ovsdb-idl: Preserve change_seqno when deleting rows.

In the case of a weak reference, clearing all change_seqno's can delete
useful information. Instead of clearing all seqno's when removing
track_node, only clear those values in cases including row insertion,
and row deleting if no dst_arcs remain.

Fixes: 95689f1 ("ovsdb-idl: Preserve references for deleted rows.")
Reported-at: https://issues.redhat.com/browse/FDP-193
Signed-off-by: Mike Pattrick <mkp@redhat.com>
Acked-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Simon Horman <horms@ovn.org>

lib/ovsdb-idl.c

@@ -177,6 +177,7 @@ static void ovsdb_idl_row_mark_backrefs_for_reparsing(struct ovsdb_idl_row *);
 static void ovsdb_idl_row_track_change(struct ovsdb_idl_row *,
                                        enum ovsdb_idl_change);
 static void ovsdb_idl_row_untrack_change(struct ovsdb_idl_row *);
+static void ovsdb_idl_row_clear_changeseqno(struct ovsdb_idl_row *);
 
 static void ovsdb_idl_txn_abort_all(struct ovsdb_idl *);
 static bool ovsdb_idl_txn_extract_mutations(struct ovsdb_idl_row *,
@@ -1353,6 +1354,7 @@ ovsdb_idl_track_clear__(struct ovsdb_idl *idl, bool flush_all)
                     row->updated = NULL;
                 }
                 ovsdb_idl_row_untrack_change(row);
+                ovsdb_idl_row_clear_changeseqno(row);
 
                 if (ovsdb_idl_row_is_orphan(row)) {
                     ovsdb_idl_row_unparse(row);
@@ -1572,6 +1574,7 @@ ovsdb_idl_process_update(struct ovsdb_idl_table *table,
                                  ru->columns);
         } else if (ovsdb_idl_row_is_orphan(row)) {
             ovsdb_idl_row_untrack_change(row);
+            ovsdb_idl_row_clear_changeseqno(row);
             ovsdb_idl_insert_row(row, ru->columns);
         } else {
             VLOG_ERR_RL(&semantic_rl, "cannot add existing row "UUID_FMT" to "
@@ -2223,11 +2226,15 @@ ovsdb_idl_row_untrack_change(struct ovsdb_idl_row *row)
         return;
     }
 
+    ovs_list_remove(&row->track_node);
+    ovs_list_init(&row->track_node);
+}
+
+static void ovsdb_idl_row_clear_changeseqno(struct ovsdb_idl_row *row)
+{
     row->change_seqno[OVSDB_IDL_CHANGE_INSERT] =
         row->change_seqno[OVSDB_IDL_CHANGE_MODIFY] =
         row->change_seqno[OVSDB_IDL_CHANGE_DELETE] = 0;
-    ovs_list_remove(&row->track_node);
-    ovs_list_init(&row->track_node);
 }
 
 static struct ovsdb_idl_row *

tests/ovsdb-idl.at

@@ -1422,6 +1422,56 @@ OVSDB_CHECK_IDL_TRACK([track, simple idl, initially populated, references, singl
 006: done
 ]])
 
+OVSDB_CHECK_IDL_TRACK([track, simple idl, initially populated, weak references, insert+delete batch],
+  [['["idltest",
+      {"op": "insert",
+       "table": "simple",
+       "row": {"s": "row0_s"},
+       "uuid-name": "uuid_row0_s"},
+      {"op": "insert",
+       "table": "simple6",
+       "row": {"name": "row0_s6",
+               "weak_ref": ["set",
+                             [["named-uuid", "uuid_row0_s"]]
+                           ]}}]']],
+  [['condition simple [true];simple6 [true]' \
+    '["idltest",
+      {"op": "insert",
+       "table": "simple",
+       "row": {"s": "row1_s"},
+       "uuid-name": "uuid_row1_s"},
+      {"op": "mutate",
+       "table": "simple6",
+       "where": [["name", "==", "row0_s6"]],
+       "mutations": [["weak_ref", "insert", ["set", [["named-uuid", "uuid_row1_s"]]]]]}]' \
+    '+["idltest",
+      {"op": "delete",
+       "table": "simple",
+       "where": [["s", "==", "row1_s"]]}]' \
+    '["idltest",
+      {"op": "insert",
+       "table": "simple",
+       "row": {"s": "row2_s"}}]']],
+  [[000: simple6: conditions unchanged
+000: simple: conditions unchanged
+001: table simple6: inserted row: name=row0_s6 weak_ref=[<0>] uuid=<1>
+001: table simple6: updated columns: name weak_ref
+001: table simple: inserted row: i=0 r=0 b=false s=row0_s u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<0>
+001: table simple: updated columns: s
+002: {"error":null,"result":[{"uuid":["uuid","<3>"]},{"count":1}]}
+003: {"error":null,"result":[{"count":1}]}
+004: table simple6: name=row0_s6 weak_ref=[<0>] uuid=<1>
+004: table simple6: updated columns: weak_ref
+004: table simple: inserted/deleted row: i=0 r=0 b=false s=row1_s u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<3>
+004: table simple: updated columns: s
+005: {"error":null,"result":[{"uuid":["uuid","<4>"]}]}
+006: table simple6: name=row0_s6 weak_ref=[<0>] uuid=<1>
+006: table simple: i=0 r=0 b=false s=row0_s u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<0>
+006: table simple: inserted row: i=0 r=0 b=false s=row2_s u=<2> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<4>
+006: table simple: updated columns: s
+007: done
+]])
+
 dnl This test checks that deleting both the destination and source of the
 dnl reference doesn't remove the reference in the source tracked record.
 OVSDB_CHECK_IDL_TRACK([track, simple idl, initially populated, weak references, multiple deletes],