From ce2c9cb0259acd2aed184499ebe41ab00da13b25 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 12 Sep 2007 15:06:57 -0700 Subject: [PATCH] kobject: remove the static array for the name Due to historical reasons, struct kobject contained a static array for the name, and a dynamic pointer in case the name got bigger than the array. That's just dumb, as people didn't always know which variable to reference, even with the accessor for the kobject name. This patch removes the static array, potentially saving a lot of memory as the majority of kobjects do not have a very long name. Thanks to Kay for the idea to do this. Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- include/linux/kobject.h | 7 ++-- lib/kobject.c | 79 ++++++++++++++++++++--------------------- 2 files changed, 42 insertions(+), 44 deletions(-) diff --git a/include/linux/kobject.h b/include/linux/kobject.h index c0fb535d7acd..8b45946e8506 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -63,7 +63,6 @@ extern const char *kobject_actions[]; struct kobject { const char * k_name; - char name[KOBJ_NAME_LEN]; struct kref kref; struct list_head entry; struct kobject * parent; @@ -188,18 +187,18 @@ extern struct kobject * kset_find_obj(struct kset *, const char *); * Use this when initializing an embedded kset with no other * fields to initialize. */ -#define set_kset_name(str) .kset = { .kobj = { .name = str } } +#define set_kset_name(str) .kset = { .kobj = { .k_name = str } } #define decl_subsys(_name,_type,_uevent_ops) \ struct kset _name##_subsys = { \ - .kobj = { .name = __stringify(_name) }, \ + .kobj = { .k_name = __stringify(_name) }, \ .ktype = _type, \ .uevent_ops =_uevent_ops, \ } #define decl_subsys_name(_varname,_name,_type,_uevent_ops) \ struct kset _varname##_subsys = { \ - .kobj = { .name = __stringify(_name) }, \ + .kobj = { .k_name = __stringify(_name) }, \ .ktype = _type, \ .uevent_ops =_uevent_ops, \ } diff --git a/lib/kobject.c b/lib/kobject.c index 1326041213dd..10ae2ebeaf96 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -170,7 +170,7 @@ int kobject_shadow_add(struct kobject *kobj, struct sysfs_dirent *shadow_parent) if (!(kobj = kobject_get(kobj))) return -ENOENT; if (!kobj->k_name) - kobj->k_name = kobj->name; + kobject_set_name(kobj, "NO_NAME"); if (!*kobj->k_name) { pr_debug("kobject attempted to be registered with no name!\n"); WARN_ON(1); @@ -181,7 +181,7 @@ int kobject_shadow_add(struct kobject *kobj, struct sysfs_dirent *shadow_parent) pr_debug("kobject %s: registering. parent: %s, set: %s\n", kobject_name(kobj), parent ? kobject_name(parent) : "", - kobj->kset ? kobj->kset->kobj.name : "" ); + kobj->kset ? kobject_name(&kobj->kset->kobj) : "" ); if (kobj->kset) { spin_lock(&kobj->kset->list_lock); @@ -255,54 +255,50 @@ int kobject_register(struct kobject * kobj) int kobject_set_name(struct kobject * kobj, const char * fmt, ...) { int error = 0; - int limit = KOBJ_NAME_LEN; + int limit; int need; va_list args; - char * name; + char *name; - /* - * First, try the static array - */ - va_start(args,fmt); - need = vsnprintf(kobj->name,limit,fmt,args); + /* find out how big a buffer we need */ + name = kmalloc(1024, GFP_KERNEL); + if (!name) { + error = -ENOMEM; + goto done; + } + va_start(args, fmt); + need = vsnprintf(name, 1024, fmt, args); va_end(args); - if (need < limit) - name = kobj->name; - else { - /* - * Need more space? Allocate it and try again - */ - limit = need + 1; - name = kmalloc(limit,GFP_KERNEL); - if (!name) { - error = -ENOMEM; - goto Done; - } - va_start(args,fmt); - need = vsnprintf(name,limit,fmt,args); - va_end(args); - - /* Still? Give up. */ - if (need >= limit) { - kfree(name); - error = -EFAULT; - goto Done; - } + kfree(name); + + /* Allocate the new space and copy the string in */ + limit = need + 1; + name = kmalloc(limit, GFP_KERNEL); + if (!name) { + error = -ENOMEM; + goto done; + } + va_start(args, fmt); + need = vsnprintf(name, limit, fmt, args); + va_end(args); + + /* something wrong with the string we copied? */ + if (need >= limit) { + kfree(name); + error = -EFAULT; + goto done; } /* Free the old name, if necessary. */ - if (kobj->k_name && kobj->k_name != kobj->name) - kfree(kobj->k_name); + kfree(kobj->k_name); /* Now, set the new name */ kobj->k_name = name; - Done: +done: return error; } - EXPORT_SYMBOL(kobject_set_name); - /** * kobject_rename - change the name of an object * @kobj: object in question. @@ -477,13 +473,16 @@ void kobject_cleanup(struct kobject * kobj) struct kobj_type * t = get_ktype(kobj); struct kset * s = kobj->kset; struct kobject * parent = kobj->parent; + const char *name = kobj->k_name; pr_debug("kobject %s: cleaning up\n",kobject_name(kobj)); - if (kobj->k_name != kobj->name) - kfree(kobj->k_name); - kobj->k_name = NULL; - if (t && t->release) + if (t && t->release) { t->release(kobj); + /* If we have a release function, we can guess that this was + * not a statically allocated kobject, so we should be safe to + * free the name */ + kfree(name); + } if (s) kset_put(s); kobject_put(parent); -- GitLab