panic: No vop_need_inactive

Hi,

I'm experiencing a recurring panic I can trigger repeatably.

The machine is:

FreeBSD 13.0-CURRENT r351604 amd64

The panic looks ZFS related. This machine performs mainly poudriere
builds. I also use portshaker to manage the ports tree.

Portshaker works by downloading ports trees and overlays in zfses, then
snapshots them, clones them placing the clones in the poudriere
namespace, then modifies the ports there applying the required overlays.

This happens to me any time I run poudriere and after the build I run
portshaker to update the ports trees, when it tries to remove the
snapshot of the freebsd base tree (which AFAIK is the base for the clone
where poudriere works).

I'm going to try to create a more clear and detailed use case, removing
from the equation complex programs like poudriere and portshaker.


Here is the panic message:

VNASSERT failed
0xfffff800abfcbd20: tag zfs, type VDIR
    usecount 0, writecount 0, refcount 1 mountedhere 0
    flags (VI_ACTIVE)
 VI_LOCKed    lock type zfs: UNLOCKED
	name = portshaker-2019-09-01:11:04:20
	parent_id = 2
	id = 269
panic: No vop_need_inactive(0xfffff800abfcbd20, 0xfffffe00ba39b3f0)
cpuid = 2
time = 1567342436
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
0xfffffe00ba39b310
vpanic() at vpanic+0x19d/frame 0xfffffe00ba39b360
panic() at panic+0x43/frame 0xfffffe00ba39b3c0
VOP_NEED_INACTIVE_APV() at VOP_NEED_INACTIVE_APV+0x8f/frame
0xfffffe00ba39b3e0
vputx() at vputx+0x1ae/frame 0xfffffe00ba39b440
vfs_mount_destroy() at vfs_mount_destroy+0x14f/frame 0xfffffe00ba39b470
dounmount() at dounmount+0x7e8/frame 0xfffffe00ba39b4d0
zfs_unmount_snap() at zfs_unmount_snap+0xbb/frame 0xfffffe00ba39b4f0
zfs_ioc_destroy_snaps() at zfs_ioc_destroy_snaps+0xb3/frame
0xfffffe00ba39b540
zfsdev_ioctl() at zfsdev_ioctl+0x54c/frame 0xfffffe00ba39b5e0
devfs_ioctl() at devfs_ioctl+0xc9/frame 0xfffffe00ba39b630
vn_ioctl() at vn_ioctl+0x13d/frame 0xfffffe00ba39b740
devfs_ioctl_f() at devfs_ioctl_f+0x1f/frame 0xfffffe00ba39b760
kern_ioctl() at kern_ioctl+0x1e4/frame 0xfffffe00ba39b7c0
sys_ioctl() at sys_ioctl+0x15d/frame 0xfffffe00ba39b890
amd64_syscall() at amd64_syscall+0x284/frame 0xfffffe00ba39b9b0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00ba39b9b0
--- syscall (54, FreeBSD ELF64, sys_ioctl), rip = 0x80049f2da, rsp =
0x7fffffffc948, rbp = 0x7fffffffc9c0 ---
KDB: enter: panic


Anyone can help?


-- 
Guido Falsi <madpilot_at_freebsd.org>