Re: current status of zfs block_cloning on CURRENT?

From: Charlie Li <vishwin_at_freebsd.org>
Date: Tue, 25 Apr 2023 03:48:57 UTC
Charlie Li wrote:
> Pete Wright wrote:
>> i've seen a few threads about the block_cloning feature causing data 
>> corruption issues on CURRENT and have been keen to avoid enabling it 
>> until the dust settles.  i was under the impression that we either 
>> reverted or disabled block_cloning on CURRENT, but when i ran "zpool 
>> upgrade" on a pool today it reported block_cloning was enabled.  this 
>> is on a system i rebuilt yesterday.
>>
> The dust has settled.
Barely...
>> i was hoping to get some clarity on the effect of having this feature 
>> enabled, is this enough to trigger the data corruption bug or does 
>> something on the zfs filesystem itself have to be enabled to trigger 
>> this?
>>
> The initial problem with block_cloning [0][1] was fixed in commits 
> e0bb199925565a3770733afd1a4d8bb2d4d0ce31 and 
> 1959e122d9328b31a62ff7508e1746df2857b592, with a sysctl added in commit 
> 068913e4ba3dd9b3067056e832cefc5ed264b5cc. A different data corruption 
> problem [2][3] was fixed in commit 
> 63ee747febbf024be0aace61161241b53245449e. All were committed between 
> 15-17 April.
> 
> [0] https://github.com/openzfs/zfs/pull/13392#issuecomment-1504239103
> [1] https://github.com/openzfs/zfs/pull/14739
> [2] https://github.com/openzfs/zfs/issues/14753
> [3] https://github.com/openzfs/zfs/pull/14761
> 
Given mjg@'s thread reporting further crashes/panics, you may want to 
keep the sysctl disabled if you upgraded the pool already.

-- 
Charlie Li
…nope, still don't have an exit line.