Changes to the default inode size

As per the bug report, the xfs-inode-size default value is in contradiction with the current upstream advice.
This patch removes the default value and accept the filesystem defaults for mkfs.xfs inode sizes.

Closes-Bug: #1879423
Change-Id: I9effc6052524ead9817454912284e3c48ce55901

charmhelpers/contrib/storage/linux/utils.py

@@ -23,6 +23,12 @@ from subprocess import (
     call
 )
 
+from charmhelpers.core.hookenv import (
+    log,
+    WARNING,
+    INFO
+)
+
 
 def _luks_uuid(dev):
     """
@@ -110,7 +116,7 @@ def is_device_mounted(device):
     return bool(re.search(r'MOUNTPOINT=".+"', out))
 
 
-def mkfs_xfs(device, force=False, inode_size=1024):
+def mkfs_xfs(device, force=False, inode_size=None):
     """Format device with XFS filesystem.
 
     By default this should fail if the device already has a filesystem on it.
@@ -118,11 +124,19 @@ def mkfs_xfs(device, force=False, inode_size=1024):
     :ptype device: tr
     :param force: Force operation
     :ptype: force: boolean
-    :param inode_size: XFS inode size in bytes
+    :param inode_size: XFS inode size in bytes; if set to 0 or None,
+        the value used will be the XFS system default
     :ptype inode_size: int"""
     cmd = ['mkfs.xfs']
     if force:
         cmd.append("-f")
+    if inode_size:
+        if inode_size >= 256 and inode_size <= 2048:
+            cmd += ['-i', "size={}".format(inode_size)]
+        else:
+            log("Config value xfs-inode-size={} is invalid. Using system default.".format(inode_size), level=WARNING)
+    else:
+            log("Using XFS filesystem with system default inode size.", level=INFO)
 
-    cmd += ['-i', "size={}".format(inode_size), device]
+    cmd += [device]
     check_call(cmd)

config.yaml

@@ -239,9 +239,13 @@ options:
       Encrypt block devices used by swift using dm-crypt, making use of
       vault for encryption key management; requires a relation to vault.
   xfs-inode-size:
-    default: 512
+    default:
     type: int
-    description: XFS inode size to use for block devices.
+    description: |
+      XFS inode size to use for block devices;
+      The value must be between 256-2048.
+      If left unset or an invalid size is used,
+      the default mkfs.xfs value is selected.
   storage-region:
     default: 1
     type: int