Re: HAMMER crash during unmount

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Hi,
:
:during my recent work with the installer (add HAMMER support) my
:DragonFly box paniced while unmounting a HAMMER volume:
:
:panic: assertion: RB_EMPTY(&hmp->rb_inos_root) in hammer_free_hmp
:Trace beginning at frame 0xda299bf0
:panic(da299c14,1e,da287000,d270b958,da299c28) at panic+0x8c
:panic(c0532657,c0559b86,c051a96d,0,d270b958) at panic+0x8c
:hammer_free_hmp(d270bb60,d270b958,da299c6c,c032ae0d,d270b958) at
:hammer_free_hmp+0xd8
:hammer_vfs_unmount(d270b958,0,0,d270b978,1) at hammer_vfs_unmount+0x33
:dounmount(d270b958,0,d270b958,0,0) at dounmount+0x1a8
:sys_unmount(da299cf0,6,bd34,0,d270a518) at sys_unmount+0xdf
:syscall2(da299d40) at syscall2+0x1ef
:Xint0x80_syscall() at Xint0x80_syscall+0x36
:Debugger("panic")
:panic: from debugger
:Uptime: 17h54m57s

    Here's the dmesg from your crash dump on leaf:

pid 20683 (dfuibe_installer), uid 0: exited on signal 11 (core dumped)
pid 20966 (dfuibe_installer), uid 0: exited on signal 11 (core dumped)
unmount(/mnt): Cannot unmount: 0 namecache references still present
unmount(/mnt): Cannot unmount: 2 process references still present
HAMMER: umount flushing..........................giving up
panic: assertion: RB_EMPTY(&hmp->rb_inos_root) in hammer_free_hmp
Trace beginning at frame 0xda299bf0

    For some reason it was having a hard time flushing dirty inodes.

    Could you tell if the disk drive was solid on while it was trying
    to umount?  There should have been about a 25-second delay (each
    '.' is one second, theoretically).

					-Matt