X-Git-Url: https://glassweightruler.freedombox.rocks/gitweb/waydroid.git/blobdiff_plain/e620e51bbb86b3fc2776e4d041df928391f944ab..0841a74bf82f59e316d8fbcfdff415bb003bc84e:/tools/helpers/mount.py

diff --git a/tools/helpers/mount.py b/tools/helpers/mount.py
index 1d61037..236ff5b 100644
--- a/tools/helpers/mount.py
+++ b/tools/helpers/mount.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 import os
 import tools.helpers.run
+from tools.helpers.version import versiontuple, kernel_version
 
 
 def ismount(folder):
@@ -109,17 +110,20 @@ def umount_all(args, folder):
         if ismount(mountpoint):
             raise RuntimeError("Failed to umount: " + mountpoint)
 
-def mount(args, source, destination, create_folders=True, umount=False, readonly=True, mount_type=None, options=None):
+def mount(args, source, destination, create_folders=True, umount=False,
+          readonly=True, mount_type=None, options=None, force=True):
     """
     Mount and create necessary directory structure.
     :param umount: when destination is already a mount point, umount it first.
+    :param force: attempt mounting even if the mount point already exists.
     """
     # Check/umount destination
     if ismount(destination):
         if umount:
             umount_all(args, destination)
         else:
-            return
+            if not force:
+                return
 
     # Check/create folders
     if not os.path.exists(destination):
@@ -146,3 +150,31 @@ def mount(args, source, destination, create_folders=True, umount=False, readonly
     # Verify, that it has worked
     if not ismount(destination):
         raise RuntimeError("Mount failed: " + source + " -> " + destination)
+
+def mount_overlay(args, lower_dirs, destination, upper_dir=None, work_dir=None,
+                  create_folders=True, readonly=True):
+    """
+    Mount an overlay.
+    """
+    dirs = [*lower_dirs]
+    options = ["lowerdir=" + (":".join(lower_dirs))]
+
+    if upper_dir:
+        dirs.append(upper_dir)
+        dirs.append(work_dir)
+        options.append("upperdir=" + upper_dir)
+        options.append("workdir=" + work_dir)
+
+    if kernel_version() >= versiontuple("4.17"):
+        options.append("xino=off")
+
+    for dir_path in dirs:
+        if not os.path.exists(dir_path):
+            if create_folders:
+                tools.helpers.run.user(args, ["mkdir", "-p", dir_path])
+            else:
+                raise RuntimeError("Mount failed, folder does not exist: " +
+                                   dir_path)
+
+    mount(args, "overlay", destination, mount_type="overlay", options=options,
+          readonly=readonly, create_folders=create_folders, force=True)