From eb41d9465cdafee45e0cb30f3b7338646221908e Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Fri, 2 Nov 2007 13:47:53 +0100 Subject: [PATCH] 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 Cc: Srivatsa Vaddagiri Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- 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 cc14656f86..d6eacda765 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 dd0f9e7f34..45e6465856 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 80f1116b8f..5a106f3fdf 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/" directory and - * "/sys/kernel/uids//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//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); -- 2.39.5