I had a kernel crash twice on me when trying to save an excel-format
file with gnumeric.  I suspect gnumeric is trying to mmap a file which
is in coda, and this just doesn't work, but I don't really know either
of these things.  (I am able to use gnumeric to read excel files and
save in gnumeric format.)

kernel is freebsd 4.2 + kame snap from 12/21/00 or so (no coda
changes, I think).  userspace is from coda cvs around 11/20 or so.

After the first time, I set dumpdev, and then got this:


panic: lockmgr: pid -2, not exclusive lock holder 5 unlocking

syncing disks... 10 4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 
1: dev:#wd/0x30005, flags:200212b0, blkno:5570864, lblkno:5570864
giving up on 1 buffers
Uptime: 5m14s

dumping to dev #ad/0x30001, offset 131456
dump ata0: resetting devices .. done
[dump noise]
---
#0  dumpsys () at ../../kern/kern_shutdown.c:469
469             if (dumping++) {
(kgdb) bt
#0  dumpsys () at ../../kern/kern_shutdown.c:469
#1  0xc015b517 in boot (howto=256) at ../../kern/kern_shutdown.c:309
#2  0xc015b8ad in panic (fmt=0xc02cf7c0 "lockmgr: pid %d, not %s %d unlocking")
    at ../../kern/kern_shutdown.c:556
#3  0xc0155e04 in lockmgr (lkp=0xc1173300, flags=6, interlkp=0xcafb9cec, p=0x0)
    at ../../kern/kern_lock.c:382
#4  0xc018484f in vop_stdunlock (ap=0xca008cc4) at ../../kern/vfs_default.c:254
#5  0xc0250229 in ufs_vnoperate (ap=0xca008cc4)
    at ../../ufs/ufs/ufs_vnops.c:2287
#6  0xc0131a0b in coda_rdwr (vp=0xc9ff3700, uiop=0xca008d3c, rw=UIO_WRITE, 
    ioflag=32, cred=0xc0cc6880, p=0x0) at vnode_if.h:865
#7  0xc01318f1 in coda_write (v=0xca008d28) at ../../coda/coda_vnops.c:390
#8  0xc025ef42 in vnode_pager_generic_putpages (vp=0xc9ff3700, m=0xca008e08, 
    bytecount=16384, flags=0, rtvals=0xca008dcc) at vnode_if.h:363
#9  0xc012da56 in coda_fbsd_putpages (v=0xca008d90)
    at ../../coda/coda_fbsd.c:188
#10 0xc025ed9e in vnode_pager_putpages (object=0xcafb4a20, m=0xca008e08, 
    count=4, sync=0, rtvals=0xca008dcc) at vnode_if.h:1126
#11 0xc025be84 in vm_pageout_flush (mc=0xca008e08, count=4, flags=0)
    at ../../vm/vm_pager.h:145
#12 0xc0258e16 in vm_object_page_clean (object=0xcafb4a20, start=0, end=0, 
    flags=4) at ../../vm/vm_object.c:655
#13 0xc0188780 in vfs_msync (mp=0xc10c5000, flags=2)
    at ../../kern/vfs_subr.c:2515
#14 0xc0188c03 in sync_fsync (ap=0xca008f7c) at ../../kern/vfs_subr.c:2823
#15 0xc01870c7 in sched_sync () at vnode_if.h:537
#16 0xc02aa9ac in fork_trampoline ()
Cannot access memory at address 0x8000.