glusterd/snapshot: Add a warning message when a volume config changes

While changing a volume configuration, there is a chance that the
brick layout on the disk might be changed. If snapshot is present
on such volumes that will effects it's working. So this patch adds
a warning message if snapshot is present while a volume config change
happen.

Change-Id: I7256863fef734841fce0bc9ad94d5d201b1813d5
Fixes: bz#1812144
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>

3 files changed, 40 insertions, 1 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-brick-ops.c b/xlators/mgmt/glusterd/src/glusterd-brick-ops.c
index 5e5421ed2dc..3af2867b82a 100644
--- a/xlators/mgmt/glusterd/src/glusterd-brick-ops.c
+++ b/xlators/mgmt/glusterd/src/glusterd-brick-ops.c
@@ -1448,6 +1448,18 @@ glusterd_op_stage_add_brick(dict_t *dict, char **op_errstr, dict_t *rsp_dict)
         goto out;
     }
 
+    if (volinfo->snap_count > 0 || !cds_list_empty(&volinfo->snap_volumes)) {
+        snprintf(msg, sizeof(msg),
+                 "Volume %s  has %" PRIu64
+                 " snapshots. "
+                 "Changing the volume configuration will not effect snapshots."
+                 "But the snapshot brick mount should be intact to "
+                 "make them function.",
+                 volname, volinfo->snap_count);
+        gf_msg("glusterd", GF_LOG_WARNING, 0, GD_MSG_SNAP_WARN, "%s", msg);
+        msg[0] = '\0';
+    }
+
     ret = dict_get_int32n(dict, "count", SLEN("count"), &count);
     if (ret) {
         gf_msg("glusterd", GF_LOG_ERROR, errno, GD_MSG_DICT_GET_FAILED,
@@ -1837,6 +1849,21 @@ glusterd_op_stage_remove_brick(dict_t *dict, char **op_errstr)
                 goto out;
             }
 
+            if (volinfo->snap_count > 0 ||
+                !cds_list_empty(&volinfo->snap_volumes)) {
+                snprintf(msg, sizeof(msg),
+                         "Volume %s  has %" PRIu64
+                         " snapshots. "
+                         "Changing the volume configuration will not effect "
+                         "snapshots."
+                         "But the snapshot brick mount should be intact to "
+                         "make them function.",
+                         volname, volinfo->snap_count);
+                gf_msg("glusterd", GF_LOG_WARNING, 0, GD_MSG_SNAP_WARN, "%s",
+                       msg);
+                msg[0] = '\0';
+            }
+
             ret = glusterd_remove_brick_validate_bricks(
                 cmd, brick_count, dict, volinfo, &errstr, GF_DEFRAG_CMD_NONE);
             if (ret)
diff --git a/xlators/mgmt/glusterd/src/glusterd-messages.h b/xlators/mgmt/glusterd/src/glusterd-messages.h
index f75ba905372..435a43df85d 100644
--- a/xlators/mgmt/glusterd/src/glusterd-messages.h
+++ b/xlators/mgmt/glusterd/src/glusterd-messages.h
@@ -302,6 +302,6 @@ GLFS_MSGID(
     GD_MSG_SHD_OBJ_GET_FAIL, GD_MSG_SVC_ATTACH_FAIL, GD_MSG_ATTACH_INFO,
     GD_MSG_DETACH_INFO, GD_MSG_SVC_DETACH_FAIL,
     GD_MSG_RPC_TRANSPORT_GET_PEERNAME_FAIL, GD_MSG_CLUSTER_RC_ENABLE,
-    GD_MSG_NFS_GANESHA_DISABLED, GD_MSG_GANESHA_NOT_RUNNING);
+    GD_MSG_NFS_GANESHA_DISABLED, GD_MSG_GANESHA_NOT_RUNNING, GD_MSG_SNAP_WARN);
 
 #endif /* !_GLUSTERD_MESSAGES_H_ */
diff --git a/xlators/mgmt/glusterd/src/glusterd-replace-brick.c b/xlators/mgmt/glusterd/src/glusterd-replace-brick.c
index a861240da31..3d13ef95ffd 100644
--- a/xlators/mgmt/glusterd/src/glusterd-replace-brick.c
+++ b/xlators/mgmt/glusterd/src/glusterd-replace-brick.c
@@ -227,6 +227,18 @@ glusterd_op_stage_replace_brick(dict_t *dict, char **op_errstr,
         is_force = _gf_true;
     }
 
+    if (volinfo->snap_count > 0 || !cds_list_empty(&volinfo->snap_volumes)) {
+        snprintf(msg, sizeof(msg),
+                 "Volume %s  has %" PRIu64
+                 " snapshots. "
+                 "Changing the volume configuration will not effect snapshots."
+                 "But the snapshot brick mount should be intact to "
+                 "make them function.",
+                 volname, volinfo->snap_count);
+        gf_msg("glusterd", GF_LOG_WARNING, 0, GD_MSG_SNAP_WARN, "%s", msg);
+        msg[0] = '\0';
+    }
+
     ret = glusterd_get_dst_brick_info(&dst_brick, volname, op_errstr,
                                       &dst_brickinfo, &host, dict,
                                       &dup_dstbrick);