From f8c28163309870048415cf58668c06a6ba2d700d Mon Sep 17 00:00:00 2001

From: Avra Sengupta <asengupt@redhat.com>

Date: Thu, 14 May 2015 15:00:59 +0530

Subject: [PATCH 09/18] glusterd/shared_storage: Provide a volume set option to

 create and mount the shared storage

     Backport of http://review.gluster.org/#/c/10793/

Introducing a global volume set option(cluster.enable-shared-storage)

which helps create and set-up the shared storage meta volume.

gluster volume set all cluster.enable-shared-storage enable

On enabling this option, the system analyzes the number of peers

in the cluster, which are currently connected, and chooses three

such peers(including the node the command is issued from). From these

peers a volume(gluster_shared_storage) is created. Depending on the

number of peers available the volume is either a replica 3

volume(if there are 3 connected peers),  or a replica 2 volume(if there

are 2 connected peers). "/var/run/gluster/ss_brick" serves as the

brick path on each node for the shared storage volume. We also mount

the shared storage at "/var/run/gluster/shared_storage" on all the nodes

in the cluster as part of enabling this option. If there is only one node

in the cluster,  or only one node is up then the command will fail

Once the volume is created, and mounted the maintainance of the

volume like adding-bricks, removing bricks etc., is expected to

be the onus of the user.

On disabling the option, we provide the user a warning, and on

affirmation from the user we stop the shared storage volume, and unmount

it from all the nodes in the cluster.

gluster volume set all cluster.enable-shared-storage disable

Change-Id: Idd92d67b93f444244f99ede9f634ef18d2945dbc

BUG: 1223201

Signed-off-by: Avra Sengupta <asengupt@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/50103

Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>

Tested-by: Rajesh Joseph <rjoseph@redhat.com>

---

 cli/src/cli-cmd-parser.c                           |  56 ++++--

 cli/src/cli-cmd-volume.c                           |  51 +++++-

 cli/src/cli-cmd.h                                  |   2 +

 cli/src/cli.h                                      |   4 +-

 extras/hook-scripts/set/post/Makefile.am           |   2 +-

 .../set/post/S32gluster_enable_shared_storage.sh   | 124 +++++++++++++

 glusterfs.spec.in                                  |   4 +

 libglusterfs/src/globals.h                         |   2 +

 xlators/mgmt/glusterd/src/glusterd-hooks.c         |  40 ++++-

 xlators/mgmt/glusterd/src/glusterd-op-sm.c         | 196 ++++++++++++++++++++-

 xlators/mgmt/glusterd/src/glusterd-op-sm.h         |   4 +

 xlators/mgmt/glusterd/src/glusterd-rpc-ops.c       |   9 +

 xlators/mgmt/glusterd/src/glusterd-sm.c            |  12 ++

 xlators/mgmt/glusterd/src/glusterd-snapshot.c      |   6 +-

 xlators/mgmt/glusterd/src/glusterd-utils.c         |  31 ++++

 xlators/mgmt/glusterd/src/glusterd-utils.h         |   2 +

 xlators/mgmt/glusterd/src/glusterd-volume-set.c    |   6 +

 xlators/mgmt/glusterd/src/glusterd.c               | 107 +++++++----

 xlators/mgmt/glusterd/src/glusterd.h               |   3 +

 19 files changed, 588 insertions(+), 73 deletions(-)

 create mode 100755 extras/hook-scripts/set/post/S32gluster_enable_shared_storage.sh

diff --git a/cli/src/cli-cmd-parser.c b/cli/src/cli-cmd-parser.c

index 2390822..caa3191 100644

--- a/cli/src/cli-cmd-parser.c

+++ b/cli/src/cli-cmd-parser.c

@@ -1406,17 +1406,19 @@ out:

 }

 int32_t

-cli_cmd_volume_set_parse (const char **words, int wordcount, dict_t **options,

-                          char **op_errstr)

+cli_cmd_volume_set_parse (struct cli_state *state, const char **words,

+                          int wordcount, dict_t **options, char **op_errstr)

 {

-        dict_t                  *dict = NULL;

-        char                    *volname = NULL;

-        int                     ret = -1;

-        int                     count = 0;

-        char                    *key = NULL;

-        char                    *value = NULL;

-        int                     i = 0;

-        char                    str[50] = {0,};

+        dict_t                 *dict      = NULL;

+        char                   *volname   = NULL;

+        int                     ret       = -1;

+        int                     count     = 0;

+        char                   *key       = NULL;

+        char                   *value     = NULL;

+        int                     i         = 0;

+        char                    str[50]   = {0,};

+        const char             *question  = NULL;

+        gf_answer_t             answer    = GF_ANSWER_NO;

         GF_ASSERT (words);

         GF_ASSERT (options);

@@ -1438,6 +1440,22 @@ cli_cmd_volume_set_parse (const char **words, int wordcount, dict_t **options,

         if (ret)

                 goto out;

+        if (!strcmp (volname, "all")) {

+                ret = dict_set_str (dict, "globalname", "All");

+                if (ret) {

+                        gf_log (THIS->name, GF_LOG_ERROR,

+                                "dict set on global key failed.");

+                        goto out;

+                }

+

+                ret = dict_set_int32 (dict, "hold_global_locks", _gf_true);

+                if (ret) {

+                        gf_log (THIS->name, GF_LOG_ERROR,

+                                "dict set on global key failed.");

+                        goto out;

+                }

+        }

+

         if ((!strcmp (volname, "help") || !strcmp (volname, "help-xml"))

             && wordcount == 3 ) {

                 ret = dict_set_str (dict, volname, volname);

@@ -1507,6 +1525,24 @@ cli_cmd_volume_set_parse (const char **words, int wordcount, dict_t **options,

                 if (ret)

                         goto out;

+

+                if ((!strcmp (key, "cluster.enable-shared-storage")) &&

+                    (!strcmp (value, "disable"))) {

+                        question = "Disabling cluster.enable-shared-storage "

+                                   "will delete the shared storage volume"

+                                   "(gluster_shared_storage), which is used "

+                                   "by snapshot scheduler, geo-replication "

+                                   "and NFS-Ganesha. Do you still want to "

+                                   "continue?";

+                        answer = cli_cmd_get_confirmation (state, question);

+                        if (GF_ANSWER_NO == answer) {

+                                gf_log ("cli", GF_LOG_ERROR, "Operation "

+                                        "cancelled, exiting");

+                                *op_errstr = gf_strdup ("Aborted by user.");

+                                ret = -1;

+                                goto out;

+                        }

+                }

         }

         ret = dict_set_int32 (dict, "count", wordcount-3);

diff --git a/cli/src/cli-cmd-volume.c b/cli/src/cli-cmd-volume.c

index da6603c..6dd3058 100644

--- a/cli/src/cli-cmd-volume.c

+++ b/cli/src/cli-cmd-volume.c

@@ -286,22 +286,28 @@ cli_cmd_volume_delete_cbk (struct cli_state *state, struct cli_cmd_word *word,

                 goto out;

         }

-        answer = cli_cmd_get_confirmation (state, question);

-

-        if (GF_ANSWER_NO == answer) {

-                ret = 0;

-                goto out;

-        }

-

         volname = (char *)words[2];

         ret = dict_set_str (dict, "volname", volname);

-

         if (ret) {

                 gf_log (THIS->name, GF_LOG_WARNING, "dict set failed");

                 goto out;

         }

+        if (!strcmp (volname, GLUSTER_SHARED_STORAGE)) {

+                question = "Deleting the shared storage volume"

+                           "(gluster_shared_storage), will affect features "

+                           "like snapshot scheduler, geo-replication "

+                           "and NFS-Ganesha. Do you still want to "

+                           "continue?";

+        }

+

+        answer = cli_cmd_get_confirmation (state, question);

+        if (GF_ANSWER_NO == answer) {

+                ret = 0;

+                goto out;

+        }

+

         CLI_LOCAL_INIT (local, words, frame, dict);

         if (proc->fn) {

@@ -473,6 +479,14 @@ cli_cmd_volume_stop_cbk (struct cli_state *state, struct cli_cmd_word *word,

                 goto out;

         }

+        if (!strcmp (volname, GLUSTER_SHARED_STORAGE)) {

+                question = "Stopping the shared storage volume"

+                           "(gluster_shared_storage), will affect features "

+                           "like snapshot scheduler, geo-replication "

+                           "and NFS-Ganesha. Do you still want to "

+                           "continue?";

+        }

+

         if (wordcount == 4) {

                 if (!strcmp("force", words[3])) {

                         flags |= GF_CLI_FLAG_OP_FORCE;

@@ -483,6 +497,7 @@ cli_cmd_volume_stop_cbk (struct cli_state *state, struct cli_cmd_word *word,

                         goto out;

                 }

         }

+

         ret = dict_set_int32 (dict, "flags", flags);

         if (ret) {

                 gf_log (THIS->name, GF_LOG_ERROR,

@@ -732,7 +747,8 @@ cli_cmd_volume_set_cbk (struct cli_state *state, struct cli_cmd_word *word,

         if (!frame)

                 goto out;

-        ret = cli_cmd_volume_set_parse (words, wordcount, &options, &op_errstr);

+        ret = cli_cmd_volume_set_parse (state, words, wordcount,

+                                        &options, &op_errstr);

         if (ret) {

                 if (op_errstr) {

                     cli_err ("%s", op_errstr);

@@ -1612,6 +1628,7 @@ cli_cmd_volume_remove_brick_cbk (struct cli_state *state,

         int                     parse_error = 0;

         int                     need_question = 0;

         cli_local_t             *local = NULL;

+        char                    *volname = NULL;

         const char *question = "Removing brick(s) can result in data loss. "

                                "Do you want to Continue?";

@@ -1628,6 +1645,22 @@ cli_cmd_volume_remove_brick_cbk (struct cli_state *state,

                 goto out;

         }

+        ret = dict_get_str (options, "volname", &volname);

+        if (ret || !volname) {

+                gf_log ("cli", GF_LOG_ERROR, "Failed to fetch volname");

+                ret = -1;

+                goto out;

+        }

+

+        if (!strcmp (volname, GLUSTER_SHARED_STORAGE)) {

+                question = "Removing brick from the shared storage volume"

+                           "(gluster_shared_storage), will affect features "

+                           "like snapshot scheduler, geo-replication "

+                           "and NFS-Ganesha. Do you still want to "

+                           "continue?";

+                need_question = _gf_true;

+        }

+

         if (!(state->mode & GLUSTER_MODE_SCRIPT) && need_question) {

                 /* we need to ask question only in case of 'commit or force' */

                 answer = cli_cmd_get_confirmation (state, question);

diff --git a/cli/src/cli-cmd.h b/cli/src/cli-cmd.h

index 94fa3e9..3a689c4 100644

--- a/cli/src/cli-cmd.h

+++ b/cli/src/cli-cmd.h

@@ -20,6 +20,8 @@

 #include "cli.h"

 #include "list.h"

+#define GLUSTER_SHARED_STORAGE      "gluster_shared_storage"

+

 #define CLI_LOCAL_INIT(local, words, frame, dictionary) \

         do {                                                 \

                 local = cli_local_get ();                    \

diff --git a/cli/src/cli.h b/cli/src/cli.h

index c9283b5..6c0fbce 100644

--- a/cli/src/cli.h

+++ b/cli/src/cli.h

@@ -248,8 +248,8 @@ int32_t

 cli_cmd_bitrot_parse (const char **words, int wordcount, dict_t **opt);

 int32_t

-cli_cmd_volume_set_parse (const char **words, int wordcount,

-                          dict_t **options, char **op_errstr);

+cli_cmd_volume_set_parse (struct cli_state *state, const char **words,

+                          int wordcount, dict_t **options, char **op_errstr);

 int32_t

 cli_cmd_ganesha_parse (struct cli_state *state, const char **words,

                        int wordcount, dict_t **options, char **op_errstr);

diff --git a/extras/hook-scripts/set/post/Makefile.am b/extras/hook-scripts/set/post/Makefile.am

index 3ec25d9..99dfaa3 100644

--- a/extras/hook-scripts/set/post/Makefile.am

+++ b/extras/hook-scripts/set/post/Makefile.am

@@ -1 +1 @@

-EXTRA_DIST = S30samba-set.sh S31ganesha-set.sh

+EXTRA_DIST = S30samba-set.sh S31ganesha-set.sh S32gluster_enable_shared_storage.sh

diff --git a/extras/hook-scripts/set/post/S32gluster_enable_shared_storage.sh b/extras/hook-scripts/set/post/S32gluster_enable_shared_storage.sh

new file mode 100755

index 0000000..28fa0e5

--- /dev/null

+++ b/extras/hook-scripts/set/post/S32gluster_enable_shared_storage.sh

@@ -0,0 +1,124 @@

+#!/bin/bash

+

+key=`echo $3 | cut -d '=' -f 1`

+val=`echo $3 | cut -d '=' -f 2`

+if [ "$key" != "cluster.enable-shared-storage" ]; then

+    exit;

+fi

+if [ "$val" != 'enable' ]; then

+    if [ "$val" != 'disable' ]; then

+        exit;

+    fi

+fi

+

+option=$val

+

+key_val_pair1=`echo $4 | cut -d ',' -f 1`

+key_val_pair2=`echo $4 | cut -d ',' -f 2`

+

+key=`echo $key_val_pair1 | cut -d '=' -f 1`

+val=`echo $key_val_pair1 | cut -d '=' -f 2`

+if [ "$key" != "is_originator" ]; then

+    exit;

+fi

+is_originator=$val;

+

+key=`echo $key_val_pair2 | cut -d '=' -f 1`

+val=`echo $key_val_pair2 | cut -d '=' -f 2`

+if [ "$key" != "local_node_hostname" ]; then

+    exit;

+fi

+local_node_hostname=$val;

+

+# Read gluster peer status to find the peers

+# which are in 'Peer in Cluster' mode and

+# are connected.

+

+number_of_connected_peers=0

+while read -r line

+do

+    # Already got two connected peers. Including the current node

+    # we have 3 peers which is enough to create a shared storage

+    # with replica 3

+    if [ "$number_of_connected_peers" == "2" ]; then

+        break;

+    fi

+

+    key=`echo $line | cut -d ':' -f 1`

+    if [ "$key" == "Hostname" ]; then

+        hostname=`echo $line | cut -d ':' -f 2 | xargs`

+    fi

+

+    if [ "$key" == "State" ]; then

+        peer_state=`echo $line | cut -d ':' -f 2 | cut -d '(' -f 1 | xargs`

+        conn_state=`echo $line | cut -d '(' -f 2 | cut -d ')' -f 1 | xargs`

+

+        if [ "$peer_state" == "Peer in Cluster" ]; then

+            if [ "$conn_state" == "Connected" ]; then

+                ((number_of_connected_peers++))

+                connected_peer[$number_of_connected_peers]=$hostname

+            fi

+        fi

+    fi

+

+done < <(gluster peer status)

+

+# Include current node in connected peer list

+((number_of_connected_peers++))

+connected_peer[$number_of_connected_peers]=$local_node_hostname

+

+# forming the create vol command

+create_cmd="gluster --mode=script --wignore volume create \

+            gluster_shared_storage replica $number_of_connected_peers"

+

+# Adding the brick names in the command

+for i in "${connected_peer[@]}"

+do

+    create_cmd=$create_cmd" "$i:/var/run/gluster/ss_brick

+done

+

+if [ "$option" == "disable" ]; then

+    # Unmount the volume on all the nodes

+    umount /var/run/gluster/shared_storage

+fi

+

+if [ "$is_originator" == 1 ]; then

+    if [ "$option" == "enable" ]; then

+        # Create and start the volume

+        $create_cmd

+        gluster --mode=script --wignore volume start gluster_shared_storage

+    fi

+

+    if [ "$option" == "disable" ]; then

+        # Stop and delete the volume

+        gluster --mode=script --wignore volume stop gluster_shared_storage

+        gluster --mode=script --wignore volume delete gluster_shared_storage

+    fi

+fi

+

+function check_volume_status()

+{

+    status=`gluster volume info gluster_shared_storage  | grep Status | cut -d ':' -f 2 | xargs`

+    echo $status

+}

+

+mount_cmd="mount -t glusterfs "$local_node_hostname":/gluster_shared_storage \

+           /var/run/gluster/shared_storage"

+

+if [ "$option" == "enable" ]; then

+    retry=0;

+    # Wait for volume to start before mounting

+    status=$(check_volume_status)

+    while [ "$status" != "Started" ]; do

+        sleep 5;

+        ((retry++))

+        if [ "$retry" == 3 ]; then

+            break;

+        fi

+        status = check_volume_status;

+    done

+    # Mount the volume on all the nodes

+    umount /var/run/gluster/shared_storage

+    mkdir -p /var/run/gluster/shared_storage

+    $mount_cmd

+fi

diff --git a/glusterfs.spec.in b/glusterfs.spec.in

index 0ec8201..a5a884f 100644

--- a/glusterfs.spec.in

+++ b/glusterfs.spec.in

@@ -1115,6 +1115,7 @@ fi

 %config %{_sharedstatedir}/glusterd/hooks/1/add-brick/pre/S28Quota-enable-root-xattr-heal.sh

 %config %{_sharedstatedir}/glusterd/hooks/1/set/post/S30samba-set.sh

 %config %{_sharedstatedir}/glusterd/hooks/1/set/post/S31ganesha-set.sh

+%config %{_sharedstatedir}/glusterd/hooks/1/set/post/S32gluster_enable_shared_storage.sh

 %config %{_sharedstatedir}/glusterd/hooks/1/start/post/S29CTDBsetup.sh

 %config %{_sharedstatedir}/glusterd/hooks/1/start/post/S30samba-start.sh

 %config %{_sharedstatedir}/glusterd/hooks/1/stop/pre/S30samba-stop.sh

@@ -1208,6 +1209,9 @@ fi

 * Sat May 31 2015 Aravinda VK <avishwan@redhat.com>

 - Added stop-all-gluster-processes.sh in glusterfs-server section (#1225331)

+* Tue May 19 2015 Avra Sengupta <asengupt@redhat.com>

+- Added S32gluster_enable_shared_storage.sh as volume set hook script (#1222013)

+

 * Fri May 29 2015 Anand Nekkunti <anekkunt@redhat.com>

 - glusterd.socket file cleanup during post run upgrade (#1222869)

diff --git a/libglusterfs/src/globals.h b/libglusterfs/src/globals.h

index b9eaf8a..ed1bb7c 100644

--- a/libglusterfs/src/globals.h

+++ b/libglusterfs/src/globals.h

@@ -43,6 +43,8 @@

 #define GD_OP_VERSION_3_7_0    30700 /* Op-version for GlusterFS 3.7.0 */

+#define GD_OP_VERSION_3_7_1    30701 /* Op-version for GlusterFS 3.7.1 */

+

 #define GD_OP_VER_PERSISTENT_AFR_XATTRS GD_OP_VERSION_3_6_0

 #include "xlator.h"

diff --git a/xlators/mgmt/glusterd/src/glusterd-hooks.c b/xlators/mgmt/glusterd/src/glusterd-hooks.c

index 569f274..3e3f189 100644

--- a/xlators/mgmt/glusterd/src/glusterd-hooks.c

+++ b/xlators/mgmt/glusterd/src/glusterd-hooks.c

@@ -162,6 +162,34 @@ glusterd_hooks_add_hooks_version (runner_t* runner)

         runner_argprintf (runner, "--version=%d", GLUSTERD_HOOK_VER);

 }

+static void

+glusterd_hooks_add_custom_args (dict_t *dict, runner_t *runner)

+{

+        char      *hooks_args     = NULL;

+        int32_t    ret            = -1;

+        xlator_t  *this           = NULL;

+

+        this = THIS;

+        GF_VALIDATE_OR_GOTO ("glusterd", this, out);

+        GF_VALIDATE_OR_GOTO (this->name, dict, out);

+        GF_VALIDATE_OR_GOTO (this->name, runner, out);

+

+        ret = dict_get_str (dict, "hooks_args", &hooks_args);

+        if (ret)

+                gf_log (this->name, GF_LOG_DEBUG,

+                        "No Hooks Arguments.");

+        else

+                gf_log (this->name, GF_LOG_DEBUG,

+                        "Hooks Args = %s", hooks_args);

+

+        if (hooks_args)

+                runner_argprintf (runner, "%s", hooks_args);

+

+out:

+        return;

+}

+

+

 int

 glusterd_hooks_set_volume_args (dict_t *dict, runner_t *runner)

 {

@@ -196,6 +224,8 @@ glusterd_hooks_set_volume_args (dict_t *dict, runner_t *runner)

                 runner_argprintf (runner, "%s=%s", key, value);

         }

+        glusterd_hooks_add_custom_args (dict, runner);

+

         ret = 0;

 out:

         return ret;

@@ -263,15 +293,7 @@ glusterd_hooks_add_op_args (runner_t *runner, glusterd_op_t op,

                         break;

                 case GD_OP_GSYNC_CREATE:

-                        ret = dict_get_str (op_ctx, "hooks_args", &hooks_args);

-                        if (ret)

-                                gf_log ("", GF_LOG_DEBUG,

-                                        "No Hooks Arguments.");

-                        else

-                                gf_log ("", GF_LOG_DEBUG,

-                                        "Hooks Args = %s", hooks_args);

-                        if (hooks_args)

-                                runner_argprintf (runner, "%s", hooks_args);

+                        glusterd_hooks_add_custom_args (op_ctx, runner);

                         break;

                 case GD_OP_ADD_BRICK:

diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c

index 326968e..9b9684e 100644

--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c

+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c

@@ -55,11 +55,36 @@

 #include <signal.h>

 #include <sys/wait.h>

+extern char ss_brick_path[PATH_MAX];

+extern char local_node_hostname[PATH_MAX];

+static int

+glusterd_set_shared_storage (dict_t *dict, char *key, char *value,

+                             char **op_errstr);

+

+/* Valid options for all volumes to be listed in the *

+ * valid_all_vol_opts table. To add newer options to *

+ * all volumes, we can just add more entries to this *

+ * table                                             *

+ */

+glusterd_all_vol_opts   valid_all_vol_opts[] = {

+        { GLUSTERD_QUORUM_RATIO_KEY },

+        { GLUSTERD_SHARED_STORAGE_KEY },

+        { NULL },

+};

+

 #define ALL_VOLUME_OPTION_CHECK(volname, key, ret, op_errstr, label)           \

         do {                                                                   \

-                gf_boolean_t    _all = !strcmp ("all", volname);               \

-                gf_boolean_t    _ratio = !strcmp (key,                         \

-                                                  GLUSTERD_QUORUM_RATIO_KEY);  \

+                gf_boolean_t    _all   = !strcmp ("all", volname);             \

+                gf_boolean_t    _ratio = _gf_false;                            \

+                int32_t         i      = 0;                                    \

+                                                                               \

+                for (i = 0; valid_all_vol_opts[i].option; i++) {               \

+                        if (!strcmp (key, valid_all_vol_opts[i].option)) {     \

+                                _ratio = _gf_true;                             \

+                                break;                                         \

+                        }                                                      \

+                }                                                              \

+                                                                               \

                 if (_all && !_ratio) {                                         \

                         ret = -1;                                              \

                         *op_errstr = gf_strdup ("Not a valid option for all "  \

@@ -682,6 +707,71 @@ out:

 }

 static int

+glusterd_validate_shared_storage (char *key, char *value, char *errstr)

+{

+        int32_t       ret      = -1;

+        int32_t       exists   = -1;

+        int32_t       count    = -1;

+        xlator_t     *this     = NULL;

+

+        this = THIS;

+        GF_VALIDATE_OR_GOTO ("glusterd", this, out);

+        GF_VALIDATE_OR_GOTO (this->name, key, out);

+        GF_VALIDATE_OR_GOTO (this->name, value, out);

+        GF_VALIDATE_OR_GOTO (this->name, errstr, out);

+

+        ret = 0;

+

+        if (strcmp (key, GLUSTERD_SHARED_STORAGE_KEY)) {

+                goto out;

+        }

+

+        if ((strcmp (value, "enable")) &&

+            (strcmp (value, "disable"))) {

+                snprintf (errstr, PATH_MAX,

+                          "Invalid option(%s). Valid options "

+                          "are 'enable' and 'disable'", value);

+                gf_log (this->name, GF_LOG_ERROR, "%s", errstr);

+                ret = -1;

+                goto out;

+        }

+

+        if (strcmp (value, "enable")) {

+                goto out;

+        }

+

+        exists = glusterd_check_volume_exists (GLUSTER_SHARED_STORAGE);

+        if (exists) {

+                snprintf (errstr, PATH_MAX,

+                          "Shared storage volume("GLUSTER_SHARED_STORAGE

+                          ") already exists.");

+                gf_log (this->name, GF_LOG_ERROR, "%s", errstr);

+                ret = -1;

+                goto out;

+        }

+

+        ret = glusterd_count_connected_peers (&count);

+        if (ret) {

+                snprintf (errstr, PATH_MAX,

+                          "Failed to calculate number of connected peers.");

+                gf_log (this->name, GF_LOG_ERROR, "%s", errstr);

+                goto out;

+        }

+

+        if (count <= 1) {

+                snprintf (errstr, PATH_MAX,

+                          "More than one node should "

+                          "be up/present in the cluster to enable this option");

+                gf_log (this->name, GF_LOG_ERROR, "%s", errstr);

+                ret = -1;

+                goto out;

+        }

+

+out:

+        return ret;

+}

+

+static int

 glusterd_op_stage_set_volume (dict_t *dict, char **op_errstr)

 {

         int                             ret                     = -1;

@@ -696,7 +786,7 @@ glusterd_op_stage_set_volume (dict_t *dict, char **op_errstr)

         int                             trash_path_len          = 0;

         int                             count                   = 0;

         int                             dict_count              = 0;

-        char                            errstr[2048]            = {0, };

+        char                            errstr[PATH_MAX]        = {0, };

         glusterd_volinfo_t              *volinfo                = NULL;

         glusterd_brickinfo_t            *brickinfo              = NULL;

         dict_t                          *val_dict               = NULL;

@@ -1000,6 +1090,14 @@ glusterd_op_stage_set_volume (dict_t *dict, char **op_errstr)

                         }

                 }

+                ret = glusterd_validate_shared_storage (key, value, errstr);

+                if (ret) {

+                        gf_log (this->name, GF_LOG_ERROR,

+                                "Failed to validate shared "

+                                "storage volume options");

+                        goto out;

+                }

+

                 if (!strcmp(key, "features.trash-dir") && trash_enabled) {

                         if (strchr (value, '/')) {

                                 snprintf (errstr, sizeof (errstr),

@@ -1918,7 +2016,8 @@ out:

 }

 static int

-glusterd_op_set_all_volume_options (xlator_t *this, dict_t *dict)

+glusterd_op_set_all_volume_options (xlator_t *this, dict_t *dict,

+                                    char **op_errstr)

 {

         char            *key            = NULL;

         char            *key_fixed      = NULL;

@@ -1942,6 +2041,7 @@ glusterd_op_set_all_volume_options (xlator_t *this, dict_t *dict)

                         "invalid key,value pair in 'volume set'");

                 goto out;

         }

+

         ret = glusterd_check_option_exists (key, &key_fixed);

         if (ret <= 0) {

                 gf_log (this->name, GF_LOG_ERROR, "Invalid key %s", key);

@@ -1952,6 +2052,13 @@ glusterd_op_set_all_volume_options (xlator_t *this, dict_t *dict)

         if (key_fixed)

                 key = key_fixed;

+        ret = glusterd_set_shared_storage (dict, key, value, op_errstr);

+        if (ret) {

+                gf_log (this->name, GF_LOG_ERROR,

+                        "Failed to set shared storage option");

+                goto out;

+        }

+

         /* If the key is cluster.op-version, set conf->op_version to the value

          * if needed and save it.

          */

@@ -2030,6 +2137,82 @@ out:

 }

 static int

+glusterd_set_shared_storage (dict_t *dict, char *key, char *value,

+                             char **op_errstr)

+{

+        int32_t       ret                  = -1;

+        int32_t       exists               = -1;

+        int32_t       count                = -1;

+        char          hooks_args[PATH_MAX] = {0, };

+        char          errstr[PATH_MAX]     = {0, };

+        xlator_t     *this                 = NULL;

+

+        this = THIS;

+        GF_VALIDATE_OR_GOTO ("glusterd", this, out);

+        GF_VALIDATE_OR_GOTO (this->name, dict, out);

+        GF_VALIDATE_OR_GOTO (this->name, key, out);

+        GF_VALIDATE_OR_GOTO (this->name, value, out);

+        GF_VALIDATE_OR_GOTO (this->name, op_errstr, out);

+

+        ret = 0;

+

+        if (strcmp (key, GLUSTERD_SHARED_STORAGE_KEY)) {

+                goto out;

+        }

+

+        /* Re-create the brick path so as to be *

+         * able to re-use it                    *