[Samba] ZFS and vfs_shadow_copy2

[Jeremy Allison]

On Wed, Mar 23, 2022 at 04:17:58PM +0100, Andrea Venturoli via samba wrote:
>
>On 3/23/22 13:52, Andrea Venturoli via samba wrote:
>
>>At least now I know it's a client side problem.
>
>After further investigation, maybe not.
>
>I'm still looking into this, but it seems to be a problem with time 
>conversion.
>
>
>
>I have:
>>root at fs:~ # date -u
>>Wed Mar 23 14:46:22 UTC 2022
>>root at fs:~ # date
>>Wed Mar 23 15:46:23 CET 2022
>
>(kernel clock set to UTC time).
>
>
>
>># zfs list -t snap
>>zroot/ezjail/fs/shares at auto_zroot-20210920080000       95.9K      -   117K  -
>> ...
>
>080000 is my local time (not UTC).
>
>So, as per VFS_SHADOW_COPY2(8), I put "shadow:localtime=yes" in smb.conf.
>
>
>
>For the above, the packet trace shows the following in the list:
>Snapshot: @GMT-2021.09.20-06.00.00
>
>Seems right, as locat time was converted to UTC.
>
>
>However, after receiving such a list, the client tries to probe some 
>of the snapshots, e.g.:
>>Create Request File: @Sep 20, 2021 06:00:00.000000000
>
>and the server obviously answers:
>>NT Status: STATUS_UNSUCCESSFUL (0xc0000001)
>
>Possibly this is the reason a wider range (long time ago, this year, 
>last month, etc...) is excluded.
>
>
>
>I have yet to test this in the wild, but putting "shadow:localtime=no" 
>allowed me to see the full list.
>Of course all the snapshots are labeled as one hour later (the last 
>being in the future).
>
>Any hint?
>Is this a bug or feature?

Unsure. We'd need to see debug level 10 logs.