Revert "kernfs: remove kernfs_addrm_cxt"

This reverts commit 99177a34110889a8f2c36420c34e3bcc9bfd8a70.

Tejun writes:
        I'm sorry but can you please revert the whole series?
        get_active() waiting while a node is deactivated has potential
        to lead to deadlock and that deactivate/reactivate interface is
        something fundamentally flawed and that cgroup will have to work
        with the remove_self() like everybody else.  IOW, I think the
        first posting was correct.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 4bc57848076c..e9ec38c86074 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -46,6 +46,13 @@ static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn)
 }
 
 /*
+ * Context structure to be used while adding/removing nodes.
+ */
+struct kernfs_addrm_cxt {
+	struct kernfs_node	*removed;
+};
+
+/*
  * mount.c
  */
 struct kernfs_super_info {
@@ -94,7 +101,10 @@ extern const struct inode_operations kernfs_dir_iops;
 
 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn);
 void kernfs_put_active(struct kernfs_node *kn);
-int kernfs_add_one(struct kernfs_node *kn, struct kernfs_node *parent);
+void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt);
+int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn,
+		   struct kernfs_node *parent);
+void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt);
 struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name,
 				    umode_t mode, unsigned flags);