Apply disk exclusions and idle policy to automatic LVM scans

AppImage/scripts/lvm_device_scope.py

@@ -0,0 +1,63 @@
+# ==========================================================
+# ProxMenux Monitor - LVM disk read scope
+# Author      : Jonatan
+# GitHub      : github.com/jcastro
+# Maintainer  : MacRimi
+# Copyright   : (c) 2026 MacRimi & contributors
+# License     : (GPL-3.0) (https://github.com/MacRimi/ProxMenux/blob/main/LICENSE)
+# Version     : 1.0
+# Last Updated: 16/10/2026
+# ==========================================================
+# Description:
+# Applies the automatic disk-read policy to LVM metadata scans in both
+# Monitor readers. Excluded and idle disks receive no power-mode probe;
+# their partitions are excluded too. No eligible devices means no scan.
+# ==========================================================
+
+import re
+import subprocess
+
+
+def lvm_device_args(standby_check):
+    """Return [] for an unrestricted scan, --devices args, or None to skip.
+
+    A failed inventory must never fall back to an unrestricted scan. None
+    is distinct from []: if every disk is excluded/idle/asleep, callers
+    must not start pvs/lvs/vgs at all.
+    """
+    try:
+        from disk_temperature_history import disk_read_policy, excluded_disk_names
+        result = subprocess.run(["lsblk", "-rno", "NAME,TYPE,PKNAME"],
+                                capture_output=True, text=True, timeout=5)
+        if result.returncode:
+            return None
+        nodes = []
+        for line in result.stdout.splitlines():
+            parts = line.split()
+            if len(parts) < 2 or parts[1] not in ("disk", "part"):
+                continue
+            name = parts[0]
+            base = name if parts[1] == "disk" else parts[2] if len(parts) > 2 else ""
+            if not re.fullmatch(r"[A-Za-z0-9._+-]+", name) or not re.fullmatch(r"[A-Za-z0-9._+-]+", base):
+                return None
+            nodes.append((name, base))
+        disks = {name for name, base in nodes if name == base}
+        if not disks or any(base not in disks for _, base in nodes):
+            return None
+        excluded = excluded_disk_names()
+        blocked = set()
+        for disk in sorted(disks):
+            # Test policy first: even CHECK POWER MODE is forbidden for an
+            # excluded/idle disk. Some USB bridges do not honour -n standby.
+            if disk_read_policy(disk, excluded) != "read" or standby_check(disk):
+                blocked.add(disk)
+        if not blocked:
+            return []
+        devices = [f"/dev/{name}" for name, base in nodes if base not in blocked]
+        if not devices:
+            return None
+        return ["--devices", ",".join(dict.fromkeys(devices))]
+    except Exception:
+        # Unavailable exclusions, topology or policy are not permission to
+        # open devices that may have been deliberately excluded.
+        return None