afr,dht,ec: Replace GF_EVENT_CHILD_MODIFIED with event SOME_DESCENDENT_DOWN/UP

Currently these are few events related to child_up/down:
GF_EVENT_CHILD_UP :  Issued when any of the protocol client
connects.
GF_EVENT_CHILD_MODIFIED : Issued by afr/dht/ec
GF_EVENT_CHILD_DOWN : Issued when any of the protocol client
disconnects.
These events get modified at the dht/afr/ec layers. Here is a
brief on the same.

DHT:
- All the subvolumes reported once, and atleast one child came
  up, then GF_EVENT_CHILD_UP is issued
- connect GF_EVENT_CHILD_UP is issued
- disconnect GF_EVENT_CHILD_MODIFIED is issued
- All the subvolumes disconnected, GF_EVENT_CHILD_DOWN is issued

AFR:
- First subvolume came up, then GF_EVENT_CHILD_UP is issued
- Subsequent subvolumes coming up, results in GF_EVENT_CHILD_MODIFIED
- Any of the subvolumes go down, then GF_EVENT_SOME_CHILD_DOWN is issued
- Last up subvolume goes down, then GF_EVENT_CHILD_DOWN is issued

Until the patch [1] introduced GF_EVENT_SOME_CHILD_UP,
GF_EVENT_CHILD_MODIFIED was issued by afr/dht when any of the subvolumes
go up or down.

Now with md-cache changes, there is a necessity to differentiate between
child up and down. Hence, introducing GF_EVENT_SOME_DESCENDENT_DOWN/UP and
getting rid of GF_EVENT_CHILD_MODIFIED.

[1] http://review.gluster.org/12573

Change-Id: I704140b6598f7ec705493251d2dbc4191c965a58
BUG: 1396038
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/15764
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: N Balachandran <nbalacha@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/xlators/cluster/ec/src/ec.c b/xlators/cluster/ec/src/ec.c
index e10de4e38aa..97786657071 100644
--- a/xlators/cluster/ec/src/ec.c
+++ b/xlators/cluster/ec/src/ec.c
@@ -471,6 +471,7 @@ ec_notify (xlator_t *this, int32_t event, void *data, void *data2)
         dict_t            *input    = NULL;
         dict_t            *output   = NULL;
         gf_boolean_t      propagate = _gf_true;
+        int32_t           orig_event = event;
 
         gf_msg_trace (this->name, 0, "NOTIFY(%d): %p, %p",
                 event, data, data2);
@@ -529,7 +530,10 @@ ec_notify (xlator_t *this, int32_t event, void *data, void *data2)
 
                 if (event != GF_EVENT_MAXVAL) {
                         if (event == old_event) {
-                                event = GF_EVENT_CHILD_MODIFIED;
+                                if (orig_event == GF_EVENT_CHILD_UP)
+                                        event = GF_EVENT_SOME_DESCENDENT_UP;
+                                else /* orig_event has to be GF_EVENT_CHILD_DOWN */
+                                        event = GF_EVENT_SOME_DESCENDENT_DOWN;
                         }
                 } else {
                         propagate = _gf_false;