Re: [pbs-devel] [PATCH proxmox-backup 09/26] api2: admin: add unmount-device endpoint to datastore

[Wolfgang Bumiller <w.bumiller@proxmox.com>]

On Tue, Jul 05, 2022 at 01:08:17PM +0000, Hannes Laimer wrote:
> unmounts the removable device mounted at the datstore path and set the
> maintenance-mode of the datastore to 'unplugged'. The worker waits for
> all running tasks to finish before unmounting.
> 
> Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
> ---
>  src/api2/admin/datastore.rs | 97 +++++++++++++++++++++++++++++++++----
>  1 file changed, 87 insertions(+), 10 deletions(-)
> 
> diff --git a/src/api2/admin/datastore.rs b/src/api2/admin/datastore.rs
> index 5448fa10..2be95f92 100644
> --- a/src/api2/admin/datastore.rs
> +++ b/src/api2/admin/datastore.rs
> @@ -22,27 +22,28 @@ use proxmox_router::{
>      Router, RpcEnvironment, RpcEnvironmentType, SubdirMap,
>  };
>  use proxmox_schema::*;
> +use proxmox_section_config::SectionConfigData;
>  use proxmox_sys::fs::{
>      file_read_firstline, file_read_optional_string, replace_file, CreateOptions,
>  };
> -use proxmox_sys::sortable;
> -use proxmox_sys::{task_log, task_warn};
> +use proxmox_sys::{sortable, task_log, task_warn, WorkerTaskContext};
>  
>  use pxar::accessor::aio::Accessor;
>  use pxar::EntryKind;
>  
>  use pbs_api_types::{
>      print_ns_and_snapshot, print_store_and_ns, Authid, BackupContent, BackupNamespace, BackupType,
> -    Counts, CryptMode, DataStoreListItem, DataStoreStatus, GarbageCollectionStatus, GroupListItem,
> -    KeepOptions, Operation, PruneJobOptions, RRDMode, RRDTimeFrame, SnapshotListItem,
> -    SnapshotVerifyState, BACKUP_ARCHIVE_NAME_SCHEMA, BACKUP_ID_SCHEMA, BACKUP_NAMESPACE_SCHEMA,
> -    BACKUP_TIME_SCHEMA, BACKUP_TYPE_SCHEMA, DATASTORE_SCHEMA, IGNORE_VERIFIED_BACKUPS_SCHEMA,
> -    MAX_NAMESPACE_DEPTH, NS_MAX_DEPTH_SCHEMA, PRIV_DATASTORE_AUDIT, PRIV_DATASTORE_BACKUP,
> -    PRIV_DATASTORE_MODIFY, PRIV_DATASTORE_PRUNE, PRIV_DATASTORE_READ, PRIV_DATASTORE_VERIFY,
> -    UPID_SCHEMA, VERIFICATION_OUTDATED_AFTER_SCHEMA,
> +    Counts, CryptMode, DataStoreConfig, DataStoreListItem, DataStoreStatus,
> +    GarbageCollectionStatus, GroupListItem, KeepOptions, MaintenanceMode, MaintenanceType,
> +    Operation, PruneJobOptions, RRDMode, RRDTimeFrame, SnapshotListItem, SnapshotVerifyState,
> +    BACKUP_ARCHIVE_NAME_SCHEMA, BACKUP_ID_SCHEMA, BACKUP_NAMESPACE_SCHEMA, BACKUP_TIME_SCHEMA,
> +    BACKUP_TYPE_SCHEMA, DATASTORE_SCHEMA, IGNORE_VERIFIED_BACKUPS_SCHEMA, MAX_NAMESPACE_DEPTH,
> +    NS_MAX_DEPTH_SCHEMA, PRIV_DATASTORE_AUDIT, PRIV_DATASTORE_BACKUP, PRIV_DATASTORE_MODIFY,
> +    PRIV_DATASTORE_PRUNE, PRIV_DATASTORE_READ, PRIV_DATASTORE_VERIFY, UPID_SCHEMA,
> +    VERIFICATION_OUTDATED_AFTER_SCHEMA,
>  };
>  use pbs_client::pxar::{create_tar, create_zip};
> -use pbs_config::CachedUserInfo;
> +use pbs_config::{BackupLockGuard, CachedUserInfo};
>  use pbs_datastore::backup_info::BackupInfo;
>  use pbs_datastore::cached_chunk_reader::CachedChunkReader;
>  use pbs_datastore::catalog::{ArchiveEntry, CatalogReader};
> @@ -106,6 +107,39 @@ fn check_privs_and_load_store(
>      Ok(datastore)
>  }
>  
> +fn do_unmount_device(
> +    _lock: BackupLockGuard,
> +    mut config: SectionConfigData,
> +    mut datastore: DataStoreConfig,
> +    worker: Option<&dyn WorkerTaskContext>,
> +) -> Result<(), Error> {
> +    datastore.set_maintenance_mode(MaintenanceMode::new(MaintenanceType::Unplugged, None));
> +    config.set_data(&datastore.name, "datastore", &datastore)?;
> +    pbs_config::datastore::save_config(&config)?;
> +    drop(_lock);
> +
> +    let mut active_operations = task_tracking::get_active_operations(&datastore.name)?;
> +    while active_operations.read + active_operations.write > 0 {

I'd again prefer to fail than loop endlessly...

> +        if let Some(worker) = worker {
> +            if worker.abort_requested() {
> +                bail!("aborted, due to user request");
> +            }
> +            task_log!(
> +                worker,
> +                "can't unmount yet, still {} read and {} write operations active",
> +                active_operations.read,
> +                active_operations.write
> +            );
> +        }
> +
> +        std::thread::sleep(std::time::Duration::new(5, 0));
> +        active_operations = task_tracking::get_active_operations(&datastore.name)?;
> +    }
> +
> +    crate::tools::disks::unmount_by_mountpoint(&datastore.path)?;
> +
> +    Ok(())
> +}
>  fn read_backup_index(
>      backup_dir: &BackupDir,
>  ) -> Result<(BackupManifest, Vec<BackupContent>), Error> {