panic: assertion: layer2->zone == zone in hammer_blockmap_free

[Matthew Dillon]

:Hi.
:Caught this panic on latest DragonFly_RELEASE_2_0 (minus the fix to
:vfs_subr.c, but the machine has less than 2G RAM), when I tried to
:destroy a PFS slave on HAMMER filesystem.  The PFS hasn't been actively
:used, only to try mirror-copy of another PFS, which is used as /usr/obj.
:The panic also occurs when I try to reblock this PFS, but no problem
:to upgrade to a PFS master.  I don't have a problem reblocking or pruning
:other PFS's or HAMMER filesystem containing them.
:...
:The kernel dump has been uploaded as ~y0netan1/crash/{kernel,vmcore}.13
:on my leaf account.
:
:Cheers.

    This looks fairly serious.  The big-block has been marked free but the
    rollback code is trying to delete a data element that still
    references it.

    I am going to need some additional information from you.  Please sync
    your filesystem and then do the following:

    hammer -f <device> blockmap > textfile
    hammer -f <device> -vvv show >> textfile

    And gzip and upload that to leaf.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>