Date: Thu, 27 Dec 2001 12:46:38 +0100 From: Wilko Bulte <wkb@freebie.xs4all.nl> To: Kevin Day <toasty@temphost.dragondata.com> Cc: hackers@FreeBSD.ORG Subject: Re: signedness in fsck Message-ID: <20011227124638.B17750@freebie.xs4all.nl> In-Reply-To: <200112270834.fBR8YfD13572@temphost.dragondata.com>; from toasty@temphost.dragondata.com on Thu, Dec 27, 2001 at 02:34:40AM -0600 References: <200112270834.fBR8YfD13572@temphost.dragondata.com>
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On Thu, Dec 27, 2001 at 02:34:40AM -0600, Kevin Day wrote:
You might want to file this as a PR (using send-pr)
so that it can be looked at by the filesystem gurus. I am not to sure
that Kirk keeps up with -hackers
Wilko
> I think I've found a bug in fsck. Some invalid values in cylinder groups
> don't get fixed.
>
> >From pass5.c:
>
> if (cg->cg_rotor < newcg->cg_ndblk)
> newcg->cg_rotor = cg->cg_rotor;
> else
> newcg->cg_rotor = 0;
> if (cg->cg_frotor < newcg->cg_ndblk)
> newcg->cg_frotor = cg->cg_frotor;
> else
> newcg->cg_frotor = 0;
> if (cg->cg_irotor < newcg->cg_niblk)
> newcg->cg_irotor = cg->cg_irotor;
> else
> newcg->cg_irotor = 0;
>
>
> All those values in the cg's are int32_t's. (signed). Somehow I ended up
> with 5 cyl groups that have "irotor" to some random negative value. fsck
> doesn't see a problem with them, but I get a panic when a create gets
> called:
>
> #5 0xc0207e6b in trap (frame={tf_fs = -1072234480, tf_es = -345702384, tf_ds = -1072234480, tf_edi = -750092288, tf_esi = -955801600,
> tf_ebp = -345663052, tf_isp = -345663072, tf_ebx = 177188131, tf_edx = -750091519, tf_ecx = 255, tf_eax = -927279650, tf_trapno = 12,
> tf_err = 0, tf_eip = -1071824083, tf_cs = 8, tf_eflags = 66183, tf_esp = -345663008, tf_ss = -1071971432}) at ../../i386/i386/trap.c:448
> #6 0xc01d432d in skpc (mask0=255, size=177188131, cp0=0xc8bad5de <Address 0xc8bad5de out of bounds>) at ../../libkern/skpc.c:50
> #7 0xc01b0398 in ffs_nodealloccg (ip=0xc7cb6300, cg=6921, ipref=27906609, mode=33188) at ../../ufs/ffs/ffs_alloc.c:1347
> #8 0xc01af567 in ffs_hashalloc (ip=0xc7cb6300, cg=6921, pref=27906609, size=33188, allocator=0xc01b0258 <ffs_nodealloccg>)
> at ../../ufs/ffs/ffs_alloc.c:863
> #9 0xc01aeffc in ffs_valloc (pvp=0xebe8d980, mode=33188, cred=0xc77fd584, vpp=0xeb659a5c) at ../../ufs/ffs/ffs_alloc.c:607
> #10 0xc01c1b0f in ufs_makeinode (mode=33188, dvp=0xebe8d980, vpp=0xeb659c64, cnp=0xeb659c78) at ../../ufs/ufs/ufs_vnops.c:2097
> #11 0xc01bf4c4 in ufs_create (ap=0xeb659bfc) at ../../ufs/ufs/ufs_vnops.c:194
>
> Here's the cyl group:
>
> $2 = {cg_firstfield = 0, cg_magic = 590421, cg_time = 1009434417, cg_cgx = 9165, cg_ncyl = 16, cg_niblk = 4032, cg_ndblk = 32768, cg_cs = {
> cs_ndir = 60, cs_nbfree = 2740, cs_nifree = 1987, cs_nffree = 679}, cg_rotor = 1288, cg_frotor = 5112, cg_irotor = -2036988557,
> cg_frsum = {0, 80, 153, 45, 14, 5, 7, 5}, cg_btotoff = 168, cg_boff = 232, cg_iusedoff = 264, cg_freeoff = 768, cg_nextfreeoff = 5436,
> cg_clustersumoff = 4860, cg_clusteroff = 4924, cg_nclusterblks = 4096, cg_sparecon = {0 <repeats 13 times>}, cg_space = "\016"}
>
>
> Notice cg_irotor is completely out of whack, but fsck thinks the FS is
> clean.
>
> I wrote a patch that made fsck detect this, but... why are these signed
> values anyway, other than historical reasons?
>
> -- Kevin
>
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---end of quoted text---
--
| / o / /_ _ email: wilko@FreeBSD.org
|/|/ / / /( (_) Bulte Arnhem, The Netherlands
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