cluster/ec: Handle absence of keys in some callback dict

Problem: This issue arises when we do a rolling update
from 3.7.5 to 3.7.9.
For 4+2 volume running 3.7.5, if we update 2 nodes
and after heal completion  kill 2 older nodes, this
problem can be seen. After update and killing of
bricks, 2 nodes will return inodelk count key in dict
while other 2 nodes will not have inodelk count in dict.
This is also true for get-link-count.
During dictionary match , ec_dict_compare, this will
lead to mismatch of answers and the file operation
on mount point will fail with IO error.

Solution:
Don't match inode, entry and link count keys while
comparing two dictionaries. However, while combining the
data in ec_dict_combine, go through all the dictionaries
and select the maximum values received in different dicts
for these keys.

master-
http://review.gluster.org/#/c/14761/

Change-Id: I33546e3619fe8f909286ee48fb0df2009cd3d22f
BUG: 1360152
Signed-off-by: Ashish Pandey <aspandey@redhat.com>
Reviewed-on: http://review.gluster.org/14761
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Signed-off-by: Ashish Pandey <aspandey@redhat.com>
Reviewed-on: http://review.gluster.org/15012

1 files changed, 10 insertions, 3 deletions

diff --git a/xlators/cluster/ec/src/ec-combine.c b/xlators/cluster/ec/src/ec-combine.c
index 4afbc5bb2b6..e609ada98b4 100644
--- a/xlators/cluster/ec/src/ec-combine.c
+++ b/xlators/cluster/ec/src/ec-combine.c
@@ -245,6 +245,9 @@ gf_boolean_t
 ec_xattr_match (dict_t *dict, char *key, data_t *value, void *arg)
 {
         if ((fnmatch(GF_XATTR_STIME_PATTERN, key, 0) == 0) ||
+            (strcmp(key, GET_LINK_COUNT) == 0) ||
+            (strcmp(key, GLUSTERFS_INODELK_COUNT) == 0) ||
+            (strcmp(key, GLUSTERFS_ENTRYLK_COUNT) == 0) ||
             (strcmp(key, GLUSTERFS_OPEN_FD_COUNT) == 0)) {
                 return _gf_false;
         }
@@ -285,8 +288,8 @@ ec_dict_compare (dict_t *dict1, dict_t *dict2)
 int32_t ec_dict_list(data_t ** list, int32_t * count, ec_cbk_data_t * cbk,
                      int32_t which, char * key)
 {
-    ec_cbk_data_t * ans;
-    dict_t * dict;
+    ec_cbk_data_t *ans = NULL;
+    dict_t *dict = NULL;
     int32_t i, max;
 
     max = *count;
@@ -672,6 +675,10 @@ int32_t ec_dict_data_combine(dict_t * dict, char * key, data_t * value,
         return ec_dict_data_merge(data->cbk, data->which, key);
     }
 
+    if (strcmp(key, GET_LINK_COUNT) == 0) {
+        return ec_dict_data_max32(data->cbk, data->which, key);
+    }
+
     if (strcmp(key, GLUSTERFS_OPEN_FD_COUNT) == 0)
     {
         return ec_dict_data_max32(data->cbk, data->which, key);
@@ -708,7 +715,7 @@ int32_t ec_dict_data_combine(dict_t * dict, char * key, data_t * value,
 
 int32_t ec_dict_combine(ec_cbk_data_t * cbk, int32_t which)
 {
-    dict_t * dict;
+    dict_t *dict = NULL;
     ec_dict_combine_t data;
     int32_t err = 0;