp[i] = NULL;

	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);

	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[] =  {

kernel/cpuset.c

+3 −12
Original line number Diff line number Diff line
@@ -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: