[pbs-devel] [PATCH proxmox-backup v2 1/4] proxmox-backup-proxy: fix leftover references on datastore removal

[Dietmar Maurer]

applied with small modifications

- simplify refresh_datastores (as suggested by Thomas)

- rename  refresh_datastores to remove_unused_datastores

On 6/2/21 1:27 PM, Dominik Csapak wrote:
> when we remove a datastore via api/cli, the proxy
> has sometimes leftover references to that datastore in its
> DATASTORE_MAP which includes an open filehandle on the
> '.lock' file
>
> this prevents unmounting/exporting the datastore even after removal,
> only a reload/restart of the proxy did help
>
> add a command to our command socket, which removes all non
> configured datastores from the map, dropping the open filehandle
>
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
>   src/api2/config/datastore.rs    |  4 +++-
>   src/backup/datastore.rs         | 16 ++++++++++++++++
>   src/bin/proxmox-backup-proxy.rs | 11 +++++++++++
>   src/server.rs                   |  8 ++++++++
>   4 files changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/src/api2/config/datastore.rs b/src/api2/config/datastore.rs
> index 6ca98b53..7299c91d 100644
> --- a/src/api2/config/datastore.rs
> +++ b/src/api2/config/datastore.rs
> @@ -403,7 +403,7 @@ pub fn update_datastore(
>       },
>   )]
>   /// Remove a datastore configuration.
> -pub fn delete_datastore(name: String, digest: Option<String>) -> Result<(), Error> {
> +pub async fn delete_datastore(name: String, digest: Option<String>) -> Result<(), Error> {
>   
>       let _lock = open_file_locked(datastore::DATASTORE_CFG_LOCKFILE, std::time::Duration::new(10, 0), true)?;
>   
> @@ -425,6 +425,8 @@ pub fn delete_datastore(name: String, digest: Option<String>) -> Result<(), Erro
>       let _ = jobstate::remove_state_file("prune", &name);
>       let _ = jobstate::remove_state_file("garbage_collection", &name);
>   
> +    crate::server::notify_datastore_removed().await?;
> +
>       Ok(())
>   }
>   
> diff --git a/src/backup/datastore.rs b/src/backup/datastore.rs
> index 584b2020..6989313d 100644
> --- a/src/backup/datastore.rs
> +++ b/src/backup/datastore.rs
> @@ -69,6 +69,22 @@ impl DataStore {
>           Ok(datastore)
>       }
>   
> +    /// removes all datastores that are not configured anymore
> +    pub fn refresh_datastores() -> Result<(), Error>{
> +        let (config, _digest) = datastore::config()?;
> +        let mut stores = HashSet::new();
> +        for (store, _) in config.sections {
> +            stores.insert(store);
> +        }
> +
> +        let mut map = DATASTORE_MAP.lock().unwrap();
> +        // removes all elements that are not in the config
> +        map.retain(|key, _| {
> +            stores.contains(key)
> +        });
> +        Ok(())
> +    }
> +
>       fn open_with_path(store_name: &str, path: &Path, config: DataStoreConfig) -> Result<Self, Error> {
>           let chunk_store = ChunkStore::open(store_name, path)?;
>   
> diff --git a/src/bin/proxmox-backup-proxy.rs b/src/bin/proxmox-backup-proxy.rs
> index a53f554a..75d40e21 100644
> --- a/src/bin/proxmox-backup-proxy.rs
> +++ b/src/bin/proxmox-backup-proxy.rs
> @@ -136,6 +136,17 @@ async fn run() -> Result<(), Error> {
>           },
>       )?;
>   
> +    // to remove references for not configured datastores
> +    commando_sock.register_command(
> +        "datastore-removed".to_string(),
> +        |_value| {
> +            if let Err(err) = proxmox_backup::backup::DataStore::refresh_datastores() {
> +                log::error!("could not refresh datastores: {}", err);
> +            }
> +            Ok(Value::Null)
> +        }
> +    )?;
> +
>       let server = daemon::create_daemon(
>           ([0,0,0,0,0,0,0,0], 8007).into(),
>           move |listener, ready| {
> diff --git a/src/server.rs b/src/server.rs
> index ba25617d..c4a36967 100644
> --- a/src/server.rs
> +++ b/src/server.rs
> @@ -100,3 +100,11 @@ pub(crate) async fn reload_proxy_certificate() -> Result<(), Error> {
>           .await?;
>       Ok(())
>   }
> +
> +pub(crate) async fn notify_datastore_removed() -> Result<(), Error> {
> +    let proxy_pid = crate::server::read_pid(buildcfg::PROXMOX_BACKUP_PROXY_PID_FN)?;
> +    let sock = crate::server::ctrl_sock_from_pid(proxy_pid);
> +    let _: Value = crate::server::send_raw_command(sock, "{\"command\":\"datastore-removed\"}\n")
> +        .await?;
> +    Ok(())
> +}