dbcheck: don't remove dangling one-way links on already deleted objects

This would typically happen when the garbage collection
removed a parent object before a child object (both with
the DISALLOW_MOVE_ON_DELETE bit set in systemFlags),
while dbcheck is running at the same time as the garbage collection.
In this case the lastKnownParent attributes points a non existing
object.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13816

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(cherry picked from commit e388e599495b6d7c38b8b6966332e27f8b958783)

diff --git a/python/samba/dbchecker.py b/python/samba/dbchecker.py
index 560ad5485a2f0273a230d095ca2036bc98ee5fd5..a11e76038e55cccc4e998ac4776f862810fd44f8 100644 (file)
--- a/python/samba/dbchecker.py
+++ b/python/samba/dbchecker.py
@@ -544,6 +544,19 @@ newSuperior: %s""" % (str(from_dn), str(to_rdn), str(to_base)))
     def err_missing_target_dn_or_GUID(self, dn, attrname, val, dsdb_dn):
         """handle a missing target DN (if specified, GUID form can't be found,
         and otherwise DN string form can't be found)"""
+
+        # Don't change anything if the object itself is deleted
+        if str(dn).find('\\0ADEL') != -1:
+            # We don't bump the error count as Samba produces these
+            # in normal operation
+            self.report("WARNING: no target object found for GUID "
+                        "component link %s in deleted object "
+                        "%s - %s" % (attrname, dn, val))
+            self.report("Not removing dangling one-way "
+                        "link on deleted object "
+                        "(tombstone garbage collection in progress?)")
+            return 0
+
         # check if its a backlink
         linkID, _ = self.get_attr_linkID_and_reverse_name(attrname)
         if (linkID & 1 == 0) and str(dsdb_dn).find('\\0ADEL') == -1:

diff --git a/selftest/knownfail.d/dbcheck-list-deleted b/selftest/knownfail.d/dbcheck-list-deleted
deleted file mode 100644 (file)
index a8fcb0a..0000000
--- a/selftest/knownfail.d/dbcheck-list-deleted
+++ /dev/null
@@ -1 +0,0 @@
-^samba4.blackbox.dbcheck-links.release-4-5-0-pre1.dbcheck_lost_deleted_user1

diff --git a/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output-lost-deleted-user1.txt b/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output-lost-deleted-user1.txt
index cfc2644b3cbb4472bf546e7ff1b47fbe024400ac..3c55de8fa01ff22a943142136cf983fc515ae3e1 100644 (file)
--- a/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output-lost-deleted-user1.txt
+++ b/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output-lost-deleted-user1.txt
@@ -1,9 +1,6 @@
 Checking 232 objects
-WARNING: no target object found for GUID component for DN value lastKnownParent in object CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp - <GUID=f28216e9-1234-5678-8b2d-6bb229563b62>;OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp
-WARNING: target DN is deleted for lastKnownParent in object CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp - <GUID=f28216e9-1234-5678-8b2d-6bb229563b62>;OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp
-Target GUID points at deleted DN '<GUID=f28216e9-1234-5678-8b2d-6bb229563b62>;OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp'
-Remove stale DN link? [YES]
-Removed deleted DN on attribute lastKnownParent
+WARNING: no target object found for GUID component link lastKnownParent in deleted object CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp - <GUID=f28216e9-1234-5678-8b2d-6bb229563b62>;OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp
+Not removing dangling one-way link on deleted object (tombstone garbage collection in progress?)
 ERROR: wrong dn[CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp] cn='fred\nDEL:2301a64c-1234-5678-851e-12d4a711cfb4' name=b'fred\nDEL:2301a64c-1234-5678-851e-12d4a711cfb4' new_dn[CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,CN=Deleted Objects,DC=release-4-5-0-pre1,DC=samba,DC=corp]
 Rename CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp to CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,CN=Deleted Objects,DC=release-4-5-0-pre1,DC=samba,DC=corp? [YES]
 Renamed CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,OU=removed,DC=release-4-5-0-pre1,DC=samba,DC=corp into CN=fred\0ADEL:2301a64c-1234-5678-851e-12d4a711cfb4,CN=Deleted Objects,DC=release-4-5-0-pre1,DC=samba,DC=corp