ostree: Use bind mounts to setup ostree root

Simplify the mounting by using bind instead of tearing down the existing
mounts and remounting them in the ostree root. This also has the benefit
of working with dirinstall when there is no separate device for /boot.

pyanaconda/packaging/__init__.py

@@ -636,29 +636,11 @@ def writeStorageLate(self):
            every payload except for dnf.  Payloads should only implement one of
            these methods by overriding the unneeded one with a pass.
         """
-        if not flags.dirInstall:
-            if iutil.getSysroot() != iutil.getTargetPhysicalRoot():
-                set_sysroot(iutil.getTargetPhysicalRoot(), iutil.getSysroot())
-
-                # Now that we have the FS layout in the target, umount
-                # things that were in the legacy sysroot, and put them in
-                # the target root, except for the physical /.  First,
-                # unmount all target filesystems.
-                self.storage.umount_filesystems()
-
-                # Explicitly mount the root on the physical sysroot
-                rootmnt = self.storage.mountpoints.get('/')
-                rootmnt.setup()
-                rootmnt.format.setup(options=rootmnt.format.options, chroot=iutil.getTargetPhysicalRoot())
-
-                self.prepareMountTargets(self.storage)
-
-                # Everything else goes in the target root, including /boot
-                # since the bootloader code will expect to find /boot
-                # inside the chroot.
-                self.storage.mount_filesystems(skip_root=True)
-
-            self.storage.write()
+        if iutil.getSysroot() != iutil.getTargetPhysicalRoot():
+            set_sysroot(iutil.getTargetPhysicalRoot(), iutil.getSysroot())
+            self.prepareMountTargets(self.storage)
+            if not flags.dirInstall:
+                self.storage.write()
 
 # Inherit abstract methods from Payload
 # pylint: disable=abstract-method

pyanaconda/packaging/rpmostreepayload.py

@@ -227,15 +227,21 @@ def install(self):
         mainctx.pop_thread_default()
 
     def prepareMountTargets(self, storage):
+        """ Prepare the ostree root """
         ostreesetup = self.data.ostreesetup
 
         varroot = iutil.getTargetPhysicalRoot() + '/ostree/deploy/' + ostreesetup.osname + '/var'
 
         # Set up bind mounts as if we've booted the target system, so
         # that %post script work inside the target.
-        binds = [(varroot,
-                  iutil.getSysroot() + '/var'),
-                 (iutil.getSysroot() + '/usr', None)]
+        binds = [(varroot, iutil.getSysroot() + '/var'),
+                 (iutil.getSysroot() + '/usr', None),
+                 (iutil.getTargetPhysicalRoot(), iutil.getSysroot() + "/sysroot"),
+                 (iutil.getTargetPhysicalRoot() + "/boot", iutil.getSysroot() + "/boot")]
+
+        # Bind mount the other filesystems from /mnt/sysimage to the ostree root
+        for path in ["/dev", "/dev/pts", "/dev/shm", "/proc", "/run", "/sys", "/sys/fs/selinux"]:
+            binds += [(iutil.getTargetPhysicalRoot()+path, iutil.getSysroot()+path)]
 
         for (src, dest) in binds:
             self._safeExecWithRedirect("mount",
@@ -245,15 +251,6 @@ def prepareMountTargets(self, storage):
                 self._safeExecWithRedirect("mount",
                                            ["--bind", "-o", "remount,ro", src, src])
 
-        # We previously bind mounted /mnt/sysimage to
-        # /mnt/sysimage/.../sysroot, but this caused issues with mount
-        # path canonicalization.  Instead, directly mount the physical
-        # device at two different paths.
-        dest = iutil.getSysroot() + "/sysroot"
-        self._safeExecWithRedirect("mount",
-                                   [storage.root_device.format.device, dest])
-        self._internal_mounts.append(dest)
-
         # Now, ensure that all other potential mount point directories such as
         # (/home) are created.  We run through the full tmpfiles here in order
         # to also allow Anaconda and %post scripts to write to directories like