glusterd: performance improvement

Issue:
In the glusertd_op_stage_create_volume(), fetching of values
from the dict is done, whereas same values are fetched
by glusterd_check_brick_order() which is called from
that function. This leads to unnecssary performance overhead.

Fix:
Instead of fetching the values again, passing the
values to the glusterd_check_brick_order()
if it's fethced before, else a NULL is passed
and then only fetching is done here.
Also, few changes are made to the code to reduce
the cost of operations such as 'fast fail' for
false conditions and a bit of code clean up.

Fixes: #1397

Change-Id: Ic7b523adbca8eb63ef9eb29c206e3b19e05c0815
Signed-off-by: nik-redhat <nladha@redhat.com>

1 files changed, 28 insertions, 24 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 7d38b0a42d7..2f3fc218093 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -14632,7 +14632,8 @@ glusterd_compare_addrinfo(struct addrinfo *first, struct addrinfo *next)
  */
 int32_t
 glusterd_check_brick_order(dict_t *dict, char *err_str, int32_t type,
-                           int32_t sub_count)
+                           char **volname, char **brick_list,
+                           int32_t *brick_count, int32_t sub_count)
 {
     int ret = -1;
     int i = 0;
@@ -14643,12 +14644,9 @@ glusterd_check_brick_order(dict_t *dict, char *err_str, int32_t type,
     addrinfo_list_t *ai_list_tmp1 = NULL;
     addrinfo_list_t *ai_list_tmp2 = NULL;
     char *brick = NULL;
-    char *brick_list = NULL;
     char *brick_list_dup = NULL;
     char *brick_list_ptr = NULL;
     char *tmpptr = NULL;
-    char *volname = NULL;
-    int32_t brick_count = 0;
     struct addrinfo *ai_info = NULL;
     char brick_addr[128] = {
         0,
@@ -14676,32 +14674,38 @@ glusterd_check_brick_order(dict_t *dict, char *err_str, int32_t type,
     ai_list->info = NULL;
     CDS_INIT_LIST_HEAD(&ai_list->list);
 
-    ret = dict_get_strn(dict, "volname", SLEN("volname"), &volname);
-    if (ret) {
-        gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_DICT_GET_FAILED,
-               "Unable to get volume name");
-        goto out;
+    if (!(*volname)) {
+        ret = dict_get_strn(dict, "volname", SLEN("volname"), &(*volname));
+        if (ret) {
+            gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_DICT_GET_FAILED,
+                   "Unable to get volume name");
+            goto out;
+        }
     }
 
-    ret = dict_get_strn(dict, "bricks", SLEN("bricks"), &brick_list);
-    if (ret) {
-        gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_DICT_GET_FAILED,
-               "Bricks check : Could not "
-               "retrieve bricks list");
-        goto out;
+    if (!(*brick_list)) {
+        ret = dict_get_strn(dict, "bricks", SLEN("bricks"), &(*brick_list));
+        if (ret) {
+            gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_DICT_GET_FAILED,
+                   "Bricks check : Could not "
+                   "retrieve bricks list");
+            goto out;
+        }
     }
 
-    ret = dict_get_int32n(dict, "count", SLEN("count"), &brick_count);
-    if (ret) {
-        gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_DICT_GET_FAILED,
-               "Bricks check : Could not "
-               "retrieve brick count");
-        goto out;
+    if (!(*brick_count)) {
+        ret = dict_get_int32n(dict, "count", SLEN("count"), &(*brick_count));
+        if (ret) {
+            gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_DICT_GET_FAILED,
+                   "Bricks check : Could not "
+                   "retrieve brick count");
+            goto out;
+        }
     }
 
-    brick_list_dup = brick_list_ptr = gf_strdup(brick_list);
+    brick_list_dup = brick_list_ptr = gf_strdup(*brick_list);
     /* Resolve hostnames and get addrinfo */
-    while (i < brick_count) {
+    while (i < *brick_count) {
         ++i;
         brick = strtok_r(brick_list_dup, " \n", &tmpptr);
         brick_list_dup = tmpptr;
@@ -14738,7 +14742,7 @@ glusterd_check_brick_order(dict_t *dict, char *err_str, int32_t type,
     ai_list_tmp1 = cds_list_entry(ai_list->list.next, addrinfo_list_t, list);
 
     /* Check for bad brick order */
-    while (i < brick_count) {
+    while (i < *brick_count) {
         ++i;
         ai_info = ai_list_tmp1->info;
         ai_list_tmp1 = cds_list_entry(ai_list_tmp1->list.next, addrinfo_list_t,