hammer panic

[Sascha Wildner <saw@xxxxxxxxx>]

Creating a multi volume filesystem spanning 2 partitions and then trying 
to mount_hammer only the first partition triggers an assertion. I can 
provide a dump if necessary but it should be fairly reproducable.

Unread portion of the kernel message buffer:
HAMMER(obj) Start Recovery 300000001c642ca8 - 300000001c643500 (2136 
bytes of UNDO)(RW)
HAMMER: UNDO record, cannot access buffer 2010000026bbe000
HAMMER(obj) UNDO record at 300000001c643228 failed
HAMMER(obj) End Recovery
Failed to recover HAMMER filesystem on mount
panic: assertion: volume->io.lock.refs == 0 in hammer_unload_volume
panic: from debugger
Uptime: 16m15s

dumping to dev #ad/0x20001, blockno 2097456
dump 1023 [...]

GNU gdb 6.7.1
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This GDB was configured as "i386-dragonfly".
(kgdb) bt
#0  dumpsys () at ./machine/thread.h:83
#1  0xc01d5162 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:375
#2  0xc01d5283 in panic (fmt=0xc03c0145 "from debugger") at 
/usr/src/sys/kern/kern_shutdown.c:800
#3  0xc01515b1 in db_panic (addr=-1070076140, have_addr=0, count=-1, 
modif=0xe60cd858 "") at /usr/src/sys/ddb/db_command.c:447
#4  0xc0151c1c in db_command_loop () at /usr/src/sys/ddb/db_command.c:343
#5  0xc0154194 in db_trap (type=3, code=0) at /usr/src/sys/ddb/db_trap.c:71
#6  0xc037f067 in kdb_trap (type=3, code=0, regs=0xe60cd950) at 
/usr/src/sys/platform/pc32/i386/db_interface.c:148
#7  0xc038daf7 in trap (frame=0xe60cd950) at 
/usr/src/sys/platform/pc32/i386/trap.c:842
#8  0xc037fd77 in calltrap () at 
/usr/src/sys/platform/pc32/i386/exception.s:785
#9  0xc037ef14 in Debugger (msg=0xc03c8e23 "panic") at ./cpu/cpufunc.h:73
#10 0xc01d527a in panic (fmt=0xc03bd6bf "assertion: %s in %s") at 
/usr/src/sys/kern/kern_shutdown.c:798
#11 0xc0304426 in hammer_unload_volume (volume=0xc2653d48, data=0x0) at 
/usr/src/sys/vfs/hammer/hammer_ondisk.c:280
#12 0xc0302a1f in hammer_vol_rb_tree_RB_SCAN (head=0xe981f00c, 
scancmp=0xc0302929 <hammer_vol_rb_tree_SCANCMP_ALL>, callback=0xc03043d2 
<hammer_unload_volume>,
    data=0x0) at /usr/src/sys/vfs/hammer/hammer_ondisk.c:83
#13 0xc030a143 in hammer_free_hmp (mp=0xcc2b20d8) at 
/usr/src/sys/vfs/hammer/hammer_vfsops.c:592
#14 0xc030a8fb in hammer_vfs_mount (mp=0xcc2b20d8, mntpt=0xbfbffbb1 
<Address 0xbfbffbb1 out of bounds>, data=0xbfbff920 <Address 0xbfbff920 
out of bounds>,
    cred=0xc2606c08) at /usr/src/sys/vfs/hammer/hammer_vfsops.c:519
#15 0xc0222585 in sys_mount (uap=0xe60cdcf0) at 
/usr/src/sys/kern/vfs_syscalls.c:345
#16 0xc038d492 in syscall2 (frame=0xe60cdd40) at 
/usr/src/sys/platform/pc32/i386/trap.c:1384
#17 0xc037fe26 in Xint0x80_syscall () at 
/usr/src/sys/platform/pc32/i386/exception.s:876
#18 0x08049864 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)