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, 7 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index 53fdcf484..dab075db0 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -321,6 +321,10 @@ glusterd_store_brickinfo_write (int fd, glusterd_brickinfo_t *brickinfo)
         ret = glusterd_store_save_value (fd, GLUSTERD_STORE_KEY_BRICK_RDMA_PORT,
                                          value);
 
+        snprintf (value, sizeof(value), "%d", brickinfo->decommissioned);
+        ret = glusterd_store_save_value (fd, GLUSTERD_STORE_KEY_BRICK_DECOMMISSIONED,
+                                         value);
+
 out:
         gf_log ("", GF_LOG_DEBUG, "Returning %d", ret);
         return ret;
@@ -1637,6 +1641,9 @@ glusterd_store_retrieve_bricks (glusterd_volinfo_t *volinfo)
                                 pmap = pmap_registry_get (THIS);
                                 if (pmap->last_alloc <= brickinfo->rdma_port)
                                         pmap->last_alloc = brickinfo->rdma_port + 1;
+                        } else if (!strncmp (key, GLUSTERD_STORE_KEY_BRICK_DECOMMISSIONED,
+                                             strlen (GLUSTERD_STORE_KEY_BRICK_DECOMMISSIONED))) {
+                                gf_string2int (value, &brickinfo->decommissioned);
                         } else {
                                 gf_log ("", GF_LOG_ERROR, "Unknown key: %s",
                                         key);