[pbs-devel] [PATCH proxmox-backup v12 07/26] api: admin: add (un)mount endpoint for removable datastores

Hannes Laimer h.laimer at proxmox.com
Wed Sep 4 16:11:36 CEST 2024


Signed-off-by: Hannes Laimer <h.laimer at proxmox.com>
---
 pbs-api-types/src/maintenance.rs |   4 +
 src/api2/admin/datastore.rs      | 243 +++++++++++++++++++++++++++++--
 2 files changed, 237 insertions(+), 10 deletions(-)

diff --git a/pbs-api-types/src/maintenance.rs b/pbs-api-types/src/maintenance.rs
index 9f51292e..60181258 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 976617d9..3c95888d 100644
--- a/src/api2/admin/datastore.rs
+++ b/src/api2/admin/datastore.rs
@@ -3,7 +3,7 @@
 use std::collections::HashSet;
 use std::ffi::OsStr;
 use std::os::unix::ffi::OsStrExt;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use anyhow::{bail, format_err, Error};
@@ -13,7 +13,7 @@ use hyper::{header, Body, Response, StatusCode};
 use serde::Deserialize;
 use serde_json::{json, Value};
 use tokio_stream::wrappers::ReceiverStream;
-use tracing::{info, warn};
+use tracing::{debug, info, warn};
 
 use proxmox_async::blocking::WrappedReaderStream;
 use proxmox_async::{io::AsyncChannelWriter, stream::AsyncReaderStream};
@@ -29,6 +29,7 @@ use proxmox_sys::fs::{
     file_read_firstline, file_read_optional_string, replace_file, CreateOptions,
 };
 use proxmox_time::CalendarEvent;
+use proxmox_worker_task::WorkerTaskContext;
 
 use pxar::accessor::aio::Accessor;
 use pxar::EntryKind;
@@ -36,12 +37,12 @@ use pxar::EntryKind;
 use pbs_api_types::{
     print_ns_and_snapshot, print_store_and_ns, Authid, BackupContent, BackupNamespace, BackupType,
     Counts, CryptMode, DataStoreConfig, DataStoreListItem, DataStoreStatus,
-    GarbageCollectionJobStatus, GroupListItem, JobScheduleStatus, KeepOptions, Operation,
-    PruneJobOptions, 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, UPID_SCHEMA,
+    GarbageCollectionJobStatus, GroupListItem, JobScheduleStatus, KeepOptions, MaintenanceMode,
+    MaintenanceType, Operation, PruneJobOptions, 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, UPID_SCHEMA,
     VERIFICATION_OUTDATED_AFTER_SCHEMA,
 };
 use pbs_client::pxar::{create_tar, create_zip};
@@ -57,8 +58,8 @@ use pbs_datastore::index::IndexFile;
 use pbs_datastore::manifest::{BackupManifest, CLIENT_LOG_BLOB_NAME, MANIFEST_BLOB_NAME};
 use pbs_datastore::prune::compute_prune_info;
 use pbs_datastore::{
-    check_backup_owner, task_tracking, BackupDir, BackupGroup, DataStore, LocalChunkReader,
-    StoreProgress, CATALOG_NAME,
+    check_backup_owner, is_datastore_available, task_tracking, BackupDir, BackupGroup, DataStore,
+    LocalChunkReader, StoreProgress, CATALOG_NAME,
 };
 use pbs_tools::json::required_string_param;
 use proxmox_rest_server::{formatter, WorkerTask};
@@ -2384,6 +2385,226 @@ pub async fn set_backup_owner(
     .await?
 }
 
+/// Here we
+///
+/// 1. mount the removable device to `<PBS_RUN_DIR>/mount/<RANDOM_UUID>`
+/// 2. bind mount `<PBS_RUN_DIR>/mount/<RANDOM_UUID>/<datastore.path>` to `/mnt/datastore/<datastore.name>`
+/// 3. unmount `<PBS_RUN_DIR>/mount/<RANDOM_UUID>`
+///
+/// leaving us with the datastore being mounted directly with its name under /mnt/datastore/...
+///
+/// The reason for the randomized device mounting paths is to avoid two tasks trying to mount to
+/// the same path, this is *very* unlikely since the device is only mounted really shortly, but
+/// technically possible.
+pub fn do_mount_device(datastore: DataStoreConfig) -> Result<(), Error> {
+    if let (Some(uuid), Some(mount_point)) = (
+        datastore.backing_device.as_ref(),
+        datastore.get_mount_point(),
+    ) {
+        if pbs_datastore::is_datastore_available(&datastore) {
+            bail!("datastore '{}' is already mounted", datastore.name);
+        }
+        let tmp_mount_path = format!(
+            "{}/{:x}",
+            pbs_buildcfg::rundir!("/mount"),
+            proxmox_uuid::Uuid::generate()
+        );
+
+        let default_options = proxmox_sys::fs::CreateOptions::new();
+        proxmox_sys::fs::create_path(
+            &tmp_mount_path,
+            Some(default_options.clone()),
+            Some(default_options.clone()),
+        )?;
+
+        debug!("mounting '{uuid}' to '{}'", tmp_mount_path);
+        crate::tools::disks::mount_by_uuid(uuid, Path::new(&tmp_mount_path))?;
+
+        let full_store_path = format!(
+            "{tmp_mount_path}/{}",
+            datastore.path.trim_start_matches('/')
+        );
+
+        proxmox_sys::fs::create_path(
+            &mount_point,
+            Some(default_options.clone()),
+            Some(default_options.clone()),
+        )?;
+
+        // can't be created before it is mounted, so we have to do it here
+        proxmox_sys::fs::create_path(
+            &full_store_path,
+            Some(default_options.clone()),
+            Some(default_options.clone()),
+        )?;
+
+        info!(
+            "mounting '{}'({}) to '{}'",
+            datastore.name, datastore.path, mount_point
+        );
+        if let Err(err) =
+            crate::tools::disks::bind_mount(Path::new(&full_store_path), Path::new(&mount_point))
+        {
+            debug!("unmounting '{}'", tmp_mount_path);
+            let _ = crate::tools::disks::unmount_by_mountpoint(&tmp_mount_path);
+            let _ = std::fs::remove_dir(std::path::Path::new(&tmp_mount_path));
+            return Err(format_err!(
+                "Datastore '{}' cound not be mounted: {}.",
+                datastore.name,
+                err
+            ));
+        }
+
+        debug!("unmounting '{}'", tmp_mount_path);
+        crate::tools::disks::unmount_by_mountpoint(&tmp_mount_path)?;
+        std::fs::remove_dir(std::path::Path::new(&tmp_mount_path))?;
+
+        Ok(())
+    } else {
+        Err(format_err!(
+            "Datastore '{}' cannot be mounted because it is not removable.",
+            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 '{store}' is not removable");
+    }
+
+    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),
+    )?;
+
+    Ok(json!(upid))
+}
+
+fn do_unmount_device(
+    datastore: DataStoreConfig,
+    worker: Option<&dyn WorkerTaskContext>,
+) -> Result<(), Error> {
+    let mut active_operations = task_tracking::get_active_operations(&datastore.name)?;
+    let mut old_status = String::new();
+    while active_operations.read + active_operations.write > 0 {
+        if let Some(worker) = worker {
+            if worker.abort_requested() {
+                bail!("aborted, due to user request");
+            }
+            let status = format!(
+                "cannot unmount yet, still {} read and {} write operations active",
+                active_operations.read, active_operations.write
+            );
+            if status != old_status {
+                info!("{status}");
+                old_status = status;
+            }
+        }
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        active_operations = task_tracking::get_active_operations(&datastore.name)?;
+    }
+    if let Some(mount_point) = datastore.get_mount_point() {
+        crate::tools::disks::unmount_by_mountpoint(&mount_point)?;
+
+        let _lock = pbs_config::datastore::lock_config()?;
+        let (mut section_config, _digest) = pbs_config::datastore::config()?;
+        let mut store_config: DataStoreConfig =
+            section_config.lookup("datastore", &datastore.name)?;
+        store_config.maintenance_mode = None;
+        section_config.set_data(&datastore.name, "datastore", &store_config)?;
+        pbs_config::datastore::save_config(&section_config)?;
+    }
+    Ok(())
+}
+
+#[api(
+    protected: true,
+    input: {
+        properties: {
+            store: { schema: DATASTORE_SCHEMA },
+        },
+    },
+    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, 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 '{store}' is not removable");
+    }
+
+    if !is_datastore_available(&datastore) {
+        bail!("datastore '{store}' is not mounted");
+    }
+
+    datastore.set_maintenance_mode(Some(MaintenanceMode::new(MaintenanceType::Unmount, None)))?;
+    section_config.set_data(&store, "datastore", &datastore)?;
+    pbs_config::datastore::save_config(&section_config)?;
+
+    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_daemon::command_socket::path_from_pid(proxy_pid);
+        let _ = proxmox_daemon::command_socket::send_raw(
+            sock,
+            &format!(
+                "{{\"command\":\"update-datastore-cache\",\"args\":\"{}\"}}\n",
+                &store
+            ),
+        )
+        .await;
+    }
+
+    let upid = WorkerTask::new_thread(
+        "unmount-device",
+        Some(store),
+        auth_id.to_string(),
+        to_stdout,
+        move |worker| do_unmount_device(datastore, Some(&worker)),
+    )?;
+
+    Ok(json!(upid))
+}
+
 #[sortable]
 const DATASTORE_INFO_SUBDIRS: SubdirMap = &[
     (
@@ -2422,6 +2643,7 @@ 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?!
@@ -2456,6 +2678,7 @@ 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),
-- 
2.39.2





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