[NetBSD-7] Panic in nfsd

[BERTRAND Joël <joel.bertrand%systella.fr@localhost>]

	Hello,

	I have installed a FreeBSD diskless client on a NetBSD server (x86 i7 
64 bits). This afternoon, this server crashes without any usable dump 
(as it has paniced twice, rootfs was corrupted). Panic occurs when nfs 
client did a lot of concurrent nfs access. In message, I only have :

Jan  4 17:07:23 legendre /netbsd: vpanic() at netbsd:vpanic+0x13c
Jan  4 17:07:23 legendre /netbsd: snprintf() at netbsd:snprintf
Jan  4 17:07:23 legendre /netbsd: ufs_dirbadentry() at 
netbsd:ufs_dirbadentry
Jan  4 17:07:23 legendre /netbsd: ufs_lookup() at netbsd:ufs_lookup+0x4c3
Jan  4 17:07:23 legendre /netbsd: VOP_LOOKUP() at netbsd:VOP_LOOKUP+0x34
Jan  4 17:07:23 legendre /netbsd: lookup_once() at netbsd:lookup_once+0x18b
Jan  4 17:07:23 legendre /netbsd: namei_tryemulroot() at 
netbsd:namei_tryemulroot+0x612
Jan  4 17:07:23 legendre /netbsd: lookup_for_nfsd() at 
netbsd:lookup_for_nfsd+0x4e
Jan  4 17:07:23 legendre /netbsd: nfs_namei() at netbsd:nfs_namei+0x1ca
Jan  4 17:07:23 legendre /netbsd: nfsrv_lookup() at 
netbsd:nfsrv_lookup+0x264
Jan  4 17:07:23 legendre /netbsd: do_nfssvc() at netbsd:do_nfssvc+0x41d
Jan  4 17:07:23 legendre /netbsd: syscall() at netbsd:syscall+0x9a
Jan  4 17:07:23 legendre /netbsd: --- syscall (number 155) ---

	Kernel is built from netbsd-7 CVS tree (28th of december 2015).
I haven't seen recently any similar issue. Client has mounted its rootfs 
with following options : TCP, vers=3.

	Does someone has seen the same trouble ?

	Regards,

	JKB