cluster/dht: Don't store the entire uuid for subvols

Comparing the uuid string of the local node against that stored in the
local_subvol information is inefficient, especially as it is
done for every file to be migrated. The code has now been changed
to set the value of info to 1 if the nodeuuid is that of the node
making the comparison so this becomes an integer comparison.

Change-Id: I7491d59caad3b71dbf5facc94dcde0cd53962775
BUG: 1451434
Signed-off-by: N Balachandran <nbalacha@redhat.com>

4 files changed, 40 insertions, 19 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 1cc2f08abf..c7069a9dbc 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -3938,7 +3938,7 @@ dht_find_local_subvol_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         int           i              = 0;
         int           index          = 0;
         int           found          = 0;
-
+        nodeuuid_info_t *tmp_ptr     = NULL;
 
         VALIDATE_OR_GOTO (frame, out);
         VALIDATE_OR_GOTO (frame->local, out);
@@ -4023,8 +4023,8 @@ dht_find_local_subvol_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 }
 
                 conf->local_nodeuuids[index].count = count;
-                conf->local_nodeuuids[index].uuids
-                                 = GF_CALLOC (count, sizeof (uuid_t), 1);
+                conf->local_nodeuuids[index].elements
+                               = GF_CALLOC (count, sizeof (nodeuuid_info_t), 1);
 
                 /* The node-uuids are guaranteed to be returned in the same
                  * order as the bricks
@@ -4039,9 +4039,15 @@ dht_find_local_subvol_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                      uuid_str = next_uuid_str) {
 
                         next_uuid_str = strtok_r (NULL, " ", &saveptr);
-                        gf_uuid_parse (uuid_str,
-                                       conf->local_nodeuuids[index].uuids[i]);
+                        tmp_ptr = &(conf->local_nodeuuids[index].elements[i]);
+                        gf_uuid_parse (uuid_str, tmp_ptr->uuid);
+
+                        if (!gf_uuid_compare (tmp_ptr->uuid,
+                                              conf->defrag->node_uuid)) {
+                                tmp_ptr->info = REBAL_NODEUUID_MINE;
+                        }
                         i++;
+                        tmp_ptr = NULL;
                 }
         }
 
@@ -4061,8 +4067,8 @@ dht_find_local_subvol_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 
  unwind:
 
-        GF_FREE (conf->local_nodeuuids[index].uuids);
-        conf->local_nodeuuids[index].uuids = NULL;
+        GF_FREE (conf->local_nodeuuids[index].elements);
+        conf->local_nodeuuids[index].elements = NULL;
 
         DHT_STACK_UNWIND (getxattr, frame, -1, local->op_errno, NULL, xdata);
  out:
diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index 9b39596f87..f3e2c5cf41 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -10,6 +10,7 @@
 
 #include <regex.h>
 #include <signal.h>
+#include <fnmatch.h>
 
 #include "dht-mem-types.h"
 #include "dht-messages.h"
@@ -47,10 +48,10 @@
 */
 extern char *xattrs_to_heal[];
 
+/* Rebalance nodeuuid flags */
+#define REBAL_NODEUUID_MINE   0x01
 
 
-#include <fnmatch.h>
-
 typedef int (*dht_selfheal_dir_cbk_t) (call_frame_t *frame, void *cookie,
                                        xlator_t     *this,
                                        int32_t       op_ret, int32_t op_errno,
@@ -515,10 +516,15 @@ typedef struct gf_tier_conf {
         char                         volname[GD_VOLUME_NAME_MAX + 1];
 } gf_tier_conf_t;
 
-typedef struct subvol_nodeuuids {
-        uuid_t *uuids;
+typedef struct nodeuuid_info {
+        char info; /* Set to 1 is this is my node's uuid*/
+        uuid_t uuid; /* Store the nodeuuid as well for debugging*/
+} nodeuuid_info_t;
+
+typedef struct subvol_nodeuuids_info {
+        nodeuuid_info_t *elements;
         int count;
-} subvol_nodeuuid_t;
+} subvol_nodeuuids_info_t;
 
 
 struct gf_defrag_info_ {
@@ -662,7 +668,7 @@ struct dht_conf {
 
         /*local subvol storage for rebalance*/
         xlator_t       **local_subvols;
-        subvol_nodeuuid_t       *local_nodeuuids;
+        subvol_nodeuuids_info_t       *local_nodeuuids;
         int32_t          local_subvols_cnt;
 
         /*
diff --git a/xlators/cluster/dht/src/dht-helper.c b/xlators/cluster/dht/src/dht-helper.c
index ee92a0b9c0..5c3d37ad10 100644
--- a/xlators/cluster/dht/src/dht-helper.c
+++ b/xlators/cluster/dht/src/dht-helper.c
@@ -1178,7 +1178,8 @@ dht_init_local_subvolumes (xlator_t *this, dht_conf_t *conf)
                                         gf_dht_mt_xlator_t);
 
         /* FIX FIX : do this dynamically*/
-        conf->local_nodeuuids = GF_CALLOC (cnt, sizeof (subvol_nodeuuid_t),
+        conf->local_nodeuuids = GF_CALLOC (cnt,
+                                           sizeof (subvol_nodeuuids_info_t),
                                            gf_dht_nodeuuids_t);
 
         if (!conf->local_subvols || !conf->local_nodeuuids) {
diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c
index e932eaa3ad..dd29d7db05 100644
--- a/xlators/cluster/dht/src/dht-rebalance.c
+++ b/xlators/cluster/dht/src/dht-rebalance.c
@@ -2447,7 +2447,12 @@ gf_defrag_ctx_subvols_init (dht_dfoffset_ctx_t *offset_var, xlator_t *this) {
 /* Return value
  * 0 : this node does not migrate the file
  * 1 : this node migrates the file
+ *
+ * Use the hash value of the gfid to determine which node will migrate files.
+ * Using the gfid instead of the name also ensures that the same node handles
+ * all hardlinks.
  */
+
 int
 gf_defrag_should_i_migrate (xlator_t *this, int local_subvol_index, uuid_t gfid)
 {
@@ -2468,13 +2473,14 @@ gf_defrag_should_i_migrate (xlator_t *this, int local_subvol_index, uuid_t gfid)
         }
 
         str = uuid_utoa_r (gfid, buf);
-
         ret = dht_hash_compute (this, 0, str, &hashval);
         if (ret == 0) {
                 index = (hashval % conf->local_nodeuuids[i].count);
-                if (!gf_uuid_compare (conf->defrag->node_uuid,
-                                      conf->local_nodeuuids[i].uuids[index]))
+                if (conf->local_nodeuuids[i].elements[index].info
+                                 == REBAL_NODEUUID_MINE) {
+                        /* Index matches this node's nodeuuid.*/
                         ret = 1;
+                }
         }
         return ret;
 }
@@ -4306,7 +4312,7 @@ gf_defrag_start_crawl (void *data)
         xlator_t                *old_THIS               = NULL;
         int                      j                      = 0;
         gf_boolean_t             fc_thread_started      = _gf_false;
-
+        uuid_t                  *uuid_ptr               = NULL;
 
         this = data;
         if (!this)
@@ -4444,10 +4450,12 @@ gf_defrag_start_crawl (void *data)
                 for (i = 0 ; i < conf->local_subvols_cnt; i++) {
                         gf_msg (this->name, GF_LOG_INFO, 0, 0, "local subvols "
                                 "are %s", conf->local_subvols[i]->name);
+
                         for (j = 0; j < conf->local_nodeuuids[i].count; j++) {
+                                uuid_ptr = &(conf->local_nodeuuids[i].elements[j].uuid);
                                 gf_msg (this->name, GF_LOG_INFO, 0, 0,
                                         "node uuids are %s",
-                                  uuid_utoa(conf->local_nodeuuids[i].uuids[j]));
+                                        uuid_utoa(*uuid_ptr));
                         }
                 }