From 1b4d8fe1d9cd1b558f2f093f909090c49fcda6b4 Mon Sep 17 00:00:00 2001 From: Dumitru Ceara Date: Mon, 17 May 2021 11:22:27 +0200 Subject: ovsdb-idl: Consider all tables when computing expected cond seqno. In ovsdb_idl_db_set_condition(), take into account all pending condition changes for all tables when computing the db->cond_seqno at which the monitor is expected to be updated. In the following scenario, with two tables, A and B, the old code performed the following steps: 1. Initial db->cond_seqno = X. 2. Client changes condition for table A: - A->new_cond gets set - expected cond seqno returned to the client: X + 1 3. ovsdb-idl sends the monitor_cond_change for table A - A->req_cond <- A->new_cond 4. Client changes condition for table B: - B->new_cond gets set - expected cond seqno returned to the client: X + 1 - however, because the condition change at step 3 is still not replied to, table B's monitor_cond_change request is not sent yet. 5. ovsdb-idl receives the reply for the condition change at step 3: - db->cond_seqno <- X + 1 6. ovsdb-idl sends the monitor_cond_change for table B 7. ovsdb-idl receives the reply for the condition change at step 6: - db->cond_seqno <- X + 2 The client was incorrectly informed that it will have all relevant updates for table B at seqno X + 1 while actually that happens later, at seqno X + 2. Fixes: 46437c5232bd ("ovsdb-idl: Enhance conditional monitoring API") Acked-by: Ben Pfaff Signed-off-by: Dumitru Ceara (cherry picked from commit b5bb044fbe4c1395dcde5cc7d5081ef0099bb8b3) Signed-off-by: Ilya Maximets --- lib/ovsdb-idl.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/lib/ovsdb-idl.c b/lib/ovsdb-idl.c index 2fc8a91e3..325050f21 100644 --- a/lib/ovsdb-idl.c +++ b/lib/ovsdb-idl.c @@ -1575,7 +1575,6 @@ ovsdb_idl_db_set_condition(struct ovsdb_idl_db *db, { struct ovsdb_idl_condition *table_cond; struct ovsdb_idl_table *table = ovsdb_idl_db_table_from_class(db, tc); - unsigned int curr_seqno = db->cond_seqno; /* Compare the new condition to the last known condition which can be * either "new" (not sent yet), "requested" or "acked", in this order. @@ -1596,8 +1595,27 @@ ovsdb_idl_db_set_condition(struct ovsdb_idl_db *db, } /* Conditions will be up to date when we receive replies for already - * requested and new conditions, if any. */ - return curr_seqno + (table->new_cond ? 1 : 0) + (table->req_cond ? 1 : 0); + * requested and new conditions, if any. This includes condition change + * requests for other tables too. + */ + if (table->new_cond) { + /* New condition will be sent out after all already requested ones + * are acked. + */ + bool any_req_cond = false; + for (size_t i = 0; i < db->class_->n_tables; i++) { + if (db->tables[i].req_cond) { + any_req_cond = true; + break; + } + } + return db->cond_seqno + any_req_cond + 1; + } else { + /* Already requested conditions should be up to date at + * db->cond_seqno + 1 while acked conditions are already up to date. + */ + return db->cond_seqno + !!table->req_cond; + } } /* Sets the replication condition for 'tc' in 'idl' to 'condition' and -- cgit v1.2.1