msdos panic

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

Hi,
copying a file to a msdos-formatted USB key I get:
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+0
x31c
clusteralloc(1e58a00, 69baf, 4, c375b04, c375b00, badcafe) at netbsd:clusterallo
c+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_writ
e+0x5c
syscall_plain(c375ed0, 3, 0, 1, 0, 400a6174) at netbsd:syscall_plain+0x12c
?(4, 23548, 10000, badcafe, badcafe, badcafe) at 0x1009308
db> 

Anyone else seeing this ? This is on a 32bit sparc64 kernel, with
DEBUG+DIAGNOSTIC.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--