kern/114489: panic: _mtx_lock_sleep: in aic7xxx_osm.h (with backtrace)

[Michael W Lucas]

>Number:         114489
>Category:       kern
>Synopsis:       panic: _mtx_lock_sleep: in aic7xxx_osm.h (with backtrace)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Jul 11 01:10:04 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Michael W Lucas
>Release:        FreeBSD 7.0-CURRENT i386
>Organization:
none
>Environment:
System: FreeBSD pesty.blackhelicopters.org 7.0-CURRENT FreeBSD 7.0-CURRENT #0: Wed May 23 13:29:50 EDT 2007 mwlucas at pesty.blackhelicopters.org:/usr/obj/usr/src/sys/GENERIC i386

This is a standard i386 system with an external SCSI array attached.
Verbose dmesg is attached.

>Description:

This system performs fine on an April 22 2007 kernel.  I updated to
-current on July 4, 2007, and immediately started seeing these panics.
Upon further testing I found that I could read data just fine from the
SCSI drives, but that attempting to write to the drives resulted in
this panic.  The panic message and backtrace are attached.

>How-To-Repeat:

/dev/da7 is my test drive.  I can run:

# fdisk /dev/da7

and read the slice table as often as I wish without trouble.  A simple
write operation such as

# fdisk -BI /dev/da7

panics the system.  This does not happen every time, but if I run this
command a few times in a row it regularly and reliably panics.  My
record is five successful "fdisk -BI /dev/da7" runs one after the
other in quick succession before the sixth panics the system.

>Fix:




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