All symbols starting with `d' in ufs/ffs

• dblksize ufs/ffs/fs.h:466
• dbtofsb ufs/ffs/fs.h:377
• DEFAULTOPT ufs/ffs/fs.h:129
• doasyncfree ufs/ffs/ffs_alloc.c:306
• doclusterread ufs/ffs/ffs_vnops.c:218
• doclusterwrite ufs/ffs/ffs_vnops.c:220
• DOUBLE ufs/ffs/ffs_inode.c:134
• dtog ufs/ffs/fs.h:407
• dtogd ufs/ffs/fs.h:408