return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN);
}
+/**
+ * path_mounted - check whether path is mounted
+ * @path: path to check
+ *
+ * Determine whether @path refers to the root of a mount.
+ *
+ * Return: true if @path is the root of a mount, false if not.
+ */
+static inline bool path_mounted(const struct path *path)
+{
+ return path->mnt->mnt_root == path->dentry;
+}
+
static void warn_mandlock(void)
{
pr_warn_once("=======================================================\n"
if (!may_mount())
return -EPERM;
- if (path->dentry != path->mnt->mnt_root)
+ if (!path_mounted(path))
return -EINVAL;
if (!check_mnt(mnt))
return -EINVAL;
int type;
int err = 0;
- if (path->dentry != path->mnt->mnt_root)
+ if (!path_mounted(path))
return -EINVAL;
type = flags_to_propagation_type(ms_flags);
if (!check_mnt(mnt))
return -EINVAL;
- if (path->dentry != mnt->mnt.mnt_root)
+ if (!path_mounted(path))
return -EINVAL;
if (!can_change_locked_flags(mnt, mnt_flags))
if (!check_mnt(mnt))
return -EINVAL;
- if (path->dentry != path->mnt->mnt_root)
+ if (!path_mounted(path))
return -EINVAL;
if (!can_change_locked_flags(mnt, mnt_flags))
err = -EINVAL;
/* To and From paths should be mount roots */
- if (from_path->dentry != from_path->mnt->mnt_root)
+ if (!path_mounted(from_path))
goto out;
- if (to_path->dentry != to_path->mnt->mnt_root)
+ if (!path_mounted(to_path))
goto out;
/* Setting sharing groups is only allowed across same superblock */
if (old->mnt.mnt_flags & MNT_LOCKED)
goto out;
- if (old_path->dentry != old_path->mnt->mnt_root)
+ if (!path_mounted(old_path))
goto out;
if (d_is_dir(new_path->dentry) !=
}
/* Refuse the same filesystem on the same mount point */
- if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb &&
- path->mnt->mnt_root == path->dentry)
+ if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb && path_mounted(path))
return -EBUSY;
if (d_is_symlink(newmnt->mnt.mnt_root))
if (new_mnt == root_mnt || old_mnt == root_mnt)
goto out4; /* loop, on the same file system */
error = -EINVAL;
- if (root.mnt->mnt_root != root.dentry)
+ if (!path_mounted(&root))
goto out4; /* not a mountpoint */
if (!mnt_has_parent(root_mnt))
goto out4; /* not attached */
- if (new.mnt->mnt_root != new.dentry)
+ if (!path_mounted(&new))
goto out4; /* not a mountpoint */
if (!mnt_has_parent(new_mnt))
goto out4; /* not attached */
struct mount *mnt = real_mount(path->mnt);
int err = 0;
- if (path->dentry != mnt->mnt.mnt_root)
+ if (!path_mounted(path))
return -EINVAL;
if (kattr->mnt_userns) {