cluster/dht: Rebalance will be a new glusterfs process

rebalance will not use any maintainance clients. It is replaced by syncops,
with the volfile. Brickop (communication between glusterd<->glusterfs process)
is used for status and stop commands.

Dept-first traversal of dir is maintained, but data is migrated as and when
encounterd.
fix-layout (dir)
do
        Complete migrate-data of dir
        fix-layout (subdir)
done

Rebalance state is saved in the vol file, for restart-ability.
A disconnect event and pidfile state determine the defrag-status

Signed-off-by: shishirng <shishirng@gluster.com>
Change-Id: Iec6c80c84bbb2142d840242c28db3d5f5be94d01
BUG: 763844
Reviewed-on: http://review.gluster.com/2540
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>

1 files changed, 40 insertions, 6 deletions

diff --git a/xlators/cluster/dht/src/dht.c b/xlators/cluster/dht/src/dht.c
index 18fee7cd3c6..816bf868e88 100644
--- a/xlators/cluster/dht/src/dht.c
+++ b/xlators/cluster/dht/src/dht.c
@@ -182,11 +182,20 @@ out:
 int
 notify (xlator_t *this, int event, void *data, ...)
 {
-        int ret = -1;
+        int              ret = -1;
+        va_list          ap;
+        dict_t          *output = NULL;
 
         GF_VALIDATE_OR_GOTO ("dht", this, out);
 
-        ret = dht_notify (this, event, data);
+
+        if (!data)
+                goto out;
+
+        va_start (ap, data);
+        output = va_arg (ap, dict_t*);
+
+        ret = dht_notify (this, event, data, output);
 
 out:
         return ret;
@@ -343,10 +352,13 @@ out:
 int
 init (xlator_t *this)
 {
-        dht_conf_t    *conf = NULL;
-        char          *temp_str = NULL;
-        int            ret = -1;
-        int            i = 0;
+        dht_conf_t                      *conf           = NULL;
+        char                            *temp_str       = NULL;
+        int                              ret            = -1;
+        int                              i              = 0;
+        gf_defrag_info_t                *defrag         = NULL;
+        int                              cmd            = 0;
+
 
         GF_VALIDATE_OR_GOTO ("dht", this, err);
 
@@ -366,6 +378,24 @@ init (xlator_t *this)
                 goto err;
         }
 
+        ret = dict_get_int32 (this->options, "rebalance-cmd", &cmd);
+
+        if (cmd) {
+                defrag = GF_CALLOC (1, sizeof (gf_defrag_info_t),
+                                    gf_defrag_info_mt);
+
+                GF_VALIDATE_OR_GOTO (this->name, defrag, err);
+
+                LOCK_INIT (&defrag->lock);
+
+                defrag->is_exiting = 0;
+
+                defrag->cmd = cmd;
+
+                conf->defrag = defrag;
+        }
+
+
         conf->search_unhashed = GF_DHT_LOOKUP_UNHASHED_ON;
         if (dict_get_str (this->options, "lookup-unhashed", &temp_str) == 0) {
                 /* If option is not "auto", other options _should_ be boolean */
@@ -550,5 +580,9 @@ struct volume_options options[] = {
         { .key  = {"decommissioned-bricks"},
           .type = GF_OPTION_TYPE_ANY,
         },
+        { .key  = {"rebalance-cmd"},
+          .type = GF_OPTION_TYPE_INT,
+        },
+
         { .key  = {NULL} },
 };