ofproto-dpif-upcall: Fix push_dp_ops to handle all errors.

push_dp_ops only handles delete ops errors but ignores the modify
ops results. It's better to handle all the dp operation errors in
a consistent way.

This patch prevents the inconsistency by considering modify failure
in revalidators.

To note, we cannot perform two state transitions and change ukey_state
into UKEY_EVICTED directly here, because, if we do so, the
sweep will remove the ukey alone and leave dp flow alive. Later, the
dump will retrieve the dp flow and might even recover it. This will
contribute the stats of this dp flow twice.

Signed-off-by: Peng He <[email protected]>
Signed-off-by: Eelco Chaudron <[email protected]>

ofproto/ofproto-dpif-upcall.c

@@ -53,6 +53,7 @@
 VLOG_DEFINE_THIS_MODULE(ofproto_dpif_upcall);
 
 COVERAGE_DEFINE(dumped_duplicate_flow);
+COVERAGE_DEFINE(dumped_inconsistent_flow);
 COVERAGE_DEFINE(dumped_new_flow);
 COVERAGE_DEFINE(handler_duplicate_upcall);
 COVERAGE_DEFINE(revalidate_missed_dp_flow);
@@ -258,6 +259,7 @@ enum ukey_state {
  UKEY_CREATED = 0,
  UKEY_VISIBLE, /* Ukey is in umap, datapath flow install is queued. */
  UKEY_OPERATIONAL, /* Ukey is in umap, datapath flow is installed. */
+ UKEY_INCONSISTENT, /* Ukey is in umap, datapath flow is inconsistent. */
  UKEY_EVICTING, /* Ukey is in umap, datapath flow delete is queued. */
  UKEY_EVICTED, /* Ukey is in umap, datapath flow is deleted. */
  UKEY_DELETED, /* Ukey removed from umap, ukey free is deferred. */
@@ -1999,15 +2001,20 @@ transition_ukey_at(struct udpif_key *ukey, enum ukey_state dst,
  * UKEY_VISIBLE -> UKEY_EVICTED
  * A handler attempts to install the flow, but the datapath rejects it.
  * Consider that the datapath has already destroyed it.
+ * UKEY_OPERATIONAL -> UKEY_INCONSISTENT
+ * A revalidator modifies the flow with error returns.
+ * UKEY_INCONSISTENT -> UKEY_EVICTING
+ * A revalidator decides to evict the datapath flow.
  * UKEY_OPERATIONAL -> UKEY_EVICTING
  * A revalidator decides to evict the datapath flow.
  * UKEY_EVICTING -> UKEY_EVICTED
  * A revalidator has evicted the datapath flow.
  * UKEY_EVICTED -> UKEY_DELETED
  * A revalidator has removed the ukey from the umap and is deleting it.
  */
- if (ukey->state == dst - 1 || (ukey->state == UKEY_VISIBLE &&
- dst < UKEY_DELETED)) {
+ if (ukey->state == dst - 1 ||
+ (ukey->state == UKEY_VISIBLE && dst < UKEY_DELETED) ||
+ (ukey->state == UKEY_OPERATIONAL && dst == UKEY_EVICTING)) {
  ukey->state = dst;
  } else {
  struct ds ds = DS_EMPTY_INITIALIZER;
@@ -2490,26 +2497,31 @@ push_dp_ops(struct udpif *udpif, struct ukey_op *ops, size_t n_ops)
 
  for (i = 0; i < n_ops; i++) {
  struct ukey_op *op = &ops[i];
- struct dpif_flow_stats *push, *stats, push_buf;
-
- stats = op->dop.flow_del.stats;
- push = &push_buf;
-
- if (op->dop.type != DPIF_OP_FLOW_DEL) {
- /* Only deleted flows need their stats pushed. */
- continue;
- }
 
  if (op->dop.error) {
- /* flow_del error, 'stats' is unusable. */
  if (op->ukey) {
  ovs_mutex_lock(&op->ukey->mutex);
- transition_ukey(op->ukey, UKEY_EVICTED);
+ if (op->dop.type == DPIF_OP_FLOW_DEL) {
+ transition_ukey(op->ukey, UKEY_EVICTED);
+ } else {
+ /* Modification of the flow failed. */
+ transition_ukey(op->ukey, UKEY_INCONSISTENT);
+ }
  ovs_mutex_unlock(&op->ukey->mutex);
  }
  continue;
  }
 
+ if (op->dop.type != DPIF_OP_FLOW_DEL) {
+ /* Only deleted flows need their stats pushed. */
+ continue;
+ }
+
+ struct dpif_flow_stats *push, *stats, push_buf;
+
+ stats = op->dop.flow_del.stats;
+ push = &push_buf;
+
  if (op->ukey) {
  ovs_mutex_lock(&op->ukey->mutex);
  transition_ukey(op->ukey, UKEY_EVICTED);
@@ -2857,6 +2869,15 @@ revalidate(struct revalidator *revalidator)
  continue;
  }
 
+ if (ukey->state == UKEY_INCONSISTENT) {
+ ukey->dump_seq = dump_seq;
+ reval_op_init(&ops[n_ops++], UKEY_DELETE, udpif, ukey,
+ &recircs, &odp_actions);
+ ovs_mutex_unlock(&ukey->mutex);
+ COVERAGE_INC(dumped_inconsistent_flow);
+ continue;
+ }
+
  if (ukey->state <= UKEY_OPERATIONAL) {
  /* The flow is now confirmed to be in the datapath. */
  transition_ukey(ukey, UKEY_OPERATIONAL);
@@ -2945,13 +2966,14 @@ revalidator_sweep__(struct revalidator *revalidator, bool purge)
  }
  ukey_state = ukey->state;
  if (ukey_state == UKEY_OPERATIONAL
+ || (ukey_state == UKEY_INCONSISTENT)
  || (ukey_state == UKEY_VISIBLE && purge)) {
  struct recirc_refs recircs = RECIRC_REFS_EMPTY_INITIALIZER;
  bool seq_mismatch = (ukey->dump_seq != dump_seq
  && ukey->reval_seq != reval_seq);
  enum reval_result result;
 
- if (purge) {
+ if (purge || ukey_state == UKEY_INCONSISTENT) {
  result = UKEY_DELETE;
  } else if (!seq_mismatch) {
  result = UKEY_KEEP;

tests/dpif-netdev.at

@@ -812,3 +812,46 @@ AT_CHECK([tail -n 1 p2.pcap.txt], [0], [dnl
 ])
 OVS_VSWITCHD_STOP
 AT_CLEANUP
+
+AT_SETUP([dpif-netdev - revalidators handle dp modification fail correctly])
+OVS_VSWITCHD_START(
+ [add-port br0 p1 \
+ -- set interface p1 type=dummy \
+ -- set bridge br0 datapath-type=dummy \
+ -- add-port br0 p2 \
+ -- set interface p2 type=dummy --
+ ])
+
+AT_CHECK([ovs-ofctl add-flow br0 'table=0,in_port=p1,actions=p2'])
+AT_CHECK([ovs-appctl netdev-dummy/receive p1 'ipv4(src=10.0.0.1,dst=10.0.0.2),tcp(src=1,dst=2)'])
+AT_CHECK([ovs-appctl netdev-dummy/receive p1 'ipv4(src=10.0.0.1,dst=10.0.0.2),tcp(src=1,dst=2)'])
+
+AT_CHECK([ovs-appctl dpctl/dump-flows | sed 's/.*thread://' | strip_xout_keep_actions ], [0], [
+recirc_id(0),in_port(1),packet_type(ns=0,id=0),eth_type(0x0800),ipv4(frag=no), packets:0, bytes:0, used:0.0s, actions:2
+])
+
+dnl Wait for the dp flow to enter OPERATIONAL state.
+AT_CHECK([ovs-appctl revalidator/wait])
+
+AT_CHECK([ovs-appctl revalidator/pause])
+
+dnl Delete all dp flows, so flow modification will fail.
+AT_CHECK([ovs-appctl dpctl/del-flows])
+
+AT_CHECK([ovs-appctl revalidator/resume])
+
+dnl Replace OpenFlow rules, trigger revalidation and wait for it to complete.
+AT_CHECK([echo 'table=0,in_port=p1,ip actions=ct(commit)' | ovs-ofctl --bundle replace-flows br0 -])
+AT_CHECK([ovs-appctl revalidator/wait])
+
+dnl Inconsistent ukey should be deleted.
+AT_CHECK([ovs-appctl upcall/show | grep keys | grep -q -v 0], [1])
+
+dnl Check the log for the flow modification error.
+AT_CHECK([grep -q -E ".*failed to put.*$" ovs-vswitchd.log])
+
+dnl Remove warning logs to let test suite pass.
+OVS_VSWITCHD_STOP(["dnl
+ /.*failed to put.*$/d
+ /.*failed to flow_del.*$/d"])
+AT_CLEANUP