kern/38892: current DEBUG+DIAGNOSTIC+msdosfs panic

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

>Number:         38892
>Category:       kern
>Synopsis:       current DEBUG+DIAGNOSTIC+msdosfs panic
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 08 16:15:00 +0000 2008
>Originator:     Manuel Bouyer
>Release:        NetBSD 4.99.64
>Organization:
>Environment:
NetBSD java.lip6.fr 4.99.64 NetBSD 4.99.64 (GENERIC_SUN4U) #4: Fri Jun  6 
20:55:09 CEST 2008  
bouyer@rock:/dsk/l1/misc/bouyer/tmp/sparc/obj/dsk/l1/misc/bouyer/current/src/sys/arch/sparc/compile/GENERIC_SUN4U
 sparc64
Architecture: sparc64
Machine: sparc64
GENERIC_SUN4U kernel config + DEBUG + DIAGNOSTIC options
>Description:

        trying to write a file a 1gb msdos-formatted USB key immediatly
        panics the kernel:
panic: kernel diagnostic assertion "bp->b_vp == NULL || bp->b_vp->v_tag != 
VT_UFS || ISSET(bp->b_flags, B_COWDONE)" failed: file 
"/dsk/l1/misc/bouyer/current/src/sys/kern/vfs_bio.c", line 887
Stopped in pid 373.1 (cp) at    netbsd:cpu_Debugger+0x4:        nop
db> tr
__kernassert(16cdb28, 1717a88, 377, 1717e08, 0, 0) at netbsd:__kernassert+0x30
bdwrite(1ec1410, c390000, e000, 1, 0, 1000000) at netbsd:bdwrite+0x17c
updatefats(1e58a00, 1ec1570, 178, e000, 1ec1570, 1) at netbsd:updatefats+0x190
chainalloc(ffffffff, a3bc, 4, ffffffff, c375b04, c375b00) at 
netbsd:chainalloc+0x31c
clusteralloc(1e58a00, 69baf, 4, c375b04, c375b00, badcafe) at 
netbsd:clusteralloc+0x1f8
extendfile(c339ef0, 4, 0, 0, 0, e) at netbsd:extendfile+0x8c
msdosfs_write(1b, 0, 0, 10000, ffffffff, c339ef0) at netbsd:msdosfs_write+0x268 
VOP_WRITE(c3278c0, c375cc8, 10, af49650, ffffffff, c5) at netbsd:VOP_WRITE+0x40 
vn_write(c103570, c103570, c375cc8, 10000, 1, badcafe) at netbsd:vn_write+0xb8  
dofilewrite(16, c103570, 23548, 10000, c103570, 1) at netbsd:dofilewrite+0x64   
sys_write(c3235c0, c375dd0, c375e10, 1054c, badcafe, badcafe) at 
netbsd:sys_write+0x5c
syscall_plain(c375ed0, 3, 0, 1, 0, 400a6174) at netbsd:syscall_plain+0x12c
?(4, 23548, 10000, badcafe, badcafe, badcafe) at 0x1009308
db>
        
>How-To-Repeat:
        mount -t msdos /dev/sd0a /mnt
        cp /netbsd /mnt
>Fix: