diff options
| -rw-r--r-- | fs/kernfs/dir.c | 37 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 2 |
2 files changed, 38 insertions, 1 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index c9323956c63c..7fb5a72cc96d 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -1311,7 +1311,7 @@ static void kernfs_activate_one(struct kernfs_node *kn) kn->flags |= KERNFS_ACTIVATED; - if (kernfs_active(kn) || (kn->flags & KERNFS_REMOVING)) + if (kernfs_active(kn) || (kn->flags & (KERNFS_HIDDEN | KERNFS_REMOVING))) return; WARN_ON_ONCE(kn->parent && RB_EMPTY_NODE(&kn->rb)); @@ -1347,6 +1347,41 @@ void kernfs_activate(struct kernfs_node *kn) up_write(&root->kernfs_rwsem); } +/** + * kernfs_show - show or hide a node + * @kn: kernfs_node to show or hide + * @show: whether to show or hide + * + * If @show is %false, @kn is marked hidden and deactivated. A hidden node is + * ignored in future activaitons. If %true, the mark is removed and activation + * state is restored. This function won't implicitly activate a new node in a + * %KERNFS_ROOT_CREATE_DEACTIVATED root which hasn't been activated yet. + * + * To avoid recursion complexities, directories aren't supported for now. + */ +void kernfs_show(struct kernfs_node *kn, bool show) +{ + struct kernfs_root *root = kernfs_root(kn); + + if (WARN_ON_ONCE(kernfs_type(kn) == KERNFS_DIR)) + return; + + down_write(&root->kernfs_rwsem); + + if (show) { + kn->flags &= ~KERNFS_HIDDEN; + if (kn->flags & KERNFS_ACTIVATED) + kernfs_activate_one(kn); + } else { + kn->flags |= KERNFS_HIDDEN; + if (kernfs_active(kn)) + atomic_add(KN_DEACTIVATED_BIAS, &kn->active); + kernfs_drain(kn); + } + + up_write(&root->kernfs_rwsem); +} + static void __kernfs_remove(struct kernfs_node *kn) { struct kernfs_node *pos; diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index b77d257c1f7e..73f5c120def8 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -108,6 +108,7 @@ enum kernfs_node_flag { KERNFS_HAS_SEQ_SHOW = 0x0040, KERNFS_HAS_MMAP = 0x0080, KERNFS_LOCKDEP = 0x0100, + KERNFS_HIDDEN = 0x0200, KERNFS_SUICIDAL = 0x0400, KERNFS_SUICIDED = 0x0800, KERNFS_EMPTY_DIR = 0x1000, @@ -430,6 +431,7 @@ struct kernfs_node *kernfs_create_link(struct kernfs_node *parent, const char *name, struct kernfs_node *target); void kernfs_activate(struct kernfs_node *kn); +void kernfs_show(struct kernfs_node *kn, bool show); void kernfs_remove(struct kernfs_node *kn); void kernfs_break_active_protection(struct kernfs_node *kn); void kernfs_unbreak_active_protection(struct kernfs_node *kn); |