[pbs-devel] [PATCH proxmox-backup] Avoid lost updates to configuration during datastore deletion

[Christian Ebner]

Thanks for the patch!

Only minor comments...

`Avoid lost updates to configuration during datastore deletion`

the title might mention that this are concurrent config updates, so maybe:

`fix: avoid loss of concurrent config changes during datastore deletion`

On 10/30/25 11:51 AM, Robert Obkircher wrote:
> Previously, the following steps created files in /srv/test2 but
> removed test2 from the configuration:

Apart from the steps to reproduce (which is always nice to have!), this 
should maybe also state that this fixes a race between the initial 
reading of the datastore config before destroying the datastore and 
concurrent config changes, by re-reading the config in a locked context 
before removing the just destroyed datastore from it.

> 
>    proxmox-backup-manager datastore create test1 /srv/test1
>    proxmox-backup-manager datastore remove test1 --destroy-data &
>    sleep 0.1
>    proxmox-backup-manager datastore create test2 /srv/test2
> 
> Reported-by: https://forum.proxmox.com/threads/possible-bug-when-deleting-a-datastore.174715/
This can be shortened to only include the thread ID, e.g.:
https://forum.proxmox.com/threads/174715/


> Signed-off-by: Robert Obkircher <r.obkircher at proxmox.com>
> ---
>   pbs-datastore/src/datastore.rs | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
> index 03830616..14dad93a 100644
> --- a/pbs-datastore/src/datastore.rs
> +++ b/pbs-datastore/src/datastore.rs
> @@ -2154,6 +2154,8 @@ impl DataStore {
>           if ok {
>               info!("Removing datastore from config...");
>               let _lock = pbs_config::datastore::lock_config()?;
> +            // read again to avoid loosing concurrent modifications
> +            let (mut config, _digest) = pbs_config::datastore::config()?;
>               let _ = config.sections.remove(name);
>               pbs_config::datastore::save_config(&config)?;
>           }

With these changes to the commit message addressed, consider:

Reviewed-by: Christian Ebner <c.ebner at proxmox.com>Tested-by: Christian 
Ebner <c.ebner at proxmox.com>