cluster/dht: fixes to should_layout_fix logic

* Don't consider "dir-spread-count" option. This option is not
supported.
* Consider transition to weighted to equal distribution or vice-versa
a valid case for fixing the layout.

Change-Id: I0dcfe555dae9269ce20a41611cfdaa4f96c9e98b
BUG: 1196615
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-on: http://review.gluster.org/9809
Reviewed-by: N Balachandran <nbalacha@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

2 files changed, 53 insertions, 12 deletions

diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index 9e0228aa279..779b470585c 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -392,6 +392,11 @@ typedef enum {
         GF_DHT_MIGRATE_HARDLINK_IN_PROGRESS
 } gf_dht_migrate_data_type_t;
 
+typedef enum {
+        GF_DHT_EQUAL_DISTRIBUTION,
+        GF_DHT_WEIGHTED_DISTRIBUTION
+} dht_distribution_type_t;
+
 #define ENTRY_MISSING(op_ret, op_errno) (op_ret == -1 && op_errno == ENOENT)
 
 #define is_revalidate(loc) (dht_inode_ctx_layout_get (loc->inode, this, NULL) == 0)
diff --git a/xlators/cluster/dht/src/dht-selfheal.c b/xlators/cluster/dht/src/dht-selfheal.c
index 1583ee5c602..a6658cc4cbb 100644
--- a/xlators/cluster/dht/src/dht-selfheal.c
+++ b/xlators/cluster/dht/src/dht-selfheal.c
@@ -405,16 +405,49 @@ out:
         return count;
 }
 
+dht_distribution_type_t
+dht_distribution_type (xlator_t *this, dht_layout_t *layout)
+{
+        dht_distribution_type_t type        = GF_DHT_EQUAL_DISTRIBUTION;
+        int                     i           = 0;
+        uint32_t                start_range = 0, range = 0, diff = 0;
+
+        if ((this == NULL) || (layout == NULL) || (layout->cnt < 1)) {
+                goto out;
+        }
+
+        for (i = 0; i < layout->cnt; i++) {
+                if (start_range == 0) {
+                        start_range = layout->list[i].stop
+                                - layout->list[i].start;
+                        continue;
+                }
+
+                range = layout->list[i].stop - layout->list[i].start;
+                diff = abs (range - start_range);
+
+                if ((range != 0) && (diff > layout->cnt)) {
+                        type = GF_DHT_WEIGHTED_DISTRIBUTION;
+                        break;
+                }
+        }
+
+out:
+        return type;
+}
+
 gf_boolean_t
 dht_should_fix_layout (call_frame_t *frame, dht_layout_t **inmem,
                        dht_layout_t **ondisk)
 {
-        gf_boolean_t  fixit        = _gf_true;
-        dht_local_t  *local        = NULL;
-        int           layout_span  = 0, decommissioned_bricks = 0;
-        int           spread_count = 0;
-        int           ret          = 0;
-        dht_conf_t   *conf         = NULL;
+        gf_boolean_t             fixit                        = _gf_true;
+        dht_local_t             *local                        = NULL;
+        int                      layout_span                  = 0;
+        int                      ondisk_decommissioned_bricks = 0;
+        int                      ret                          = 0;
+        dht_conf_t              *conf                         = NULL;
+        dht_distribution_type_t  inmem_dist_type              = 0;
+        dht_distribution_type_t  ondisk_dist_type             = 0;
 
         conf = frame->this->private;
 
@@ -444,13 +477,16 @@ dht_should_fix_layout (call_frame_t *frame, dht_layout_t **inmem,
 
         layout_span = dht_layout_span (*ondisk);
 
-        decommissioned_bricks = dht_decommissioned_bricks_in_layout (frame->this,
-                                                                     *ondisk);
-        spread_count = conf->dir_spread_cnt ? conf->dir_spread_cnt
-                : conf->subvolume_cnt;
+        ondisk_decommissioned_bricks
+                = dht_decommissioned_bricks_in_layout (frame->this,
+                                                       *ondisk);
+        inmem_dist_type = dht_distribution_type (frame->this, *inmem);
+        ondisk_dist_type = dht_distribution_type (frame->this, *ondisk);
 
-        if ((decommissioned_bricks == 0) && (layout_span
-                                             == spread_count))
+        if ((ondisk_decommissioned_bricks == 0)
+            && (layout_span == (conf->subvolume_cnt
+                                - conf->decommission_subvols_cnt))
+            && (inmem_dist_type == ondisk_dist_type))
                 fixit = _gf_false;
 
 out: