diff options
| -rw-r--r-- | fs/sysfs/dir.c | 8 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 13 | ||||
| -rw-r--r-- | include/linux/kobject.h | 11 | ||||
| -rw-r--r-- | include/linux/sysfs.h | 1 | ||||
| -rw-r--r-- | lib/kobject.c | 11 |
5 files changed, 43 insertions, 1 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index a63eb4ba786..7e54bac8c4b 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -614,6 +614,14 @@ int sysfs_create_subdir(struct kobject *kobj, const char *name, KOBJ_NS_TYPE_NONE, NULL, name, p_sd); } +/** + * sysfs_read_ns_type: return associated ns_type + * @kobj: the kobject being queried + * + * Each kobject can be tagged with exactly one namespace type + * (i.e. network or user). Return the ns_type associated with + * this object if any + */ static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj) { const struct kobj_ns_type_operations *ops; diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 93847d54c2e..6a13105b559 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -58,7 +58,7 @@ struct sysfs_dirent { struct sysfs_dirent *s_sibling; const char *s_name; - const void *s_ns; + const void *s_ns; /* namespace tag */ union { struct sysfs_elem_dir s_dir; struct sysfs_elem_symlink s_symlink; @@ -82,6 +82,7 @@ struct sysfs_dirent { #define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK) #define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR) +/* identify any namespace tag on sysfs_dirents */ #define SYSFS_NS_TYPE_MASK 0xff00 #define SYSFS_NS_TYPE_SHIFT 8 @@ -93,6 +94,10 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd) return sd->s_flags & SYSFS_TYPE_MASK; } +/* + * Return any namespace tags on this dirent. + * enum kobj_ns_type is defined in linux/kobject.h + */ static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd) { return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT; @@ -123,6 +128,12 @@ struct sysfs_addrm_cxt { /* * mount.c */ + +/* + * Each sb is associated with a set of namespace tags (i.e. + * the network namespace of the task which mounted this sysfs + * instance). + */ struct sysfs_super_info { const void *ns[KOBJ_NS_TYPES]; }; diff --git a/include/linux/kobject.h b/include/linux/kobject.h index d9456f69904..b60d2dfe4e6 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -136,12 +136,23 @@ struct kobj_attribute { extern const struct sysfs_ops kobj_sysfs_ops; +/* + * Namespace types which are used to tag kobjects and sysfs entries. + * Network namespace will likely be the first. + */ enum kobj_ns_type { KOBJ_NS_TYPE_NONE = 0, KOBJ_NS_TYPES }; struct sock; + +/* + * Callbacks so sysfs can determine namespaces + * @current_ns: return calling task's namespace + * @netlink_ns: return namespace to which a sock belongs (right?) + * @initial_ns: return the initial namespace (i.e. init_net_ns) + */ struct kobj_ns_type_operations { enum kobj_ns_type type; const void *(*current_ns)(void); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 976c4664b21..47f1c95b529 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -178,6 +178,7 @@ struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd); void sysfs_put(struct sysfs_dirent *sd); void sysfs_printk_last_file(void); +/* Called to clear a ns tag when it is no longer valid */ void sysfs_exit_ns(enum kobj_ns_type type, const void *tag); int __must_check sysfs_init(void); diff --git a/lib/kobject.c b/lib/kobject.c index b2c6d1f56e6..f07c57252e8 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -948,6 +948,17 @@ const void *kobj_ns_initial(enum kobj_ns_type type) return ns; } +/* + * kobj_ns_exit - invalidate a namespace tag + * + * @type: the namespace type (i.e. KOBJ_NS_TYPE_NET) + * @ns: the actual namespace being invalidated + * + * This is called when a tag is no longer valid. For instance, + * when a network namespace exits, it uses this helper to + * make sure no sb's sysfs_info points to the now-invalidated + * netns. + */ void kobj_ns_exit(enum kobj_ns_type type, const void *ns) { sysfs_exit_ns(type, ns); |