glusterd: Changes to provide interface for USS

The changes which consists of the translators for the USS (User Servicable
Snapshots) is submitted as a separate patch. Current patch provides the
CLI access to the feature.

Change-Id: I6b98a42fcfa82f0870d8048fe0bb53141565e9c6
BUG: 1094815
Signed-off-by: Varun Shastry <vshastry@redhat.com>
Reviewed-on: http://review.gluster.org/7705
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>

10 files changed, 913 insertions, 174 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-handler.c b/xlators/mgmt/glusterd/src/glusterd-handler.c
index e203e5af01f..733bea236ed 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handler.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handler.c
@@ -4138,6 +4138,65 @@ glusterd_brick_rpc_notify (struct rpc_clnt *rpc, void *mydata,
 }
 
 int
+__glusterd_snapd_rpc_notify (struct rpc_clnt *rpc, void *mydata,
+                             rpc_clnt_event_t event, void *data)
+{
+        xlator_t                *this           = NULL;
+        glusterd_conf_t         *conf           = NULL;
+        glusterd_volinfo_t      *volinfo        = NULL;
+        int                     ret             = 0;
+
+        this = THIS;
+        GF_ASSERT (this);
+        conf = this->private;
+        GF_ASSERT (conf);
+
+        volinfo = mydata;
+        if (!volinfo)
+                return 0;
+
+        switch (event) {
+        case RPC_CLNT_CONNECT:
+                gf_log (this->name, GF_LOG_DEBUG, "got RPC_CLNT_CONNECT");
+
+                (void) glusterd_snapd_set_online_status (volinfo, _gf_true);
+
+                break;
+
+        case RPC_CLNT_DISCONNECT:
+                if (glusterd_is_snapd_online (volinfo)) {
+                        gf_msg (this->name, GF_LOG_INFO, 0,
+                                GD_MSG_NODE_DISCONNECTED,
+                                "snapd for volume %s has disconnected from "
+                                "glusterd.", volinfo->volname);
+
+                        (void) glusterd_snapd_set_online_status
+                                                          (volinfo, _gf_false);
+                }
+                break;
+
+        case RPC_CLNT_DESTROY:
+                glusterd_volinfo_unref (volinfo);
+                break;
+
+        default:
+                gf_log (this->name, GF_LOG_TRACE,
+                        "got some other RPC event %d", event);
+                break;
+        }
+
+        return ret;
+}
+
+int
+glusterd_snapd_rpc_notify (struct rpc_clnt *rpc, void *mydata,
+                             rpc_clnt_event_t event, void *data)
+{
+        return glusterd_big_locked_notify (rpc, mydata, event, data,
+                                           __glusterd_snapd_rpc_notify);
+}
+
+int
 __glusterd_nodesvc_rpc_notify (struct rpc_clnt *rpc, void *mydata,
                                rpc_clnt_event_t event, void *data)
 {
diff --git a/xlators/mgmt/glusterd/src/glusterd-handshake.c b/xlators/mgmt/glusterd/src/glusterd-handshake.c
index 2901b98d847..115dd8bd145 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handshake.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handshake.c
@@ -162,6 +162,7 @@ build_volfile_path (const char *volname, char *path,
         const char              *volname_ptr            = NULL;
         char                     path_prefix [PATH_MAX] = {0,};
         xlator_t                *this                   = NULL;
+        char                    *volname_tmp            = NULL;
 
         this = THIS;
         GF_ASSERT (this);
@@ -170,7 +171,18 @@ build_volfile_path (const char *volname, char *path,
         GF_ASSERT (volname);
         GF_ASSERT (path);
 
-        if (strstr (volname, "gluster/")) {
+        if (strstr (volname, "snapd/")) {
+                volname_tmp = strchr (volname, '/') + 1;
+                ret = glusterd_volinfo_find (volname_tmp, &volinfo);
+                if (ret == -1) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Couldn't find volinfo");
+                        goto out;
+                }
+                glusterd_get_snapd_volfile (volinfo, path, path_len);
+                ret = 1;
+                goto out;
+        } else if (strstr (volname, "gluster/")) {
                 server = strchr (volname, '/') + 1;
                 glusterd_get_nodesvc_volfile (server, priv->workdir,
                                               path, path_len);
diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index 4ad53c126e6..73f4c152460 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -2072,6 +2072,11 @@ glusterd_op_set_volume (dict_t *dict)
 
         if (!global_opts_set) {
                 gd_update_volume_op_versions (volinfo);
+
+                ret = glusterd_handle_snapd_option (volinfo);
+                if (ret)
+                        goto out;
+
                 ret = glusterd_create_volfiles_and_notify_services (volinfo);
                 if (ret) {
                         gf_log (this->name, GF_LOG_ERROR,
@@ -2098,6 +2103,11 @@ glusterd_op_set_volume (dict_t *dict)
                 list_for_each_entry (voliter, &priv->volumes, vol_list) {
                         volinfo = voliter;
                         gd_update_volume_op_versions (volinfo);
+
+                        ret = glusterd_handle_snapd_option (volinfo);
+                        if (ret)
+                                goto out;
+
                         ret = glusterd_create_volfiles_and_notify_services (volinfo);
                         if (ret) {
                                 gf_log (this->name, GF_LOG_ERROR,
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index bd9f7ba39af..6f48767b8a3 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -230,10 +230,10 @@ glusterd_get_uuid (uuid_t *uuid)
 
 int
 glusterd_submit_request_unlocked (struct rpc_clnt *rpc, void *req,
-				  call_frame_t *frame, rpc_clnt_prog_t *prog,
-				  int procnum, struct iobref *iobref,
-				  xlator_t *this, fop_cbk_fn_t cbkfn,
-				  xdrproc_t xdrproc)
+                                  call_frame_t *frame, rpc_clnt_prog_t *prog,
+                                  int procnum, struct iobref *iobref,
+                                  xlator_t *this, fop_cbk_fn_t cbkfn,
+                                  xdrproc_t xdrproc)
 {
         int                     ret         = -1;
         struct iobuf            *iobuf      = NULL;
@@ -312,17 +312,17 @@ glusterd_submit_request (struct rpc_clnt *rpc, void *req,
                          xlator_t *this, fop_cbk_fn_t cbkfn, xdrproc_t xdrproc)
 {
         glusterd_conf_t         *priv = THIS->private;
-	int ret = -1;
+        int ret = -1;
 
-	synclock_unlock (&priv->big_lock);
-	{
-		ret = glusterd_submit_request_unlocked (rpc, req, frame, prog,
-							procnum, iobref, this,
-							cbkfn, xdrproc);
-	}
-	synclock_lock (&priv->big_lock);
+        synclock_unlock (&priv->big_lock);
+        {
+                ret = glusterd_submit_request_unlocked (rpc, req, frame, prog,
+                                                        procnum, iobref, this,
+                                                        cbkfn, xdrproc);
+        }
+        synclock_lock (&priv->big_lock);
 
-	return ret;
+        return ret;
 }
 
 
@@ -1919,7 +1919,6 @@ glusterd_brick_unlink_socket_file (glusterd_volinfo_t *volinfo,
         char                    socketpath[PATH_MAX] = {0};
         xlator_t                *this = NULL;
         glusterd_conf_t         *priv = NULL;
-        int                     ret = 0;
 
         GF_ASSERT (volinfo);
         GF_ASSERT (brickinfo);
@@ -1931,15 +1930,8 @@ glusterd_brick_unlink_socket_file (glusterd_volinfo_t *volinfo,
         GLUSTERD_GET_VOLUME_DIR (path, volinfo, priv);
         glusterd_set_brick_socket_filepath (volinfo, brickinfo, socketpath,
                                             sizeof (socketpath));
-        ret = unlink (socketpath);
-        if (ret && (ENOENT == errno)) {
-                ret = 0;
-        } else {
-                gf_log (this->name, GF_LOG_ERROR, "Failed to remove %s"
-                        " error: %s", socketpath, strerror (errno));
-        }
 
-        return ret;
+        return glusterd_unlink_file (socketpath);
 }
 
 int32_t
@@ -3124,9 +3116,9 @@ glusterd_compare_friend_volume (dict_t *peer_data, int32_t count,
                 *status = GLUSTERD_VOL_COMP_UPDATE_REQ;
                 goto out;
         } else if (version < volinfo->version) {
-		*status = GLUSTERD_VOL_COMP_SCS;
-		goto out;
-	}
+                *status = GLUSTERD_VOL_COMP_SCS;
+                goto out;
+        }
 
         //Now, versions are same, compare cksums.
         //
@@ -3443,6 +3435,7 @@ glusterd_spawn_daemons (void *opaque)
 {
         glusterd_conf_t *conf = THIS->private;
         gf_boolean_t    start_bricks = !conf->restart_done;
+        int             ret             = -1;
 
         if (start_bricks) {
                 glusterd_restart_bricks (conf);
@@ -3450,7 +3443,9 @@ glusterd_spawn_daemons (void *opaque)
         }
         glusterd_restart_gsyncds (conf);
         glusterd_restart_rebalance (conf);
-        return 0;
+        ret = glusterd_restart_snapds (conf);
+
+        return ret;
 }
 
 void
@@ -5526,7 +5521,7 @@ out:
 
 void
 glusterd_get_nodesvc_dir (char *server, char *workdir,
-                                char *path, size_t len)
+                          char *path, size_t len)
 {
         GF_ASSERT (len == PATH_MAX);
         snprintf (path, len, "%s/%s", workdir, server);
@@ -5534,7 +5529,7 @@ glusterd_get_nodesvc_dir (char *server, char *workdir,
 
 void
 glusterd_get_nodesvc_rundir (char *server, char *workdir,
-                                   char *path, size_t len)
+                             char *path, size_t len)
 {
         char    dir[PATH_MAX] = {0};
         GF_ASSERT (len == PATH_MAX);
@@ -5545,7 +5540,7 @@ glusterd_get_nodesvc_rundir (char *server, char *workdir,
 
 void
 glusterd_get_nodesvc_pidfile (char *server, char *workdir,
-                                    char *path, size_t len)
+                              char *path, size_t len)
 {
         char    dir[PATH_MAX] = {0};
         GF_ASSERT (len == PATH_MAX);
@@ -5556,7 +5551,7 @@ glusterd_get_nodesvc_pidfile (char *server, char *workdir,
 
 void
 glusterd_get_nodesvc_volfile (char *server, char *workdir,
-                                    char *volfile, size_t len)
+                              char *volfile, size_t len)
 {
         char  dir[PATH_MAX] = {0,};
         GF_ASSERT (len == PATH_MAX);
@@ -5666,6 +5661,12 @@ out:
         return rpc;
 }
 
+inline struct rpc_clnt*
+glusterd_snapd_get_rpc (glusterd_volinfo_t *volinfo)
+{
+        return volinfo->snapd.rpc;
+}
+
 struct rpc_clnt*
 glusterd_nodesvc_get_rpc (char *server)
 {
@@ -5715,7 +5716,8 @@ glusterd_nodesvc_set_rpc (char *server, struct rpc_clnt *rpc)
 }
 
 int32_t
-glusterd_nodesvc_connect (char *server, char *socketpath) {
+glusterd_nodesvc_connect (char *server, char *socketpath)
+{
         int                     ret = 0;
         dict_t                  *options = NULL;
         struct rpc_clnt         *rpc = NULL;
@@ -5899,9 +5901,25 @@ glusterd_is_nodesvc_running (char *server)
 }
 
 int32_t
-glusterd_nodesvc_unlink_socket_file (char *server)
+glusterd_unlink_file (char *sockfpath)
 {
         int             ret = 0;
+
+        ret = unlink (sockfpath);
+        if (ret) {
+                if (ENOENT == errno)
+                        ret = 0;
+                else
+                        gf_log (THIS->name, GF_LOG_ERROR, "Failed to remove %s"
+                                " error: %s", sockfpath, strerror (errno));
+        }
+
+        return ret;
+}
+
+int32_t
+glusterd_nodesvc_unlink_socket_file (char *server)
+{
         char            sockfpath[PATH_MAX] = {0,};
         char            rundir[PATH_MAX] = {0,};
         glusterd_conf_t *priv = THIS->private;
@@ -5912,15 +5930,7 @@ glusterd_nodesvc_unlink_socket_file (char *server)
         glusterd_nodesvc_set_socket_filepath (rundir, MY_UUID,
                                               sockfpath, sizeof (sockfpath));
 
-        ret = unlink (sockfpath);
-        if (ret && (ENOENT == errno)) {
-                ret = 0;
-        } else {
-                gf_log (THIS->name, GF_LOG_ERROR, "Failed to remove %s"
-                        " error: %s", sockfpath, strerror (errno));
-        }
-
-        return ret;
+        return glusterd_unlink_file (sockfpath);
 }
 
 int32_t
@@ -5936,7 +5946,7 @@ glusterd_nodesvc_stop (char *server, int sig)
         (void)glusterd_nodesvc_disconnect (server);
 
         glusterd_get_nodesvc_pidfile (server, priv->workdir,
-                                            pidfile, sizeof (pidfile));
+                                      pidfile, sizeof (pidfile));
         ret = glusterd_service_stop (server, pidfile, sig, _gf_true);
 
         if (ret == 0) {
@@ -6218,7 +6228,6 @@ out:
         return ret;
 }
 
-
 int
 glusterd_check_generate_start_nfs ()
 {
@@ -7876,7 +7885,7 @@ glusterd_sm_tr_log_transition_add_to_dict (dict_t *dict,
 {
         int     ret = -1;
         char    key[512] = {0};
-	char    timestr[64] = {0,};
+        char    timestr[64] = {0,};
         char    *str = NULL;
 
         GF_ASSERT (dict);
@@ -12890,3 +12899,369 @@ glusterd_enable_default_options (glusterd_volinfo_t *volinfo, char *option)
 out:
         return ret;
 }
+
+/* Snapd functions */
+int
+glusterd_is_snapd_enabled (glusterd_volinfo_t *volinfo)
+{
+        int              ret    = 0;
+        xlator_t        *this   = THIS;
+
+        ret = dict_get_str_boolean (volinfo->dict, "features.uss", -2);
+        if (ret == -2) {
+                gf_log (this->name, GF_LOG_DEBUG, "Key features.uss not "
+                        "present in the volinfo dict");
+                ret = 0;
+
+        } else if (ret == -1) {
+                gf_log (this->name, GF_LOG_ERROR, "Failed to get "
+                        "'features.uss' from %s volume dict",
+                        volinfo->volname);
+                ret = 0;
+        }
+
+        return ret;
+}
+
+void
+glusterd_get_snapd_rundir (glusterd_volinfo_t *volinfo,
+                           char *path, int path_len)
+{
+        char                    workdir [PATH_MAX]      = {0,};
+        glusterd_conf_t        *priv                    = THIS->private;
+
+        GLUSTERD_GET_VOLUME_DIR (workdir, volinfo, priv);
+
+        snprintf (path, path_len, "%s/run", workdir);
+}
+
+void
+glusterd_get_snapd_volfile (glusterd_volinfo_t *volinfo,
+                            char *path, int path_len)
+{
+        char                    workdir [PATH_MAX]      = {0,};
+        glusterd_conf_t        *priv                    = THIS->private;
+
+        GLUSTERD_GET_VOLUME_DIR (workdir, volinfo, priv);
+
+        snprintf (path, path_len, "%s/%s-snapd.vol", workdir,
+                  volinfo->volname);
+}
+
+void
+glusterd_get_snapd_pidfile (glusterd_volinfo_t *volinfo,
+                            char *path, int path_len)
+{
+        char            rundir [PATH_MAX]      = {0,};
+
+        glusterd_get_snapd_rundir (volinfo, rundir, sizeof (rundir));
+
+        snprintf (path, path_len, "%s/%s-snapd.pid", rundir, volinfo->volname);
+}
+
+void
+glusterd_set_snapd_socket_filepath (glusterd_volinfo_t *volinfo,
+                                    char *path, int path_len)
+{
+        char                    sockfilepath[PATH_MAX] = {0,};
+        char                    rundir[PATH_MAX]       = {0,};
+
+        glusterd_get_snapd_rundir (volinfo, rundir, sizeof (rundir));
+        snprintf (sockfilepath, sizeof (sockfilepath), "%s/run-%s",
+                  rundir, uuid_utoa (MY_UUID));
+
+        glusterd_set_socket_filepath (sockfilepath, path, path_len);
+}
+
+gf_boolean_t
+glusterd_is_snapd_running (glusterd_volinfo_t *volinfo)
+{
+        char                     pidfile [PATH_MAX]     = {0,};
+        int                      pid                    = -1;
+        glusterd_conf_t         *priv                   = THIS->private;
+
+        glusterd_get_snapd_pidfile (volinfo, pidfile,
+                                    sizeof (pidfile));
+
+        return gf_is_service_running (pidfile, &pid);
+}
+
+int
+glusterd_restart_snapds (glusterd_conf_t *priv)
+{
+        glusterd_volinfo_t      *volinfo        = NULL;
+        int                      ret            = 0;
+        xlator_t                *this           = THIS;
+
+        list_for_each_entry (volinfo, &priv->volumes, vol_list) {
+                if (volinfo->status == GLUSTERD_STATUS_STARTED &&
+                    glusterd_is_snapd_enabled (volinfo)) {
+                        ret = glusterd_snapd_start (volinfo, _gf_false);
+                        if (ret) {
+                                gf_log (this->name, GF_LOG_ERROR,
+                                        "Couldn't start snapd for vol: %s",
+                                        volinfo->volname);
+                                goto out;
+                        }
+                }
+        }
+out:
+        return ret;
+}
+
+gf_boolean_t
+glusterd_is_snapd_online (glusterd_volinfo_t *volinfo)
+{
+        return volinfo->snapd.online;
+}
+
+void
+glusterd_snapd_set_online_status (glusterd_volinfo_t *volinfo,
+                                  gf_boolean_t status)
+{
+        volinfo->snapd.online = status;
+}
+
+inline void
+glusterd_snapd_set_rpc (glusterd_volinfo_t *volinfo, struct rpc_clnt *rpc)
+{
+        volinfo->snapd.rpc = rpc;
+}
+
+int32_t
+glusterd_snapd_connect (glusterd_volinfo_t *volinfo, char *socketpath)
+{
+        int                     ret = 0;
+        dict_t                  *options = NULL;
+        struct rpc_clnt         *rpc = NULL;
+        glusterd_conf_t         *priv = THIS->private;
+
+        rpc = glusterd_snapd_get_rpc (volinfo);
+
+        if (rpc == NULL) {
+                /* Setting frame-timeout to 10mins (600seconds).
+                 * Unix domain sockets ensures that the connection is reliable.
+                 * The default timeout of 30mins used for unreliable network
+                 * connections is too long for unix domain socket connections.
+                 */
+                ret = rpc_transport_unix_options_build (&options, socketpath,
+                                                        600);
+                if (ret)
+                        goto out;
+
+                glusterd_volinfo_ref (volinfo);
+
+                synclock_unlock (&priv->big_lock);
+                ret = glusterd_rpc_create (&rpc, options,
+                                           glusterd_snapd_rpc_notify,
+                                           volinfo);
+                synclock_lock (&priv->big_lock);
+                if (ret)
+                        goto out;
+
+                (void) glusterd_snapd_set_rpc (volinfo, rpc);
+        }
+out:
+        return ret;
+}
+
+int32_t
+glusterd_snapd_disconnect (glusterd_volinfo_t *volinfo)
+{
+        struct rpc_clnt         *rpc = NULL;
+        glusterd_conf_t         *priv = THIS->private;
+
+        rpc = glusterd_snapd_get_rpc (volinfo);
+        (void)glusterd_snapd_set_rpc (volinfo, NULL);
+
+        if (rpc)
+                glusterd_rpc_clnt_unref (priv, rpc);
+
+        return 0;
+}
+
+int32_t
+glusterd_snapd_start (glusterd_volinfo_t *volinfo, gf_boolean_t wait)
+{
+        int32_t                 ret                        = -1;
+        xlator_t               *this                       = NULL;
+        glusterd_conf_t        *priv                       = NULL;
+        runner_t                runner                     = {0,};
+        char                    pidfile[PATH_MAX]          = {0,};
+        char                    logfile[PATH_MAX]          = {0,};
+        char                    volfile[PATH_MAX]          = {0,};
+        char                    glusterd_uuid [1024]       = {0,};
+        char                    rundir[PATH_MAX]           = {0,};
+        char                    sockfpath[PATH_MAX]        = {0,};
+        char                    volfileid[256]             = {0};
+        char                    valgrind_logfile[PATH_MAX] = {0};
+        int                     snapd_port                 = 0;
+        char                   *volname                    = volinfo->volname;
+        char                    snapd_id [PATH_MAX]        = {0,};
+        char                    msg [1024]                 = {0,};
+
+        this = THIS;
+        GF_ASSERT(this);
+
+        if (glusterd_is_snapd_running (volinfo)) {
+                ret = 0;
+                goto connect;
+        }
+
+        priv = this->private;
+
+        glusterd_get_snapd_rundir (volinfo, rundir, sizeof (rundir));
+        ret = mkdir (rundir, 0777);
+
+        if ((ret == -1) && (EEXIST != errno)) {
+                gf_log (this->name, GF_LOG_ERROR, "Unable to create rundir %s",
+                        rundir);
+                goto out;
+        }
+
+        glusterd_get_snapd_pidfile (volinfo, pidfile, sizeof (pidfile));
+        glusterd_get_snapd_volfile (volinfo, volfile, sizeof (volfile));
+
+        ret = sys_access (volfile, F_OK);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "snapd Volfile %s is not present", volfile);
+                goto out;
+        }
+
+        snprintf (logfile, PATH_MAX, "%s/%s-snapd.log",
+                  DEFAULT_LOG_FILE_DIRECTORY, volname);
+
+        snprintf (volfileid, sizeof (volfileid), "snapd/%s", volname);
+        glusterd_set_snapd_socket_filepath (volinfo, sockfpath,
+                                            sizeof (sockfpath));
+
+        runinit (&runner);
+
+        if (priv->valgrind) {
+                snprintf (valgrind_logfile, PATH_MAX,
+                          "%s/valgrind-%s-snapd.log",
+                          DEFAULT_LOG_FILE_DIRECTORY, volname);
+
+                runner_add_args (&runner, "valgrind", "--leak-check=full",
+                                 "--trace-children=yes", "--track-origins=yes",
+                                 NULL);
+                runner_argprintf (&runner, "--log-file=%s", valgrind_logfile);
+        }
+
+        snprintf (snapd_id, sizeof (snapd_id), "snapd-%s", volname);
+        runner_add_args (&runner, SBIN_DIR"/glusterfsd",
+                         "-s", "localhost",
+                         "--volfile-id", volfileid,
+                         "-p", pidfile,
+                         "-l", logfile,
+                         "--brick-name", snapd_id,
+                         "-S", sockfpath, NULL);
+
+        snapd_port = volinfo->snapd.port;
+        if (!snapd_port) {
+                snapd_port = pmap_registry_alloc (THIS);
+                if (!snapd_port) {
+                        snprintf (msg, sizeof (msg), "Could not allocate port "
+                                  "for snapd service for volume %s", volname);
+
+                        runner_log (&runner, this->name, GF_LOG_DEBUG, msg);
+                        ret = -1;
+                        goto out;
+                }
+        }
+
+        runner_add_arg (&runner, "--brick-port");
+        runner_argprintf (&runner, "%d", snapd_port);
+        runner_add_arg (&runner, "--xlator-option");
+        runner_argprintf (&runner, "%s-server.listen-port=%d",
+                         volname, snapd_port);
+
+        snprintf (msg, sizeof (msg),
+                  "Starting the snapd service for volume %s", volname);
+        runner_log (&runner, this->name, GF_LOG_DEBUG, msg);
+
+        if (!wait) {
+                ret = runner_run_nowait (&runner);
+        } else {
+                synclock_unlock (&priv->big_lock);
+                {
+                        ret = runner_run (&runner);
+                }
+                synclock_lock (&priv->big_lock);
+        }
+
+connect:
+        if (ret == 0)
+                glusterd_snapd_connect (volinfo, sockfpath);
+
+out:
+        return ret;
+}
+
+int
+glusterd_snapd_stop (glusterd_volinfo_t *volinfo)
+{
+        char                    pidfile [PATH_MAX]        = {0,};
+        char                    sockfpath [PATH_MAX]      = {0,};
+        glusterd_conf_t        *priv                      = THIS->private;
+        int                     ret                       = 0;
+
+        (void)glusterd_snapd_disconnect (volinfo);
+
+        if (!glusterd_is_snapd_running (volinfo))
+                goto out;
+
+        glusterd_get_snapd_pidfile (volinfo, pidfile, sizeof (pidfile));
+        ret = glusterd_service_stop ("snapd", pidfile, SIGTERM, _gf_true);
+
+        if (ret == 0) {
+                glusterd_set_snapd_socket_filepath (volinfo, sockfpath,
+                                                    sizeof (sockfpath));
+                (void)glusterd_unlink_file (sockfpath);
+        }
+out:
+        return ret;
+}
+
+int
+glusterd_handle_snapd_option (glusterd_volinfo_t *volinfo)
+{
+        int             ret     = 0;
+        xlator_t       *this    = THIS;
+
+        if (volinfo->is_snap_volume)
+                return 0;
+
+        if (glusterd_is_snapd_enabled (volinfo)) {
+                if (!glusterd_is_volume_started (volinfo))
+                        goto out;
+
+                ret = glusterd_create_snapd_volfile (volinfo);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR, "Couldn't create "
+                                "snapd volfile for volume: %s",
+                                volinfo->volname);
+                        goto out;
+                }
+
+                ret = glusterd_snapd_start (volinfo, _gf_false);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR, "Couldn't start "
+                                "snapd for volume: %s", volinfo->volname);
+                        goto out;
+                }
+
+        } else if (glusterd_is_snapd_running (volinfo)) {
+                ret = glusterd_snapd_stop (volinfo);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Couldn't stop snapd for volume: %s",
+                                volinfo->volname);
+                        goto out;
+                }
+        }
+
+out:
+        return ret;
+}
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.h b/xlators/mgmt/glusterd/src/glusterd-utils.h
index 91a4c3c2418..4b6e2b0cdbc 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.h
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.h
@@ -204,7 +204,7 @@ glusterd_is_nodesvc_running ();
 
 void
 glusterd_get_nodesvc_dir (char *server, char *workdir,
-                                char *path, size_t len);
+                          char *path, size_t len);
 int32_t
 glusterd_nfs_server_start ();
 
@@ -839,4 +839,56 @@ glusterd_snapshot_restore_cleanup (dict_t *rsp_dict,
                                    glusterd_volinfo_t *volinfo,
                                    glusterd_snap_t *snap);
 
+int
+glusterd_unlink_file (char *sock_file_path);
+
+/* Snapd functions */
+int
+glusterd_handle_snapd_option (glusterd_volinfo_t *volinfo);
+
+int32_t
+glusterd_snapd_disconnect (glusterd_volinfo_t *volinfo);
+
+void
+glusterd_get_snapd_dir (glusterd_volinfo_t *volinfo,
+                        char *path, int path_len);
+
+void
+glusterd_get_snapd_rundir (glusterd_volinfo_t *volinfo,
+                           char *path, int path_len);
+
+void
+glusterd_get_snapd_volfile (glusterd_volinfo_t *volinfo,
+                            char *path, int path_len);
+
+void
+glusterd_get_snapd_pidfile (glusterd_volinfo_t *volinfo,
+                            char *path, int path_len);
+
+void
+glusterd_set_snapd_socket_filepath (glusterd_volinfo_t *volinfo,
+                                    char *path, int path_len);
+
+gf_boolean_t
+glusterd_is_snapd_running (glusterd_volinfo_t *volinfo);
+
+int
+glusterd_snapd_stop (glusterd_volinfo_t *volinfo);
+
+int
+glusterd_snapd_start (glusterd_volinfo_t *volinfo, gf_boolean_t wait);
+
+int
+glusterd_is_snapd_enabled (glusterd_volinfo_t *volinfo);
+
+gf_boolean_t
+glusterd_is_snapd_online (glusterd_volinfo_t *volinfo);
+
+void
+glusterd_snapd_set_online_status (glusterd_volinfo_t *volinfo,
+                                  gf_boolean_t status);
+
+int
+glusterd_restart_snapds (glusterd_conf_t *priv);
+/* End snapd functions */
 #endif
diff --git a/xlators/mgmt/glusterd/src/glusterd-volgen.c b/xlators/mgmt/glusterd/src/glusterd-volgen.c
index 165fdd882b1..fa4f88f9a06 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volgen.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volgen.c
@@ -961,54 +961,54 @@ out:
 static void
 volgen_apply_filters (char *orig_volfile)
 {
-	DIR           *filterdir = NULL;
-	struct dirent  entry = {0,};
-	struct dirent *next = NULL;
-	char          *filterpath = NULL;
-	struct stat    statbuf = {0,};
-
-	filterdir = opendir(FILTERDIR);
-	if (!filterdir) {
-		return;
-	}
-
-	while ((readdir_r(filterdir,&entry,&next) == 0) && next) {
-		if (!strncmp(entry.d_name,".",sizeof(entry.d_name))) {
-			continue;
-		}
-		if (!strncmp(entry.d_name,"..",sizeof(entry.d_name))) {
-			continue;
-		}
-		/*
-		 * d_type isn't guaranteed to be present/valid on all systems,
-		 * so do an explicit stat instead.
-		 */
-		if (gf_asprintf(&filterpath,"%s/%.*s",FILTERDIR,
-				sizeof(entry.d_name), entry.d_name) == (-1)) {
-			continue;
-		}
-		/* Deliberately use stat instead of lstat to allow symlinks. */
-		if (stat(filterpath,&statbuf) == (-1)) {
-			goto free_fp;
-		}
-		if (!S_ISREG(statbuf.st_mode)) {
-			goto free_fp;
-		}
-		/*
-		 * We could check the mode in statbuf directly, or just skip
-		 * this entirely and check for EPERM after exec fails, but this
-		 * is cleaner.
-		 */
-		if (access(filterpath,X_OK) != 0) {
-			goto free_fp;
-		}
-		if (runcmd(filterpath,orig_volfile,NULL)) {
-			gf_log("",GF_LOG_ERROR,"failed to run filter %.*s",
-			       (int)sizeof(entry.d_name), entry.d_name);
-		}
+        DIR           *filterdir = NULL;
+        struct dirent  entry = {0,};
+        struct dirent *next = NULL;
+        char          *filterpath = NULL;
+        struct stat    statbuf = {0,};
+
+        filterdir = opendir(FILTERDIR);
+        if (!filterdir) {
+                return;
+        }
+
+        while ((readdir_r(filterdir,&entry,&next) == 0) && next) {
+                if (!strncmp(entry.d_name,".",sizeof(entry.d_name))) {
+                        continue;
+                }
+                if (!strncmp(entry.d_name,"..",sizeof(entry.d_name))) {
+                        continue;
+                }
+                /*
+                 * d_type isn't guaranteed to be present/valid on all systems,
+                 * so do an explicit stat instead.
+                 */
+                if (gf_asprintf(&filterpath,"%s/%.*s",FILTERDIR,
+                                sizeof(entry.d_name), entry.d_name) == (-1)) {
+                        continue;
+                }
+                /* Deliberately use stat instead of lstat to allow symlinks. */
+                if (stat(filterpath,&statbuf) == (-1)) {
+                        goto free_fp;
+                }
+                if (!S_ISREG(statbuf.st_mode)) {
+                        goto free_fp;
+                }
+                /*
+                 * We could check the mode in statbuf directly, or just skip
+                 * this entirely and check for EPERM after exec fails, but this
+                 * is cleaner.
+                 */
+                if (access(filterpath,X_OK) != 0) {
+                        goto free_fp;
+                }
+                if (runcmd(filterpath,orig_volfile,NULL)) {
+                        gf_log("",GF_LOG_ERROR,"failed to run filter %.*s",
+                               (int)sizeof(entry.d_name), entry.d_name);
+                }
 free_fp:
-		GF_FREE(filterpath);
-	}
+                GF_FREE(filterpath);
+        }
 }
 
 static int
@@ -1063,7 +1063,7 @@ volgen_write_volfile (volgen_graph_t *graph, char *filename)
 
         GF_FREE (ftmp);
 
-	volgen_apply_filters(filename);
+        volgen_apply_filters(filename);
 
         return 0;
 
@@ -1656,9 +1656,9 @@ server_graph_builder (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
                 if (!rbxl)
                         return -1;
 
-		ptranst = glusterd_get_trans_type_rb (volinfo->transport_type);
-		if (NULL == ptranst)
-			return -1;
+                ptranst = glusterd_get_trans_type_rb (volinfo->transport_type);
+                if (NULL == ptranst)
+                        return -1;
 
                 if (username) {
                         ret = xlator_set_option (rbxl, "username", username);
@@ -2203,20 +2203,97 @@ out:
 
 }
 
+
+static xlator_t *
+volgen_graph_build_client (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
+                           char *hostname, char *subvol, char *xl_id,
+                           char *transt, dict_t *set_dict)
+{
+        xlator_t                *xl                 = NULL;
+        int                      ret                = -2;
+        uint32_t                 client_type        = GF_CLIENT_OTHER;
+        char                    *str                = NULL;
+        char                    *ssl_str            = NULL;
+        gf_boolean_t             ssl_bool           = _gf_false;
+
+        GF_ASSERT (graph);
+        GF_ASSERT (subvol);
+        GF_ASSERT (xl_id);
+        GF_ASSERT (transt);
+
+        xl = volgen_graph_add_nolink (graph, "protocol/client",
+                                      "%s", xl_id);
+        if (!xl)
+                goto err;
+
+        ret = xlator_set_option (xl, "ping-timeout", "42");
+        if (ret)
+                goto err;
+
+        if (hostname) {
+                ret = xlator_set_option (xl, "remote-host", hostname);
+                if (ret)
+                        goto err;
+        }
+
+        ret = xlator_set_option (xl, "remote-subvolume", subvol);
+        if (ret)
+                goto err;
+
+        ret = xlator_set_option (xl, "transport-type", transt);
+        if (ret)
+                goto err;
+
+        ret = dict_get_uint32 (set_dict, "trusted-client",
+                               &client_type);
+
+        if (!ret && client_type == GF_CLIENT_TRUSTED) {
+                str = NULL;
+                str = glusterd_auth_get_username (volinfo);
+                if (str) {
+                        ret = xlator_set_option (xl, "username",
+                                                 str);
+                        if (ret)
+                                goto err;
+                }
+
+                str = glusterd_auth_get_password (volinfo);
+                if (str) {
+                        ret = xlator_set_option (xl, "password",
+                                                 str);
+                        if (ret)
+                                goto err;
+                }
+        }
+
+        if (dict_get_str(set_dict,"client.ssl",&ssl_str) == 0) {
+                if (gf_string2boolean(ssl_str,&ssl_bool) == 0) {
+                        if (ssl_bool) {
+                                ret = xlator_set_option(xl,
+                                        "transport.socket.ssl-enabled",
+                                        "true");
+                                if (ret) {
+                                        goto err;
+                                }
+                        }
+                }
+        }
+
+        return xl;
+err:
+        return NULL;
+}
+
 static int
 volgen_graph_build_clients (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
                             dict_t *set_dict, void *param)
 {
         int                      i                  = 0;
         int                      ret                = -1;
-        uint32_t                 client_type        = GF_CLIENT_OTHER;
         char                     transt[16]         = {0,};
         char                    *volname            = NULL;
-        char                    *str                = NULL;
         glusterd_brickinfo_t    *brick              = NULL;
         xlator_t                *xl                 = NULL;
-        char                    *ssl_str            = NULL;
-        gf_boolean_t             ssl_bool;
 
         volname = volinfo->volname;
 
@@ -2243,59 +2320,14 @@ volgen_graph_build_clients (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
                 strcpy (transt, "tcp");
 
         i = 0;
-        ret = -1;
         list_for_each_entry (brick, &volinfo->bricks, brick_list) {
-                ret = -1;
-                xl = volgen_graph_add_nolink (graph, "protocol/client",
-                                              "%s", brick->brick_id);
-                if (!xl)
-                        goto out;
-                ret = xlator_set_option (xl, "ping-timeout", "42");
-                if (ret)
-                        goto out;
-                ret = xlator_set_option (xl, "remote-host", brick->hostname);
-                if (ret)
-                        goto out;
-                ret = xlator_set_option (xl, "remote-subvolume", brick->path);
-                if (ret)
-                        goto out;
-                ret = xlator_set_option (xl, "transport-type", transt);
-                if (ret)
+                xl = volgen_graph_build_client (graph, volinfo,
+                                                brick->hostname, brick->path,
+                                                brick->brick_id,
+                                                transt, set_dict);
+                if (!xl) {
+                        ret = -1;
                         goto out;
-
-                ret = dict_get_uint32 (set_dict, "trusted-client",
-                                       &client_type);
-
-                if (!ret && client_type == GF_CLIENT_TRUSTED) {
-                        str = NULL;
-                        str = glusterd_auth_get_username (volinfo);
-                        if (str) {
-                                ret = xlator_set_option (xl, "username",
-                                                         str);
-                                if (ret)
-                                        goto out;
-                        }
-
-                        str = glusterd_auth_get_password (volinfo);
-                        if (str) {
-                                ret = xlator_set_option (xl, "password",
-                                                         str);
-                                if (ret)
-                                        goto out;
-                        }
-                }
-
-                if (dict_get_str(set_dict,"client.ssl",&ssl_str) == 0) {
-                        if (gf_string2boolean(ssl_str,&ssl_bool) == 0) {
-                                if (ssl_bool) {
-                                        ret = xlator_set_option(xl,
-                                                "transport.socket.ssl-enabled",
-                                                "true");
-                                        if (ret) {
-                                                goto out;
-                                        }
-                                }
-                        }
                 }
 
                 i++;
@@ -2360,6 +2392,70 @@ out:
         return ret;
 }
 
+/**
+ * This is the build graph function for user-serviceable snapshots.
+ * Generates  snapview-client
+ */
+static int
+volgen_graph_build_snapview_client (volgen_graph_t *graph,
+                                    glusterd_volinfo_t *volinfo,
+                                    char *volname, dict_t *set_dict)
+{
+        int                ret                  = 0;
+        xlator_t          *prev_top             = NULL;
+        xlator_t          *prot_clnt            = NULL;
+        xlator_t          *svc                  = NULL;
+        char               transt [16]          = {0,};
+        char              *svc_args[]           = {"features/snapview-client",
+                                                   "%s-snapview-client"};
+        char               subvol [1024]        = {0,};
+        char               xl_id [1024]         = {0,};
+
+        prev_top = (xlator_t *)(graph->graph.first);
+
+        snprintf (subvol, sizeof (subvol), "snapd-%s", volinfo->volname);
+        snprintf (xl_id, sizeof (xl_id), "%s-snapd-client", volinfo->volname);
+
+        get_transport_type (volinfo, set_dict, transt, _gf_false);
+
+        prot_clnt = volgen_graph_build_client (graph, volinfo, NULL, subvol,
+                                               xl_id, transt, set_dict);
+        if (!prot_clnt) {
+                ret = -1;
+                goto out;
+        }
+
+        svc = volgen_graph_add_nolink (graph, svc_args[0], svc_args[1],
+                                       volname);
+        if (!svc) {
+                ret = -1;
+                goto out;
+        }
+
+        /**
+         * Ordering the below two traslators (cur_top & prot_clnt) is important
+         * as snapview client implementation is built on the policy that
+         * normal volume path goes to FIRST_CHILD and snap world operations
+         * goes to SECOND_CHILD
+         **/
+        ret = volgen_xlator_link (graph->graph.first, prev_top);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_ERROR, "failed to link the "
+                        "snapview-client to distribute");
+                goto out;
+        }
+
+        ret = volgen_xlator_link (graph->graph.first, prot_clnt);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_ERROR, "failed to link the "
+                        "snapview-client to snapview-server");
+                goto out;
+        }
+
+out:
+        return ret;
+}
+
 gf_boolean_t
 _xl_is_client_decommissioned (xlator_t *xl, glusterd_volinfo_t *volinfo)
 {
@@ -2599,26 +2695,26 @@ out:
 }
 
 static int client_graph_set_perf_options(volgen_graph_t *graph,
-					 glusterd_volinfo_t *volinfo,
-					 dict_t *set_dict)
+                                         glusterd_volinfo_t *volinfo,
+                                         dict_t *set_dict)
 {
-	data_t *tmp_data = NULL;
-	char *volname = NULL;
-
-	/*
-	 * Logic to make sure NFS doesn't have performance translators by
-	 * default for a volume
-	 */
-	volname = volinfo->volname;
-	tmp_data = dict_get (set_dict, "nfs-volume-file");
-	if (!tmp_data)
-		return volgen_graph_set_options_generic(graph, set_dict,
-							volinfo,
-							&perfxl_option_handler);
-	else
-		return volgen_graph_set_options_generic(graph, set_dict,
-							volname,
-							&nfsperfxl_option_handler);
+        data_t *tmp_data = NULL;
+        char *volname = NULL;
+
+        /*
+         * Logic to make sure NFS doesn't have performance translators by
+         * default for a volume
+         */
+        volname = volinfo->volname;
+        tmp_data = dict_get (set_dict, "nfs-volume-file");
+        if (!tmp_data)
+                return volgen_graph_set_options_generic(graph, set_dict,
+                                                        volinfo,
+                                                        &perfxl_option_handler);
+        else
+                return volgen_graph_set_options_generic(graph, set_dict,
+                                                        volname,
+                                                        &nfsperfxl_option_handler);
 }
 
 static int
@@ -2815,6 +2911,13 @@ client_graph_builder (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
         if (ret)
                 goto out;
 
+        if (!volinfo->is_snap_volume && glusterd_is_snapd_enabled (volinfo)) {
+                ret = volgen_graph_build_snapview_client
+                                           (graph, volinfo, volname, set_dict);
+                if (ret == -1)
+                        goto out;
+        }
+
         /* add debug translators depending on the options */
         ret = check_and_add_debug_xl (graph, set_dict, volname,
                                       "client");
@@ -3534,7 +3637,7 @@ build_quotad_graph (volgen_graph_t *graph, dict_t *mod_dict)
         dict_t             *set_dict      = NULL;
         int                ret            = 0;
         xlator_t           *quotad_xl     = NULL;
-	char		   *skey	  = NULL;
+        char               *skey          = NULL;
 
         this = THIS;
         priv = this->private;
@@ -4000,13 +4103,110 @@ out:
 }
 
 int
-glusterd_create_quotad_volfile ()
+glusterd_generate_snapd_volfile (volgen_graph_t *graph,
+                                 glusterd_volinfo_t *volinfo)
+{
+        xlator_t       *xl              = NULL;
+        char           *username        = NULL;
+        char           *passwd          = NULL;
+        int             ret             = 0;
+        char            key [PATH_MAX]  = {0, };
+        dict_t         *set_dict        = NULL;
+        char           *loglevel        = NULL;
+        char           *xlator          = NULL;
+
+        set_dict = dict_copy (volinfo->dict, NULL);
+        if (!set_dict)
+                return -1;
+
+        ret = dict_get_str (set_dict, "xlator", &xlator);
+        if (!ret) {
+                ret = dict_get_str (set_dict, "loglevel", &loglevel);
+                if (ret) {
+                        gf_log ("glusterd", GF_LOG_ERROR, "could not get both"
+                                " translator name and loglevel for log level "
+                                "request");
+                        return -1;
+                }
+        }
+
+        xl = volgen_graph_add (graph, "features/snapview-server",
+                               volinfo->volname);
+        if (!xl)
+                return -1;
+
+        ret = xlator_set_option (xl, "volname", volinfo->volname);
+        if (ret)
+                return -1;
+
+        xl = volgen_graph_add (graph, "performance/io-threads",
+                               volinfo->volname);
+        if (!xl)
+                return -1;
+
+        snprintf (key, sizeof (key), "snapd-%s", volinfo->volname);
+        xl = volgen_graph_add_as (graph, "debug/io-stats", key);
+        if (!xl)
+                return -1;
+
+        xl = volgen_graph_add (graph, "protocol/server", volinfo->volname);
+        if (!xl)
+                return -1;
+
+        ret = xlator_set_option (xl, "transport-type", "tcp");
+        if (ret)
+                return -1;
+
+        username = glusterd_auth_get_username (volinfo);
+        passwd = glusterd_auth_get_password (volinfo);
+
+        snprintf (key, sizeof (key), "auth.login.snapd-%s.allow",
+                                                        volinfo->volname);
+        ret = xlator_set_option (xl, key, username);
+        if (ret)
+                return -1;
+
+        snprintf (key, sizeof (key), "auth.login.%s.password", username);
+        ret = xlator_set_option (xl, key, passwd);
+        if (ret)
+                return -1;
+
+        ret = volgen_graph_set_options_generic
+                (graph, set_dict,
+                 (xlator && loglevel)? (void *)set_dict: volinfo,
+                 (xlator && loglevel) ?
+                 &server_spec_extended_option_handler:
+                 &server_spec_option_handler);
+
+        return ret;
+}
+
+int
+glusterd_create_snapd_volfile (glusterd_volinfo_t *volinfo)
+{
+        volgen_graph_t  graph                   = {0,};
+        int             ret                     = -1;
+        char            filename [PATH_MAX]     = {0,};
+
+        glusterd_get_snapd_volfile (volinfo, filename, PATH_MAX);
+
+        ret = glusterd_generate_snapd_volfile (&graph, volinfo);
+        if (!ret)
+                ret = volgen_write_volfile (&graph, filename);
+
+        volgen_graph_free (&graph);
+
+        return ret;
+}
+
+int
+glusterd_create_quotad_volfile (void *data)
 {
         char             filepath[PATH_MAX] = {0,};
         glusterd_conf_t *conf               = THIS->private;
 
         glusterd_get_nodesvc_volfile ("quotad", conf->workdir,
-                                            filepath, sizeof (filepath));
+                                      filepath, sizeof (filepath));
         return glusterd_create_global_volfile (build_quotad_graph,
                                                filepath, NULL);
 }
diff --git a/xlators/mgmt/glusterd/src/glusterd-volgen.h b/xlators/mgmt/glusterd/src/glusterd-volgen.h
index dab5e1ff03d..f4959f1e6c2 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volgen.h
+++ b/xlators/mgmt/glusterd/src/glusterd-volgen.h
@@ -125,6 +125,7 @@ void glusterd_get_shd_filepath (char *filename);
 int glusterd_create_nfs_volfile ();
 int glusterd_create_shd_volfile ();
 int glusterd_create_quotad_volfile ();
+int glusterd_create_snapd_volfile (glusterd_volinfo_t *volinfo);
 
 int glusterd_delete_volfile (glusterd_volinfo_t *volinfo,
                              glusterd_brickinfo_t *brickinfo);
diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-ops.c b/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
index 1eff081516e..9b390321087 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
@@ -1941,6 +1941,10 @@ glusterd_op_start_volume (dict_t *dict, char **op_errstr)
         if (ret)
                 goto out;
 
+        ret = glusterd_handle_snapd_option (volinfo);
+        if (ret)
+                goto out;
+
         ret = glusterd_nodesvcs_handle_graph_change (volinfo);
 
 out:
@@ -2006,10 +2010,15 @@ glusterd_stop_volume (glusterd_volinfo_t *volinfo)
                 runner_end (&runner);
         }
 
+        ret = glusterd_handle_snapd_option (volinfo);
+        if (ret)
+                goto out;
+
         ret = glusterd_nodesvcs_handle_graph_change (volinfo);
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR, "Failed to notify graph "
                         "change for %s volume", volinfo->volname);
+
                 goto out;
         }
 
diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-set.c b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
index ffac2f4ac82..26e86209007 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-set.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-set.c
@@ -1095,6 +1095,15 @@ struct volopt_map_entry glusterd_volopt_map[] = {
           .flags       = OPT_FLAG_CLIENT_OPT | OPT_FLAG_XLATOR_OPT
         },
 
+        { .key         = "features.uss",
+          .voltype     = "features/snapview-server",
+          .op_version  = 4,
+          .value       = "uss",
+          .flags       = OPT_FLAG_CLIENT_OPT | OPT_FLAG_XLATOR_OPT,
+          .description = "Enable/Disable User Servicable Snapshots on the "
+                         "volume."
+        },
+
 #ifdef HAVE_LIB_Z
         /* Compressor-decompressor xlator options
          * defaults used from xlator/features/compress/src/cdc.h
diff --git a/xlators/mgmt/glusterd/src/glusterd.h b/xlators/mgmt/glusterd/src/glusterd.h
index 02441c9148b..57a5862a368 100644
--- a/xlators/mgmt/glusterd/src/glusterd.h
+++ b/xlators/mgmt/glusterd/src/glusterd.h
@@ -123,6 +123,12 @@ typedef struct {
 } nodesrv_t;
 
 typedef struct {
+        struct rpc_clnt  *rpc;
+        int               port;
+        gf_boolean_t      online;
+} glusterd_snapd_t;
+
+typedef struct {
         struct _volfile_ctx     *volfile;
         pthread_mutex_t          mutex;
         struct list_head         peers;
@@ -372,6 +378,8 @@ struct glusterd_volinfo_ {
         pthread_mutex_t           reflock;
         int                       refcnt;
         gd_quorum_status_t        quorum_status;
+
+        glusterd_snapd_t          snapd;
 };
 
 typedef enum gd_snap_status_ {
@@ -856,6 +864,10 @@ glusterd_brick_rpc_notify (struct rpc_clnt *rpc, void *mydata,
                           rpc_clnt_event_t event, void *data);
 
 int
+glusterd_snapd_rpc_notify (struct rpc_clnt *rpc, void *mydata,
+                             rpc_clnt_event_t event, void *data);
+
+int
 glusterd_nodesvc_rpc_notify (struct rpc_clnt *rpc, void *mydata,
                              rpc_clnt_event_t event, void *data);