Re: current status of zfs block_cloning on CURRENT?

From: Charlie Li <vishwin_at_freebsd.org>
Date: Tue, 25 Apr 2023 03:41:02 UTC
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.
> 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

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