From e0c5e81b5b6b4e5229281b086303eb95ef6ffffa Mon Sep 17 00:00:00 2001
From: Teo Mrnjavac <teo@kde.org>
Date: Thu, 10 Nov 2016 15:58:48 +0100
Subject: [PATCH] Write Btrfs subvolume lines to fstab.

---
 src/modules/fstab/main.py | 41 +++++++++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/modules/fstab/main.py b/src/modules/fstab/main.py
index 05b094fdc..622f55c44 100644
--- a/src/modules/fstab/main.py
+++ b/src/modules/fstab/main.py
@@ -21,6 +21,7 @@
 
 import os
 import re
+import subprocess
 
 import libcalamares
 
@@ -180,10 +181,33 @@ class FstabGenerator(object):
             print(FSTAB_HEADER, file=fstab_file)
 
             for partition in self.partitions:
-                dct = self.generate_fstab_line_info(partition)
+                # Special treatment for a btrfs root with @ and @home subvolumes
+                if partition["fs"] == "btrfs" and partition["mountPoint"] == "/":
+                    output = subprocess.check_output(['btrfs',
+                                                      'subvolume',
+                                                      'list',
+                                                      self.root_mount_point])
+                    output_lines = output.splitlines()
+                    for line in output_lines:
+                        if line.endswith(b'path @'):
+                            root_entry = partition
+                            root_entry["subvol"] = "@"
+                            dct = self.generate_fstab_line_info(root_entry)
+                            if dct:
+                                self.print_fstab_line(dct, file=fstab_file)
+                        elif line.endswith(b'path @home'):
+                            home_entry = partition
+                            home_entry["mountPoint"] = "/home"
+                            home_entry["subvol"] = "@home"
+                            dct = self.generate_fstab_line_info(home_entry)
+                            if dct:
+                                self.print_fstab_line(dct, file=fstab_file)
 
-                if dct:
-                    self.print_fstab_line(dct, file=fstab_file)
+                else:
+                    dct = self.generate_fstab_line_info(partition)
+
+                    if dct:
+                        self.print_fstab_line(dct, file=fstab_file)
 
             if self.root_is_ssd:
                 # Mount /tmp on a tmpfs
@@ -224,12 +248,21 @@ class FstabGenerator(object):
         if mount_point == "/":
             self.root_is_ssd = is_ssd
 
+        if filesystem == "btrfs" and "subvol" in partition:
+            return dict(device="UUID=" + partition["uuid"],
+                        mount_point=mount_point,
+                        fs=filesystem,
+                        options=",".join(["subvol={}".format(partition["subvol"]),
+                                          options]),
+                        check=check,
+                        )
+
         return dict(device="UUID=" + partition["uuid"],
                     mount_point=mount_point or "swap",
                     fs=filesystem,
                     options=options,
                     check=check,
-                   )
+                    )
 
     def print_fstab_line(self, dct, file=None):
         """ Prints line to '/etc/fstab' file. """