glusterd: Added volume-id to 'op' dictionary

Volume-id passed in op dictionary would help detect possible split brains
among peers in a cluster. The idea is to check if the volume's id and
the vol-id that was passed are equal.
ie, same volume name, but different volume id indicate that glusterd
'metadata' of one of the participating peers is stale or there is
a split brain.

This is over and above the existing checksum based validation of peer
supplied cluster 'metadata' (ie, volume info file).

Change-Id: I1049ef249e417e540ccb4243e450f92fcd0f46f9
BUG: 797734
Signed-off-by: Krishnan Parthasarathi <kp@gluster.com>
Reviewed-on: http://review.gluster.com/3083
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 817cbbc32..7198a1307 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -5328,3 +5328,31 @@ glusterd_is_local_brick (xlator_t *this, glusterd_volinfo_t *volinfo,
 out:
         return local;
 }
+int
+glusterd_validate_volume_id (dict_t *op_dict, glusterd_volinfo_t *volinfo)
+{
+        int     ret             = -1;
+        char    *volid_str      = NULL;
+        uuid_t  vol_uid         = {0, };
+
+        ret = dict_get_str (op_dict, "vol-id", &volid_str);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_ERROR, "Failed to get volume id");
+                goto out;
+        }
+        ret = uuid_parse (volid_str, vol_uid);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_ERROR, "Failed to parse uuid");
+                goto out;
+        }
+
+        if (uuid_compare (vol_uid, volinfo->volume_id)) {
+                gf_log (THIS->name, GF_LOG_ERROR, "Volume ids are different. "
+                        "Possibly a split brain among peers.");
+                ret = -1;
+                goto out;
+        }
+
+out:
+        return ret;
+}