repeatable ZFS panic: share->excl

[Tim Kientzle]

Pawel Jakub Dawidek wrote:
> On Fri, Mar 13, 2009 at 02:08:03PM -0400, John Baldwin wrote:
>> John Baldwin wrote:
>>> Yes, I think that is the real bug.  Looking at this further I think
>>> zfs_get_xattrdir() will return the vnode locked if it has to create a
>>> new node via zfs_make_attrdir() but only returns it held and unlocked if
>>> it finds an existing one.  So my new patch is to just fix
>>> zfs_get_xattrdir() to unlock the vnode if it creates a new one like so:
>>>
>>> (Sorry, TBird is probably going to butcher all the whitespace):
>>>
>>> ---
>>> //depot/user/jhb/lock/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c
>>> +++
>>> /Users/jhb/work/p4/lock/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_dir.c 
>>>
>>> @@ -940,6 +940,7 @@
>>>         /* NB: we already did dmu_tx_wait() if necessary */
>>>         goto top;
>>>     }
>>> +    VOP_UNLOCK(*xvpp, 0);
>>>
>>>     return (error);
>>> }
>>>
>>> A non-butchered version is at www.FreeBSD.org/~jhb/patches/zfs_ea.patch.
>> So lulf@ reports success with this patch.  Pawel, can you review it?
> 
> Yes, it works for me too and looks good. The only thing we need to
> change is to check for error beeing 0 before unlocking the vnode.
> The zfs_make_xattrdir() function can still return with EIO, so I'd add
> something like this:
> 
> 	if (error == 0)
> 		VOP_UNLOCK(*xvpp, 0);
> 
> Thank you John for spending time on tracking this one down.

Any estimate on when this can be committed?

I'm waiting to re-enable the extended attribute
archiving support in tar until this is fixed.

Tim