convert selinuxfs

Tree has invariant part + two subtrees that get replaced upon each
policy load.  Invariant parts stay for the lifetime of filesystem,
these two subdirs - from policy load to policy load (serialized
on lock_rename(root, ...)).

All object creations are via d_alloc_name()+d_add() inside selinuxfs,
all removals are via simple_recursive_removal().

Turn those d_add() into d_make_persistent()+dput() and that's mostly it.

Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index f088776dbbd36f010521e852e655cfe0ec9b94bc..eae565358db41a42eb0e787fe4d5e8c8c9a36778 100644 (file)
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1205,7 +1205,8 @@ static struct dentry *sel_attach(struct dentry *parent, const char *name,
                iput(inode);
                return ERR_PTR(-ENOMEM);
        }
-       d_add(dentry, inode);
+       d_make_persistent(dentry, inode);
+       dput(dentry);
        return dentry;
 }
 
@@ -1934,10 +1935,11 @@ static struct dentry *sel_make_swapover_dir(struct super_block *sb,
        /* directory inodes start off with i_nlink == 2 (for "." entry) */
        inc_nlink(inode);
        inode_lock(sb->s_root->d_inode);
-       d_add(dentry, inode);
+       d_make_persistent(dentry, inode);
        inc_nlink(sb->s_root->d_inode);
        inode_unlock(sb->s_root->d_inode);
-       return dentry;
+       dput(dentry);
+       return dentry;  // borrowed
 }
 
 #define NULL_FILE_NAME "null"
@@ -2080,7 +2082,7 @@ static int sel_init_fs_context(struct fs_context *fc)
 static void sel_kill_sb(struct super_block *sb)
 {
        selinux_fs_info_free(sb);
-       kill_litter_super(sb);
+       kill_anon_super(sb);
 }
 
 static struct file_system_type sel_fs_type = {