diff options
| -rw-r--r-- | include/linux/kobject.h | 2 | ||||
| -rw-r--r-- | lib/kobject.c | 39 |
2 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/kobject.h b/include/linux/kobject.h index 7950a37a7146..8f6d12151048 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -191,6 +191,8 @@ static inline struct kobj_type *get_ktype(struct kobject *kobj) } extern struct kobject *kset_find_obj(struct kset *, const char *); +extern struct kobject *kset_find_obj_hinted(struct kset *, const char *, + struct kobject *); /* The global /sys/kernel/ kobject for people to chain off of */ extern struct kobject *kernel_kobj; diff --git a/lib/kobject.c b/lib/kobject.c index f07c57252e82..82dc34c095c2 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -746,17 +746,56 @@ void kset_unregister(struct kset *k) */ struct kobject *kset_find_obj(struct kset *kset, const char *name) { + return kset_find_obj_hinted(kset, name, NULL); +} + +/** + * kset_find_obj_hinted - search for object in kset given a predecessor hint. + * @kset: kset we're looking in. + * @name: object's name. + * @hint: hint to possible object's predecessor. + * + * Check the hint's next object and if it is a match return it directly, + * otherwise, fall back to the behavior of kset_find_obj(). Either way + * a reference for the returned object is held and the reference on the + * hinted object is released. + */ +struct kobject *kset_find_obj_hinted(struct kset *kset, const char *name, + struct kobject *hint) +{ struct kobject *k; struct kobject *ret = NULL; spin_lock(&kset->list_lock); + + if (!hint) + goto slow_search; + + /* end of list detection */ + if (hint->entry.next == kset->list.next) + goto slow_search; + + k = container_of(hint->entry.next, struct kobject, entry); + if (!kobject_name(k) || strcmp(kobject_name(k), name)) + goto slow_search; + + ret = kobject_get(k); + goto unlock_exit; + +slow_search: list_for_each_entry(k, &kset->list, entry) { if (kobject_name(k) && !strcmp(kobject_name(k), name)) { ret = kobject_get(k); break; } } + +unlock_exit: spin_unlock(&kset->list_lock); + + if (hint) + kobject_put(hint); + return ret; } |