appliance-tools/0001-Populate-fstab-5-and-bootloader-configuration-for-Bt.patch

From 27119bc104b3a7d5835a570987f9f1f1d7b011c3 Mon Sep 17 00:00:00 2001
From: Neal Gompa <ngompa13@gmail.com>
Date: Wed, 26 Aug 2020 16:43:58 -0400
Subject: [PATCH] Populate fstab(5) and bootloader configuration for Btrfs
 subvolumes

In order for an image to be setup fully on boot, we need to populate
fstab(5) configuration and ensure the bootloader has the right
references for where the Btrfs filesystems are located on the disk.
---
 appcreate/appliance.py     | 42 +++++++++++++++++++++++++++++++++-----
 appcreate/partitionedfs.py | 15 ++++++++++----
 2 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/appcreate/appliance.py b/appcreate/appliance.py
index a1a0a67..863083a 100644
--- a/appcreate/appliance.py
+++ b/appcreate/appliance.py
@@ -76,23 +76,36 @@ class ApplianceImageCreator(ImageCreator):
         self.grub2inst_params = []
 
     def _get_fstab(self):
-        s = ""
+        f = ""
+        has_btrfs_subvolumes = False
         for mp in self.__instloop.mountOrder:
             p = None
             for p1 in self.__instloop.partitions:
+                if p1['fstype'] == "btrfs" and not p1['mountpoint'].startswith('/'):
+                    # This btrfs filesystem uses subvolumes
+                    has_btrfs_subvolumes = True
                 if p1['mountpoint'] == mp:
                     p = p1
                     break
-
+            if p['fstype'] == "btrfs" and not p['mountpoint'].startswith('/'):
+                # There's no mountpoint to export to fstab, so skip
+                continue
             if not p['UUID'] is None:
-                mountdev = p['UUID']
+                mountdev = "UUID=%s" % p['UUID']
             else:
                 mountdev = "LABEL=_%s" % p['mountpoint']
-            s +=  "%(mountdev)s  %(mountpoint)s %(fstype)s    defaults,noatime 0 0\n" %  {
+            f +=  "%(mountdev)s  %(mountpoint)s %(fstype)s    defaults,noatime 0 0\n" %  {
                 'mountdev': mountdev,
                 'mountpoint': p['mountpoint'],
                 'fstype': p['fstype'] }
-        return s
+        if has_btrfs_subvolumes:
+            for s in self.__instloop.subvolumes:
+                f +=  "%(mountdev)s  %(mountpoint)s %(fstype)s    subvol=%(name)s,noatime 0 0\n" %  {
+                    'mountdev': "UUID=%s" % s['UUID'],
+                    'mountpoint': s['mountpoint'],
+                    'fstype': "btrfs",
+                    'name': s['name'] }
+        return f
 
     def _create_mkinitrd_config(self):
         #write  to tell which modules to be included in initrd
@@ -298,6 +311,16 @@ class ApplianceImageCreator(ImageCreator):
                 else:
                     rootdev = "LABEL=_/"
 
+        for s in self.__instloop.subvolumes:
+            if s['mountpoint'] == "/boot":
+                bootdevnum = s['num'] - 1
+            elif s['mountpoint'] == "/" and bootdevnum is None:
+                bootdevnum = s['num'] - 1
+
+            if s['mountpoint'] == "/":
+                rootdevnum = s['num'] - 1
+                rootdev = s['UUID']
+
         prefix = ""
         if bootdevnum == rootdevnum:
             prefix = "/boot"
@@ -358,6 +381,15 @@ class ApplianceImageCreator(ImageCreator):
                     rootdev = p['UUID']
                 else:
                     rootdev = "LABEL=_/"
+        for s in self.__instloop.subvolumes:
+            if s['mountpoint'] == "/boot":
+                bootdevnum = s['num'] - 1
+            elif s['mountpoint'] == "/" and bootdevnum is None:
+                bootdevnum = s['num'] - 1
+
+            if s['mountpoint'] == "/":
+                rootdevnum = s['num'] - 1
+                rootdev = s['UUID']
         prefix = ""
         if bootdevnum == rootdevnum:
             prefix = "/boot"
diff --git a/appcreate/partitionedfs.py b/appcreate/partitionedfs.py
index 50206c4..9e81d2e 100644
--- a/appcreate/partitionedfs.py
+++ b/appcreate/partitionedfs.py
@@ -66,7 +66,12 @@ class PartitionedMount(Mount):
                                 'num': None}) # Partition number
 
     def add_subvolume(self, parent, mountpoint, name):
-        self.subvolumes.append({'parent': parent, 'mountpoint': mountpoint, 'name': name})
+        self.subvolumes.append({'parent': parent, # parent location for subvolume
+                                'mountpoint': mountpoint, # Mount relative to chroot
+                                'name': name, # subvolume name
+                                'device': None, # kpartx device node for partition
+                                'UUID': None, # UUID for partition
+                                'num': None}) # Partition number
 
     def __format_disks(self):
         logging.debug("Formatting disks")
@@ -299,11 +304,14 @@ class PartitionedMount(Mount):
         others = []
         ordered = []
         for s in self.subvolumes:
+            s['device'] = subprocess.Popen(["findmnt", "-n", "-o", "SOURCE", "%s%s" % (self.mountdir, s['parent'])], stdout=subprocess.PIPE).communicate()[0].decode("utf-8").strip()
+            s['UUID'] = self.__getuuid(s['device'])
+            s['num'] = int(s['device'].rsplit('p', 1)[1])
             if s['mountpoint'] == '/':
                 ordered.append(s)
             else:
                 others.append(s)
-  
+
         ordered += others
         for s in ordered:
             base = "%s%s" % (self.mountdir, s['parent'])
@@ -313,8 +321,7 @@ class PartitionedMount(Mount):
             subprocess.call(['btrfs', 'subvol', 'create', path])
             subprocess.call(['mkdir', '-p', mountpath])
             logging.debug("Mounting Btrfs subvolume %s at path %s" % (s['name'], mountpath))
-            device = subprocess.Popen(["findmnt", "-n", "-o", "SOURCE", base], stdout=subprocess.PIPE).communicate()[0].decode("utf-8").strip()
-            subprocess.call(['mount', '-t', 'btrfs', '-o', 'subvol=%s' % s['name'], device, mountpath])
+            subprocess.call(['mount', '-t', 'btrfs', '-o', 'subvol=%s' % s['name'], s['device'], mountpath])
 
     def mount(self):
         for dev in list(self.disks.keys()):
-- 
2.26.2