cli/glusterd: Added support for dispersed volumes

Two new options have been added to the 'create' command of the cli
interface:

    disperse [<count>] redundancy <count>

Both are optional. A dispersed volume is created by specifying, at
least, one of them. If 'disperse' is missing or it's present but
'<count>' does not, the number of bricks enumerated in the command
line is taken as the disperse count.

If 'redundancy' is missing, the lowest optimal value is assumed. A
configuration is considered optimal (for most workloads) when the
disperse count - redundancy count is a power of 2. If the resulting
redundancy is 1, the volume is created normally, but if it's greater
than 1, a warning is shown to the user and he/she must answer yes/no
to continue volume creation. If there isn't any optimal value for
the given number of bricks, a warning is also shown and, if the user
accepts, a redundancy of 1 is used.

If 'redundancy' is specified and the resulting volume is not optimal,
another warning is shown to the user.

A distributed-disperse volume can be created using a number of bricks
multiple of the disperse count.

Change-Id: Iab93efbe78e905cdb91f54f3741599f7ea6645e4
BUG: 1118629
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/7782
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index c31d8a8ad71..086a6550a72 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -844,6 +844,18 @@ glusterd_volume_exclude_options_write (int fd, glusterd_volinfo_t *volinfo)
         if (ret)
                 goto out;
 
+        snprintf (buf, sizeof (buf), "%d", volinfo->disperse_count);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_VOL_DISPERSE_CNT,
+                                   buf);
+        if (ret)
+                goto out;
+
+        snprintf (buf, sizeof (buf), "%d", volinfo->redundancy_count);
+        ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_VOL_REDUNDANCY_CNT,
+                                   buf);
+        if (ret)
+                goto out;
+
         snprintf (buf, sizeof (buf), "%d", volinfo->version);
         ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_VOL_VERSION, buf);
         if (ret)
@@ -2618,6 +2630,12 @@ glusterd_store_update_volinfo (glusterd_volinfo_t *volinfo)
                 } else if (!strncmp (key, GLUSTERD_STORE_KEY_VOL_REPLICA_CNT,
                                      strlen (GLUSTERD_STORE_KEY_VOL_REPLICA_CNT))) {
                         volinfo->replica_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_VOL_DISPERSE_CNT,
+                                     strlen (GLUSTERD_STORE_KEY_VOL_DISPERSE_CNT))) {
+                        volinfo->disperse_count = atoi (value);
+                } else if (!strncmp (key, GLUSTERD_STORE_KEY_VOL_REDUNDANCY_CNT,
+                                     strlen (GLUSTERD_STORE_KEY_VOL_REDUNDANCY_CNT))) {
+                        volinfo->redundancy_count = atoi (value);
                 } else if (!strncmp (key, GLUSTERD_STORE_KEY_VOL_TRANSPORT,
                                      strlen (GLUSTERD_STORE_KEY_VOL_TRANSPORT))) {
                         volinfo->transport_type = atoi (value);
@@ -2754,6 +2772,11 @@ glusterd_store_update_volinfo (glusterd_volinfo_t *volinfo)
                                 GF_ASSERT (volinfo->replica_count > 0);
                         break;
 
+                        case GF_CLUSTER_TYPE_DISPERSE:
+                                GF_ASSERT (volinfo->disperse_count > 0);
+                                GF_ASSERT (volinfo->redundancy_count > 0);
+                        break;
+
                         default:
                                 GF_ASSERT (0);
                         break;