[pbs-devel] [PATCH proxmox-backup 2/2] api: disks: directory: fail if mount unit already exists

[Fiona Ebner]

Without this check, if a mount unit is present, but the file system is
not mounted, it will just get overwritten. The unit might belong to an
existing datastore.

There already is a check against a duplicate datastore, but only after
the mount unit is already overwritten and having the add-datastore
flag present is not a precondition to trigger the issue.

The check is done even if the newly created directory datastore is
removable. While in that case, the mount unit is not overwritten, the
conflict for the mount point is still present, so it is nice to fail
early.

Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---
 src/api2/node/disks/directory.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/api2/node/disks/directory.rs b/src/api2/node/disks/directory.rs
index 7bdf0111..d4690d45 100644
--- a/src/api2/node/disks/directory.rs
+++ b/src/api2/node/disks/directory.rs
@@ -204,6 +204,11 @@ pub fn create_datastore_disk(
         }
     }
 
+    let (mount_unit_path, _) = datastore_mount_unit_path_info(&mount_point);
+    if std::path::PathBuf::from(&mount_unit_path).exists() {
+        bail!("systemd mount unit {mount_unit_path:?} already exists");
+    }
+
     let upid_str = WorkerTask::new_thread(
         "dircreate",
         Some(name.clone()),
-- 
2.39.5