Re: kern/50070: fsck OK but mount: incorrect super block

["J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>]

The following reply was made to PR kern/50070; it has been noted by GNATS.

From: "J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/50070: fsck OK but mount: incorrect super block
Date: Mon, 3 Aug 2015 12:54:23 +0200

 On 02 Aug 2015, at 22:20, David Holland <dholland-bugs%netbsd.org@localhost> wrote:
 
 > Do we know if all accesses to the cylinder group data are via
 > cg_space[]?
 
 No accesses through cg_space[], all accesses are through offset fields
 of "struct cg".
 
 The filesystem from martin@ has
 
 fs_bsize 16384
 fs_fpg 94368
 
 cg_old_btotoff 168
 cg_clusteroff 14900
 cg_nextfreeoff 16375
 
 With these values the cluster bitmap runs from 14900 to 16374.
 
 This matches "cg_nextfreeoff" so the file system should work as
 expected as long as "cg_nextfreeoff <= fs_bsize".
 
 Looks like "cg_space" is used only from userland tools (fsck_ffs,
 newfs, makefs and resize_ffs).
 
 > If anything uses sizeof(cg) to index into the data we're
 > probably in trouble.
 > 
 > -- 
 > David A. Holland
 > dholland%netbsd.org@localhost
 > 
 
 --
 J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig (Germany)