namespaces: move max-depth check to api type

and use it when creating a sync job, and simplify the check on updating
(only check the final, resulting config instead of each intermediate
version).

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

pbs-api-types/src/datastore.rs

@@ -719,6 +719,17 @@ impl BackupNamespace {
         }
         Ok(new)
     }
+
+    /// Check whether adding `depth` levels of sub-namespaces exceeds the max depth limit
+    pub fn check_max_depth(&self, depth: usize) -> Result<(), Error> {
+        let ns_depth = self.depth();
+        if ns_depth + depth > MAX_NAMESPACE_DEPTH {
+            bail!(
+                "namespace '{self}'s depth and recursion depth exceed limit: {ns_depth} + {depth} > {MAX_NAMESPACE_DEPTH}",
+            );
+        }
+        Ok(())
+    }
 }
 
 impl fmt::Display for BackupNamespace {

src/api2/config/sync.rs

@@ -1,8 +1,6 @@
 use ::serde::{Deserialize, Serialize};
 use anyhow::{bail, Error};
 use hex::FromHex;
-use pbs_api_types::BackupNamespace;
-use pbs_api_types::MAX_NAMESPACE_DEPTH;
 use serde_json::Value;
 
 use proxmox_router::{http_bail, Permission, Router, RpcEnvironment};
@@ -147,6 +145,15 @@ pub fn create_sync_job(
         bail!("permission check failed");
     }
 
+    if let Some(max_depth) = config.max_depth {
+        if let Some(ref ns) = config.ns {
+            ns.check_max_depth(max_depth)?;
+        }
+        if let Some(ref ns) = config.remote_ns {
+            ns.check_max_depth(max_depth)?;
+        }
+    }
+
     let (mut section_config, _digest) = sync::config()?;
 
     if section_config.sections.get(&config.id).is_some() {
@@ -321,18 +328,6 @@ pub fn update_sync_job(
         }
     }
 
-    let check_max_depth = |ns: &BackupNamespace, depth| -> Result<(), Error> {
-        if ns.depth() + depth >= MAX_NAMESPACE_DEPTH {
-            bail!(
-                "namespace and recursion depth exceed limit: {} + {} >= {}",
-                ns.depth(),
-                depth,
-                MAX_NAMESPACE_DEPTH
-            );
-        }
-        Ok(())
-    };
-
     if let Some(comment) = update.comment {
         let comment = comment.trim().to_string();
         if comment.is_empty() {
@@ -346,9 +341,6 @@ pub fn update_sync_job(
         data.store = store;
     }
     if let Some(ns) = update.ns {
-        if let Some(explicit_depth) = update.max_depth.or(data.max_depth) {
-            check_max_depth(&ns, explicit_depth)?;
-        }
         data.ns = Some(ns);
     }
     if let Some(remote) = update.remote {
@@ -358,9 +350,6 @@ pub fn update_sync_job(
         data.remote_store = remote_store;
     }
     if let Some(remote_ns) = update.remote_ns {
-        if let Some(explicit_depth) = update.max_depth.or(data.max_depth) {
-            check_max_depth(&remote_ns, explicit_depth)?;
-        }
         data.remote_ns = Some(remote_ns);
     }
     if let Some(owner) = update.owner {
@@ -394,13 +383,16 @@ pub fn update_sync_job(
         data.remove_vanished = update.remove_vanished;
     }
     if let Some(max_depth) = update.max_depth {
+        data.max_depth = Some(max_depth);
+    }
+
+    if let Some(max_depth) = data.max_depth {
         if let Some(ref ns) = data.ns {
-            check_max_depth(ns, max_depth)?;
+            ns.check_max_depth(max_depth)?;
         }
         if let Some(ref ns) = data.remote_ns {
-            check_max_depth(ns, max_depth)?;
+            ns.check_max_depth(max_depth)?;
         }
-        data.max_depth = Some(max_depth);
     }
 
     if !check_sync_job_modify_access(&user_info, &auth_id, &data) {

src/server/pull.rs

@@ -1,6 +1,5 @@
 //! Sync datastore from remote server
 
-use std::cmp::min;
 use std::collections::{HashMap, HashSet};
 use std::convert::TryFrom;
 use std::io::{Seek, SeekFrom};
@@ -18,8 +17,8 @@ use proxmox_sys::task_log;
 
 use pbs_api_types::{
     Authid, BackupNamespace, DatastoreWithNamespace, GroupFilter, GroupListItem, NamespaceListItem,
-    Operation, RateLimitConfig, Remote, SnapshotListItem, MAX_NAMESPACE_DEPTH,
-    PRIV_DATASTORE_AUDIT, PRIV_DATASTORE_BACKUP, PRIV_DATASTORE_MODIFY,
+    Operation, RateLimitConfig, Remote, SnapshotListItem, PRIV_DATASTORE_AUDIT,
+    PRIV_DATASTORE_BACKUP, PRIV_DATASTORE_MODIFY,
 };
 
 use pbs_client::{
@@ -81,8 +80,10 @@ impl PullParameters {
     ) -> Result<Self, Error> {
         let store = DataStore::lookup_datastore(store, Some(Operation::Write))?;
 
-        let max_depth =
-            max_depth.map(|max_depth| min(max_depth, MAX_NAMESPACE_DEPTH - remote_ns.depth()));
+        if let Some(max_depth) = max_depth {
+            ns.check_max_depth(max_depth)?;
+            remote_ns.check_max_depth(max_depth)?;
+        }
 
         let (remote_config, _digest) = pbs_config::remote::config()?;
         let remote: Remote = remote_config.lookup("remote", remote)?;