panic: assertion: leaf->base.obj_id == ip->obj_id in hammer_ip_delete_range

[YONETANI Tomokazu <qhwt+dfly@xxxxxxxxxx>]

Hi.
I caught this panic while running pbulk and vkernel on the same machine.
The PC has 1.5G bytes of main memory, occasionally using the swap up to
20M or so bytes (according to top).
The kernel is built from source as of cf0e75a4(+ small modifications not
touching the kernel).  I've turned off periodic/daily/160.clean-hammer
and run `hammer cleanup /pfs/*' by hand only occasionally (but I'm sure
I can't fill up this 1TB hard drive anyway).  The hammer filesystem version
is 2.  I'll upload the vmcore to leaf on request.

Cheers.

(kgdb) bt
#0  dumpsys () at ./machine/thread.h:83
#1  0xc01a0c79 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:378
#2  0xc01a0f3e in panic (fmt=0xc02fe5be "assertion: %s in %s")
    at /usr/src/sys/kern/kern_shutdown.c:813
#3  0xc02812e0 in hammer_ip_delete_range (cursor=0xd88b4c9c, ip=0xe19acb50,
    ran_beg=0, ran_end=9223372036854775807, truncating=2)
    at /usr/src/sys/vfs/hammer/hammer_object.c:1946
#4  0xc02788bf in hammer_sync_inode (trans=0xd818a114, ip=0xe19acb50)
    at /usr/src/sys/vfs/hammer/hammer_inode.c:2714
#5  0xc0276a5b in hammer_flusher_slave_thread (arg=0xd6e78510)
    at /usr/src/sys/vfs/hammer/hammer_flusher.c:496
#6  0xc01a981a in lwkt_deschedule_self (td=Cannot access memory at address 0x8
)
    at /usr/src/sys/kern/lwkt_thread.c:271

(kgdb) p ip->obj_id
$1 = 374280419483
(kgdb) p leaf->base
$2 = {obj_id = 374247118508, key = 16384, create_tid = 374281176448,
  delete_tid = 0, rec_type = 16, obj_type = 2 '\002', btype = 82 'R',
  localization = 393218}
(kgdb)