get rid of insanity with namespace roots in tomoyo

passing *any* namespace root to __d_path() as root is equivalent
to just passing it {NULL, NULL}; no need to bother with finding
the root of our namespace in there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 18369d4..6a4f849 100644 (file)
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -89,27 +89,12 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname,
                sp = dentry->d_op->d_dname(dentry, newname + offset,
                                           newname_len - offset);
        } else {
-               /* Taken from d_namespace_path(). */
-               struct path root;
-               struct path ns_root = { };
-               struct path tmp;
-
-               read_lock(&current->fs->lock);
-               root = current->fs->root;
-               path_get(&root);
-               read_unlock(&current->fs->lock);
-               spin_lock(&vfsmount_lock);
-               if (root.mnt && root.mnt->mnt_ns)
-                       ns_root.mnt = mntget(root.mnt->mnt_ns->root);
-               if (ns_root.mnt)
-                       ns_root.dentry = dget(ns_root.mnt->mnt_root);
-               spin_unlock(&vfsmount_lock);
+               struct path ns_root = {.mnt = NULL, .dentry = NULL};
+
                spin_lock(&dcache_lock);
-               tmp = ns_root;
-               sp = __d_path(path, &tmp, newname, newname_len);
+               /* go to whatever namespace root we are under */
+               sp = __d_path(path, &ns_root, newname, newname_len);
                spin_unlock(&dcache_lock);
-               path_put(&root);
-               path_put(&ns_root);
                /* Prepend "/proc" prefix if using internal proc vfs mount. */
                if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) &&
                    (strcmp(path->mnt->mnt_sb->s_type->name, "proc") == 0)) {