i386/139725: zdb dumps core on FreeBSD/i386 when examining zpool contents

[Henno Schooljan]

>Number:         139725
>Category:       i386
>Synopsis:       zdb dumps core on FreeBSD/i386 when examining zpool contents
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Oct 18 19:40:01 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Henno Schooljan
>Release:        8.0-RC1
>Organization:
>Environment:
FreeBSD  8.0-RC1 FreeBSD 8.0-RC1 #0: Thu Sep 17 20:45:19 UTC 2009     root at almeida.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
When using zdb on FreeBSD/i386 8.0-RC1 to examine a ZFS file system pool (in this case the pool 'tank'), zdb crashes and dumps core when the pool is examined, e.g. the command

# zdb -i tank

produces the following output:

Assertion failed: (rwlp->rw_count == 0), file /usr/src/cddl/lib/libzpool/../../../cddl/contrib/opensolaris/lib/libzpool/common/kernel.c, line 203.

Abort trap


Just running zdb without parameters or with -C runs ok, this accesses only the zpool.cache file it looks like.


I have reproduced this error using a live filesystem/fixit i386 CD to minimize any local changes.

Using the amd64 8.0-RC1 livefs CD works fine, so I filed this as a i386 bug.
>How-To-Repeat:
Boot from a FreeBSD/i386 8.0-RC1 livefs CD (e.g. 8.0-RC1-i386-livefs.iso)
Go to the repair/fixit live filesystem to get a fixit prompt
Enter these commands (we have a ZFS zpool named tank somewhere):

# kldload /mnt2/kernel/boot/opensolaris.ko
# kldload /mnt2/kernel/boot/zfs.ko
# mkdir /boot/zfs

# zpool import -o altroot=/mnt tank
(use additional -f option if necessary)

# zdb -i

In livefs ode it will generate an additional "filesystem is full" error because the coredump is too large for the md filesystem here.
>Fix:
Unknown. Problem only manifests itself on i386.

>Release-Note:
>Audit-Trail:
>Unformatted: