From 41a212859a4dd583d3aa032cdd3efa564c4f189f Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 6 May 2014 12:50:08 -0700 Subject: [PATCH] slub: use sysfs'es release mechanism for kmem_cache debugobjects warning during netfilter exit: ------------[ cut here ]------------ WARNING: CPU: 6 PID: 4178 at lib/debugobjects.c:260 debug_print_object+0x8d/0xb0() ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x20 Modules linked in: CPU: 6 PID: 4178 Comm: kworker/u16:2 Tainted: G W 3.11.0-next-20130906-sasha #3984 Workqueue: netns cleanup_net Call Trace: dump_stack+0x52/0x87 warn_slowpath_common+0x8c/0xc0 warn_slowpath_fmt+0x46/0x50 debug_print_object+0x8d/0xb0 __debug_check_no_obj_freed+0xa5/0x220 debug_check_no_obj_freed+0x15/0x20 kmem_cache_free+0x197/0x340 kmem_cache_destroy+0x86/0xe0 nf_conntrack_cleanup_net_list+0x131/0x170 nf_conntrack_pernet_exit+0x5d/0x70 ops_exit_list+0x5e/0x70 cleanup_net+0xfb/0x1c0 process_one_work+0x338/0x550 worker_thread+0x215/0x350 kthread+0xe7/0xf0 ret_from_fork+0x7c/0xb0 Also during dcookie cleanup: WARNING: CPU: 12 PID: 9725 at lib/debugobjects.c:260 debug_print_object+0x8c/0xb0() ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x20 Modules linked in: CPU: 12 PID: 9725 Comm: trinity-c141 Not tainted 3.15.0-rc2-next-20140423-sasha-00018-gc4ff6c4 #408 Call Trace: dump_stack (lib/dump_stack.c:52) warn_slowpath_common (kernel/panic.c:430) warn_slowpath_fmt (kernel/panic.c:445) debug_print_object (lib/debugobjects.c:262) __debug_check_no_obj_freed (lib/debugobjects.c:697) debug_check_no_obj_freed (lib/debugobjects.c:726) kmem_cache_free (mm/slub.c:2689 mm/slub.c:2717) kmem_cache_destroy (mm/slab_common.c:363) dcookie_unregister (fs/dcookies.c:302 fs/dcookies.c:343) event_buffer_release (arch/x86/oprofile/../../../drivers/oprofile/event_buffer.c:153) __fput (fs/file_table.c:217) ____fput (fs/file_table.c:253) task_work_run (kernel/task_work.c:125 (discriminator 1)) do_notify_resume (include/linux/tracehook.h:196 arch/x86/kernel/signal.c:751) int_signal (arch/x86/kernel/entry_64.S:807) Sysfs has a release mechanism. Use that to release the kmem_cache structure if CONFIG_SYSFS is enabled. Only slub is changed - slab currently only supports /proc/slabinfo and not /sys/kernel/slab/*. We talked about adding that and someone was working on it. [akpm@linux-foundation.org: fix CONFIG_SYSFS=n build] [akpm@linux-foundation.org: fix CONFIG_SYSFS=n build even more] Signed-off-by: Christoph Lameter Reported-by: Sasha Levin Tested-by: Sasha Levin Acked-by: Greg KH Cc: Thomas Gleixner Cc: Pekka Enberg Cc: Russell King Cc: Bart Van Assche Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/slub_def.h | 9 +++++++++ mm/slab.h | 1 + mm/slab_common.c | 13 +++++++++++-- mm/slub.c | 30 ++++++++---------------------- 4 files changed, 29 insertions(+), 24 deletions(-) diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index f2f7398848cf..d82abd40a3c0 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -101,4 +101,13 @@ struct kmem_cache { struct kmem_cache_node *node[MAX_NUMNODES]; }; +#ifdef CONFIG_SYSFS +#define SLAB_SUPPORTS_SYSFS +void sysfs_slab_remove(struct kmem_cache *); +#else +static inline void sysfs_slab_remove(struct kmem_cache *s) +{ +} +#endif + #endif /* _LINUX_SLUB_DEF_H */ diff --git a/mm/slab.h b/mm/slab.h index 3045316b7c9d..6bd4c353704f 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -91,6 +91,7 @@ __kmem_cache_alias(const char *name, size_t size, size_t align, #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) int __kmem_cache_shutdown(struct kmem_cache *); +void slab_kmem_cache_release(struct kmem_cache *); struct seq_file; struct file; diff --git a/mm/slab_common.c b/mm/slab_common.c index f3cfccf76dda..102cc6fca3d3 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -323,6 +323,12 @@ static int kmem_cache_destroy_memcg_children(struct kmem_cache *s) } #endif /* CONFIG_MEMCG_KMEM */ +void slab_kmem_cache_release(struct kmem_cache *s) +{ + kfree(s->name); + kmem_cache_free(kmem_cache, s); +} + void kmem_cache_destroy(struct kmem_cache *s) { get_online_cpus(); @@ -352,8 +358,11 @@ void kmem_cache_destroy(struct kmem_cache *s) rcu_barrier(); memcg_free_cache_params(s); - kfree(s->name); - kmem_cache_free(kmem_cache, s); +#ifdef SLAB_SUPPORTS_SYSFS + sysfs_slab_remove(s); +#else + slab_kmem_cache_release(s); +#endif goto out_put_cpus; out_unlock: diff --git a/mm/slub.c b/mm/slub.c index 042a47b4d0f5..2b1ce697fc4b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -210,14 +210,11 @@ enum track_item { TRACK_ALLOC, TRACK_FREE }; #ifdef CONFIG_SYSFS static int sysfs_slab_add(struct kmem_cache *); static int sysfs_slab_alias(struct kmem_cache *, const char *); -static void sysfs_slab_remove(struct kmem_cache *); static void memcg_propagate_slab_attrs(struct kmem_cache *s); #else 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 memcg_propagate_slab_attrs(struct kmem_cache *s) { } #endif @@ -3238,24 +3235,7 @@ static inline int kmem_cache_close(struct kmem_cache *s) int __kmem_cache_shutdown(struct kmem_cache *s) { - int rc = kmem_cache_close(s); - - if (!rc) { - /* - * Since slab_attr_store may take the slab_mutex, we should - * release the lock while removing the sysfs entry in order to - * avoid a deadlock. Because this is pretty much the last - * operation we do and the lock will be released shortly after - * that in slab_common.c, we could just move sysfs_slab_remove - * to a later point in common code. We should do that when we - * have a common sysfs framework for all allocators. - */ - mutex_unlock(&slab_mutex); - sysfs_slab_remove(s); - mutex_lock(&slab_mutex); - } - - return rc; + return kmem_cache_close(s); } /******************************************************************** @@ -5122,6 +5102,11 @@ static void memcg_propagate_slab_attrs(struct kmem_cache *s) #endif } +static void kmem_cache_release(struct kobject *k) +{ + slab_kmem_cache_release(to_slab(k)); +} + static const struct sysfs_ops slab_sysfs_ops = { .show = slab_attr_show, .store = slab_attr_store, @@ -5129,6 +5114,7 @@ static const 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) @@ -5255,7 +5241,7 @@ out_put_kobj: goto out; } -static void sysfs_slab_remove(struct kmem_cache *s) +void sysfs_slab_remove(struct kmem_cache *s) { if (slab_state < FULL) /* -- 2.20.1