From 67597074a385ab1d45e6af3b13e296e20d815ab7 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 7 Jan 2008 22:29:05 -0800 Subject: [PATCH] SLUB: Fix sysfs refcounting If CONFIG_SYSFS is set then free the kmem_cache structure when sysfs tells us its okay. Otherwise there is the danger (as pointed out by Al Viro) that sysfs thinks the kobject still exists after kmem_cache_destroy() removed it. Signed-off-by: Christoph Lameter Reviewed-by: Pekka J Enberg --- mm/slub.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) Index: linux-2.6/mm/slub.c =================================================================== --- linux-2.6.orig/mm/slub.c 2008-01-31 15:05:21.925431873 -0800 +++ linux-2.6/mm/slub.c 2008-01-31 15:05:23.393455644 -0800 @@ -247,7 +247,10 @@ static void sysfs_slab_remove(struct kme static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) { return 0; } -static inline void sysfs_slab_remove(struct kmem_cache *s) {} +static inline void sysfs_slab_remove(struct kmem_cache *s) +{ + kfree(s); +} #endif /******************************************************************** @@ -2322,7 +2325,6 @@ void kmem_cache_destroy(struct kmem_cach if (kmem_cache_close(s)) WARN_ON(1); sysfs_slab_remove(s); - kfree(s); } else up_write(&slub_lock); } @@ -3937,6 +3939,13 @@ static ssize_t slab_attr_store(struct ko return err; } +static void kmem_cache_release(struct kobject *kobj) +{ + struct kmem_cache *s = to_slab(kobj); + + kfree(s); +} + static struct sysfs_ops slab_sysfs_ops = { .show = slab_attr_show, .store = slab_attr_store, @@ -3944,6 +3953,7 @@ static struct sysfs_ops slab_sysfs_ops = static struct kobj_type slab_ktype = { .sysfs_ops = &slab_sysfs_ops, + .release = kmem_cache_release }; static int uevent_filter(struct kset *kset, struct kobject *kobj) @@ -4045,6 +4055,7 @@ static void sysfs_slab_remove(struct kme { kobject_uevent(&s->kobj, KOBJ_REMOVE); kobject_del(&s->kobj); + kobject_put(&s->kobj); } /*