Description: Add support for ext4 variable sized inodes
 This is backwardly compatible with ext2/ext3 fixed sized inodes.
Author: Colin King <colin.king@canonical.com>
Bug-Debian: https://bugs.debian.org/511121
Bug-Ubuntu: https://bugs.launchpad.net/bugs/345488
Last-Update: 2018-10-25

Index: b/stage2/fsys_ext2fs.c
===================================================================
--- a/stage2/fsys_ext2fs.c
+++ b/stage2/fsys_ext2fs.c
@@ -652,6 +652,8 @@
   int off;			/* offset within block of directory entry (off mod blocksize) */
   int loc;			/* location within a directory */
   int blk;			/* which data blk within dir entry (off div blocksize) */
+  int inodes_per_block;		/* number of inodes in each block */
+  int inode_offset;		/* inode offset in block */
   long map;			/* fs pointer of a particular block from dir entry */
   struct ext2_dir_entry *dp;	/* pointer to directory entry */
 #ifdef E2DEBUG
@@ -687,9 +689,9 @@
 	  return 0;
 	}
       gdp = GROUP_DESC;
-      ino_blk = gdp[desc].bg_inode_table +
-	(((current_ino - 1) % (SUPERBLOCK->s_inodes_per_group))
-	 >> log2 (EXT2_INODES_PER_BLOCK (SUPERBLOCK)));
+      inodes_per_block =  EXT2_BLOCK_SIZE (SUPERBLOCK) / EXT2_INODE_SIZE(SUPERBLOCK);
+      inode_offset = ((current_ino - 1) % (SUPERBLOCK->s_inodes_per_group));
+      ino_blk = gdp[desc].bg_inode_table + (inode_offset / inodes_per_block);
 #ifdef E2DEBUG
       printf ("inode table fsblock=%d\n", ino_blk);
 #endif /* E2DEBUG */