ovsdb-idl: Fix *_is_new() IDL functions.

Currently all functions of the type *_is_new() always return
'false'. This patch resolves this issue by using the
'OVSDB_IDL_CHANGE_INSERT' 'change_seqno' instead of the
'OVSDB_IDL_CHANGE_MODIFY' 'change_seqno' to determine if a row
is new and by resetting the 'OVSDB_IDL_CHANGE_INSERT'
'change_seqno' on clear.

Further to this, the code is also updated to match the following
behaviour:

When a row is inserted, the 'OVSDB_IDL_CHANGE_INSERT'
'change_seqno' is updated to match the new database
change_seqno. The 'OVSDB_IDL_CHANGE_MODIFY' 'change_seqno'
is not set for inserted rows (only for updated rows).

At the end of a run, ovsdb_idl_db_track_clear() should be
called to clear all tracking information, this includes
resetting all row 'change_seqno' to zero. This will ensure
that subsequent runs will not see a previously 'new' row.

add_tracked_change_for_references() is updated to only
track rows that reference the current row.

Also, update unit tests in order to test the *_is_new(),
*_is_delete() functions.

Suggested-by: Dumitru Ceara <dceara@redhat.com>
Reported-at: https://bugzilla.redhat.com/1883562
Fixes: ca545a787a ("ovsdb-idl.c: Increase seqno for change-tracking of table references.")
Signed-off-by: Mark Gray <mark.d.gray@redhat.com>
Acked-by: Han Zhou <hzhou@ovn.org>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

lib/ovsdb-idl.c

@@ -1959,6 +1959,11 @@ ovsdb_idl_db_track_clear(struct ovsdb_idl_db *db)
                     free(row->updated);
                     row->updated = NULL;
                 }
+
+                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);
                 if (ovsdb_idl_row_is_orphan(row) && row->tracked_old_datum) {
@@ -2684,22 +2689,25 @@ ovsdb_idl_process_update2(struct ovsdb_idl_table *table,
     return OVSDB_IDL_UPDATE_DB_CHANGED;
 }
 
-/* Recursively add rows to tracked change lists for current row
+/* Recursively add rows to tracked change lists for all rows that reference
- * and the rows that reference this row. */
+   'row'. */
 static void
 add_tracked_change_for_references(struct ovsdb_idl_row *row)
 {
-    if (ovs_list_is_empty(&row->track_node) &&
+    const struct ovsdb_idl_arc *arc;
-            ovsdb_idl_track_is_set(row->table)) {
+    LIST_FOR_EACH (arc, dst_node, &row->dst_arcs) {
-        ovs_list_push_back(&row->table->track_list,
+        struct ovsdb_idl_row *ref = arc->src;
-                           &row->track_node);
-        row->change_seqno[OVSDB_IDL_CHANGE_MODIFY]
-            = row->table->change_seqno[OVSDB_IDL_CHANGE_MODIFY]
-            = row->table->db->change_seqno + 1;
 
-        const struct ovsdb_idl_arc *arc;
+        if (ovs_list_is_empty(&ref->track_node) &&
-        LIST_FOR_EACH (arc, dst_node, &row->dst_arcs) {
+            ovsdb_idl_track_is_set(ref->table)) {
-            add_tracked_change_for_references(arc->src);
+                ovs_list_push_back(&ref->table->track_list,
+                                   &ref->track_node);
+
+            ref->change_seqno[OVSDB_IDL_CHANGE_MODIFY]
+                = ref->table->change_seqno[OVSDB_IDL_CHANGE_MODIFY]
+                = ref->table->db->change_seqno + 1;
+
+            add_tracked_change_for_references(ref);
         }
     }
 }
@@ -2767,7 +2775,14 @@ ovsdb_idl_row_change__(struct ovsdb_idl_row *row, const struct json *row_json,
                     row->change_seqno[change]
                         = row->table->change_seqno[change]
                         = row->table->db->change_seqno + 1;
+
                     if (table->modes[column_idx] & OVSDB_IDL_TRACK) {
+                        if (ovs_list_is_empty(&row->track_node) &&
+                            ovsdb_idl_track_is_set(row->table)) {
+                            ovs_list_push_back(&row->table->track_list,
+                                               &row->track_node);
+                        }
+
                         add_tracked_change_for_references(row);
                         if (!row->updated) {
                             row->updated = bitmap_allocate(class->n_columns);
@@ -4843,6 +4858,7 @@ ovsdb_idl_txn_insert(struct ovsdb_idl_txn *txn,
     hmap_insert(&row->table->rows, &row->hmap_node, uuid_hash(&row->uuid));
     hmap_insert(&txn->txn_rows, &row->txn_node, uuid_hash(&row->uuid));
     ovsdb_idl_add_to_indexes(row);
+
     return row;
 }
 

ovsdb/ovsdb-idlc.in

@@ -279,13 +279,21 @@ const struct %(s)s *%(s)s_table_track_get_first(const struct %(s)s_table *);
              (ROW) = %(s)s_track_get_next(ROW))
 
 
-/* Returns true if 'row' was inserted since the last change tracking reset. */
+/* Returns true if 'row' was inserted since the last change tracking reset.
+ *
+ * Note: This can only be used to test rows of tracked changes. This cannot be
+ * used to test if an uncommitted row that has been added locally is new or it
+ * may given unexpected results. */
 static inline bool %(s)s_is_new(const struct %(s)s *row)
 {
-    return %(s)s_row_get_seqno(row, OVSDB_IDL_CHANGE_MODIFY) == 0;
+    return %(s)s_row_get_seqno(row, OVSDB_IDL_CHANGE_INSERT) > 0;
 }
 
-/* Returns true if 'row' was deleted since the last change tracking reset. */
+/* Returns true if 'row' was deleted since the last change tracking reset.
+ *
+ * Note: This can only be used to test rows of tracked changes. This cannot be
+ * used to test if an uncommitted row that has been added locally has been
+ * deleted or it may given unexpected results. */
 static inline bool %(s)s_is_deleted(const struct %(s)s *row)
 {
     return %(s)s_row_get_seqno(row, OVSDB_IDL_CHANGE_DELETE) > 0;
@@ -333,6 +341,14 @@ struct %(s)s *%(s)s_cursor_data(struct ovsdb_idl_cursor *);
 void %(s)s_init(struct %(s)s *);
 void %(s)s_delete(const struct %(s)s *);
 struct %(s)s *%(s)s_insert(struct ovsdb_idl_txn *);
+
+/* Returns true if the tracked column referenced by 'enum %(s)s_column_id' of
+ * the row referenced by 'struct %(s)s *' was updated since the last change
+ * tracking reset.
+ *
+ * Note: This can only be used to test rows of tracked changes. This cannot be
+ * used to test if an uncommitted row that has been added locally has been
+ * updated or it may given unexpected results. */
 bool %(s)s_is_updated(const struct %(s)s *, enum %(s)s_column_id);
 ''' % {'s': structName, 'S': structName.upper()})
 

tests/ovsdb-idl.at

@@ -1162,6 +1162,7 @@ OVSDB_CHECK_IDL_TRACK([track, simple idl, initially populated],
        "where": [],
        "row": {"b": true}}]']],
   [[000: i=1 r=2 b=true s=mystring u=<0> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<1> <2>] uuid=<3>
+000: inserted row: uuid=<3>
 000: updated columns: b ba i ia r ra s sa u ua
 001: {"error":null,"result":[{"count":2}]}
 002: i=0 r=0 b=true s= u=<4> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<5>
@@ -1224,6 +1225,7 @@ OVSDB_CHECK_IDL_TRACK([track, simple idl, initially empty, various ops],
   [[000: empty
 001: {"error":null,"result":[{"uuid":["uuid","<0>"]},{"uuid":["uuid","<1>"]}]}
 002: i=1 r=2 b=true s=mystring u=<2> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<3> <4>] uuid=<0>
+002: inserted row: uuid=<0>
 002: updated columns: b ba i ia r ra s sa u ua
 003: {"error":null,"result":[{"count":2}]}
 004: i=0 r=0 b=true s= u=<5> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
@@ -1235,6 +1237,7 @@ OVSDB_CHECK_IDL_TRACK([track, simple idl, initially empty, various ops],
 006: updated columns: r
 007: {"error":null,"result":[{"uuid":["uuid","<6>"]}]}
 008: i=-1 r=125 b=false s= u=<5> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
+008: inserted row: uuid=<6>
 008: updated columns: ba i ia r ra
 009: {"error":null,"result":[{"count":2}]}
 010: i=-1 r=125 b=false s=newstring u=<5> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
@@ -1242,7 +1245,7 @@ OVSDB_CHECK_IDL_TRACK([track, simple idl, initially empty, various ops],
 010: updated columns: s
 010: updated columns: s
 011: {"error":null,"result":[{"count":1}]}
-012: ##deleted## uuid=<1>
+012: deleted row: uuid=<1>
 013: reconnect
 014: i=-1 r=125 b=false s=newstring u=<5> ia=[1] ra=[1.5] ba=[false] sa=[] ua=[] uuid=<6>
 014: i=1 r=123.5 b=true s=mystring u=<2> ia=[1 2 3] ra=[-0.5] ba=[true] sa=[abc def] ua=[<3> <4>] uuid=<0>

tests/test-ovsdb.c

@@ -2030,7 +2030,7 @@ print_idl(struct ovsdb_idl *idl, int step)
 }
 
 static void
-print_idl_track(struct ovsdb_idl *idl, int step, unsigned int seqno)
+print_idl_track(struct ovsdb_idl *idl, int step)
 {
     const struct idltest_simple *s;
     const struct idltest_link1 *l1;
@@ -2038,26 +2038,42 @@ print_idl_track(struct ovsdb_idl *idl, int step, unsigned int seqno)
     int n = 0;
 
     IDLTEST_SIMPLE_FOR_EACH_TRACKED (s, idl) {
-        if (idltest_simple_row_get_seqno(s, OVSDB_IDL_CHANGE_DELETE) >= seqno) {
+        if (idltest_simple_is_deleted(s)) {
-            printf("%03d: ##deleted## uuid="UUID_FMT"\n", step, UUID_ARGS(&s->header_.uuid));
+            printf("%03d: deleted row: uuid="UUID_FMT"\n", step,
+                   UUID_ARGS(&s->header_.uuid));
         } else {
             print_idl_row_simple(s, step);
+            if (idltest_simple_is_new(s)) {
+                printf("%03d: inserted row: uuid="UUID_FMT"\n", step,
+                       UUID_ARGS(&s->header_.uuid));
+            }
         }
         n++;
     }
     IDLTEST_LINK1_FOR_EACH_TRACKED (l1, idl) {
-        if (idltest_simple_row_get_seqno(s, OVSDB_IDL_CHANGE_DELETE) >= seqno) {
+        if (idltest_link1_is_deleted(l1)) {
-            printf("%03d: ##deleted## uuid="UUID_FMT"\n", step, UUID_ARGS(&s->header_.uuid));
+            printf("%03d: deleted row: uuid="UUID_FMT"\n", step,
+                   UUID_ARGS(&l1->header_.uuid));
         } else {
             print_idl_row_link1(l1, step);
+            if (idltest_link1_is_new(l1)) {
+                printf("%03d: inserted row: uuid="UUID_FMT"\n", step,
+                       UUID_ARGS(&l1->header_.uuid));
+            }
         }
         n++;
     }
     IDLTEST_LINK2_FOR_EACH_TRACKED (l2, idl) {
-        if (idltest_simple_row_get_seqno(s, OVSDB_IDL_CHANGE_DELETE) >= seqno) {
+        if (idltest_link2_is_deleted(l2)) {
-            printf("%03d: ##deleted## uuid="UUID_FMT"\n", step, UUID_ARGS(&s->header_.uuid));
+            printf("%03d: deleted row: uuid="UUID_FMT"\n", step,
+                   UUID_ARGS(&l2->header_.uuid));
         } else {
             print_idl_row_link2(l2, step);
+            if (idltest_link2_is_new(l2)) {
+                printf("%03d: inserted row: uuid="UUID_FMT"\n", step,
+                       UUID_ARGS(&l2->header_.uuid));
+            }
+
         }
         n++;
     }
@@ -2465,7 +2481,7 @@ do_idl(struct ovs_cmdl_context *ctx)
 
             /* Print update. */
             if (track) {
-                print_idl_track(idl, step++, ovsdb_idl_get_seqno(idl));
+                print_idl_track(idl, step++);
                 ovsdb_idl_track_clear(idl);
             } else {
                 print_idl(idl, step++);