Re: [pbs-devel] [PATCH proxmox-backup v3 06/24] api2: admin: add (un)mount endpoint for removable datastores

[Christian Ebner <c.ebner@proxmox.com>]

a few comments inline

On 4/9/24 12:59, Hannes Laimer wrote:
> Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
> ---
>   pbs-api-types/src/datastore.rs   |  12 ++
>   pbs-api-types/src/maintenance.rs |   4 +
>   src/api2/admin/datastore.rs      | 189 +++++++++++++++++++++++++++++--
>   3 files changed, 196 insertions(+), 9 deletions(-)
> 
> diff --git a/pbs-api-types/src/datastore.rs b/pbs-api-types/src/datastore.rs
> index f57957d2..b6d238ed 100644
> --- a/pbs-api-types/src/datastore.rs
> +++ b/pbs-api-types/src/datastore.rs
> @@ -351,6 +351,18 @@ impl DataStoreConfig {
>               .and_then(|str| MaintenanceMode::API_SCHEMA.parse_property_string(str).ok())
>               .and_then(|value| MaintenanceMode::deserialize(value).ok())
>       }
> +
> +    pub fn set_maintenance_mode(&mut self, mode: Option<MaintenanceMode>) {
> +        self.maintenance_mode = mode.and_then(|mode| {
> +            let mut writer = String::new();
> +            mode.serialize(proxmox_schema::ser::PropertyStringSerializer::new(
> +                &mut writer,
> +                &MaintenanceMode::API_SCHEMA,
> +            ))
> +            .ok()?;
> +            Some(writer)
> +        });
> +    }
>   }
>   
>   #[api(
> diff --git a/pbs-api-types/src/maintenance.rs b/pbs-api-types/src/maintenance.rs
> index e7ffbcd0..3868688c 100644
> --- a/pbs-api-types/src/maintenance.rs
> +++ b/pbs-api-types/src/maintenance.rs
> @@ -78,6 +78,10 @@ pub struct MaintenanceMode {
>   }
>   
>   impl MaintenanceMode {
> +    pub fn new(ty: MaintenanceType, message: Option<String>) -> Self {
> +        Self { ty, message }
> +    }
> +
>       /// Used for deciding whether the datastore is cleared from the internal cache after the last
>       /// task finishes, so all open files are closed.
>       pub fn is_offline(&self) -> bool {
> diff --git a/src/api2/admin/datastore.rs b/src/api2/admin/datastore.rs
> index f7164b87..92f6adc2 100644
> --- a/src/api2/admin/datastore.rs
> +++ b/src/api2/admin/datastore.rs
> @@ -26,23 +26,24 @@ use proxmox_sortable_macro::sortable;
>   use proxmox_sys::fs::{
>       file_read_firstline, file_read_optional_string, replace_file, CreateOptions,
>   };
> -use proxmox_sys::{task_log, task_warn};
> +use proxmox_sys::{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};
> @@ -59,6 +60,7 @@ use pbs_datastore::{
>   };
>   use pbs_tools::json::required_string_param;
>   use proxmox_rest_server::{formatter, WorkerTask};
> +use proxmox_section_config::SectionConfigData;
>   
>   use crate::api2::backup::optional_ns_param;
>   use crate::api2::node::rrd::create_value_from_rrd;
> @@ -2240,6 +2242,173 @@ pub async fn set_backup_owner(
>       .await?
>   }
>   
> +pub fn do_mount_device(
> +    _lock: Option<BackupLockGuard>,
> +    mut config: SectionConfigData,
> +    mut datastore: DataStoreConfig,
> +    worker: Option<&dyn WorkerTaskContext>,
> +) -> Result<(), Error> {
> +    if let Some(uuid) = datastore.backing_device.as_ref() {
> +        if pbs_datastore::check_if_available(&datastore).is_ok() {
> +            return Err(format_err!("device '{}' is already mounted", &uuid));
> +        }

use `bail` here and inline the `uuid`:

bail!("device '{uuid}' is already mounted");

> +        let mount_point_path = std::path::Path::new(&datastore.path);
> +        if let Some(worker) = worker {
> +            task_log!(worker, "mounting '{}' to '{}'", uuid, datastore.path);

inline `uuid`

> +        }
> +        crate::tools::disks::mount_by_uuid(uuid, mount_point_path)?;
> +
> +        datastore.set_maintenance_mode(None);
> +        config.set_data(&datastore.name, "datastore", &datastore)?;
> +        pbs_config::datastore::save_config(&config)?;
> +
> +        Ok(())
> +    } else {
> +        Err(format_err!(
> +            "Datastore '{}' can't be mounted because it is not removable.",
> +            &datastore.name

this does not need to be a reference, you can pass in `datastore.name`

> +        ))
> +    }
> +}
> +
> +#[api(
> +    protected: true,
> +    input: {
> +        properties: {
> +            store: {
> +                schema: DATASTORE_SCHEMA,
> +            },
> +        }
> +    },
> +    returns: {
> +        schema: UPID_SCHEMA,
> +    },
> +    access: {
> +        permission: &Permission::Privilege(&["datastore", "{store}"], PRIV_DATASTORE_AUDIT, false),
> +    },
> +)]
> +/// Mount removable datastore.
> +pub fn mount(store: String, rpcenv: &mut dyn RpcEnvironment) -> Result<Value, Error> {
> +    let (section_config, _digest) = pbs_config::datastore::config()?;
> +    let datastore: DataStoreConfig = section_config.lookup("datastore", &store)?;
> +
> +    if datastore.backing_device.is_none() {
> +        bail!("datastore '{}' is not removable", &store);
> +    }
> +
> +    let lock = pbs_config::datastore::lock_config()?;
> +    let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
> +    let to_stdout = rpcenv.env_type() == RpcEnvironmentType::CLI;
> +
> +    let upid = WorkerTask::new_thread(
> +        "mount-device",
> +        Some(store),
> +        auth_id.to_string(),
> +        to_stdout,
> +        move |worker| do_mount_device(Some(lock), section_config, datastore, Some(&worker)),
> +    )?;

What is the motivation for doing this inside a dedicated worker task? Is 
this expected to take a considerable amount of time in some cases?

> +
> +    Ok(json!(upid))
> +}
> +
> +fn do_unmount_device(
> +    force: bool,
> +    datastore: DataStoreConfig,
> +    worker: Option<&dyn WorkerTaskContext>,
> +) -> Result<(), Error> {
> +    if force {
> +        let _ = crate::tools::disks::unmount_by_mountpoint(&datastore.path);
> +        return Ok(());
> +    }
> +
> +    let mut active_operations = task_tracking::get_active_operations(&datastore.name)?;
> +    while active_operations.read + active_operations.write > 0 {
> +        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(())
> +}
> +
> +#[api(
> +    protected: true,
> +    input: {
> +        properties: {
> +            store: { schema: DATASTORE_SCHEMA },
> +            force: {
> +                type: Boolean,
> +                description: "Force unmount even if there are active operations.",
> +                optional: true,
> +                default: false,
> +            },
> +        },
> +    },
> +    returns: {
> +        schema: UPID_SCHEMA,
> +    },
> +    access: {
> +        permission: &Permission::Privilege(&["datastore", "{store}"], PRIV_DATASTORE_MODIFY, true),
> +    }
> +)]
> +/// Unmount a removable device that is associated with the datastore
> +pub async fn unmount(
> +    store: String,
> +    force: bool,
> +    rpcenv: &mut dyn RpcEnvironment,
> +) -> Result<Value, Error> {
> +    let _lock = pbs_config::datastore::lock_config()?;
> +    let (mut section_config, _digest) = pbs_config::datastore::config()?;
> +    let mut datastore: DataStoreConfig = section_config.lookup("datastore", &store)?;
> +
> +    if datastore.backing_device.is_none() {
> +        bail!("datastore '{}' is not removable", &store);
> +    }
> +
> +    let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
> +    let to_stdout = rpcenv.env_type() == RpcEnvironmentType::CLI;
> +
> +    datastore.set_maintenance_mode(Some(MaintenanceMode::new(MaintenanceType::Unplugged, None)));
> +    section_config.set_data(&datastore.name, "datastore", &datastore)?;
> +    pbs_config::datastore::save_config(&section_config)?;
> +    drop(_lock);
> +
> +    if let Ok(proxy_pid) = proxmox_rest_server::read_pid(pbs_buildcfg::PROXMOX_BACKUP_PROXY_PID_FN)
> +    {
> +        let sock = proxmox_rest_server::ctrl_sock_from_pid(proxy_pid);
> +        let _ = proxmox_rest_server::send_raw_command(
> +            sock,
> +            &format!(
> +                "{{\"command\":\"update-datastore-cache\",\"args\":\"{}\"}}\n",
> +                &store

`store` can be inlined as well here, also no need for taking it by reference

> +            ),
> +        )
> +        .await;
> +    }
> +
> +    let upid = WorkerTask::new_thread(
> +        "unmount-device",
> +        Some(store),
> +        auth_id.to_string(),
> +        to_stdout,
> +        move |worker| do_unmount_device(force, datastore, Some(&worker)),
> +    )?;
> +
> +    Ok(json!(upid))
> +}
> +
>   #[sortable]
>   const DATASTORE_INFO_SUBDIRS: SubdirMap = &[
>       (
> @@ -2278,6 +2447,7 @@ const DATASTORE_INFO_SUBDIRS: SubdirMap = &[
>               .get(&API_METHOD_LIST_GROUPS)
>               .delete(&API_METHOD_DELETE_GROUP),
>       ),
> +    ("mount", &Router::new().post(&API_METHOD_MOUNT)),
>       (
>           "namespace",
>           // FIXME: move into datastore:: sub-module?!
> @@ -2312,6 +2482,7 @@ const DATASTORE_INFO_SUBDIRS: SubdirMap = &[
>               .delete(&API_METHOD_DELETE_SNAPSHOT),
>       ),
>       ("status", &Router::new().get(&API_METHOD_STATUS)),
> +    ("unmount", &Router::new().post(&API_METHOD_UNMOUNT)),
>       (
>           "upload-backup-log",
>           &Router::new().upload(&API_METHOD_UPLOAD_BACKUP_LOG),