From d09aeb368cedf29546997f2d143cac7e9b8fc119 Mon Sep 17 00:00:00 2001
From: Michael Marineau <michael.marineau@coreos.com>
Date: Wed, 11 Feb 2015 17:05:36 -0800
Subject: [PATCH] disk_util: allocate the maximum number of usable inodes

This change changes the default 'bytes-per-inode' ration from 16K to 4K,
the block size. To prevent this from wasting too much space change the
inode size from the default 256 to the minimum size, 128. Larger inodes
are used to store extended attributes more efficiently but since we do
not use SELinux the majority of files do not have security attributes.

These defaults may be modified via the new `bytes_per_inode` and
`inode_size` options.
---
 build_library/disk_util | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/build_library/disk_util b/build_library/disk_util
index 36dfd6d4ba..633d464f73 100755
--- a/build_library/disk_util
+++ b/build_library/disk_util
@@ -45,9 +45,10 @@ def LoadPartitionConfig(options):
   valid_layout_keys = set((
       '_comment', 'type', 'num', 'label', 'blocks', 'block_size', 'fs_blocks',
       'fs_block_size', 'fs_type', 'features', 'uuid', 'part_alignment', 'mount',
-      'binds', 'fs_subvolume'))
+      'binds', 'fs_subvolume', 'fs_bytes_per_inode', 'fs_inode_size'))
   integer_layout_keys = set((
-      'blocks', 'block_size', 'fs_blocks', 'fs_block_size', 'part_alignment'))
+      'blocks', 'block_size', 'fs_blocks', 'fs_block_size', 'part_alignment',
+      'fs_bytes_per_inode', 'fs_inode_size'))
   required_layout_keys = set(('type', 'num', 'label', 'blocks'))
 
   filename = options.disk_layout_file
@@ -108,6 +109,10 @@ def LoadPartitionConfig(options):
         if part.get('fs_type', None) != 'btrfs':
           raise InvalidLayout('Invalid fs: only btrfs supports subvolumes')
 
+      if 'fs_bytes_per_inode' in part or 'fs_inode_size' in part:
+        if part.get('fs_type', None) not in ('ext2', 'ext4'):
+          raise InvalidLayout('Invalid fs: only extX supports inode options')
+
   def Align(count, alignment):
     offset = count % alignment
     if offset:
@@ -393,6 +398,8 @@ def FormatExt(part, device):
   Sudo(['mke2fs', '-q',
                   '-t', part['fs_type'],
                   '-b', part['fs_block_size'],
+                  '-i', part.get('fs_bytes_per_inode', part['fs_block_size']),
+                  '-I', part.get('fs_inode_size', 128),
                   device,
                   part['fs_blocks']])