Date: Thu, 9 Jan 2003 19:03:49 -0500 From: Jake Burkholder <jake@locore.ca> To: Marcel Moolenaar <marcel@xcllnt.net> Cc: current@FreeBSD.ORG, gordon@FreeBSD.ORG Subject: Re: Superblock layout hosed on LP64 systems [was: Re: HEADS UP: VFS changes breaks GPT] Message-ID: <20030109190349.E4032@locore.ca> In-Reply-To: <20030109232943.GA1189@athlon.pn.xcllnt.net>; from marcel@xcllnt.net on Thu, Jan 09, 2003 at 03:29:43PM -0800 References: <20030109091230.GA4320@dhcp01.pn.xcllnt.net> <20030109232943.GA1189@athlon.pn.xcllnt.net>
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Apparently, On Thu, Jan 09, 2003 at 03:29:43PM -0800, Marcel Moolenaar said words to the effect of; > On Thu, Jan 09, 2003 at 01:12:30AM -0800, Marcel Moolenaar wrote: > > > > GPT based systems are unable to mount the root file system. I > > haven't had the time to dig into this, but we must be making > > assumptions we previously didn't make. In any case ia64 is > > hosed. More to come... > > Ok, after digging a bit I noticed that the super block layout > has changed in a way that makes it incompatible with previous > super blocks. It appears to be the alignment of fs_uuid on > revision 1.36 of sys/ufs/ffs/fs.h. > > Previously: > Sizeof superblock=1376 > Offset of magic=1372 > > Now: > Sizeof superblock=1384 > Offset of magic=1380 It might be worth putting in some CTASSERTs to verify that the size of the superblock and/or offsets of important fields don't change. This would give 64 bit people a heads up before they try to boot a broken kernel, and would make compiling a kernel on one of the reference boxes more useful for people who don't have a 64 bit machine for runtime testing. Jake > > This typically results in not being able to fsck the file system > with a post-change fsck on a pre-change kernel and not being able > to mount the file system with a post-change kernel. > > The following patch fixes the problem (and fixes the misuse of > uuid for something that is not universally unique): > > Index: fs.h > =================================================================== > RCS file: /home/ncvs/src/sys/ufs/ffs/fs.h,v > retrieving revision 1.36 > diff -u -r1.36 fs.h > --- fs.h 8 Jan 2003 22:53:54 -0000 1.36 > +++ fs.h 9 Jan 2003 23:23:28 -0000 > @@ -117,7 +117,7 @@ > * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in > * the super block for this name. > */ > -#define MAXMNTLEN 472 > +#define MAXMNTLEN 468 > > /* > * The volume name for this filesystem is maintained in fs_volname. > @@ -311,7 +311,8 @@ > int8_t fs_old_flags; /* old FS_ flags */ > u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ > u_char fs_volname[MAXVOLLEN]; /* volume name */ > - u_int64_t fs_uuid; /* system-wide unique uid */ > + u_int64_t fs_swuid; /* system-wide unique id */ > + int32_t fs_pad; > /* these fields retain the current block allocation info */ > int32_t fs_cgrotor; /* last cg searched */ > void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */ > > -- > Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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