A commit to the database takes multiple trips through the main loop. In that time, the database could change, but ovn-controller can't properly react to the changes until the commit has succeeded or failed. Since commit f1fd765733 (ovn-controller: Avoid blocking to commit OVSDB transactions), Open vSwitch has failed to properly re-check the contents of the database following a successful commit. That meant that it was possible for ovn-controller to fail to react to a database change until much later, if nothing else happened for some time.
Reported-by; Alex Wang <al...@nicira.com> Reported-at: http://openvswitch.org/pipermail/dev/2015-July/058176.html Signed-off-by: Ben Pfaff <b...@nicira.com> --- ovn/controller/ovn-controller.c | 48 +++++++++++++++++++++++++---------------- 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/ovn/controller/ovn-controller.c b/ovn/controller/ovn-controller.c index 0657140..affc14b 100644 --- a/ovn/controller/ovn-controller.c +++ b/ovn/controller/ovn-controller.c @@ -189,28 +189,40 @@ idl_loop_commit_and_wait(struct idl_loop *loop) struct ovsdb_idl_txn *txn = loop->committing_txn; if (txn) { enum ovsdb_idl_txn_status status = ovsdb_idl_txn_commit(txn); - switch (status) { - case TXN_INCOMPLETE: - break; + if (status != TXN_INCOMPLETE) { + switch (status) { + case TXN_TRY_AGAIN: + /* We want to re-evaluate the database when it's changed from + * the contents that it had when we started the commit. (That + * might have already happened.) */ + loop->skip_seqno = loop->precommit_seqno; + if (ovsdb_idl_get_seqno(loop->idl) != loop->skip_seqno) { + poll_immediate_wake(); + } + break; + + case TXN_SUCCESS: + /* If the database has already changed since we started the + * commit, re-evaluate it immediately to avoid missing a change + * for a while. */ + if (ovsdb_idl_get_seqno(loop->idl) != loop->precommit_seqno) { + poll_immediate_wake(); + } + break; + + case TXN_UNCHANGED: + case TXN_ABORTED: + case TXN_NOT_LOCKED: + case TXN_ERROR: + break; + + case TXN_UNCOMMITTED: + case TXN_INCOMPLETE: + OVS_NOT_REACHED(); - case TXN_TRY_AGAIN: - loop->skip_seqno = loop->precommit_seqno; - if (ovsdb_idl_get_seqno(loop->idl) != loop->skip_seqno) { - poll_immediate_wake(); } - /* Fall through. */ - case TXN_UNCHANGED: - case TXN_ABORTED: - case TXN_SUCCESS: - case TXN_NOT_LOCKED: - case TXN_ERROR: ovsdb_idl_txn_destroy(txn); loop->committing_txn = NULL; - break; - - case TXN_UNCOMMITTED: - OVS_NOT_REACHED(); - } } -- 2.1.3 _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
