glusterd: support for volume version and cksumv3.1.0qa8

Signed-off-by: Vijay Bellur <vijay@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1310 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1310

10 files changed, 600 insertions, 17 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-handler.c b/xlators/mgmt/glusterd/src/glusterd-handler.c
index 7e9a82e306a..00162e913ea 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handler.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handler.c
@@ -119,7 +119,8 @@ glusterd_friend_find_by_uuid (uuid_t uuid,
 }
 
 static int
-glusterd_handle_friend_req (rpcsvc_request_t *req, uuid_t  uuid, char *hostname, int port)
+glusterd_handle_friend_req (rpcsvc_request_t *req, uuid_t  uuid,
+                            char *hostname, int port, dict_t *dict)
 {
         int                             ret = -1;
         glusterd_peerinfo_t             *peerinfo = NULL;
@@ -159,6 +160,7 @@ glusterd_handle_friend_req (rpcsvc_request_t *req, uuid_t  uuid, char *hostname,
         if (hostname)
                 ctx->hostname = gf_strdup (hostname);
         ctx->req = req;
+        ctx->vols = dict;
 
         event->ctx = ctx;
 
@@ -176,6 +178,8 @@ out:
         if (0 != ret) {
                 if (ctx && ctx->hostname)
                         GF_FREE (ctx->hostname);
+                if (ctx && ctx->vols)
+                        dict_destroy (ctx->vols);
                 if (ctx)
                         GF_FREE (ctx);
         }
@@ -742,7 +746,7 @@ out:
                 defrag->mount);
 
         snprintf (cmd_str, 1024, "umount %s", defrag->mount);
-        system (cmd_str);
+        ret = system (cmd_str);
         volinfo->defrag = NULL;
         LOCK_DESTROY (&defrag->lock);
         GF_FREE (defrag);
@@ -1291,7 +1295,8 @@ glusterd_handle_incoming_friend_req (rpcsvc_request_t *req)
 {
         int32_t                 ret = -1;
         gd1_mgmt_friend_req     friend_req = {{0},};
-        char                    str[50];
+        char                    str[50] = {0,};
+        dict_t                  *dict = NULL;
 
         GF_ASSERT (req);
         if (!gd_xdr_to_mgmt_friend_req (req->msg[0], &friend_req)) {
@@ -1304,8 +1309,22 @@ glusterd_handle_incoming_friend_req (rpcsvc_request_t *req)
         gf_log ("glusterd", GF_LOG_NORMAL,
                 "Received probe from uuid: %s", str);
 
+        dict = dict_new ();
+        if (!dict) {
+                ret = -1;
+                goto out;
+        }
+
+        ret = dict_unserialize (friend_req.vols.vols_val,
+                                friend_req.vols.vols_len,
+                                &dict);
+
+        if (ret)
+                goto out;
+
         ret = glusterd_handle_friend_req (req, friend_req.uuid,
-                                          friend_req.hostname, friend_req.port);
+                                          friend_req.hostname, friend_req.port,
+                                          dict);
 
 out:
 
@@ -1728,7 +1747,8 @@ glusterd_xfer_friend_remove_resp (rpcsvc_request_t *req, char *hostname, int por
 }
 
 int
-glusterd_xfer_friend_add_resp (rpcsvc_request_t *req, char *hostname, int port)
+glusterd_xfer_friend_add_resp (rpcsvc_request_t *req, char *hostname, int port,
+                               int32_t op_ret)
 {
         gd1_mgmt_friend_rsp  rsp = {{0}, };
         int32_t              ret = -1;
@@ -1737,7 +1757,7 @@ glusterd_xfer_friend_add_resp (rpcsvc_request_t *req, char *hostname, int port)
 
         GF_ASSERT (hostname);
 
-        rsp.op_ret = 0;
+        rsp.op_ret = op_ret;
         this = THIS;
         GF_ASSERT (this);
 
diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index b243e78951b..3b4b390d144 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -253,7 +253,7 @@ out:
         return ret;
 }
 
-static int
+int
 glusterd_volume_create_generate_volfiles (glusterd_volinfo_t *volinfo)
 {
         int32_t         ret = -1;
@@ -800,6 +800,7 @@ glusterd_op_create_volume (gd1_mgmt_stage_op_req *req)
                 i++;
         }
         list_add_tail (&volinfo->vol_list, &priv->volumes);
+        volinfo->version++;
 
         ret = glusterd_store_create_volume (volinfo);
 
@@ -811,6 +812,10 @@ glusterd_op_create_volume (gd1_mgmt_stage_op_req *req)
                 goto out;
 
 
+        ret = glusterd_volume_compute_cksum (volinfo);
+        if (ret)
+                goto out;
+
 out:
         return ret;
 }
@@ -942,6 +947,12 @@ glusterd_op_add_brick (gd1_mgmt_stage_op_req *req)
                         goto out;
         }
 
+        volinfo->version++;
+
+        ret = glusterd_volume_compute_cksum (volinfo);
+        if (ret)
+                goto out;
+
         ret = glusterd_store_update_volume (volinfo);
 
         if (ret)
@@ -1879,6 +1890,12 @@ glusterd_op_remove_brick (gd1_mgmt_stage_op_req *req)
                         goto out;
         }
 
+        volinfo->version++;
+
+        ret = glusterd_volume_compute_cksum (volinfo);
+        if (ret)
+                goto out;
+
         ret = glusterd_store_update_volume (volinfo);
 
         if (ret)
diff --git a/xlators/mgmt/glusterd/src/glusterd-sm.c b/xlators/mgmt/glusterd/src/glusterd-sm.c
index 18b0b1aa5eb..c12a11a8fb2 100644
--- a/xlators/mgmt/glusterd/src/glusterd-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-sm.c
@@ -306,6 +306,7 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
         glusterd_friend_sm_event_t      *new_event = NULL;
         glusterd_friend_sm_event_type_t event_type = GD_FRIEND_EVENT_NONE;
         int                             status = 0;
+        int32_t                         op_ret = -1;
 
         GF_ASSERT (ctx);
         ev_ctx = ctx;
@@ -315,11 +316,18 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
         uuid_copy (peerinfo->uuid, ev_ctx->uuid);
 
         //Build comparison logic here.
+        ret = glusterd_compare_friend_data (ev_ctx->vols, &status);
+        if (ret)
+                goto out;
 
-        if (!status)
+        if (GLUSTERD_VOL_COMP_RJT != status) {
                 event_type = GD_FRIEND_EVENT_LOCAL_ACC;
-        else
+                op_ret = 0;
+        }
+        else {
                 event_type = GD_FRIEND_EVENT_LOCAL_RJT;
+                op_ret = -1;
+        }
 
         ret = glusterd_friend_sm_new_event (event_type, &new_event);
 
@@ -344,7 +352,7 @@ glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
         glusterd_friend_sm_inject_event (new_event);
 
         ret = glusterd_xfer_friend_add_resp (ev_ctx->req, ev_ctx->hostname,
-                                             ev_ctx->port);
+                                             ev_ctx->port, op_ret);
 
 out:
         gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
@@ -408,7 +416,7 @@ glusterd_sm_t  glusterd_state_req_rcvd [] = {
         {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
         {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
         {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
-        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
+        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
         {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
         {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
         {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
diff --git a/xlators/mgmt/glusterd/src/glusterd-sm.h b/xlators/mgmt/glusterd/src/glusterd-sm.h
index 65cf6dc8905..6490f3d526d 100644
--- a/xlators/mgmt/glusterd/src/glusterd-sm.h
+++ b/xlators/mgmt/glusterd/src/glusterd-sm.h
@@ -124,6 +124,7 @@ typedef struct glusterd_friend_req_ctx_ {
         char                    *hostname;
         rpcsvc_request_t        *req;
         int                      port;
+        dict_t                  *vols;
 } glusterd_friend_req_ctx_t;
 
 typedef glusterd_friend_req_ctx_t glusterd_friend_update_ctx_t;
diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index 2cee89516db..ee47696da96 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -134,9 +134,9 @@ glusterd_store_create_brick (glusterd_volinfo_t *volinfo,
 
 
         snprintf (buf, sizeof(buf), "hostname=%s\n", brickinfo->hostname);
-        write (fd, buf, strlen(buf));
+        ret = write (fd, buf, strlen(buf));
         snprintf (buf, sizeof(buf), "path=%s\n", brickinfo->path);
-        write (fd, buf, strlen(buf));
+        ret = write (fd, buf, strlen(buf));
 
         ret = 0;
 
@@ -293,18 +293,24 @@ glusterd_store_create_volume (glusterd_volinfo_t *volinfo)
         if (ret)
                 goto out;
 
-        snprintf (buf, sizeof (buf), "%d", volinfo->status);
+/*        snprintf (buf, sizeof (buf), "%d", volinfo->port);
         ret = glusterd_store_save_value (volinfo->shandle,
                                         GLUSTERD_STORE_KEY_VOL_PORT, buf);
         if (ret)
                 goto out;
-
+*/
         snprintf (buf, sizeof (buf), "%d", volinfo->sub_count);
         ret = glusterd_store_save_value (volinfo->shandle,
                                         GLUSTERD_STORE_KEY_VOL_SUB_COUNT, buf);
         if (ret)
                 goto out;
 
+        snprintf (buf, sizeof (buf), "%d", volinfo->version);
+        ret = glusterd_store_save_value (volinfo->shandle,
+                                        GLUSTERD_STORE_KEY_VOL_VERSION, buf);
+        if (ret)
+                goto out;
+
         list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
                 ret = glusterd_store_create_brick (volinfo, brickinfo);
                 if (ret)
@@ -328,7 +334,7 @@ int32_t
 glusterd_store_delete_volume (glusterd_volinfo_t *volinfo)
 {
         char    pathname[PATH_MAX] = {0,};
-        int32_t ret = -1;
+        int32_t ret = 0;
         glusterd_conf_t *priv = NULL;
         DIR     *dir = NULL;
         struct dirent *entry = NULL;
diff --git a/xlators/mgmt/glusterd/src/glusterd-store.h b/xlators/mgmt/glusterd/src/glusterd-store.h
index 1889e5f58bd..10fb4a3af01 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.h
+++ b/xlators/mgmt/glusterd/src/glusterd-store.h
@@ -46,6 +46,7 @@
 #define GLUSTERD_STORE_KEY_VOL_PORT   "port"
 #define GLUSTERD_STORE_KEY_VOL_SUB_COUNT   "sub_count"
 #define GLUSTERD_STORE_KEY_VOL_BRICK  "brick"
+#define GLUSTERD_STORE_KEY_VOL_VERSION  "version"
 
 #define GLUSTERD_STORE_KEY_BRICK_HOSTNAME "hostname"
 #define GLUSTERD_STORE_KEY_BRICK_PATH "path"
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 35dfa3dfba3..f0115c05b19 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -927,3 +927,491 @@ glusterd_is_cli_op_req (int32_t op)
 
         return _gf_false;
 }
+
+
+int
+glusterd_volume_compute_cksum (glusterd_volinfo_t  *volinfo)
+{
+        int32_t                 ret = -1;
+        glusterd_conf_t         *priv = NULL;
+        char                    path[PATH_MAX] = {0,};
+        char                    cksum_path[PATH_MAX] = {0,};
+        char                    filepath[PATH_MAX] = {0,};
+        DIR                     *dir = NULL;
+        struct dirent           *entry = NULL;
+        int                     fd = -1;
+        uint32_t                cksum = 0;
+        char                    buf[4096] = {0,};
+
+        GF_ASSERT (volinfo);
+
+        priv = THIS->private;
+        GF_ASSERT (priv);
+
+        GLUSTERD_GET_VOLUME_DIR (path, volinfo, priv);
+
+        snprintf (cksum_path, sizeof (cksum_path), "%s/%s",
+                  path, GLUSTERD_CKSUM_FILE);
+
+        fd = open (cksum_path, O_RDWR | O_APPEND | O_CREAT, 0644);
+
+        if (-1 == fd) {
+                gf_log ("", GF_LOG_ERROR, "Unable to open %s, errno: %d",
+                        cksum_path, errno);
+                ret = -1;
+                goto out;
+        }
+
+
+        dir = opendir (path);
+
+        glusterd_for_each_entry (entry, dir);
+
+/*        while (entry) {
+
+                snprintf (filepath, sizeof (filepath), "%s/%s", path,
+                          entry->d_name);
+
+                if (!strcmp (entry->d_name, "bricks") ||
+                     !strcmp (entry->d_name, "run")) {
+                        glusterd_for_each_entry (entry, dir);
+                        continue;
+                }
+
+                ret = get_checksum_for_path (filepath, &cksum);
+
+                if (ret) {
+                        gf_log ("", GF_LOG_ERROR, "Unable to get checksum"
+                                " for path: %s", filepath);
+                        goto out;
+                }
+
+                snprintf (buf, sizeof (buf), "%s=%u\n", entry->d_name, cksum);
+                ret = write (fd, buf, strlen (buf));
+
+                if (ret <= 0) {
+                        ret = -1;
+                        goto out;
+                }
+
+                glusterd_for_each_entry (entry, dir);
+        }
+*/
+
+        snprintf (filepath, sizeof (filepath), "%s/%s", path,
+                  GLUSTERD_VOLUME_INFO_FILE);
+
+        ret = get_checksum_for_path (filepath, &cksum);
+
+        if (ret) {
+                gf_log ("", GF_LOG_ERROR, "Unable to get checksum"
+                        " for path: %s", filepath);
+                goto out;
+        }
+
+        snprintf (buf, sizeof (buf), "%s=%u\n", "info", cksum);
+        ret = write (fd, buf, strlen (buf));
+
+        if (ret <= 0) {
+                ret = -1;
+                goto out;
+        }
+
+        ret = get_checksum_for_file (fd, &cksum);
+
+        if (ret)
+                goto out;
+
+       volinfo->cksum = cksum;
+
+out:
+       if (fd > 0)
+               close (fd);
+
+       if (dir)
+               closedir (dir);
+
+       gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
+
+       return ret;
+}
+
+int32_t
+glusterd_add_volume_to_dict (glusterd_volinfo_t *volinfo,
+                             dict_t  *dict, int32_t count)
+{
+        int32_t                 ret = -1;
+        char                    key[512] = {0,};
+        glusterd_brickinfo_t    *brickinfo = NULL;
+        int32_t                 i = 1;
+
+        GF_ASSERT (dict);
+        GF_ASSERT (volinfo);
+
+        snprintf (key, sizeof (key), "volume%d.name", count);
+        ret = dict_set_str (dict, key, volinfo->volname);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.type", count);
+        ret = dict_set_int32 (dict, key, volinfo->type);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.brick_count", count);
+        ret = dict_set_int32 (dict, key, volinfo->brick_count);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.version", count);
+        ret = dict_set_int32 (dict, key, volinfo->version);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.status", count);
+        ret = dict_set_int32 (dict, key, volinfo->status);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.sub_count", count);
+        ret = dict_set_int32 (dict, key, volinfo->sub_count);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.ckusm", count);
+        ret = dict_set_int64 (dict, key, volinfo->cksum);
+        if (ret)
+                goto out;
+
+        list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
+                memset (&key, 0, sizeof (key));
+                snprintf (key, sizeof (key), "volume%d.brick%d.hostname",
+                          count, i);
+                ret = dict_set_str (dict, key, brickinfo->hostname);
+                if (ret)
+                        goto out;
+
+                memset (&key, 0, sizeof (key));
+                snprintf (key, sizeof (key), "volume%d.brick%d.path",
+                          count, i);
+                ret = dict_set_str (dict, key, brickinfo->path);
+                if (ret)
+                        goto out;
+
+                i++;
+        }
+
+
+out:
+        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
+
+        return ret;
+}
+
+int32_t
+glusterd_build_volume_dict (dict_t **vols)
+{
+        int32_t                 ret = -1;
+        dict_t                  *dict = NULL;
+        glusterd_conf_t         *priv = NULL;
+        glusterd_volinfo_t      *volinfo = NULL;
+        int32_t                 count = 0;
+
+        priv = THIS->private;
+
+        dict = dict_new ();
+
+        if (!dict)
+                goto out;
+
+        list_for_each_entry (volinfo, &priv->volumes, vol_list) {
+                count++;
+                ret = glusterd_add_volume_to_dict (volinfo, dict, count);
+                if (ret)
+                        goto out;
+        }
+
+
+        ret = dict_set_int32 (dict, "count", count);
+        if (ret)
+                goto out;
+
+        *vols = dict;
+out:
+        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
+        if (ret)
+                dict_destroy (dict);
+
+        return ret;
+}
+
+int32_t
+glusterd_compare_friend_volume (dict_t *vols, int32_t count, int32_t *status)
+{
+
+        int32_t                 ret = -1;
+        char                    key[512] = {0,};
+        glusterd_volinfo_t      *volinfo = NULL;
+        char                    *volname = NULL;
+        uint32_t                cksum = 0;
+        int32_t                 version = 0;
+
+        GF_ASSERT (vols);
+        GF_ASSERT (status);
+
+        snprintf (key, sizeof (key), "volume%d.name", count);
+        ret = dict_get_str (vols, key, &volname);
+        if (ret)
+                goto out;
+
+        ret = glusterd_volinfo_find (volname, &volinfo);
+
+        if (ret) {
+                *status = GLUSTERD_VOL_COMP_UPDATE_REQ;
+                ret = 0;
+                goto out;
+        }
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.version", count);
+        ret = dict_get_int32 (vols, key, &version);
+        if (ret)
+                goto out;
+
+        if (version != volinfo->version) {
+                //Mismatch detected
+                ret = 0;
+                gf_log ("", GF_LOG_ERROR, "Version of volume %s differ."
+                        "local version = %d, remote version = %d",
+                        volinfo->volname, volinfo->version, version);
+                *status = GLUSTERD_VOL_COMP_UPDATE_REQ;
+                goto out;
+        }
+
+        //Now, versions are same, compare cksums.
+        //
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.ckusm", count);
+        ret = dict_get_uint32 (vols, key, &cksum);
+        if (ret)
+                goto out;
+
+        if (cksum != volinfo->cksum) {
+                ret = 0;
+                gf_log ("", GF_LOG_ERROR, "Cksums of volume %s differ."
+                        " local cksum = %d, remote cksum = %d",
+                        volinfo->volname, volinfo->cksum, cksum);
+                *status = GLUSTERD_VOL_COMP_RJT;
+                goto out;
+        }
+
+        *status = GLUSTERD_VOL_COMP_SCS;
+
+out:
+        gf_log ("", GF_LOG_DEBUG, "Returning with ret: %d, status: %d",
+                ret, *status);
+        return ret;
+}
+
+int32_t
+glusterd_import_friend_volume (dict_t *vols, int count)
+{
+
+        int32_t                 ret = -1;
+        glusterd_conf_t         *priv = NULL;
+        char                    key[512] = {0,};
+        glusterd_volinfo_t      *volinfo = NULL;
+        char                    *volname = NULL;
+        char                    *hostname = NULL;
+        char                    *path = NULL;
+        glusterd_brickinfo_t    *brickinfo = NULL;
+        glusterd_brickinfo_t    *tmp = NULL;
+        int                     new_volinfo = 0;
+        int                     i = 1;
+
+        GF_ASSERT (vols);
+
+        snprintf (key, sizeof (key), "volume%d.name", count);
+        ret = dict_get_str (vols, key, &volname);
+        if (ret)
+                goto out;
+
+        priv = THIS->private;
+
+        ret = glusterd_volinfo_find (volname, &volinfo);
+
+        if (ret) {
+                ret = glusterd_volinfo_new (&volinfo);
+                if (ret)
+                        goto out;
+                strncpy (volinfo->volname, volname, sizeof (volinfo->volname));
+                new_volinfo = 1;
+        }
+
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.type", count);
+        ret = dict_get_int32 (vols, key, &volinfo->type);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.brick_count", count);
+        ret = dict_get_int32 (vols, key, &volinfo->brick_count);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.version", count);
+        ret = dict_get_int32 (vols, key, &volinfo->version);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.status", count);
+        ret = dict_get_int32 (vols, key, (int32_t *)&volinfo->status);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.sub_count", count);
+        ret = dict_get_int32 (vols, key, &volinfo->sub_count);
+        if (ret)
+                goto out;
+
+        memset (&key, 0, sizeof (key));
+        snprintf (key, sizeof (key), "volume%d.ckusm", count);
+        ret = dict_get_uint32 (vols, key, &volinfo->cksum);
+        if (ret)
+                goto out;
+
+        list_for_each_entry_safe (brickinfo, tmp, &volinfo->bricks,
+                                   brick_list) {
+                ret = glusterd_brickinfo_delete (brickinfo);
+                if (ret)
+                        goto out;
+        }
+
+        while (i <= volinfo->brick_count) {
+
+                memset (&key, 0, sizeof (key));
+                snprintf (key, sizeof (key), "volume%d.brick%d.hostname",
+                          count, i);
+                ret = dict_get_str (vols, key, &hostname);
+                if (ret)
+                        goto out;
+
+                memset (&key, 0, sizeof (key));
+                snprintf (key, sizeof (key), "volume%d.brick%d.path",
+                          count, i);
+                ret = dict_get_str (vols, key, &path);
+                if (ret)
+                        goto out;
+
+                ret = glusterd_brickinfo_new (&brickinfo);
+                if (ret)
+                        goto out;
+
+                strcpy (brickinfo->path, path);
+                strcpy (brickinfo->hostname, hostname);
+
+                list_add_tail (&brickinfo->brick_list, &volinfo->bricks);
+
+                i++;
+        }
+
+        if (new_volinfo) {
+                list_add_tail (&volinfo->vol_list, &priv->volumes);
+                ret = glusterd_store_create_volume (volinfo);
+        } else {
+                ret = glusterd_store_update_volume (volinfo);
+        }
+
+        ret = glusterd_volume_create_generate_volfiles (volinfo);
+        if (ret)
+                goto out;
+
+        //volinfo->version++;
+
+        ret = glusterd_volume_compute_cksum (volinfo);
+        if (ret)
+                goto out;
+
+
+out:
+        gf_log ("", GF_LOG_DEBUG, "Returning with ret: %d", ret);
+        return ret;
+}
+
+
+int32_t
+glusterd_import_friend_volumes (dict_t  *vols)
+{
+        int32_t                 ret = -1;
+        int32_t                 count = 0;
+        int                     i = 1;
+
+        GF_ASSERT (vols);
+
+        ret = dict_get_int32 (vols, "count", &count);
+        if (ret)
+                goto out;
+
+        while (i <= count) {
+                ret = glusterd_import_friend_volume (vols, i);
+                if (ret)
+                        goto out;
+
+                i++;
+        }
+
+out:
+        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);
+        return ret;
+}
+
+int32_t
+glusterd_compare_friend_data (dict_t  *vols, int32_t *status)
+{
+        int32_t                 ret = -1;
+        int32_t                 count = 0;
+        int                     i = 1;
+
+        GF_ASSERT (vols);
+        GF_ASSERT (status);
+
+        ret = dict_get_int32 (vols, "count", &count);
+        if (ret)
+                goto out;
+
+        while (i <= count) {
+                ret = glusterd_compare_friend_volume (vols, i, status);
+                if (ret)
+                        goto out;
+
+                if (GLUSTERD_VOL_COMP_RJT == *status) {
+                        ret = 0;
+                        goto out;
+                }
+
+                i++;
+        }
+
+        if (GLUSTERD_VOL_COMP_UPDATE_REQ == *status) {
+                ret = glusterd_import_friend_volumes (vols);
+                if (ret)
+                        goto out;
+        }
+
+out:
+        gf_log ("", GF_LOG_DEBUG, "Returning with ret: %d, status: %d",
+                ret, *status);
+
+        return ret;
+}
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.h b/xlators/mgmt/glusterd/src/glusterd-utils.h
index 892533c40a6..1e9469ce0fd 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.h
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.h
@@ -117,4 +117,16 @@ glusterd_brickinfo_get (char *brick, glusterd_volinfo_t *volinfo,
                         glusterd_brickinfo_t **brickinfo);
 int32_t
 glusterd_is_local_addr (char *hostname);
+
+int32_t
+glusterd_build_volume_dict (dict_t **vols);
+
+int32_t
+glusterd_compare_friend_data (dict_t  *vols, int32_t *status);
+
+int
+glusterd_volume_compute_cksum (glusterd_volinfo_t  *volinfo);
+
+int
+glusterd_volume_create_generate_volfiles (glusterd_volinfo_t *volinfo);
 #endif
diff --git a/xlators/mgmt/glusterd/src/glusterd.h b/xlators/mgmt/glusterd/src/glusterd.h
index cc1fb7786bd..4465ee316dd 100644
--- a/xlators/mgmt/glusterd/src/glusterd.h
+++ b/xlators/mgmt/glusterd/src/glusterd.h
@@ -127,6 +127,9 @@ struct glusterd_volinfo_ {
         uint64_t                rebalance_data;
         uint64_t                lookedup_files;
         glusterd_defrag_info_t  *defrag;
+
+        int                     version;
+        uint32_t                cksum;
 };
 
 typedef struct glusterd_volinfo_ glusterd_volinfo_t;
@@ -135,6 +138,13 @@ enum glusterd_op_ret {
         GLUSTERD_CONNECTION_AWAITED = 100,
 };
 
+enum glusterd_vol_comp_status_ {
+        GLUSTERD_VOL_COMP_NONE = 0,
+        GLUSTERD_VOL_COMP_SCS = 1,
+        GLUSTERD_VOL_COMP_UPDATE_REQ,
+        GLUSTERD_VOL_COMP_RJT,
+};
+
 #define GLUSTERD_DEFAULT_WORKDIR "/etc/glusterd"
 #define GLUSTERD_DEFAULT_PORT   6969
 #define GLUSTERD_INFO_FILE      "glusterd.info"
@@ -142,6 +152,7 @@ enum glusterd_op_ret {
 #define GLUSTERD_PEER_DIR_PREFIX "peers"
 #define GLUSTERD_VOLUME_INFO_FILE "info"
 #define GLUSTERD_BRICK_INFO_DIR "bricks"
+#define GLUSTERD_CKSUM_FILE "cksum"
 
 /*All definitions related to replace brick */
 #define RB_PUMP_START_CMD       "trusted.glusterfs.pump.start"
@@ -173,7 +184,8 @@ int
 glusterd_probe_begin (rpcsvc_request_t *req, const char *hoststr, int port);
 
 int
-glusterd_xfer_friend_add_resp (rpcsvc_request_t *req, char *hostname, int port);
+glusterd_xfer_friend_add_resp (rpcsvc_request_t *req, char *hostname,
+                               int port, int32_t op_ret);
 
 int
 glusterd_friend_find (uuid_t uuid, char *hostname,
diff --git a/xlators/mgmt/glusterd/src/glusterd3_1-mops.c b/xlators/mgmt/glusterd/src/glusterd3_1-mops.c
index 2c5cb8f33ab..5196055b3e1 100644
--- a/xlators/mgmt/glusterd/src/glusterd3_1-mops.c
+++ b/xlators/mgmt/glusterd/src/glusterd3_1-mops.c
@@ -639,6 +639,7 @@ glusterd3_1_friend_add (call_frame_t *frame, xlator_t *this,
         glusterd_conf_t         *priv = NULL;
         glusterd_friend_sm_event_t     *event = NULL;
         glusterd_friend_req_ctx_t *ctx = NULL;
+        dict_t                  *vols = NULL;
 
 
         if (!frame || !this || !data) {
@@ -655,15 +656,32 @@ glusterd3_1_friend_add (call_frame_t *frame, xlator_t *this,
 
         peerinfo = event->peerinfo;
 
+        ret = glusterd_build_volume_dict (&vols);
+        if (ret)
+                goto out;
+
         uuid_copy (req.uuid, priv->uuid);
         req.hostname = gf_strdup (peerinfo->hostname);
         req.port = peerinfo->port;
+
+        ret = dict_allocate_and_serialize (vols, &req.vols.vols_val,
+                                           (size_t *)&req.vols.vols_len);
+        if (ret)
+                goto out;
+
         ret = glusterd_submit_request (peerinfo, &req, frame, priv->mgmt,
                                        GD_MGMT_FRIEND_ADD,
                                        NULL, gd_xdr_from_mgmt_friend_req,
                                        this, glusterd3_1_friend_add_cbk);
 
+
 out:
+        if (req.vols.vols_val)
+                GF_FREE (req.vols.vols_val);
+
+        if (vols)
+                dict_destroy (vols);
+
         gf_log ("glusterd", GF_LOG_DEBUG, "Returning %d", ret);
         return ret;
 }