diff options
Diffstat (limited to 'fs/kernfs/kernfs-internal.h')
| -rw-r--r-- | fs/kernfs/kernfs-internal.h | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 24e9514565ac..6061b6f70d2a 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -19,8 +19,6 @@ #include <linux/kernfs.h> #include <linux/fs_context.h> -extern rwlock_t kernfs_rename_lock; - struct kernfs_iattrs { kuid_t ia_uid; kgid_t ia_gid; @@ -53,6 +51,9 @@ struct kernfs_root { struct rw_semaphore kernfs_iattr_rwsem; struct rw_semaphore kernfs_supers_rwsem; + /* kn->parent and kn->name */ + rwlock_t kernfs_rename_lock; + struct rcu_head rcu; }; @@ -108,6 +109,11 @@ static inline bool kernfs_root_is_locked(const struct kernfs_node *kn) return lockdep_is_held(&kernfs_root(kn)->kernfs_rwsem); } +static inline bool kernfs_rename_is_locked(const struct kernfs_node *kn) +{ + return lockdep_is_held(&kernfs_root(kn)->kernfs_rename_lock); +} + static inline const char *kernfs_rcu_name(const struct kernfs_node *kn) { return rcu_dereference_check(kn->name, kernfs_root_is_locked(kn)); @@ -118,14 +124,15 @@ static inline struct kernfs_node *kernfs_parent(const struct kernfs_node *kn) /* * The kernfs_node::__parent remains valid within a RCU section. The kn * can be reparented (and renamed) which changes the entry. This can be - * avoided by locking kernfs_root::kernfs_rwsem or kernfs_rename_lock. + * avoided by locking kernfs_root::kernfs_rwsem or + * kernfs_root::kernfs_rename_lock. * Both locks can be used to obtain a reference on __parent. Once the * reference count reaches 0 then the node is about to be freed * and can not be renamed (or become a different parent) anymore. */ return rcu_dereference_check(kn->__parent, kernfs_root_is_locked(kn) || - lockdep_is_held(&kernfs_rename_lock) || + kernfs_rename_is_locked(kn) || !atomic_read(&kn->count)); } |