Re: [pbs-devel] [PATCH proxmox-backup v4 06/22] api2: admin: add (un)mount endpoint for removable datastores

["Hannes Laimer" <h.laimer@proxmox.com>]

On Wed Apr 17, 2024 at 10:08 AM CEST, Christian Ebner wrote:
> some comments inline
>
> On 4/16/24 17:24, Hannes Laimer wrote:
> > Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
> > ---
> >   pbs-api-types/src/maintenance.rs |   4 +
> >   src/api2/admin/datastore.rs      | 175 +++++++++++++++++++++++++++++--
> >   2 files changed, 171 insertions(+), 8 deletions(-)
> > 
> > diff --git a/pbs-api-types/src/maintenance.rs b/pbs-api-types/src/maintenance.rs
> > index a605cc17..56d6bcb5 100644
> > --- a/pbs-api-types/src/maintenance.rs
> > +++ b/pbs-api-types/src/maintenance.rs
> > @@ -77,6 +77,10 @@ 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 35628c59..57167a82 100644
> > --- a/src/api2/admin/datastore.rs
> > +++ b/src/api2/admin/datastore.rs
> > @@ -26,20 +26,20 @@ 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, 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;
> > @@ -2278,6 +2278,163 @@ pub async fn set_backup_owner(
> >       .await?
> >   }
> >   
> > +pub fn do_mount_device(
> > +    datastore: DataStoreConfig,
> > +    worker: Option<&dyn WorkerTaskContext>,
> > +) -> Result<(), Error> {
> > +    if let Some(uuid) = datastore.backing_device.as_ref() {
> > +        if pbs_datastore::is_datastore_available(&datastore) {
> > +            bail!("device '{uuid}' is already mounted");
>
> this...
>

this also happens when creating a datastore, so creating one would fail
with mentioning a store that doesn't exist, which might be a little
weird. but no hard feelings 

> > +        }
> > +        let mount_point_path = std::path::Path::new(&datastore.path);
> > +        if let Some(worker) = worker {
> > +            task_log!(worker, "mounting '{uuid}' to '{}'", datastore.path);
>
> ... and this might include also the datastore name in the message,
> so it is easier to relate them to the store as just by the `uuid`.
> Something like:
> `... '{uuid}' for store '{store_name}' to '{store_path}' ...`
>

here it would make a lot of easier

> > +        }
> > +        crate::tools::disks::mount_by_uuid(uuid, mount_point_path)?;
> > +
> > +        Ok(())
> > +    } else {
> > +        Err(format_err!(
> > +            "Datastore '{}' can't be mounted because it is not removable.",
>
> s/can't/cannot
>
> > +            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);
>
> store can be inlined and does not need to be taken by reference here
>
> > +    }
> > +
> > +    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(datastore, Some(&worker)),
> > +    )?;
> > +
> > +    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)?;
> > +    let mut counter = 0;
> > +    while active_operations.read + active_operations.write > 0 {
> > +        if counter == 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",
>
> s/can't/cannot
>
> > +                    active_operations.read,
> > +                    active_operations.write
> > +                );
> > +            }
> > +            counter = 5000;
> > +        }
> > +        counter -= 1;
> > +        std::thread::sleep(std::time::Duration::from_millis(1));
> > +        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 (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);
> > +    }
> > +    drop(_lock);
> > +
> > +    let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
> > +    let to_stdout = rpcenv.env_type() == RpcEnvironmentType::CLI;
> > +
> > +    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\":\"{store}\"}}\n"),
> > +        )
> > +        .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 = &[
> >       (
> > @@ -2316,6 +2473,7 @@ 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?!
> > @@ -2350,6 +2508,7 @@ 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),