Re: -CURRENT panics in NFS

You should be able to just use kgdb on the old kernel and the
crashdump you already collected, provided both are still around.
Alternatively boot with this without the fix:

diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index fef1e31d197b..c4d2990b155d 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
_at__at_ -2266,6 +2266,9 _at__at_ cache_enter_time(struct vnode *dvp, struct vnode
*vp, struct componentname *cnp,
        KASSERT(cnp->cn_namelen <= NAME_MAX,
            ("%s: passed len %ld exceeds NAME_MAX (%d)", __func__,
cnp->cn_namelen,
            NAME_MAX));
+       if (dvp == vp) {
+               panic("%s: same vnodes; cnp [%s] len %ld\n", __func__,
cnp->cn_nameptr, cnp->cn_namelen);
+       }
        VNPASS(dvp != vp, dvp);
        VNPASS(!VN_IS_DOOMED(dvp), dvp);
        VNPASS(dvp->v_type != VNON, dvp);


On 2/27/21, Juraj Lutter <otis_at_freebsd.org> wrote:
> I am now running a patched kernel, without problems.
>
> I can boot to unpatched one and see the output of these ddb commands.
>
> otis
>
> —
> Juraj Lutter
> XMPP: juraj (at) lutter.sk
> GSM: +421907986576
>
>> On 27 Feb 2021, at 21:49, Mateusz Guzik <mjguzik_at_gmail.com> wrote:
>>
>> Can you dump 'struct componentname *cnp'? This should do the trick:
>> f 12
>> p cnp
>>
>
>
>


-- 
Mateusz Guzik <mjguzik gmail.com>