NetBSD Problem Report #40526

From www@NetBSD.org  Sat Jan 31 16:36:48 2009
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Date: Sat, 31 Jan 2009 16:36:48 +0000 (UTC)
From: pooka@iki.fi
Reply-To: pooka@iki.fi
To: gnats-bugs@NetBSD.org
Subject: following newfs_udf example causes a kernel panic
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>Number:         40526
>Category:       kern
>Synopsis:       following newfs_udf example causes a kernel panic
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 31 16:40:00 +0000 2009
>Closed-Date:    Wed Nov 28 10:50:06 +0000 2018
>Last-Modified:  Wed Nov 28 10:50:06 +0000 2018
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
5.0_BETA
>Description:
Following an example in newfs_udf(8) causes a KASSERT kernel panic
in kern_physio. I did not investigate if it leads to problems on
non-DIAGNOSTIC kernels.
>How-To-Repeat:
dd if=/dev/zero of=bigdisk.2048.udf seek=9999999 count=1
vnconfig -c vnd0 bigdisk.2048.udf 2048/1/1/1
newfs_udf -L bigdisk /dev/rvnd0d

>Fix:
I described the underlying technical problem in:
http://mail-index.netbsd.org/tech-kern/2008/11/25/msg003649.html

I don't know if the problem can be fixed for 5.0, especially considering
there were no responses on tech-kern, but at least the example would be
nice to remove from the man page so that no other poor soul encounters
crash-by-rtfm.

>Release-Note:

>Audit-Trail:
From: David Laight <david@l8s.co.uk>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: kern/40526: following newfs_udf example causes a kernel panic
Date: Sat, 31 Jan 2009 19:03:17 +0000

 On Sat, Jan 31, 2009 at 04:40:00PM +0000, pooka@iki.fi wrote:
 > >Synopsis:       following newfs_udf example causes a kernel panic
 ...
 > dd if=/dev/zero of=bigdisk.2048.udf seek=9999999 count=1
 > vnconfig -c vnd0 bigdisk.2048.udf 2048/1/1/1

 vnconfig can't support sparse files ...

 	David

 -- 
 David Laight: david@l8s.co.uk

From: David Holland <dholland-bugs@netbsd.org>
To: pooka@iki.fi
Cc: kern-bug-people@netbsd.org, gnats-admin@netbsd.org,
	gnats-bugs@netbsd.org, netbsd-bugs@netbsd.org
Subject: Re: kern/40526: following newfs_udf example causes a kernel panic
Date: Sat, 7 Feb 2009 21:26:45 +0000

 On Sat, Jan 31, 2009 at 04:40:00PM +0000, pooka@iki.fi wrote:
  > Following an example in newfs_udf(8) causes a KASSERT kernel panic
  > in kern_physio. I did not investigate if it leads to problems on
  > non-DIAGNOSTIC kernels.
  >
  > dd if=/dev/zero of=bigdisk.2048.udf seek=9999999 count=1
  > vnconfig -c vnd0 bigdisk.2048.udf 2048/1/1/1
  > newfs_udf -L bigdisk /dev/rvnd0d
  >
  > [...] at least the example would be nice to remove from the man
  > page so that no other poor soul encounters crash-by-rtfm.

 Can we just fix the example instead of removing it? E.g. something like

    dd if=/dev/zero of=bigdisk.2048.udf bs=10000000 count=1

 although I guess the size should be a multiple of 512...

 Note that PR 29838 already covers the fact that vnd can't handle
 sparse files, so we can treat this PR just as a doc issue.

 -- 
 David A. Holland
 dholland@netbsd.org

State-Changed-From-To: open->closed
State-Changed-By: maya@NetBSD.org
State-Changed-When: Wed, 28 Nov 2018 10:50:06 +0000
State-Changed-Why:
Thsi works now (and 29838 got fixed too)


>Unformatted:

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