snapshot: Fix restore rollback to reassign snap volume ids to bricks

Added further checks to ensure we do not go beyond prevalidate
when trying to restore a snapshot which has a nfs-gansha conf
file, in a cluster when nfs-ganesha is not enabled

The error message for the particular scenario is:
"Snapshot(<snapname>) has a nfs-ganesha export conf
file. cluster.enable-shared-storage and nfs-ganesha
should be enabled before restoring this snapshot."

Change-Id: I1b87e9907e0a5e162f26ef1ca89fe76e8da8610f
BUG: 1404118
Signed-off-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-on: http://review.gluster.org/16116
Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

6 files changed, 158 insertions, 1 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-errno.h b/xlators/mgmt/glusterd/src/glusterd-errno.h
index 55d44a5c6a1..3301e44a414 100644
--- a/xlators/mgmt/glusterd/src/glusterd-errno.h
+++ b/xlators/mgmt/glusterd/src/glusterd-errno.h
@@ -27,6 +27,7 @@ enum glusterd_op_errno {
         EG_ISSNAP      = 30813,          /* Volume is a snap volume           */
         EG_GEOREPRUN   = 30814,          /* Geo-Replication is running        */
         EG_NOTTHINP    = 30815,          /* Bricks are not thinly provisioned */
+        EG_NOGANESHA   = 30816,          /* Global nfs-ganesha is not enabled */
 };
 
 #endif
diff --git a/xlators/mgmt/glusterd/src/glusterd-ganesha.c b/xlators/mgmt/glusterd/src/glusterd-ganesha.c
index 746a3d1e364..8dde82e89ed 100644
--- a/xlators/mgmt/glusterd/src/glusterd-ganesha.c
+++ b/xlators/mgmt/glusterd/src/glusterd-ganesha.c
@@ -159,6 +159,38 @@ manage_service (char *action)
                 " not recognized.", action);
         return ret;
 }
+
+/*
+ * Check if the cluster is a ganesha cluster or not *
+ */
+gf_boolean_t
+glusterd_is_ganesha_cluster () {
+        int                ret      = -1;
+        glusterd_conf_t   *priv     = NULL;
+        xlator_t          *this     = NULL;
+        gf_boolean_t       ret_bool = _gf_false;
+
+        this = THIS;
+        GF_VALIDATE_OR_GOTO ("ganesha", this, out);
+        priv = this->private;
+        GF_VALIDATE_OR_GOTO (this->name, priv, out);
+
+        ret = dict_get_str_boolean (priv->opts,
+                                    GLUSTERD_STORE_KEY_GANESHA_GLOBAL,
+                                    _gf_false);
+        if (ret == _gf_true) {
+                ret_bool = _gf_true;
+                gf_msg_debug (this->name, 0,
+                              "nfs-ganesha is enabled for the cluster");
+        } else
+                gf_msg_debug (this->name, 0,
+                              "nfs-ganesha is disabled for the cluster");
+
+out:
+        return ret_bool;
+
+}
+
 /* Check if ganesha.enable is set to 'on', that checks if
  * a  particular volume is exported via NFS-Ganesha */
 gf_boolean_t
diff --git a/xlators/mgmt/glusterd/src/glusterd-messages.h b/xlators/mgmt/glusterd/src/glusterd-messages.h
index d48ec897bac..c8c48d42316 100644
--- a/xlators/mgmt/glusterd/src/glusterd-messages.h
+++ b/xlators/mgmt/glusterd/src/glusterd-messages.h
@@ -41,7 +41,7 @@
 
 #define GLUSTERD_COMP_BASE      GLFS_MSGID_GLUSTERD
 
-#define GLFS_NUM_MESSAGES       588
+#define GLFS_NUM_MESSAGES       589
 
 #define GLFS_MSGID_END          (GLUSTERD_COMP_BASE + GLFS_NUM_MESSAGES + 1)
 /* Messaged with message IDs */
@@ -4753,6 +4753,14 @@
  */
 #define GD_MSG_RESET_BRICK_CMD_FAIL                (GLUSTERD_COMP_BASE + 588)
 
+/*!
+ * @messageid
+ * @diagnosis
+ * @recommendedaction
+ *
+ */
+#define GD_MSG_NFS_GANESHA_DISABLED                (GLUSTERD_COMP_BASE + 589)
+
 /*------------*/
 #define glfs_msg_end_x GLFS_MSGID_END, "Invalid: End of messages"
 #endif /* !_GLUSTERD_MESSAGES_H_ */
diff --git a/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c b/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c
index d1fb849f0f0..c8af1ec21c4 100644
--- a/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c
@@ -3788,6 +3788,7 @@ glusterd_copy_nfs_ganesha_file (glusterd_volinfo_t *src_vol,
                                 GD_MSG_FILE_OP_FAILED,
                                 "Failed to open %s",
                                 dest ? src_path : dest_path);
+                        ret = -1;
                         goto out;
                 }
 
diff --git a/xlators/mgmt/glusterd/src/glusterd-snapshot.c b/xlators/mgmt/glusterd/src/glusterd-snapshot.c
index ae70bc81c2c..6a350361998 100644
--- a/xlators/mgmt/glusterd/src/glusterd-snapshot.c
+++ b/xlators/mgmt/glusterd/src/glusterd-snapshot.c
@@ -919,6 +919,76 @@ out:
         return ret;
 }
 
+/*
+ * This function validates the particulat snapshot with respect to the current
+ * cluster. If the snapshot has ganesha enabled, and the cluster is not a nfs
+ * ganesha cluster, we fail the validation. Other scenarios where either the
+ * snapshot does not have ganesha enabled or it has and the cluster is a nfs
+ * ganesha cluster, we pass the validation
+ *
+ * @param snap          snap object of the snapshot to be validated
+ * @return              Negative value on Failure and 0 in success
+ */
+int32_t
+glusterd_snapshot_validate_ganesha_conf (glusterd_snap_t *snap,
+                                         char **op_errstr,
+                                         uint32_t *op_errno)
+{
+        int                     ret                    = -1;
+        glusterd_volinfo_t      *snap_vol              = NULL;
+        xlator_t                *this                  = NULL;
+
+        this = THIS;
+        GF_VALIDATE_OR_GOTO ("snapshot", this, out);
+        GF_VALIDATE_OR_GOTO (this->name, snap, out);
+        GF_VALIDATE_OR_GOTO (this->name, op_errstr, out);
+        GF_VALIDATE_OR_GOTO (this->name, op_errno, out);
+
+        snap_vol = list_entry (snap->volumes.next,
+                               glusterd_volinfo_t, vol_list);
+
+        GF_VALIDATE_OR_GOTO (this->name, snap_vol, out);
+
+        /*
+         * Check if the snapshot has ganesha enabled *
+         */
+        if (glusterd_check_ganesha_export(snap_vol) == _gf_false) {
+                /*
+                 * If the snapshot has not been exported via ganesha *
+                 * then we can proceed.                              *
+                 */
+                ret = 0;
+                goto out;
+        }
+
+        /*
+         * At this point we are certain that the snapshot has been exported *
+         * via ganesha. So we check if the cluster is a nfs-ganesha cluster *
+         * If it a nfs-ganesha cluster, then we proceed. Else we fail.      *
+         */
+        if (glusterd_is_ganesha_cluster() != _gf_true) {
+                ret = gf_asprintf (op_errstr, "Snapshot(%s) has a "
+                                   "nfs-ganesha export conf file. "
+                                   "cluster.enable-shared-storage and "
+                                   "nfs-ganesha should be enabled "
+                                   "before restoring this snapshot.",
+                                   snap->snapname);
+                *op_errno = EG_NOGANESHA;
+                if (ret < 0) {
+                        goto out;
+                }
+
+                gf_msg (this->name, GF_LOG_ERROR, EINVAL,
+                        GD_MSG_NFS_GANESHA_DISABLED, "%s", *op_errstr);
+                ret = -1;
+                goto out;
+        }
+
+        ret = 0;
+out:
+        return ret;
+}
+
 /* This function is called before actual restore is taken place. This function
  * will validate whether the snapshot volumes are ready to be restored or not.
  *
@@ -989,6 +1059,15 @@ glusterd_snapshot_restore_prevalidate (dict_t *dict, char **op_errstr,
                 goto out;
         }
 
+        ret = glusterd_snapshot_validate_ganesha_conf (snap, op_errstr,
+                                                       op_errno);
+        if (ret) {
+                gf_msg (this->name, GF_LOG_ERROR, 0,
+                        GD_MSG_SNAPSHOT_OP_FAILED,
+                        "ganesha conf validation failed.");
+                goto out;
+        }
+
         ret = dict_set_str (rsp_dict, "snapname", snapname);
         if (ret) {
                 gf_msg (this->name, GF_LOG_ERROR, 0,
@@ -8851,6 +8930,7 @@ glusterd_snapshot_revert_partial_restored_vol (glusterd_volinfo_t *volinfo)
         int                     ret                     = 0;
         char                    pathname [PATH_MAX]     = {0,};
         char                    trash_path[PATH_MAX]    = {0,};
+        glusterd_brickinfo_t   *brickinfo               = NULL;
         glusterd_volinfo_t     *reverted_vol            = NULL;
         glusterd_volinfo_t     *snap_vol                = NULL;
         glusterd_volinfo_t     *tmp_vol                 = NULL;
@@ -8905,6 +8985,38 @@ glusterd_snapshot_revert_partial_restored_vol (glusterd_volinfo_t *volinfo)
                                       snapvol_list) {
                 cds_list_add_tail (&snap_vol->snapvol_list,
                                    &reverted_vol->snap_volumes);
+
+                cds_list_for_each_entry (brickinfo, &snap_vol->bricks,
+                                         brick_list) {
+                        /*
+                         * If the brick is not of this peer, or snapshot is    *
+                         * missed for the brick don't restore the xattr for it *
+                         */
+                        if ((!gf_uuid_compare (brickinfo->uuid, MY_UUID)) &&
+                            (brickinfo->snap_status != -1)) {
+                                /*
+                                 * We need to restore volume id of all snap *
+                                 * bricks to volume id of the snap volume.  *
+                                 */
+                                ret = sys_lsetxattr (brickinfo->path,
+                                                     GF_XATTR_VOL_ID_KEY,
+                                                     snap_vol->volume_id,
+                                                   sizeof (snap_vol->volume_id),
+                                                     XATTR_REPLACE);
+                                if (ret == -1) {
+                                        gf_msg (this->name, GF_LOG_ERROR, 0,
+                                                GD_MSG_SETXATTR_FAIL,
+                                                "Failed to set extended "
+                                                "attribute %s on %s. "
+                                                "Reason: %s, snap: %s",
+                                                GF_XATTR_VOL_ID_KEY,
+                                                brickinfo->path,
+                                                strerror (errno),
+                                                snap_vol->volname);
+                                        goto out;
+                                }
+                        }
+                }
         }
 
         /* Since we retrieved the volinfo from store now we don't
diff --git a/xlators/mgmt/glusterd/src/glusterd.h b/xlators/mgmt/glusterd/src/glusterd.h
index a5d964a29d6..02d9e85e487 100644
--- a/xlators/mgmt/glusterd/src/glusterd.h
+++ b/xlators/mgmt/glusterd/src/glusterd.h
@@ -1078,6 +1078,9 @@ int glusterd_op_stage_set_ganesha (dict_t *dict, char **op_errstr);
 int glusterd_op_set_ganesha (dict_t *dict, char **errstr);
 int ganesha_manage_export (dict_t *dict, char *value, char **op_errstr);
 int manage_export_config (char *volname, char *value, char **op_errstr);
+
+gf_boolean_t
+glusterd_is_ganesha_cluster ();
 gf_boolean_t glusterd_check_ganesha_export (glusterd_volinfo_t *volinfo);
 int stop_ganesha (char **op_errstr);
 int tear_down_cluster (gf_boolean_t run_teardown);