HAMMER: RB_EMPTY assertion panic

[Matthew Dillon]

:Hello,
:
:panic: assertion: RB_EMPTY(&hmp->rb_inos_root) in hammer_free_hmp
:Trace beginning at frame 0xcb0f3bb4
:panic(cb0f3bd8,cad78000,0,c9b04d58,cb0f3bec) at panic+0x8c
:panic(c051f5f7,c054313b,c05073f5,0,c9b04d58) at panic+0x8c
:hammer_free_hmp(c9b04f60,c9b04d58,cb0f3c30,c0312db8,c9b04d58) at
:hammer_free_hmp+0xa5 hammer_vfs_unmount
:(c9b04d58,80000,80000,c9b04d78,1) at hammer_vfs_unmount+0x33 dounmount
:(c9b04d58,80000,c9b04d58,1,cb0f3c80) at dounmount+0x1a8
:vfs_umountall_callback(c9b04d58,0,c0625694,0,1) at
:vfs_umountall_callback+0x13 mountlist_scan(c030bc6a,0,6) at
:mountlist_scan+0xe8 vfs_unmountall(0,0,0,0,cb0f3cbc) at vfs_unmountall
:+0x11 boot(0,cb0f3d34,c04d1672,cb0f3cf0,6) at boot+0x21d sys_reboot
:(cb0f3cf0,6,2fb3d,0,c9b099d8) at sys_reboot+0x23 syscall2(cb0f3d40) at
:syscall2+0x1e9 Xint0x80_syscall() at Xint0x80_syscall+0x36
:Debugger("panic")
:Stopped at      Debugger+0x34:  movb    $0,in_Debugger.3949
:
:I was doing a reboot. Mysteriously, a core dump has not been created so
:I will try my best to reproduce it.
:
:-- 
:Gergo Szakal MD <bastyaelvtars at gmail.com>

    Shoot, a core dump would have told us why there were still inodes
    in the tree.  That assertion occurs at the tail end of the umount code,
    basically saying "Hey, there shouldn't be any inode structures left at
    this point".

    The most likely cause is that a process got stuck and couldn't close()
    all of its file descriptors, leaving a vnode active on the mount.  Did
    you happen to see any stuck process or forced-unmount warnings?

					-Matt