support for de-commissioning a node using 'remove-brick'

to achieve this, we now create volume-file with
'decommissioned-nodes' option in distribute volume, then just
perform the rebalance set of operations (with 'force' flag set).

now onwards, the 'remove-brick' (with 'start' option) operation tries
to migrate data from removed bricks to existing bricks.

'remove-brick' also supports similar options as of replace-brick.

* (no options) -> works as 'force', will have the current behavior
         of remove-brick, ie., no data-migration, volume changes.

* start  (starts remove-brick with data-migration/draining process,
          which takes care of migrating data and once complete, will
          commit the changes to volume file)
* pause  (stop data migration, but keep the volume file intact with
          extra options whatever is set)
* abort  (stop data-migration, and fall back to old configuration)
* commit (if volume is stopped, commits the changes to volumefile)
* force  (stops the data-migration and commits the changes to
          volume file)

Change-Id: I3952bcfbe604a0952e68b6accace7014d5e401d3
BUG: 1952
Reviewed-on: http://review.gluster.com/118
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index 3b30fb0806e..53556984a33 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -2297,7 +2297,7 @@ glusterd_op_stage_validate (glusterd_op_t op, dict_t *dict, char **op_errstr,
                         break;
 
                 case GD_OP_REMOVE_BRICK:
-                        ret = glusterd_op_stage_remove_brick (dict);
+                        ret = glusterd_op_stage_remove_brick (dict, op_errstr);
                         break;
 
                 case GD_OP_LOG_FILENAME:
@@ -2387,7 +2387,7 @@ glusterd_op_commit_perform (glusterd_op_t op, dict_t *dict, char **op_errstr,
                         break;
 
                 case GD_OP_REMOVE_BRICK:
-                        ret = glusterd_op_remove_brick (dict);
+                        ret = glusterd_op_remove_brick (dict, op_errstr);
                         break;
 
                 case GD_OP_LOG_FILENAME:
@@ -2565,6 +2565,7 @@ glusterd_bricks_select_remove_brick (dict_t *dict, char **op_errstr)
         int32_t                                 i = 1;
         char                                    key[256] = {0,};
         glusterd_pending_node_t                 *pending_node = NULL;
+        int32_t                                 force = 0;
 
         ret = dict_get_str (dict, "volname", &volname);
 
@@ -2586,6 +2587,12 @@ glusterd_bricks_select_remove_brick (dict_t *dict, char **op_errstr)
                 goto out;
         }
 
+        ret = dict_get_int32 (dict, "force", &force);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_INFO, "force flag is not set");
+                ret = 0;
+                goto out;
+        }
 
         while ( i <= count) {
                 snprintf (key, 256, "brick%d", i);