Snapshot: Gluster snapshot restore feature

Implemented gluster snapshot restore feature. The restore is done
by replacing the origin volume with the snap volume.

TODO: After the restore the snapshot volume should be deleted. As of
      now the deletion work is pending.

Change-Id: Ib137fb6bb84a74030607ffa47f89cd705dc7e1ff
Signed-off-by: Rajesh Joseph <rjoseph@redhat.com>

1 files changed, 33 insertions, 138 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-snapshot.c b/xlators/mgmt/glusterd/src/glusterd-snapshot.c
index acc8bef16..8419cfb25 100644
--- a/xlators/mgmt/glusterd/src/glusterd-snapshot.c
+++ b/xlators/mgmt/glusterd/src/glusterd-snapshot.c
@@ -48,139 +48,6 @@ char *
 generate_snapname (char *volname, char *name, gf_boolean_t volume_from_cg);
 
 
-/* This function will do the actual snapshot restore on the brick.
- *
- * @param brickinfo     brickinfo structure
- * @param snapname      name of the snap which will be restored
- *
- * @return              Negative value on Failure and 0 in success
- */
-int
-glusterd_snapshot_restore_brick_snap (glusterd_brickinfo_t *brickinfo,
-                                      char *snapname)
-{
-        int             ret             = -1;
-        char            *device         = NULL;
-        xlator_t        *this           = NULL;
-        runner_t        runner          = {0,};
-        glusterd_conf_t *conf           = NULL;
-        char            msg[PATH_MAX]   = {0,};
-
-        this = THIS;
-        GF_ASSERT (this);
-        conf = this->private;
-
-        GF_ASSERT (conf);
-        GF_ASSERT (brickinfo);
-        GF_ASSERT (snapname);
-
-        /* Using the brickinfo get the actual device name */
-        device = glusterd_get_brick_mount_details (brickinfo);
-
-        runinit (&runner);
-        snprintf (msg, sizeof (msg), "Restoring snapshot of the brick %s:%s "
-                  "to %s snap", brickinfo->hostname, brickinfo->path, snapname);
-
-        /* Command for restoring the snapshot */
-        runner_add_args (&runner, "/sbin/lvconvert", "--merge", device, NULL);
-        runner_log (&runner, "", GF_LOG_DEBUG, msg);
-
-        synclock_unlock (&conf->big_lock);
-        /* Run the actual command */
-        ret = runner_run (&runner);
-        synclock_lock (&conf->big_lock);
-
-        if (ret) {
-                gf_log (this->name, GF_LOG_ERROR, "snapshot restore of the "
-                        "brick (%s:%s) of device %s failed",
-                        brickinfo->hostname, brickinfo->path, device);
-                goto out;
-        }
-
-out:
-        return ret;
-}
-
-/* This function will restore the snapshot for the entire volume.
- *
- * @param snap          snap object which needs to be restored
- * @param op_errstr     In case of any failure error message will be returned
- *                      in this variable
- * @return              Negative value on Failure and 0 in success
- */
-int
-glusterd_snapshot_restore_snap (glusterd_snap_t *snap, char **op_errstr)
-{
-        int                     ret             = -1;
-        xlator_t                *this           = NULL;
-        glusterd_volinfo_t      *volinfo        = NULL;
-        glusterd_brickinfo_t    *brickinfo      = NULL;
-
-        this = THIS;
-
-        GF_ASSERT (this);
-        GF_ASSERT (snap);
-        GF_ASSERT (snap->snap_volume);
-        GF_ASSERT (op_errstr);
-
-        /* For restore always take volinfo stored in snap. Do not use
-         * volinfo of the original volume*/
-        volinfo = snap->snap_volume;
-
-        list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
-                /* This code is executed on each node of the volume. We need
-                 * to run the restore only on those bricks which are present
-                 * in this node. Therefore check if node belongs to this node
-                 * or not.
-                 */
-                if (uuid_compare (brickinfo->uuid, MY_UUID)) {
-                        continue; /* Bricks not present in this node */
-                }
-
-                /* This case should never occur as volume is already stopped.
-                 * Just to avoid a case where the brick is explicitly started
-                 * by the user we have this check here.
-                 */
-                if (glusterd_is_brick_started (brickinfo)) {
-                        ret = gf_asprintf (op_errstr, "Brick (%s: %s) is "
-                                           "running therefore snapshot cannot "
-                                           "be restored", brickinfo->hostname,
-                                           brickinfo->path);
-                        if (ret < 0) {
-                                goto out;
-                        }
-
-                        gf_log (this->name, GF_LOG_ERROR, "%s", *op_errstr);
-                        ret = -1;
-                        goto out;
-                }
-
-                /* Do the actual snapshot restore */
-                ret = glusterd_snapshot_restore_brick_snap (brickinfo,
-                                                            snap->snap_name);
-                if (ret) {
-                        ret = gf_asprintf (op_errstr, "Snapshot restore failed"
-                                           " for %s:%s", brickinfo->hostname,
-                                           brickinfo->path);
-                        if (ret < 0) {
-                                goto out;
-                        }
-
-                        gf_log (this->name, GF_LOG_ERROR, "%s", *op_errstr);
-                        ret = -1;
-                        goto out;
-                }
-
-        }
-
-        /* TODO: Move this code to postvalidate */
-        snap->snap_restored = _gf_true;
-        /* TODO: persist the change in store */
-
-out:
-        return ret;
-}
-
 /* This function will restore a snapshot for the entire
  * volume or the entire CG (Consistency Group)
  *
@@ -260,7 +127,7 @@ glusterd_snapshot_restore (dict_t *dict, char **op_errstr)
                 }
 
                 /* Restore the snap for the entire volume */
-                ret = glusterd_snapshot_restore_snap (snap, op_errstr);
+                ret = gd_restore_snap_volume (volinfo, snap->snap_volume);
                 if (ret) {
                         /* No need to update op_errstr because it is assumed
                          * that the called function will do that in case of
@@ -289,10 +156,12 @@ out:
  * @param dict          dictionary containing snapshot restore request
  * @param op_errstr     In case of any failure error message will be returned
  *                      in this variable
+ * @param rsp_dict      response dictionary
  * @return              Negative value on Failure and 0 in success
  */
 int
-glusterd_snapshot_restore_prevalidate (dict_t *dict, char **op_errstr)
+glusterd_snapshot_restore_prevalidate (dict_t *dict, char **op_errstr,
+                                       dict_t *rsp_dict)
 {
         int                     ret             = -1;
         int64_t                 i               = 0;
@@ -300,6 +169,7 @@ glusterd_snapshot_restore_prevalidate (dict_t *dict, char **op_errstr)
         gf_boolean_t            snap_restored   = _gf_false;
         char                    *volname        = NULL;
         char                    *snapname       = NULL;
+        char                    *cgname         = NULL;
         glusterd_volinfo_t      *volinfo        = NULL;
         glusterd_snap_t         *snap           = NULL;
         xlator_t                *this           = NULL;
@@ -310,6 +180,30 @@ glusterd_snapshot_restore_prevalidate (dict_t *dict, char **op_errstr)
         GF_ASSERT (this);
         GF_ASSERT (dict);
         GF_ASSERT (op_errstr);
+        GF_ASSERT (rsp_dict);
+
+        ret = dict_get_str (dict, "cgname", &cgname);
+        if (ret) {
+                ret = dict_get_str (dict, "snapname", &snapname);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to get "
+                                "neither snapname nor cgname");
+                        goto out;
+                }
+                ret = dict_set_str (rsp_dict, "snapname", snapname);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to set "
+                                "snap name");
+                        goto out;
+                }
+        } else {
+                ret = dict_set_str (rsp_dict, "cgname", cgname);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to set "
+                                "CG name");
+                        goto out;
+                }
+        }
 
         ret = dict_get_int64 (dict, "volcount", &volcount);
 
@@ -3234,7 +3128,7 @@ glusterd_do_snap (glusterd_volinfo_t *volinfo, char *snapname, dict_t *dict,
         }
 
         ret = generate_snap_client_volfiles (volinfo, snap_volume,
-                                            GF_CLIENT_TRUSTED);
+                                            GF_CLIENT_TRUSTED, _gf_false);
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR, "generating the trusted "
                         "client volfiles for the snap %s (volume: %s) failed",
@@ -3243,7 +3137,7 @@ glusterd_do_snap (glusterd_volinfo_t *volinfo, char *snapname, dict_t *dict,
         }
 
         ret = generate_snap_client_volfiles (volinfo, snap_volume,
-                                            GF_CLIENT_OTHER);
+                                            GF_CLIENT_OTHER, _gf_false);
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR, "generating the client "
                         "volfiles for the snap %s (volume: %s) failed",
@@ -4657,7 +4551,8 @@ glusterd_snapshot_prevalidate (dict_t *dict, char **op_errstr,
                 break;
 
         case GF_SNAP_OPTION_TYPE_RESTORE:
-                ret = glusterd_snapshot_restore_prevalidate (dict, op_errstr);
+                ret = glusterd_snapshot_restore_prevalidate (dict, op_errstr,
+                                                             rsp_dict);
                 if (ret) {
                         gf_log (this->name, GF_LOG_WARNING, "Snapshot restore "
                                         "validation failed");