Hello, there!

pmb/helpers/mount.py

@@ -0,0 +1,90 @@
+"""
+Copyright 2017 Oliver Smith
+
+This file is part of pmbootstrap.
+
+pmbootstrap is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+pmbootstrap is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with pmbootstrap.  If not, see <http://www.gnu.org/licenses/>.
+"""
+import os
+import pmb.helpers.run
+
+
+def ismount(folder):
+    """
+    Ismount() implementation, that works for mount --bind.
+    Workaround for: https://bugs.python.org/issue29707
+    """
+    folder = os.path.abspath(folder)
+    with open("/proc/mounts", "r") as handle:
+        for line in handle:
+            words = line.split()
+            if len(words) >= 2 and words[1] == folder:
+                return True
+    return False
+
+
+def bind(args, source, destination, create_folders=True):
+    """
+    Mount --bind a folder and create necessary directory structure.
+    """
+    if ismount(destination):
+        return
+
+    # Check/create folders
+    for path in [source, destination]:
+        if os.path.exists(path):
+            continue
+        if create_folders:
+            pmb.helpers.run.root(args, ["mkdir", "-p", path])
+        else:
+            raise RuntimeError("Mount failed, folder does not exist: " +
+                               path)
+
+    # Actually mount the folder
+    pmb.helpers.run.root(args, ["mount", "--bind", source, destination])
+
+    # Verify, that it has worked
+    if not ismount(destination):
+        raise RuntimeError("Mount failed: " + source + " -> " + destination)
+
+# Mount a blockdevice
+
+
+def bind_blockdevice(args, source, destination):
+    # Skip existing mountpoint
+    if ismount(destination):
+        return
+
+    # Create empty file
+    if not os.path.exists(destination):
+        pmb.helpers.run.root(args, ["touch", destination])
+
+    # Mount
+    pmb.helpers.run.root(args, ["mount", "--bind", source,
+                                destination])
+
+
+def umount_all(args, folder):
+    """
+    Umount all folders, that are mounted inside a given folder.
+    """
+    folder = os.path.abspath(folder)
+    with open("/proc/mounts", "r") as handle:
+        for line in handle:
+            words = line.split()
+            if len(words) < 2 or not words[1].startswith(folder):
+                continue
+            pmb.helpers.run.root(args, ["umount", words[1]])
+            if ismount(words[1]):
+                raise RuntimeError("Failed to umount: " + words[1])