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, 6 insertions, 3 deletions

diff --git a/rpc/xdr/src/glusterfs-fops.x b/rpc/xdr/src/glusterfs-fops.x
index 3b73499814d..7b0bcb33213 100644
--- a/rpc/xdr/src/glusterfs-fops.x
+++ b/rpc/xdr/src/glusterfs-fops.x
@@ -77,6 +77,9 @@ enum glusterfs_fop_t {
         GF_FOP_MAXVALUE
 };
 
+/* Note: Removed event GF_EVENT_CHILD_MODIFIED=8, hence
+ *to preserve backward compatibiliy, GF_EVENT_TRANSPORT_CLEANUP = 9
+ */
 enum glusterfs_event_t {
         GF_EVENT_PARENT_UP = 1,
         GF_EVENT_POLLIN,
@@ -85,8 +88,7 @@ enum glusterfs_event_t {
         GF_EVENT_CHILD_UP,
         GF_EVENT_CHILD_DOWN,
         GF_EVENT_CHILD_CONNECTING,
-        GF_EVENT_CHILD_MODIFIED,
-        GF_EVENT_TRANSPORT_CLEANUP,
+        GF_EVENT_TRANSPORT_CLEANUP = 9,
         GF_EVENT_TRANSPORT_CONNECTED,
         GF_EVENT_VOLFILE_MODIFIED,
         GF_EVENT_GRAPH_NEW,
@@ -98,8 +100,9 @@ enum glusterfs_event_t {
         GF_EVENT_VOLUME_BARRIER_OP,
         GF_EVENT_UPCALL,
         GF_EVENT_SCRUB_STATUS,
-        GF_EVENT_SOME_CHILD_DOWN,
+        GF_EVENT_SOME_DESCENDENT_DOWN,
         GF_EVENT_SCRUB_ONDEMAND,
+        GF_EVENT_SOME_DESCENDENT_UP,
         GF_EVENT_MAXVAL
 };