[PATCH 075/196] fix struct user_info export's sysfs interaction

Greg Kroah-Hartman
2008-01-25T07:41:37Z

From: Kay Sievers <kay.sievers@vrfy.org>

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: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
include/linux/sched.h | 9 +---
kernel/ksysfs.c | 7 +--
kernel/user.c | 104 ++++++++++++++++++++++++-------------------------
3 files changed, 55 insertions(+), 65 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index cc14656..d6eacda 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -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);

diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index dd0f9e7..45e6465 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -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;

diff --git a/kernel/user.c b/kernel/user.c
index 80f1116..5a106f3 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -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);
--
1.5.3.8