Support partitioning of hybrid boot disks

Anaconda needs to be able to create hybrid boot disks. For example:

  clearpart --all --initlabel --disklabel=gpt
  part prepboot  --size=4    --fstype=prepboot
  part biosboot  --size=1    --fstype=biosboot
  part /boot/efi --size=100  --fstype=efi
  part /boot     --size=1000 --fstype=ext4 --label=boot
  part /         --grow      --fstype xfs

However, this kickstart snippet is not working with two or more disks.
The bootloader-related partitions should be all created on the disk
the computer will boot from, but Blivet does that only for platform
-specific partitions. The rest of them are created on any disk with
enough space.

It looks like this can be easily fixed by setting the same weight
to all of these partitions regardless of the current platform.

See: rhinstaller/anaconda#5298

blivet/devices/partition.py

@@ -452,28 +452,24 @@ def _get_weight(self):
         if isinstance(self.req_base_weight, int):
             return self.req_base_weight
 
-        # now we have the weights for varying mountpoints and fstypes by platform
-        weight = 0
-        if self.format.mountable and self.format.mountpoint == "/boot":
-            weight = 2000
-        elif (self.format.mountable and
-              self.format.mountpoint == "/boot/efi" and
-              self.format.type in ("efi", "macefi") and
-              arch.is_efi()):
-            weight = 5000
-        elif arch.is_x86() and self.format.type == "biosboot" and not arch.is_efi():
-            weight = 5000
-        elif self.format.mountable and arch.is_arm():
-            # On ARM images '/' must be the last partition.
-            if self.format.mountpoint == "/":
-                weight = -100
-        elif arch.is_ppc():
-            if arch.is_pmac() and self.format.type == "appleboot":
-                weight = 5000
-            elif arch.is_ipseries() and self.format.type == "prepboot":
-                weight = 5000
-
-        return weight
+        # Now we have the weights for varying mountpoints and fstypes by platform.
+        mountpoint = self.format.mountpoint if self.format.mountable else None
+        format_type = self.format.type
+
+        if mountpoint == "/boot":
+            return 2000
+
+        if mountpoint == "/boot/efi" and format_type in ("efi", "macefi"):
+            return 5000
+
+        if format_type in ("biosboot", "appleboot", "prepboot"):
+            return 5000
+
+        # On ARM images '/' must be the last partition.
+        if mountpoint == "/" and arch.is_arm():
+            return -100
+
+        return 0
 
     def _set_weight(self, weight):
         self.req_base_weight = weight

tests/unit_tests/devices_test/partition_test.py

@@ -68,9 +68,11 @@ def test_weight_1(self, *patches):
 
             # weights for / and /boot are not platform-specific (except for arm)
             fmt.mountpoint = "/"
+            fmt.type = "xfs"
             self.assertEqual(dev.weight, 0)
 
             fmt.mountpoint = "/boot"
+            fmt.type = "ext4"
             self.assertEqual(dev.weight, 2000)
 
             #
@@ -92,7 +94,7 @@ def test_weight_1(self, *patches):
 
             fmt.mountpoint = "/boot/efi"
             fmt.type = "efi"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             #
             # UEFI
@@ -102,9 +104,10 @@ def test_weight_1(self, *patches):
             self.assertEqual(dev.weight, 5000)
 
             fmt.type = "biosboot"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             fmt.mountpoint = "/"
+            fmt.type = "xfs"
             self.assertEqual(dev.weight, 0)
 
             #
@@ -115,6 +118,7 @@ def test_weight_1(self, *patches):
             arch.is_arm.return_value = True
 
             fmt.mountpoint = "/"
+            fmt.type = "xfs"
             self.assertEqual(dev.weight, -100)
 
             #
@@ -126,38 +130,41 @@ def test_weight_1(self, *patches):
             arch.is_ipseries.return_value = False
 
             fmt.mountpoint = "/"
+            fmt.type = "xfs"
             self.assertEqual(dev.weight, 0)
 
             fmt.type = "prepboot"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             fmt.type = "appleboot"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             arch.is_pmac.return_value = True
             self.assertEqual(dev.weight, 5000)
 
             fmt.type = "prepboot"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             arch.is_pmac.return_value = False
             arch.is_ipseries.return_value = True
             self.assertEqual(dev.weight, 5000)
 
             fmt.type = "appleboot"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             fmt.mountpoint = "/boot/efi"
             fmt.type = "efi"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             fmt.type = "biosboot"
-            self.assertEqual(dev.weight, 0)
+            self.assertEqual(dev.weight, 5000)
 
             fmt.mountpoint = "/"
+            fmt.type = "xfs"
             self.assertEqual(dev.weight, 0)
 
             fmt.mountpoint = "/boot"
+            fmt.type = "ext4"
             self.assertEqual(dev.weight, 2000)
 
     def test_weight_2(self):