glusterd/snapshot: Activation and De-activation of snapshot

Previously, snapshots by default were activated on creation and there was
no option to activate or deactivate them on demand.

This will allow the user to activate and deactivate on demand.
The CLI goes as follows

1) Activate the snap using a command "gluster snapshot activate <snapname> [force]"
2) Deactivate the snap using a command "gluster snapshot deactivate <snapname>"

Note: Even now the snapshot will be activated during creation.

Change-Id: I0946d800780f26c63fa1fcaf29aabc900140448f
BUG: 1061685
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Reviewed-on: http://review.gluster.org/7476
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijaikumar Mallikarjuna <vmallika@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 293 insertions, 40 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-snapshot.c b/xlators/mgmt/glusterd/src/glusterd-snapshot.c
index 9c64fe2d61a..73723422bc7 100644
--- a/xlators/mgmt/glusterd/src/glusterd-snapshot.c
+++ b/xlators/mgmt/glusterd/src/glusterd-snapshot.c
@@ -2854,16 +2854,6 @@ glusterd_handle_snapshot_status (rpcsvc_request_t *req, glusterd_op_t op,
                 }
         }
 
-        /* Volume lock is not necessary for snapshot status, hence
-         * turning it off
-         */
-        ret = dict_set_int8 (dict, "hold_vol_locks", 0);
-        if (ret) {
-                gf_log (this->name, GF_LOG_ERROR, "Setting volume lock "
-                        "flag failed");
-                goto out;
-        }
-
         ret = glusterd_mgmt_v3_initiate_snap_phases (req, op, dict);
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR, "Failed to initiate "
@@ -3751,35 +3741,13 @@ glusterd_do_snap_vol (glusterd_volinfo_t *origin_vol, glusterd_snap_t *snap,
                 goto out;
         }
 
-        list_for_each_entry (brickinfo, &snap_vol->bricks, brick_list) {
-                if (uuid_compare (brickinfo->uuid, MY_UUID))
-                        continue;
+        /*Starting the snap volume without GF_CLI_FLAG_OP_FORCE option*/
+        ret = glusterd_start_volume (snap_vol, 0);
 
-                if (brickinfo->snap_status == -1) {
-                        gf_log (this->name, GF_LOG_INFO,
-                                "not starting snap brick %s:%s for "
-                                "for the snap %s (volume: %s)",
-                                brickinfo->hostname, brickinfo->path,
-                                snap->snapname, origin_vol->volname);
-                        continue;
-                }
-
-                ret = glusterd_brick_start (snap_vol, brickinfo, _gf_true);
-                if (ret) {
-                        gf_log (this->name, GF_LOG_WARNING, "starting the "
-                                "brick %s:%s for the snap %s (volume: %s) "
-                                "failed", brickinfo->hostname, brickinfo->path,
-                                snap->snapname, origin_vol->volname);
-                        goto out;
-                }
-        }
-
-        snap_vol->status = GLUSTERD_STATUS_STARTED;
-        ret = glusterd_store_volinfo (snap_vol,
-                                      GLUSTERD_VOLINFO_VER_AC_INCREMENT);
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR,
-                        "Failed to store snap volinfo");
+                        "Failed to activate snap volume %s of the snap %s",
+                        snap_vol->volname, snap->snapname);
                 goto out;
         }
 
@@ -3794,6 +3762,105 @@ out:
         return snap_vol;
 }
 
+/*This is the prevalidate function for both activate and deactive of snap
+ * For Activate operation pass is_op_activate as _gf_true
+ * For Deactivate operation pass is_op_activate as _gf_false
+ * */
+int
+glusterd_snapshot_activate_deactivate_prevalidate (dict_t *dict,
+                char **op_errstr, dict_t *rsp_dict, gf_boolean_t is_op_activate)
+{
+        int32_t                 ret                   = -1;
+        char                    *snapname             = NULL;
+        xlator_t                *this                 = NULL;
+        glusterd_snap_t         *snap                 = NULL;
+        glusterd_volinfo_t      *snap_volinfo         = NULL;
+        char                    err_str[PATH_MAX]     = "";
+        gf_loglevel_t           loglevel              = GF_LOG_ERROR;
+        glusterd_volume_status  volume_status         = GLUSTERD_STATUS_STOPPED;
+        int                     flags                 = 0;
+
+        this = THIS;
+
+        if (!dict || !op_errstr) {
+                gf_log (this->name, GF_LOG_ERROR, "input parameters NULL");
+                goto out;
+        }
+
+        ret = dict_get_str (dict, "snapname", &snapname);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "Getting the snap name "
+                        "failed");
+                goto out;
+        }
+
+        snap = glusterd_find_snap_by_name (snapname);
+        if (!snap) {
+                snprintf (err_str, sizeof (err_str), "Snap %s does not exist.",
+                        snapname);
+                ret = -1;
+                goto out;
+        }
+
+        /*If its activation of snap then fetch the flags*/
+        if (is_op_activate) {
+                ret = dict_get_int32 (dict, "flags", &flags);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Unable to get flags");
+                        goto out;
+                }
+        }
+
+        /* TODO : As of now there is only volume in snapshot.
+        * Change this when multiple volume snapshot is introduced
+        */
+        snap_volinfo = list_entry (snap->volumes.next, glusterd_volinfo_t,
+                        vol_list);
+        if (!snap_volinfo) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Unable to fetch snap_volinfo");
+                ret = -1;
+                goto out;
+        }
+
+        /*TODO: When multiple snapvolume are involved a cummulative
+         * logic is required to tell whether is snapshot is
+         * started/partially started/stopped*/
+        if (is_op_activate) {
+                volume_status = GLUSTERD_STATUS_STARTED;
+        }
+
+        if (snap_volinfo->status == volume_status) {
+                if (is_op_activate) {
+                        /* if flag is to GF_CLI_FLAG_OP_FORCE
+                         * try to start the snap volume, even
+                         * if the volume_status is GLUSTERD_STATUS_STARTED.
+                         * By doing so we try to bring
+                         * back the brick processes that are down*/
+                        if (!(flags & GF_CLI_FLAG_OP_FORCE)) {
+                                snprintf (err_str, sizeof (err_str),
+                                     "Snap %s is already activated.", snapname);
+                                ret = -1;
+                        }
+                } else {
+                        snprintf (err_str, sizeof (err_str),
+                                "Snap %s is already deactivated.", snapname);
+                        ret = -1;
+                }
+                goto out;
+        }
+        ret = 0;
+out:
+
+        if (ret && err_str[0] != '\0') {
+                gf_log (this->name, loglevel, "%s", err_str);
+                *op_errstr = gf_strdup (err_str);
+        }
+
+        return ret;
+}
+
 /* This is a snapshot remove handler function. This function will be
  * executed in the originator node. This function is responsible for
  * calling mgmt v3 framework to do the actual remove on all the bricks
@@ -4009,6 +4076,134 @@ out:
 }
 
 int32_t
+glusterd_snapshot_activate_commit (dict_t *dict, char **op_errstr,
+                                 dict_t *rsp_dict)
+{
+        int32_t                   ret                  = -1;
+        char                     *snapname             = NULL;
+        glusterd_snap_t          *snap                 = NULL;
+        glusterd_volinfo_t       *snap_volinfo         = NULL;
+        xlator_t                 *this                 = NULL;
+        int                      flags                 = 0;
+
+        this = THIS;
+        GF_ASSERT (this);
+        GF_ASSERT (dict);
+        GF_ASSERT (rsp_dict);
+        GF_ASSERT (op_errstr);
+
+        if (!dict || !op_errstr) {
+                gf_log (this->name, GF_LOG_ERROR, "input parameters NULL");
+                goto out;
+        }
+
+        ret = dict_get_str (dict, "snapname", &snapname);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "Getting the snap name "
+                        "failed");
+                goto out;
+        }
+
+        ret = dict_get_int32 (dict, "flags", &flags);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "Unable to get flags");
+                goto out;
+        }
+
+        snap = glusterd_find_snap_by_name (snapname);
+        if (!snap) {
+                gf_log (this->name, GF_LOG_ERROR, "Snap %s does not exist",
+                        snapname);
+                ret = -1;
+                goto out;
+        }
+
+        /* TODO : As of now there is only volume in snapshot.
+        * Change this when multiple volume snapshot is introduced
+        */
+        snap_volinfo = list_entry (snap->volumes.next, glusterd_volinfo_t,
+                        vol_list);
+        if (!snap_volinfo) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Unable to fetch snap_volinfo");
+                        ret = -1;
+                        goto out;
+        }
+
+        ret = glusterd_start_volume (snap_volinfo, flags);
+
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Failed to activate snap volume %s of the snap %s",
+                        snap_volinfo->volname, snap->snapname);
+                goto out;
+        }
+        ret = 0;
+out:
+        return ret;
+}
+
+int32_t
+glusterd_snapshot_deactivate_commit (dict_t *dict, char **op_errstr,
+                                 dict_t *rsp_dict)
+{
+        int32_t                   ret                  = -1;
+        char                     *snapname             = NULL;
+        glusterd_snap_t          *snap                 = NULL;
+        glusterd_volinfo_t       *snap_volinfo         = NULL;
+        xlator_t                 *this                 = NULL;
+
+        this = THIS;
+        GF_ASSERT (this);
+        GF_ASSERT (dict);
+        GF_ASSERT (rsp_dict);
+        GF_ASSERT (op_errstr);
+
+        if (!dict || !op_errstr) {
+                gf_log (this->name, GF_LOG_ERROR, "input parameters NULL");
+                goto out;
+        }
+
+        ret = dict_get_str (dict, "snapname", &snapname);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "Getting the snap name "
+                        "failed");
+                goto out;
+        }
+
+        snap = glusterd_find_snap_by_name (snapname);
+        if (!snap) {
+                gf_log (this->name, GF_LOG_ERROR, "Snap %s does not exist",
+                        snapname);
+                ret = -1;
+                goto out;
+        }
+
+        /* TODO : As of now there is only volume in snapshot.
+        * Change this when multiple volume snapshot is introduced
+        */
+        snap_volinfo = list_entry (snap->volumes.next, glusterd_volinfo_t,
+                        vol_list);
+        if (!snap_volinfo) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Unable to fetch snap_volinfo");
+                        ret = -1;
+                        goto out;
+        }
+
+        ret = glusterd_stop_volume (snap_volinfo);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "Failed to deactivate"
+                        "snap %s", snapname);
+                goto out;
+        }
+
+        ret = 0;
+out:
+        return ret;
+}
+
+int32_t
 glusterd_snapshot_remove_commit (dict_t *dict, char **op_errstr,
                                  dict_t *rsp_dict)
 {
@@ -5220,6 +5415,27 @@ glusterd_snapshot (dict_t *dict, char **op_errstr, dict_t *rsp_dict)
                 }
 
                 break;
+        case  GF_SNAP_OPTION_TYPE_ACTIVATE:
+                ret = glusterd_snapshot_activate_commit (dict, op_errstr,
+                                                 rsp_dict);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_WARNING, "Failed to "
+                                "activate snapshot");
+                        goto out;
+                }
+
+                break;
+
+        case GF_SNAP_OPTION_TYPE_DEACTIVATE:
+                ret = glusterd_snapshot_deactivate_commit (dict, op_errstr,
+                                                 rsp_dict);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_WARNING, "Failed to "
+                                "deactivate snapshot");
+                        goto out;
+                }
+
+                break;
 
         case GF_SNAP_OPTION_TYPE_STATUS:
                 ret = glusterd_snapshot_status_commit (dict, op_errstr,
@@ -5395,6 +5611,25 @@ glusterd_snapshot_prevalidate (dict_t *dict, char **op_errstr,
                         goto out;
                 }
                 break;
+
+        case  GF_SNAP_OPTION_TYPE_ACTIVATE:
+                ret = glusterd_snapshot_activate_deactivate_prevalidate (dict,
+                                                op_errstr, rsp_dict, _gf_true);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_WARNING, "Snapshot activate "
+                                        "validation failed");
+                        goto out;
+                }
+                break;
+        case GF_SNAP_OPTION_TYPE_DEACTIVATE:
+                ret = glusterd_snapshot_activate_deactivate_prevalidate (dict,
+                                                op_errstr, rsp_dict, _gf_false);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                        "Snapshot deactivate validation failed");
+                        goto out;
+                }
+                break;
         case GF_SNAP_OPTION_TYPE_DELETE:
                 ret = glusterd_snapshot_remove_prevalidate (dict, op_errstr,
                                                             rsp_dict);
@@ -5457,7 +5692,6 @@ glusterd_snapshot_postvalidate (dict_t *dict, int32_t op_ret, char **op_errstr,
                         goto out;
                 }
                 break;
-
         case GF_SNAP_OPTION_TYPE_DELETE:
         case GF_SNAP_OPTION_TYPE_RESTORE:
                 ret = glusterd_snapshot_update_snaps_post_validate (dict,
@@ -5469,7 +5703,12 @@ glusterd_snapshot_postvalidate (dict_t *dict, int32_t op_ret, char **op_errstr,
                         goto out;
                 }
                 break;
-
+        case GF_SNAP_OPTION_TYPE_ACTIVATE:
+        case GF_SNAP_OPTION_TYPE_DEACTIVATE:
+                 /*Nothing to be done. But want to
+                 * avoid the default case warning*/
+                ret = 0;
+                break;
         default:
                 gf_log (this->name, GF_LOG_WARNING, "invalid snap command");
                 goto out;
@@ -5603,8 +5842,22 @@ glusterd_handle_snapshot_fn (rpcsvc_request_t *req)
                                 "failed: %s", err_str);
                 }
                 break;
-        case GF_SNAP_OPTION_TYPE_START:
-        case GF_SNAP_OPTION_TYPE_STOP:
+        case  GF_SNAP_OPTION_TYPE_ACTIVATE:
+                ret = glusterd_mgmt_v3_initiate_snap_phases (req, cli_op,
+                                                             dict);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "Snapshot activate failed: %s", err_str);
+                }
+                break;
+        case GF_SNAP_OPTION_TYPE_DEACTIVATE:
+                ret = glusterd_mgmt_v3_initiate_snap_phases (req, cli_op,
+                                                             dict);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "Snapshot deactivate failed: %s", err_str);
+                }
+                break;
         case GF_SNAP_OPTION_TYPE_STATUS:
                 ret = glusterd_handle_snapshot_status (req, cli_op, dict,
                                                        err_str,