fix(ns-api): find storage by mount point

The local storage is identified by a names section
`ns_data`.

On upgrade, the fstab UCI config is rewritten:
existing sections are preserved but all names are deleted.

This prevent to correctly display the configured storage
inside the UI.

packages/ns-api/files/ns.storage

@@ -20,6 +20,12 @@ def run(cmd):
     except:
         return utils.generic_error("command_failed")
 
+def get_storage_info(u):
+    for section in utils.get_all_by_type(u, 'fstab', 'mount'):
+        if u.get('fstab', section, 'target', default='') == '/mnt/data':
+            return u.get_all('fstab', section)
+    return None
+
 def list_devices():
     devices = []
     p = subprocess.run(["/usr/bin/lsblk", "--json", "-b", "--output-all"], check=True, capture_output=True, text=True)
@@ -63,7 +69,7 @@ def get_configuration():
 
     ret = {"name": None, "size": None, "path": None, "model": None, "vendor": None}
     try:
-        info = u.get_all("fstab", "ns_data")
+        info = get_storage_info(u)
         p = subprocess.run(["/usr/bin/lsblk", "--json", "-b", "--output-all"], check=True, capture_output=True, text=True)
         data = json.loads(p.stdout)
         cur = None