panic: Negative bio_offset (-15050100712783872) on bio 0xc7725d50

[Poul-Henning Kamp]

In message <20030917082738.GW26878 at cicely12.cicely.de>, Bernd Walter writes:
>On Wed, Sep 17, 2003 at 09:07:24AM +0200, Poul-Henning Kamp wrote:
>> In message <20030916102534.J2924 at gamplex.bde.org>, Bruce Evans writes:
>> 
>> >This is either disk corruption or an ffs bug.  ffs passes the garbage
>> >block number 0xffffe5441ae9720 to bread.  GEOM then handles this austerely
>> >by panicing.  Garbage block numbers, including negative ones, can possibly
>> >be created by applications seeking to preposterous offsets, so they should
>> >not be handled with panics.
>> 
>> They most certainly should!  If the range checking in any filesystem
>> is not able to catch these cases I insist that GEOM do so with a panic.
>
>What is wrong with returning an IO error?
>
>I always hated panics because of filesystem corruptions.
>An alternative would be to just bring that filesystem down.
>Its easy to panic a whole system with a bogus filesystem on a removeable
>media.

I hate panics too, but this would be an indication of a serious
filesystem error, so a panic is in order.  Otherwise we would be
unlikely to ever receive a report which would allow us to fix
the problem.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.