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Commit 9410091d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup updates from Tejun Heo:
 "Nothing major. Two notable fixes are Li's second stab at fixing the
  long-standing race condition in the mount path and suppression of
  spurious warning from cgroup_get(). All other changes are trivial"

* 'for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: mark cgroup_get() with __maybe_unused
  cgroup: avoid attaching a cgroup root to two different superblocks, take 2
  cgroup: fix spurious warnings on cgroup_is_dead() from cgroup_sk_alloc()
  cgroup: move cgroup_subsys_state parent field for cache locality
  cpuset: Remove cpuset_update_active_cpus()'s parameter.
  cgroup: switch to BUG_ON()
  cgroup: drop duplicate header nsproxy.h
  kernel: convert css_set.refcount from atomic_t to refcount_t
  kernel: convert cgroup_namespace.count from atomic_t to refcount_t
parents ad1490bc 310b4816

include/linux/cgroup-defs.h

+8 −4
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/wait.h>

#include <linux/mutex.h>

#include <linux/rcupdate.h>

#include <linux/refcount.h>

#include <linux/percpu-refcount.h>

#include <linux/percpu-rwsem.h>

#include <linux/workqueue.h>
@@ -106,9 +107,6 @@ struct cgroup_subsys_state { 
	/* reference count - access via css_[try]get() and css_put() */

	struct percpu_ref refcnt;



	/* PI: the parent css */

	struct cgroup_subsys_state *parent;



	/* siblings list anchored at the parent's ->children */

	struct list_head sibling;

	struct list_head children;
@@ -138,6 +136,12 @@ struct cgroup_subsys_state { 
	/* percpu_ref killing and RCU release */

	struct rcu_head rcu_head;

	struct work_struct destroy_work;



	/*

	 * PI: the parent css.	Placed here for cache proximity to following

	 * fields of the containing structure.

	 */

	struct cgroup_subsys_state *parent;

};



/*
@@ -156,7 +160,7 @@ struct css_set { 
	struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];



	/* reference count */

	atomic_t refcount;

	refcount_t refcount;



	/* the default cgroup associated with this css_set */

	struct cgroup *dfl_cgrp;

include/linux/cgroup.h

+4 −4
Original line number Diff line number Diff line
@@ -17,11 +17,11 @@ 
#include <linux/seq_file.h>

#include <linux/kernfs.h>

#include <linux/jump_label.h>

#include <linux/nsproxy.h>

#include <linux/types.h>

#include <linux/ns_common.h>

#include <linux/nsproxy.h>

#include <linux/user_namespace.h>

#include <linux/refcount.h>



#include <linux/cgroup-defs.h>
@@ -661,7 +661,7 @@ static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} 
#endif	/* CONFIG_CGROUP_DATA */



struct cgroup_namespace {

	atomic_t		count;

	refcount_t		count;

	struct ns_common	ns;

	struct user_namespace	*user_ns;

	struct ucounts		*ucounts;
@@ -696,12 +696,12 @@ copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, 
static inline void get_cgroup_ns(struct cgroup_namespace *ns)

{

	if (ns)

		atomic_inc(&ns->count);

		refcount_inc(&ns->count);

}



static inline void put_cgroup_ns(struct cgroup_namespace *ns)

{

	if (ns && atomic_dec_and_test(&ns->count))

	if (ns && refcount_dec_and_test(&ns->count))

		free_cgroup_ns(ns);

}

include/linux/cpuset.h

+2 −2
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static inline void cpuset_dec(void) 


extern int cpuset_init(void);

extern void cpuset_init_smp(void);

extern void cpuset_update_active_cpus(bool cpu_online);

extern void cpuset_update_active_cpus(void);

extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);

extern void cpuset_cpus_allowed_fallback(struct task_struct *p);

extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
@@ -155,7 +155,7 @@ static inline bool cpusets_enabled(void) { return false; } 
static inline int cpuset_init(void) { return 0; }

static inline void cpuset_init_smp(void) {}



static inline void cpuset_update_active_cpus(bool cpu_online)

static inline void cpuset_update_active_cpus(void)

{

	partition_sched_domains(1, NULL, NULL);

}

kernel/cgroup/cgroup-internal.h

+4 −3
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/kernfs.h>

#include <linux/workqueue.h>

#include <linux/list.h>

#include <linux/refcount.h>



/*

 * A cgroup can be associated with multiple css_sets as different tasks may
@@ -134,7 +135,7 @@ static inline void put_css_set(struct css_set *cset) 
	 * can see it. Similar to atomic_dec_and_lock(), but for an

	 * rwlock

	 */

	if (atomic_add_unless(&cset->refcount, -1, 1))

	if (refcount_dec_not_one(&cset->refcount))

		return;



	spin_lock_irqsave(&css_set_lock, flags);
@@ -147,7 +148,7 @@ static inline void put_css_set(struct css_set *cset) 
 */

static inline void get_css_set(struct css_set *cset)

{

	atomic_inc(&cset->refcount);

	refcount_inc(&cset->refcount);

}



bool cgroup_ssid_enabled(int ssid);
@@ -163,7 +164,7 @@ int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen, 


void cgroup_free_root(struct cgroup_root *root);

void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts);

int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask);

int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask, int ref_flags);

int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);

struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags,

			       struct cgroup_root *root, unsigned long magic,

kernel/cgroup/cgroup-v1.c

+17 −3
Original line number Diff line number Diff line
@@ -346,7 +346,7 @@ static int cgroup_task_count(const struct cgroup *cgrp) 


	spin_lock_irq(&css_set_lock);

	list_for_each_entry(link, &cgrp->cset_links, cset_link)

		count += atomic_read(&link->cset->refcount);

		count += refcount_read(&link->cset->refcount);

	spin_unlock_irq(&css_set_lock);

	return count;

}
@@ -1072,6 +1072,7 @@ struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags, 
	struct cgroup_subsys *ss;

	struct dentry *dentry;

	int i, ret;

	bool new_root = false;



	cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
@@ -1181,10 +1182,11 @@ struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags, 
		ret = -ENOMEM;

		goto out_unlock;

	}

	new_root = true;



	init_cgroup_root(root, &opts);



	ret = cgroup_setup_root(root, opts.subsys_mask);

	ret = cgroup_setup_root(root, opts.subsys_mask, PERCPU_REF_INIT_DEAD);

	if (ret)

		cgroup_free_root(root);
@@ -1200,6 +1202,18 @@ struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags, 
	dentry = cgroup_do_mount(&cgroup_fs_type, flags, root,

				 CGROUP_SUPER_MAGIC, ns);



	/*

	 * There's a race window after we release cgroup_mutex and before

	 * allocating a superblock. Make sure a concurrent process won't

	 * be able to re-use the root during this window by delaying the

	 * initialization of root refcnt.

	 */

	if (new_root) {

		mutex_lock(&cgroup_mutex);

		percpu_ref_reinit(&root->cgrp.self.refcnt);

		mutex_unlock(&cgroup_mutex);

	}



	/*

	 * If @pinned_sb, we're reusing an existing root and holding an

	 * extra ref on its sb.  Mount is complete.  Put the extra ref.
@@ -1286,7 +1300,7 @@ static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css, 
	u64 count;



	rcu_read_lock();

	count = atomic_read(&task_css_set(current)->refcount);

	count = refcount_read(&task_css_set(current)->refcount);

	rcu_read_unlock();

	return count;

}