zfs code - Aug 2007 - IO error on mount for encrypted dataset

Does the ARC get flushed for a dataset when it is unmounted ?
What does change when a dataset is unmounted ?

The context of the problem is this:

create a pool,
provide the pool encryption key,
create a dataset with encryption turned on,
put data into that dataset
	I see it getting encrypted and written to disk by zio_write,
zfs umount -a
zfs mount -a
	I can read the data back - yeah!.

However if I export the pool and then reimport it the mount fails with 
an IO error (and yes I did remember to give the pool the key again).

A little dtracing shows me that a zap_lookup of VERSION for the 
encrypted dataset is returning EIO, that causes the mount to ultimately 
fail.

--
Darren J Moffat

Darren J Moffat wrote:
> Does the ARC get flushed for a dataset when it is unmounted ?
Yes
> What does change when a dataset is unmounted ?
> 
Pretty much everything associated with the dataset should be evicted...
its possible that some of the meta-data may hang around I suppose (I
don''t remember off-hand).
> The context of the problem is this:
> 
> create a pool,
> provide the pool encryption key,
> create a dataset with encryption turned on,
> put data into that dataset
> 	I see it getting encrypted and written to disk by zio_write,
> zfs umount -a
> zfs mount -a
> 	I can read the data back - yeah!.
> 
> However if I export the pool and then reimport it the mount fails with 
> an IO error (and yes I did remember to give the pool the key again).
> 
> A little dtracing shows me that a zap_lookup of VERSION for the 
> encrypted dataset is returning EIO, that causes the mount to ultimately 
> fail.
Could be that this meta data does not get evicted at unmount.
> 
> --
> Darren J Moffat
> _______________________________________________
> zfs-code mailing list
> zfs-code at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-code

Mark Maybee wrote:
>> create a pool,
>> provide the pool encryption key,
>> create a dataset with encryption turned on,
>> put data into that dataset
>>     I see it getting encrypted and written to disk by zio_write,
>> zfs umount -a
>> zfs mount -a
>>     I can read the data back - yeah!.
I also did a zpool scrub in here and it was clean.
>> However if I export the pool and then reimport it the mount fails with 
>> an IO error (and yes I did remember to give the pool the key again).
>>
>> A little dtracing shows me that a zap_lookup of VERSION for the 
>> encrypted dataset is returning EIO, that causes the mount to 
>> ultimately fail.
After this EIO happens zpool status says that the dataset has an error :-(

-- 
Darren J Moffat