Re: repeatable ZFS panic: share->excl

>> ... ZFS bug ... lock up if it receives ... extattr_list_link system 
>> call ...  Tar recently added support for backing up extended 
>> attributes.
> 
> I just rebuilt world on one box and the problem went away. Your fix I 
> assume?

Yes, I've disabled the ability to backup extended attributes.
I'm not happy about it, but it seemed prudent for now.

>> 2) Is this on extraction or just create?
> 
> The problem occurs with just tar create. I'm not sure why pkg_add 
> provokes it.

I just remembered that pkg_add sometimes uses "tar -c | tar -x"
to copy a lot of files from the staging area to the final
destination.  So there is a tar create step in there.

>> 3) Can you run tar under "ktrace" and figure out what system call is 
>> provoking the problem?
> 
> I'm not sure how I could dump the ktrace.out after a panic.
>   A truss of a tar create on a zfs volume shows the last call to be:
> 
> __acl_get_file(...) ERR#45 'Operation not supported'
> shared lock of (lockmgr) zfs _at_ /usr/src/sys/kern/vfs_lookup.c:442

Yep, the libarchive code tries to get ACLs first,
then tries to list any extended attributes.  The
very next system call after this should be either
extattr_list_link or extattr_list_file (depending
on whether symlinks are being followed or not).

This is also consistent with the backtrace you provided
in your earlier message.

So it is exactly the same problem.

Tim