libgfapi: Added support to fetch volume info from glusterd and store in glfs object.

Defined new APIs in the libgfapi module, given a glfs object,
 * to send handshake RPC call to glusterd process to fetch UUID of the volume
 * store it in the glusterfs_context linked to the glfs object.
 * to parse UUID from its cannonical string format into 16-byte array
   before sending it to the libgfapi users.

Defined a RPC call in glusterd which can be used to query volume related
info by other processes using 'clnt_handshake_procs'.

Note - Currently this RPC call to glusterd process is used only to fetch UUID.
But it can be extended to get other volume related structures as well.

In addition to the above, defined a new variable to keep track of such handshake
RPCs still in progress to make sure all the corresponding RPC callbacks have been
processed before libgfapi returns the glfs object initialized.

Also bumping up the GFAPI current version number since there is a new API
"glfs_get_volume_id" defined and exposed by libgfapi as part of these changes.

Change-Id: I303f76d7177d32d25bdb301b1dbcf5cd73f42807
BUG: 1090363
Signed-off-by: Soumya Koduri <skoduri@redhat.com>
Reviewed-on: http://review.gluster.org/7218
Reviewed-by: Anand Avati <avati@redhat.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 137 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-handshake.c b/xlators/mgmt/glusterd/src/glusterd-handshake.c
index 2b89545c80d..dbaa972937b 100644
--- a/xlators/mgmt/glusterd/src/glusterd-handshake.c
+++ b/xlators/mgmt/glusterd/src/glusterd-handshake.c
@@ -1001,10 +1001,147 @@ glusterd_mgmt_hndsk_versions_ack (rpcsvc_request_t *req)
                                             __glusterd_mgmt_hndsk_versions_ack);
 }
 
+int
+__server_get_volume_info (rpcsvc_request_t *req)
+{
+        int                     ret             = -1;
+        int32_t                 op_errno        = ENOENT;
+        gf_get_volume_info_req	vol_info_req    = {{0,}};
+        gf_get_volume_info_rsp	vol_info_rsp    = {0,};
+        char                    *volname        = NULL;
+        glusterd_volinfo_t      *volinfo        = NULL;
+        dict_t                  *dict           = NULL;
+        dict_t                  *dict_rsp       = NULL;
+        char                    *volume_id_str  = NULL;
+        int32_t                 flags           = 0;
+
+        ret = xdr_to_generic (req->msg[0], &vol_info_req,
+                             (xdrproc_t)xdr_gf_get_volume_info_req);
+        if (ret < 0) {
+                //failed to decode msg;
+                req->rpc_err = GARBAGE_ARGS;
+                goto out;
+        }
+        gf_log ("glusterd", GF_LOG_INFO, "Received get volume info req");
+
+        if (vol_info_req.dict.dict_len) {
+                /* Unserialize the dictionary */
+                dict  = dict_new ();
+                if (!dict) {
+                        gf_log ("", GF_LOG_WARNING, "Out of Memory");
+                        op_errno = ENOMEM;
+                        ret = -1;
+                        goto out;
+                }
+
+                ret = dict_unserialize (vol_info_req.dict.dict_val,
+                                        vol_info_req.dict.dict_len,
+                                        &dict);
+                if (ret < 0) {
+                        gf_log ("glusterd", GF_LOG_ERROR,
+                                "failed to "
+                                "unserialize req-buffer to dictionary");
+                        op_errno = -ret;
+                        ret = -1;
+                        goto out;
+                } else {
+                        dict->extra_stdfree = vol_info_req.dict.dict_val;
+                }
+        }
+
+        ret = dict_get_int32 (dict, "flags", &flags);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_ERROR, "failed to get flags");
+                op_errno = -ret;
+                ret = -1;
+                goto out;
+        }
+
+        if (!flags) {
+                //Nothing to query about. Just return success
+                gf_log (THIS->name, GF_LOG_ERROR, "No flags set");
+                ret = 0;
+                goto out;
+        }
+
+        ret = dict_get_str (dict, "volname", &volname);
+        if (ret) {
+                op_errno = EINVAL;
+                ret = -1;
+                goto out;
+        }
+
+        ret = glusterd_volinfo_find (volname, &volinfo);
+        if (ret) {
+                op_errno = EINVAL;
+                ret = -1;
+                goto out;
+        }
+
+        if (flags | (int32_t)GF_GET_VOLUME_UUID) {
+                volume_id_str = gf_strdup (uuid_utoa (volinfo->volume_id));
+                if (!volume_id_str) {
+                        op_errno = ENOMEM;
+                        ret = -1;
+                        goto out;
+                }
+
+                dict_rsp = dict_new ();
+                if (!dict_rsp) {
+                        gf_log ("", GF_LOG_WARNING, "Out of Memory");
+                        op_errno = ENOMEM;
+                        ret = -1;
+                        goto out;
+                }
+                ret = dict_set_dynstr (dict_rsp, "volume_id", volume_id_str);
+                if (ret) {
+                        op_errno = -ret;
+                        ret = -1;
+                        goto out;
+                }
+        }
+        ret = dict_allocate_and_serialize (dict_rsp, &vol_info_rsp.dict.dict_val,
+                                           &vol_info_rsp.dict.dict_len);
+        if (ret) {
+                op_errno = -ret;
+                ret = -1;
+                goto out;
+        }
+
+out:
+        vol_info_rsp.op_ret = ret;
+        vol_info_rsp.op_errno = op_errno;
+        vol_info_rsp.op_errstr = "";
+        glusterd_submit_reply (req, &vol_info_rsp, NULL, 0, NULL,
+                               (xdrproc_t)xdr_gf_get_volume_info_rsp);
+        ret = 0;
+
+        if (dict) {
+                dict_unref (dict);
+        }
+
+        if (dict_rsp) {
+                dict_unref (dict_rsp);
+        }
+
+        if (vol_info_rsp.dict.dict_val) {
+                GF_FREE (vol_info_rsp.dict.dict_val);
+        }
+        return ret;
+}
+
+int
+server_get_volume_info (rpcsvc_request_t *req)
+{
+        return glusterd_big_locked_handler (req,
+                                            __server_get_volume_info);
+}
+
 rpcsvc_actor_t gluster_handshake_actors[] = {
         [GF_HNDSK_NULL]         = {"NULL",        GF_HNDSK_NULL,         NULL,                NULL, 0, DRC_NA},
         [GF_HNDSK_GETSPEC]      = {"GETSPEC",     GF_HNDSK_GETSPEC,      server_getspec,      NULL, 0, DRC_NA},
         [GF_HNDSK_EVENT_NOTIFY] = {"EVENTNOTIFY", GF_HNDSK_EVENT_NOTIFY, server_event_notify, NULL, 0, DRC_NA},
+        [GF_HNDSK_GET_VOLUME_INFO] = {"GETVOLUMEINFO", GF_HNDSK_GET_VOLUME_INFO, server_get_volume_info, NULL, 0, DRC_NA},
 };