Re: git: 2a58b312b62f - main - zfs: merge openzfs/zfs@431083f75

From: Pawel Jakub Dawidek <pjd_at_FreeBSD.org>
Date: Mon, 17 Apr 2023 10:43:09 UTC
On 4/17/23 18:15, Pawel Jakub Dawidek wrote:
> There were three issues that I know of after the recent OpenZFS merge:
> 
> 1. Data corruption unrelated to block cloning, so it can happen even 
> with block cloning disabled or not in use. This was the problematic commit:
>      https://github.com/openzfs/zfs/commit/519851122b1703b8445ec17bc89b347cea965bb9
> 
> It was reverted in 63ee747febbf024be0aace61161241b53245449e.
> 
> 2. Data corruption with embedded blocks when block cloning is enabled. 
> It can happen when compression is enabled and the block contains between 
> 60 to 112 bytes (this might be hard to determine). Fix exists, it is 
> merged to OpenZFS already, but isn't in FreeBSD yet.
>      OpenZFS pull request: https://github.com/openzfs/zfs/pull/14739
> 
> 3. Panic on VERIFY(zil_replaying(zfsvfs->z_log, tx)). This is triggered 
> when block cloning is enabled, the sync property is set to disabled and 
> copy_file_range(2) is used. Easy fix exists, it is not yet merged to 
> OpenZFS and not yet in FreeBSD HEAD.
>      OpenZFS pull request: https://github.com/openzfs/zfs/pull/14758
> 
> Block cloning was disabled in 46ac8f2e7d9601311eb9b3cd2fed138ff4a11a66, 
> so 2 and 3 should not occur.

As of 068913e4ba3dd9b3067056e832cefc5ed264b5cc all known issues are 
fixed, as far as I can tell.

Block cloning remains disabled for now just to be on the safe side, but 
can be enabled by setting sysctl vfs.zfs.bclone_enabled to 1.

Don't relay on this sysctl as it will be removed in 2-3 weeks.

-- 
Pawel Jakub Dawidek