Re: [pbs-devel] [PATCH proxmox-backup v3 07/24] api2: removable datastore creation

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

On Mon Apr 15, 2024 at 6:02 PM CEST, Christian Ebner wrote:
> On 4/9/24 12:59, Hannes Laimer wrote:
> > Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
> > ---
> >   src/api2/config/datastore.rs | 52 ++++++++++++++++++++++++++++++++++--
> >   1 file changed, 50 insertions(+), 2 deletions(-)
> > 
> > diff --git a/src/api2/config/datastore.rs b/src/api2/config/datastore.rs
> > index 3081e1f4..0194d7d4 100644
> > --- a/src/api2/config/datastore.rs
> > +++ b/src/api2/config/datastore.rs
> > @@ -8,7 +8,7 @@ use serde_json::Value;
> >   use proxmox_router::{http_bail, Permission, Router, RpcEnvironment, RpcEnvironmentType};
> >   use proxmox_schema::{api, param_bail, ApiType};
> >   use proxmox_section_config::SectionConfigData;
> > -use proxmox_sys::{task_warn, WorkerTaskContext};
> > +use proxmox_sys::{task_log, task_warn, WorkerTaskContext};
> >   use proxmox_uuid::Uuid;
> >   
> >   use pbs_api_types::{
> > @@ -20,7 +20,8 @@ use pbs_config::BackupLockGuard;
> >   use pbs_datastore::chunk_store::ChunkStore;
> >   
> >   use crate::api2::admin::{
> > -    prune::list_prune_jobs, sync::list_sync_jobs, verify::list_verification_jobs,
> > +    datastore::do_mount_device, prune::list_prune_jobs, sync::list_sync_jobs,
> > +    verify::list_verification_jobs,
> >   };
> >   use crate::api2::config::prune::{delete_prune_job, do_create_prune_job};
> >   use crate::api2::config::sync::delete_sync_job;
> > @@ -72,6 +73,31 @@ pub(crate) fn do_create_datastore(
> >       datastore: DataStoreConfig,
> >       worker: Option<&dyn WorkerTaskContext>,
> >   ) -> Result<(), Error> {
> > +    if datastore.backing_device.is_some() {
> > +        let mut mount_point: PathBuf = PathBuf::from(&datastore.path);
>
> There is no need for the additional type annotation, the type is already 
> given by the return type of the `PathBuf::from()`.
>
> > +
> > +        let default_options = proxmox_sys::fs::CreateOptions::new();
> > +        proxmox_sys::fs::create_path(
> > +            &mount_point,
> > +            Some(default_options.clone()),
> > +            Some(default_options),
> > +        )?;
> > +        do_mount_device(None, config.clone(), datastore.clone(), worker)?;
> > +
> > +        mount_point.push(".chunks");
> > +        if mount_point.is_dir() {
> > +            config.set_data(&datastore.name, "datastore", &datastore)?;
> > +            pbs_config::datastore::save_config(&config)?;
> > +            if let Some(worker) = worker {
> > +                task_log!(
> > +                    worker,
> > +                    "created removable datastore, chunkstore already exists"
> > +                );
> > +                return Ok(());
> > +            }
> > +        }
>
> If `.chunks` already exists on the mounted datastore, but it is not a 
> directory, then I guess something is off. Can and should this be handled 
> early, or is this already fully covered by the `ChunkStore::create` call 
> later on?
>

ChunkStore::create will fail in that case

> > +    }
> > +
> >       let path: PathBuf = datastore.path.clone().into();
> >   
> >       let tuning: DatastoreTuning = serde_json::from_value(
> > @@ -122,6 +148,28 @@ pub fn create_datastore(
> >           param_bail!("name", "datastore '{}' already exists.", config.name);
> >       }
> >   
> > +    if let Some(uuid) = &config.backing_device {
> > +        let already_used_by = section_config
> > +            .sections
> > +            .iter()
> > +            .flat_map(|(datastore_name, (_, config))| {
> > +                config
> > +                    .as_object()
> > +                    .and_then(|cfg| cfg.get("backing-device"))
> > +                    .and_then(|backing_device| backing_device.as_str())
> > +                    .filter(|&device_uuid| device_uuid == uuid)
> > +                    .map(|_| datastore_name)
> > +            })
> > +            .next();
> > +
> > +        if let Some(datastore_name) = already_used_by {
> > +            param_bail!(
> > +                "backing-device",
> > +                "device already in use by datastore '{datastore_name}'",
> > +            );
> > +        }
> > +    }
> > +
> >       let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
> >       let to_stdout = rpcenv.env_type() == RpcEnvironmentType::CLI;
> >