Delete last snapshot in group fails with Directory not empty (os error 39)

[maximmonin]

We recently upgraded pbs server from 3.2 version to 3.4
Installation: PBS version 3.4.1-1.
api call: delete snapshot:

curl -s -k -X DELETE "$PBS1_PROXMOX_URL/admin/datastore/storage/snapshots?ns=vm&backup-type=host&backup-id=H-162523-5f8d6fbf-bc36-4071-94a1-64ab1d06cc9b&backup-time=1746625495" \
-H "Authorization: PBSAPIToken=$PBS1_PROXMOX_TOKEN:$PBS1_PROXMOX_SECRET"

ls -la /storage/ns/vm/host/H-162523-5f8d6fbf-bc36-4071-94a1-64ab1d06cc9b
drwxr-xr-x 2 backup backup 4096 May  7 16:45 2025-05-07T13:44:55Z
-rw-r--r-- 1 backup backup   58 May  7 16:45 notes
-rw-r--r-- 1 backup backup   20 May  7 16:33 owner

Description: If the group notes files exist - the API call deletes the snapshot/"owner" file and tries to delete the groups directory, but fails with a non-empty directory error.

removing group directory "/storage/ns/vm/host/H-162523-5f8d6fbf-bc36-4071-94a1-64ab1d06cc9b" failed - Directory not empty (os error 39)

If I manually delete the "notes" file for the snapshot group, the API call succeeds.

Api call works ok with "notes" file with pbs version 3.2.14-1, but fails with versions 3.3.7-1, 3.4.1-1.

 

[Neobin]

For reference:
https://bugzilla.proxmox.com/show_bug.cgi?id=6358

 

[maximmonin]

More notes
Version 3.2.14 - did not try to delete the group directory - after api call directory existed with notes and owner files in it and snapshot delete worked ok.