Subject: Re: native bootstrap code won't boot converted Ultrix filesystem
To: None <jonathan@DSG.Stanford.EDU>
From: Charles M. Hannum <mycroft@gnu.ai.mit.edu>
List: port-pmax
Date: 09/14/1994 01:20:07 
   On a Ultrix filesystem converted with fsck -c 1, the values in the
   superblock for fs->fs_qbmask and fs->fs_qfmask aren't useful -- I'd
   guess they're probably zero.

I had a similar problem with the i386 boot code.  To fix it, I added:

	/*
	 * Deal with old file system format.  This is borrowed from
	 * ffs_oldfscompat() in ufs/ffs/ffs_vfsops.c.
	 */
	if (fs->fs_inodefmt < FS_44INODEFMT) {			/* XXX */
		fs->fs_qbmask = ~fs->fs_bmask;			/* XXX */
		fs->fs_qfmask = ~fs->fs_fmask;			/* XXX */
	}							/* XXX */

right after reading the superblock.