sysfs, kobject: add sysfs wrapper for kernfs_enable_ns()

Currently, kobject is invoking kernfs_enable_ns() directly.  This is
fine now as sysfs and kernfs are enabled and disabled together.  If
sysfs is disabled, kernfs_enable_ns() is switched to dummy
implementation too and everything is fine; however, kernfs will soon
have its own config option CONFIG_KERNFS and !SYSFS && KERNFS will be
possible, which can make kobject call into non-dummy
kernfs_enable_ns() with NULL kernfs_node pointers leading to an oops.

Introduce sysfs_enable_ns() which is a wrapper around
kernfs_enable_ns() so that it can be made a noop depending only on
CONFIG_SYSFS regardless of the planned CONFIG_KERNFS.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo 2014-02-07 13:32:07 -05:00 committed by Greg Kroah-Hartman
parent 3eef34ad7d
commit fa4cd451cc
2 changed files with 10 additions and 1 deletions

View File

@ -244,6 +244,11 @@ void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
int __must_check sysfs_init(void);
static inline void sysfs_enable_ns(struct kernfs_node *kn)
{
return kernfs_enable_ns(kn);
}
#else /* CONFIG_SYSFS */
static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
@ -416,6 +421,10 @@ static inline int __must_check sysfs_init(void)
return 0;
}
static inline void sysfs_enable_ns(struct kernfs_node *kn)
{
}
#endif /* CONFIG_SYSFS */
static inline int __must_check sysfs_create_file(struct kobject *kobj,

View File

@ -94,7 +94,7 @@ static int create_dir(struct kobject *kobj)
BUG_ON(ops->type >= KOBJ_NS_TYPES);
BUG_ON(!kobj_ns_type_registered(ops->type));
kernfs_enable_ns(kobj->sd);
sysfs_enable_ns(kobj->sd);
}
return 0;