setup: properly detect is_chroot on Btrfs (#55089)

* setup: properly detect is_chroot on Btrfs

Fixes #55006

* Use get_bin_path for stat

* Remove comment

changelogs/fragments/55006-setup-is_chroot-btrfs.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - setup - properly detect is_chroot on Btrfs (https://github.com/ansible/ansible/issues/55006)

lib/ansible/module_utils/facts/system/chroot.py

@@ -8,7 +8,7 @@ import os
 from ansible.module_utils.facts.collector import BaseFactCollector
 
 
-def is_chroot():
+def is_chroot(module=None):
 
     is_chroot = None
 
@@ -22,7 +22,17 @@ def is_chroot():
             is_chroot = my_root.st_ino != proc_root.st_ino or my_root.st_dev != proc_root.st_dev
         except Exception:
             # I'm not root or no proc, fallback to checking it is inode #2
-            is_chroot = (my_root.st_ino != 2)
+            fs_root_ino = 2
+
+            if module is not None:
+                stat_path = module.get_bin_path('stat')
+                if stat_path:
+                    cmd = [stat_path, '-f', '--format=%T', '/']
+                    rc, out, err = module.run_command(cmd)
+                    if 'btrfs' in out:
+                        fs_root_ino = 256
+
+            is_chroot = (my_root.st_ino != fs_root_ino)
 
     return is_chroot
 
@@ -32,4 +42,4 @@ class ChrootFactCollector(BaseFactCollector):
     _fact_ids = set(['is_chroot'])
 
     def collect(self, module=None, collected_facts=None):
-        return {'is_chroot': is_chroot()}
+        return {'is_chroot': is_chroot(module)}

lib/ansible/modules/system/systemd.py

@@ -508,7 +508,7 @@ def main():
                         if rc != 0:
                             module.fail_json(msg="Unable to %s service %s: %s" % (action, unit, err))
             # check for chroot
-            elif is_chroot():
+            elif is_chroot(module):
                 module.warn("Target is a chroot. This can lead to false positives or prevent the init system tools from working.")
             else:
                 # this should not happen?