Add Blockdev tags to indicate device usage

Allow installer to tag devices with purpose for display
in USED DISKS in the filesystem view.

Signed-off-by: Ryan Harper <ryan.harper@canonical.com>

subiquity/controllers/filesystem.py

@@ -153,6 +153,7 @@ class FilesystemController(ControllerPolicy):
                                                    size=BIOS_GRUB_SIZE_BYTES,
                                                    fstype=None,
                                                    flag='bios_grub')
+                current_disk.set_tag('(boot)')
 
                 # adjust downward the partition size to accommodate
                 # the offset and bios/grub partition

subiquity/models/blockdev.py

@@ -128,6 +128,7 @@ class Blockdev():
         self._filesystems = {}
         self._mounts = {}
         self._mountactions = {}
+        self._tag = ''
         self.bcache = []
         self.lvm = []
         self.holders = []
@@ -165,6 +166,7 @@ class Blockdev():
         self.bcache = []
         self.lvm = []
         self.holders = []
+        self.tag = ''
 
     @property
     def id(self):
@@ -274,6 +276,13 @@ class Blockdev():
     def lastpartnumber(self):
         return len(self.disk.partitions)
 
+    @property
+    def tag(self):
+        return self._tag
+
+    def set_tag(self, tag):
+        self._tag = tag
+
     def delete_partition(self, partnum=None, sector=None, mountpoint=None):
         # find part and then call deletePartition()
         # find and remove from self.fstable

subiquity/models/filesystem.py

@@ -282,7 +282,8 @@ class FilesystemModel(ModelPolicy):
                 spare_devices.append(raiddev)
 
         # auto increment md number based in registered devices
-        raid_dev_name = '/dev/md{}'.format(len(self.raid_devices))
+        raid_shortname = 'md{}'.format(len(self.raid_devices))
+        raid_dev_name = '/dev/' + raid_shortname
         raid_serial = '{}_serial'.format(raid_dev_name)
         raid_model = '{}_model'.format(raid_dev_name)
         raid_parttype = 'gpt'
@@ -294,11 +295,13 @@ class FilesystemModel(ModelPolicy):
         raid_parts = []
         for dev in raid_devices:
             dev.set_holder(raid_dev_name)
+            dev.set_tag('member of MD ' + raid_shortname)
             for num, action in dev.partitions.items():
                 raid_parts.append(action.action_id)
         spare_parts = []
         for dev in spare_devices:
             dev.set_holder(raid_dev_name)
+            dev.set_tag('member of MD ' + raid_shortname)
             for num, action in dev.partitions.items():
                 spare_parts.append(action.action_id)
 
@@ -344,7 +347,8 @@ class FilesystemModel(ModelPolicy):
         cache_device = self.get_disk(bcachespec['cache_device'].split()[0])
 
         # auto increment md number based in registered devices
-        bcache_dev_name = '/dev/bcache{}'.format(len(self.bcache_devices))
+        bcache_shortname = 'bcache{}'.format(len(self.bcache_devices))
+        bcache_dev_name = '/dev/' + bcache_shortname
         bcache_serial = '{}_serial'.format(bcache_dev_name)
         bcache_model = '{}_model'.format(bcache_dev_name)
         bcache_parttype = 'gpt'
@@ -359,6 +363,15 @@ class FilesystemModel(ModelPolicy):
         backing_device.set_holder(bcache_dev_name)
         cache_device.set_holder(bcache_dev_name)
 
+        # tag device use
+        backing_device.set_tag('backing store for ' + bcache_shortname)
+        cache_tag = cache_device.tag
+        if len(cache_tag) > 0:
+            cache_tag += ", " + bcache_shortname
+        else:
+            cache_tag = "cache for " + bcache_shortname
+        cache_device.set_tag(cache_tag)
+
         # add it to the model's info dict
         bcache_dev_info = {
             'type': 'disk',

subiquity/ui/views/filesystem.py

@@ -497,8 +497,12 @@ class FilesystemView(ViewPolicy):
         log.debug('FileSystemView: building used disks')
         pl = []
         for disk in self.model.get_used_disk_names():
+            disk_obj = self.model.get_disk(disk)
             log.debug('used disk: {}'.format(disk))
-            pl.append(Text(disk))
+            disk_string = disk
+            if len(disk_obj.tag):
+                disk_string += " {}".format(disk_obj.tag)
+            pl.append(Color.info_minor(Text(disk_string)))
         if len(pl):
             return Pile(
                 [Text("USED DISKS"),