Commit eb41d946 authored by Kay Sievers's avatar Kay Sievers Committed by Greg Kroah-Hartman
Browse files

fix struct user_info export's sysfs interaction 



Clean up the use of ksets and kobjects. Kobjects are instances of
objects (like struct user_info), ksets are collections of objects of a
similar type (like the uids directory containing the user_info directories).
So, use kobjects for the user_info directories, and a kset for the "uids"
directory.

On object cleanup, the final kobject_put() was missing.

Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: default avatarKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 386f275f

include/linux/sched.h

+2 −7
Original line number Diff line number Diff line
@@ -552,18 +552,13 @@ struct user_struct { 
#ifdef CONFIG_FAIR_USER_SCHED

	struct task_group *tg;

#ifdef CONFIG_SYSFS

	struct kset kset;

	struct subsys_attribute user_attr;

	struct kobject kobj;

	struct work_struct work;

#endif

#endif

};



#ifdef CONFIG_FAIR_USER_SCHED

extern int uids_kobject_init(void);

#else

static inline int uids_kobject_init(void) { return 0; }

#endif

extern int uids_sysfs_init(void);



extern struct user_struct *find_user(uid_t);

kernel/ksysfs.c

+2 −5
Original line number Diff line number Diff line
@@ -141,11 +141,8 @@ static int __init ksysfs_init(void) 
			goto group_exit;

	}



	/*

	 * Create "/sys/kernel/uids" directory and corresponding root user's

	 * directory under it.

	 */

	error = uids_kobject_init();

	/* create the /sys/kernel/uids/ directory */

	error = uids_sysfs_init();

	if (error)

		goto notes_exit;

kernel/user.c

+51 −53
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ static void sched_switch_user(struct task_struct *p) { } 


#if defined(CONFIG_FAIR_USER_SCHED) && defined(CONFIG_SYSFS)



static struct kobject uids_kobject; /* represents /sys/kernel/uids directory */

static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */

static DEFINE_MUTEX(uids_mutex);



static inline void uids_mutex_lock(void)
@@ -128,86 +128,84 @@ static inline void uids_mutex_unlock(void) 
	mutex_unlock(&uids_mutex);

}



/* return cpu shares held by the user */

static ssize_t cpu_shares_show(struct kset *kset, char *buffer)

/* uid directory attributes */

static ssize_t cpu_shares_show(struct kobject *kobj,

			       struct kobj_attribute *attr,

			       char *buf)

{

	struct user_struct *up = container_of(kset, struct user_struct, kset);

	struct user_struct *up = container_of(kobj, struct user_struct, kobj);



	return sprintf(buffer, "%lu\n", sched_group_shares(up->tg));

	return sprintf(buf, "%lu\n", sched_group_shares(up->tg));

}



/* modify cpu shares held by the user */

static ssize_t cpu_shares_store(struct kset *kset, const char *buffer,

				size_t size)

static ssize_t cpu_shares_store(struct kobject *kobj,

				struct kobj_attribute *attr,

				const char *buf, size_t size)

{

	struct user_struct *up = container_of(kset, struct user_struct, kset);

	struct user_struct *up = container_of(kobj, struct user_struct, kobj);

	unsigned long shares;

	int rc;



	sscanf(buffer, "%lu", &shares);

	sscanf(buf, "%lu", &shares);



	rc = sched_group_set_shares(up->tg, shares);



	return (rc ? rc : size);

}



static void user_attr_init(struct subsys_attribute *sa, char *name, int mode)

static struct kobj_attribute cpu_share_attr =

	__ATTR(cpu_share, 0644, cpu_shares_show, cpu_shares_store);



/* default attributes per uid directory */

static struct attribute *uids_attributes[] = {

	&cpu_share_attr.attr,

	NULL

};



/* the lifetime of user_struct is not managed by the core (now) */

static void uids_release(struct kobject *kobj)

{

	sa->attr.name = name;

	sa->attr.mode = mode;

	sa->show = cpu_shares_show;

	sa->store = cpu_shares_store;

	return;

}



/* Create "/sys/kernel/uids/<uid>" directory and

 *  "/sys/kernel/uids/<uid>/cpu_share" file for this user.

 */

static int user_kobject_create(struct user_struct *up)

static struct kobj_type uids_ktype = {

	.sysfs_ops = &kobj_sysfs_ops,

	.default_attrs = uids_attributes,

	.release = uids_release,

};



/* create /sys/kernel/uids/<uid>/cpu_share file for this user */

static int uids_user_create(struct user_struct *up)

{

	struct kset *kset = &up->kset;

	struct kobject *kobj = &kset->kobj;

	struct kobject *kobj = &up->kobj;

	int error;



	memset(kset, 0, sizeof(struct kset));

	kobj->parent = &uids_kobject;	/* create under /sys/kernel/uids dir */

	kobject_set_name(kobj, "%d", up->uid);

	kset_init(kset);

	user_attr_init(&up->user_attr, "cpu_share", 0644);



	memset(kobj, 0, sizeof(struct kobject));

	kobj->ktype = &uids_ktype;

	kobj->kset = uids_kset;

	kobject_init(kobj);

	kobject_set_name(&up->kobj, "%d", up->uid);

	error = kobject_add(kobj);

	if (error)

		goto done;



	error = sysfs_create_file(kobj, &up->user_attr.attr);

	if (error)

		kobject_del(kobj);



	kobject_uevent(kobj, KOBJ_ADD);



done:

	return error;

}



/* create these in sysfs filesystem:

/* create these entries in sysfs:

 * 	"/sys/kernel/uids" directory

 * 	"/sys/kernel/uids/0" directory (for root user)

 * 	"/sys/kernel/uids/0/cpu_share" file (for root user)

 */

int __init uids_kobject_init(void)

int __init uids_sysfs_init(void)

{

	int error;

	uids_kset = kset_create_and_add("uids", NULL, &kernel_kset->kobj);

	if (!uids_kset)

		return -ENOMEM;



	/* create under /sys/kernel dir */

	uids_kobject.parent = &kernel_kset->kobj;

	uids_kobject.kset = kernel_kset;

	kobject_set_name(&uids_kobject, "uids");

	kobject_init(&uids_kobject);



	error = kobject_add(&uids_kobject);

	if (!error)

		error = user_kobject_create(&root_user);



	return error;

	return uids_user_create(&root_user);

}



/* work function to remove sysfs directory for a user and free up
@@ -216,7 +214,6 @@ int __init uids_kobject_init(void) 
static void remove_user_sysfs_dir(struct work_struct *w)

{

	struct user_struct *up = container_of(w, struct user_struct, work);

	struct kobject *kobj = &up->kset.kobj;

	unsigned long flags;

	int remove_user = 0;
@@ -238,9 +235,9 @@ static void remove_user_sysfs_dir(struct work_struct *w) 
	if (!remove_user)

		goto done;



	sysfs_remove_file(kobj, &up->user_attr.attr);

	kobject_uevent(kobj, KOBJ_REMOVE);

	kobject_del(kobj);

	kobject_uevent(&up->kobj, KOBJ_REMOVE);

	kobject_del(&up->kobj);

	kobject_put(&up->kobj);



	sched_destroy_user(up);

	key_put(up->uid_keyring);
@@ -267,7 +264,8 @@ static inline void free_user(struct user_struct *up, unsigned long flags) 


#else	/* CONFIG_FAIR_USER_SCHED && CONFIG_SYSFS */



static inline int user_kobject_create(struct user_struct *up) { return 0; }

int uids_sysfs_init(void) { return 0; }

static inline int uids_user_create(struct user_struct *up) { return 0; }

static inline void uids_mutex_lock(void) { }

static inline void uids_mutex_unlock(void) { }
@@ -324,7 +322,7 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) 
	struct hlist_head *hashent = uidhashentry(ns, uid);

	struct user_struct *up;



	/* Make uid_hash_find() + user_kobject_create() + uid_hash_insert()

	/* Make uid_hash_find() + uids_user_create() + uid_hash_insert()

	 * atomic.

	 */

	uids_mutex_lock();
@@ -370,7 +368,7 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) 
			return NULL;

		}



		if (user_kobject_create(new)) {

		if (uids_user_create(new)) {

			sched_destroy_user(new);

			key_put(new->uid_keyring);

			key_put(new->session_keyring);

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