# HG changeset patch
# User Thomas Gazagnaire <thomas.gazagnaire@xxxxxxxxxx>
CA-35407: Improve error message on VM.revert failure.

On VM.revert, when the snapshot chain is too long to clone the snapshoted disks what we are reverting to, then propagate the SM backend error back to the user.

Signed-off-by: Thomas Gazagnaire <thomas.gazagnaire@xxxxxxxxxx>

diff -r d01d7d81f193 ocaml/xapi/xapi_vm_snapshot.ml
--- a/ocaml/xapi/xapi_vm_snapshot.ml	Fri Dec 11 13:44:40 2009 +0000
+++ b/ocaml/xapi/xapi_vm_snapshot.ml	Fri Dec 11 13:59:30 2009 +0000
@@ -379,7 +379,14 @@
 	with e ->
 		error "revert failed: %s" (Printexc.to_string e);
 		Xapi_vm_lifecycle.force_state_reset ~__context ~self:vm ~value:`Halted;
-		raise (Api_errors.Server_error (Api_errors.vm_revert_failed, [Ref.string_of snapshot; Ref.string_of vm]))
+		match e with
+		| Api_errors.Server_error("SR_BACKEND_FAILURE_44", _) as e ->
+			error "Not enough space to create the new disk images";
+			raise e
+		| Api_errors.Server_error("SR_BACKEND_FAILURE_109", _) as e ->
+			error "Snapshot chain too long";
+			raise e
+		| _ -> raise (Api_errors.Server_error (Api_errors.vm_revert_failed, [Ref.string_of snapshot; Ref.string_of vm]))
 
 let	create_vm_from_snapshot ~__context ~snapshot =
 	let old_vm = Db.VM.get_snapshot_of ~__context ~self:snapshot in
@@ -402,7 +409,7 @@
 					 List.iter (fun (snap,_) -> Db.VM.set_snapshot_of ~__context ~self:snap ~value:new_vm) snapshots;
 					 new_vm
 				 with e ->
-					 debug "cleanin-up by deleting the VM %s" (Ref.string_of new_vm);
+					 debug "cleaning-up by deleting the VM %s" (Ref.string_of new_vm);
 					 Client.VM.destroy rpc session_id new_vm;
 					 raise e;
 				 end)