dbcheck: add support for restoring missing forward links

This recovers broken databases with duplicate and missing
forward links.

See commit a25c99c9f1fd1814c56c21848c748cd0e038eed7 for
the fix that prevents to problem from happening.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13228

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>

diff --git a/python/samba/dbchecker.py b/python/samba/dbchecker.py
index 8d8a193a7fa63e26b60c66808fee0a716e7d152f..c2c95a2e8593855b3d8f2abe3a4d3d2a924cf4f8 100644 (file)
--- a/python/samba/dbchecker.py
+++ b/python/samba/dbchecker.py
@@ -65,6 +65,7 @@ class dbcheck(object):
         self.fix_undead_linked_attributes = False
         self.fix_all_missing_backlinks = False
         self.fix_all_orphaned_backlinks = False
+        self.fix_all_missing_forward_links = False
         self.duplicate_link_cache = dict()
         self.recover_all_forward_links = False
         self.fix_rmd_flags = False
@@ -710,8 +711,14 @@ newSuperior: %s""" % (str(from_dn), str(to_rdn), str(to_base)))
             self.report("Fixed incorrect RMD_FLAGS %u" % (rmd_flags))
 
     def err_orphaned_backlink(self, obj_dn, backlink_attr, backlink_val,
-                              target_dn, forward_attr, forward_syntax):
+                              target_dn, forward_attr, forward_syntax,
+                              check_duplicates=True):
         '''handle a orphaned backlink value'''
+        if check_duplicates is True and self.has_duplicate_links(target_dn, forward_attr, forward_syntax):
+            self.report("WARNING: Keep orphaned backlink attribute " + \
+                        "'%s' in '%s' for link '%s' in '%s'" % (
+                        backlink_attr, obj_dn, forward_attr, target_dn))
+            return
         self.report("ERROR: orphaned backlink attribute '%s' in %s for link %s in %s" % (backlink_attr, obj_dn, forward_attr, target_dn))
         if not self.confirm_all('Remove orphaned backlink %s' % backlink_attr, 'fix_all_orphaned_backlinks'):
             self.report("Not removing orphaned backlink %s" % backlink_attr)
@@ -726,10 +733,10 @@ newSuperior: %s""" % (str(from_dn), str(to_rdn), str(to_base)))
     def err_recover_forward_links(self, obj, forward_attr, forward_vals):
         '''handle a duplicate links value'''
 
-        self.report("RECHECK: 'Duplicate/Correct link' lines above for attribute '%s' in '%s'" % (forward_attr, obj.dn))
+        self.report("RECHECK: 'Missing/Duplicate/Correct link' lines above for attribute '%s' in '%s'" % (forward_attr, obj.dn))
 
-        if not self.confirm_all("Commit fixes for (duplicate) forward links in attribute '%s'" % forward_attr, 'recover_all_forward_links'):
-            self.report("Not fixing corrupted (duplicate) forward links in attribute '%s' of '%s'" % (
+        if not self.confirm_all("Commit fixes for (missing/duplicate) forward links in attribute '%s'" % forward_attr, 'recover_all_forward_links'):
+            self.report("Not fixing corrupted (missing/duplicate) forward links in attribute '%s' of '%s'" % (
                         forward_attr, obj.dn))
             return
         m = ldb.Message()
@@ -1098,7 +1105,31 @@ newSuperior: %s""" % (str(from_dn), str(to_rdn), str(to_base)))
             self.check_duplicate_links(obj, attrname, syntax_oid, linkID, reverse_link_name)
 
         if len(duplicate_dict) != 0:
-            self.report("ERROR: Duplicate forward link values for attribute '%s' in '%s'" % (attrname, obj.dn))
+
+            missing_forward_links, missing_error_count = \
+                self.find_missing_forward_links_from_backlinks(obj,
+                                                         attrname, syntax_oid,
+                                                         reverse_link_name,
+                                                         unique_dict)
+            error_count += missing_error_count
+
+            forward_links = [dn for dn in unique_dict.values()]
+
+            if missing_error_count != 0:
+                self.report("ERROR: Missing and duplicate forward link values for attribute '%s' in '%s'" % (
+                            attrname, obj.dn))
+            else:
+                self.report("ERROR: Duplicate forward link values for attribute '%s' in '%s'" % (attrname, obj.dn))
+            for m in missing_forward_links:
+                self.report("Missing   link '%s'" % (m))
+                if not self.confirm_all("Schedule readding missing forward link for attribute %s" % attrname,
+                                        'fix_all_missing_forward_links'):
+                    self.err_orphaned_backlink(m.dn, reverse_link_name,
+                                               obj.dn.extended_str(), obj.dn,
+                                               attrname, syntax_oid,
+                                               check_duplicates=False)
+                    continue
+                forward_links += [m]
             for keystr in duplicate_dict.keys():
                 d = duplicate_dict[keystr]
                 for dd in d["delete"]:
@@ -1108,7 +1139,7 @@ newSuperior: %s""" % (str(from_dn), str(to_rdn), str(to_base)))
             # We now construct the sorted dn values.
             # They're sorted by the objectGUID of the target
             # See dsdb_Dn.__cmp__()
-            vals = [str(dn) for dn in sorted(unique_dict.values())]
+            vals = [str(dn) for dn in sorted(forward_links)]
             self.err_recover_forward_links(obj, attrname, vals)
             # We should continue with the fixed values
             obj[attrname] = ldb.MessageElement(vals, 0, attrname)

diff --git a/selftest/knownfail.d/samba4.blackbox.dbcheck-links b/selftest/knownfail.d/samba4.blackbox.dbcheck-links
deleted file mode 100644 (file)
index 299f8b1..0000000
--- a/selftest/knownfail.d/samba4.blackbox.dbcheck-links
+++ /dev/null
@@ -1,2 +0,0 @@
-samba4.blackbox.dbcheck-links.release-4-5-0-pre1.dbcheck_forward_link_corruption\(none\)
-samba4.blackbox.dbcheck-links.release-4-5-0-pre1.check_expected_after_dbcheck_forward_link_corruption\(none\)

diff --git a/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output_duplicate_member.txt b/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output_duplicate_member.txt
index 61990e6b9b93a4582a7f3d7fb314a5866c8eb1ba..af788ef661a76e474dfa4250d2e170216a050b9d 100644 (file)
--- a/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output_duplicate_member.txt
+++ b/source4/selftest/provisions/release-4-5-0-pre1/expected-dbcheck-link-output_duplicate_member.txt
@@ -3,7 +3,7 @@ WARNING: Link (back) mismatch for 'memberOf' (1) on 'CN=Administrator,CN=Users,D
 ERROR: Duplicate forward link values for attribute 'member' in 'CN=Enterprise Admins,CN=Users,DC=release-4-5-0-pre1,DC=samba,DC=corp'
 Duplicate link '<GUID=f4616422-30ec-473b-9d6f-a9a2d7bd1e6a>;<RMD_ADDTIME=131116484540000000>;<RMD_CHANGETIME=131116484540000000>;<RMD_FLAGS=0>;<RMD_INVOCID=4e4496a3-7fb8-4f97-8a33-d238db8b5e2d>;<RMD_LOCAL_USN=0>;<RMD_ORIGINATING_USN=3552>;<RMD_VERSION=0>;<SID=S-1-5-21-4177067393-1453636373-93818738-500>;CN=Administrator,CN=Users,DC=release-4-5-0-pre1,DC=samba,DC=corp'
 Correct   link '<GUID=f4616422-30ec-473b-9d6f-a9a2d7bd1e6a>;<RMD_ADDTIME=131116484540000000>;<RMD_CHANGETIME=131116484540000000>;<RMD_FLAGS=0>;<RMD_INVOCID=4e4496a3-7fb8-4f97-8a33-d238db8b5e2d>;<RMD_LOCAL_USN=3552>;<RMD_ORIGINATING_USN=3552>;<RMD_VERSION=0>;<SID=S-1-5-21-4177067393-1453636373-93818738-500>;CN=Administrator,CN=Users,DC=release-4-5-0-pre1,DC=samba,DC=corp'
-RECHECK: 'Duplicate/Correct link' lines above for attribute 'member' in 'CN=Enterprise Admins,CN=Users,DC=release-4-5-0-pre1,DC=samba,DC=corp'
-Commit fixes for (duplicate) forward links in attribute 'member' [YES]
+RECHECK: 'Missing/Duplicate/Correct link' lines above for attribute 'member' in 'CN=Enterprise Admins,CN=Users,DC=release-4-5-0-pre1,DC=samba,DC=corp'
+Commit fixes for (missing/duplicate) forward links in attribute 'member' [YES]
 Fixed duplicate links in attribute 'member'
 Checked 225 objects (1 errors)