Mailing List Archive

[PATCH v2 7/8] tools/ocaml/xenstored: start live update process
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Reviewed-by: Pau Ruiz Safont <pau.safont@citrix.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.com>

---
Changed since V1:
* post publicly now that the XSA is out
---
tools/ocaml/xenstored/logging.ml | 3 +++
tools/ocaml/xenstored/process.ml | 8 +++++---
tools/ocaml/xenstored/xenstored.ml | 29 ++++++++++++++++++++++-------
3 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/tools/ocaml/xenstored/logging.ml b/tools/ocaml/xenstored/logging.ml
index 1ede131329..39c3036155 100644
--- a/tools/ocaml/xenstored/logging.ml
+++ b/tools/ocaml/xenstored/logging.ml
@@ -327,6 +327,9 @@ let end_transaction ~tid ~con =
if !access_log_transaction_ops && tid <> 0
then access_logging ~tid ~con (XbOp Xenbus.Xb.Op.Transaction_end) ~level:Debug

+let live_update () =
+ xb_op ~tid:0 ~con:"" ~ty:Xenbus.Xb.Op.Debug "Live update begin"
+
let xb_answer ~tid ~con ~ty data =
let print, level = match ty with
| Xenbus.Xb.Op.Error when String.startswith "ENOENT" data -> !access_log_read_ops , Warn
diff --git a/tools/ocaml/xenstored/process.ml b/tools/ocaml/xenstored/process.ml
index c3c5dc58c0..3174d8ede5 100644
--- a/tools/ocaml/xenstored/process.ml
+++ b/tools/ocaml/xenstored/process.ml
@@ -112,6 +112,7 @@ let string_of_t t =
let launch_exn t =
let executable, rest = args_of_t t in
let args = Array.of_list (executable :: rest) in
+ info "Launching %s, args: %s" executable (String.concat " " rest);
Unix.execv args.(0) args

let validate_exn t =
@@ -151,7 +152,7 @@ let parse_live_update args =
| "-s" :: _ ->
let timeout = ref 60 in
let force = ref false in
- Arg.parse_argv ~current:(ref 1) (Array.of_list args)
+ Arg.parse_argv ~current:(ref 0) (Array.of_list args)
[. ( "-t"
, Arg.Set_int timeout
, "timeout in seconds to wait for active transactions to finish"
@@ -166,7 +167,7 @@ let parse_live_update args =
{!state with deadline = Unix.gettimeofday () +. float !timeout
; force= !force; pending= true}
| _ ->
- invalid_arg ("Unknown arguments: " ^ String.concat " " args)) ;
+ invalid_arg ("Unknown arguments: " ^ String.concat "," args)) ;
None
with
| Arg.Bad s | Arg.Help s | Invalid_argument s ->
@@ -200,7 +201,8 @@ let do_debug con t _domains cons data =
then None
else try match split None '\000' data with
| "live-update" :: params ->
- LiveUpdate.parse_live_update params
+ let dropped_trailing_nul = params |> List.rev |> List.tl |> List.rev in
+ LiveUpdate.parse_live_update dropped_trailing_nul
| "print" :: msg :: _ ->
Logging.xb_op ~tid:0 ~ty:Xenbus.Xb.Op.Debug ~con:"=======>" msg;
None
diff --git a/tools/ocaml/xenstored/xenstored.ml b/tools/ocaml/xenstored/xenstored.ml
index 500d96753b..22413271fb 100644
--- a/tools/ocaml/xenstored/xenstored.ml
+++ b/tools/ocaml/xenstored/xenstored.ml
@@ -311,6 +311,11 @@ let _ =
);
);

+ (* required for xenstore-control to detect availability of live-update *)
+ Store.mkdir store Perms.Connection.full_rights (Store.Path.of_string "/tool");
+ Store.write store Perms.Connection.full_rights
+ (Store.Path.of_string "/tool/xenstored") Sys.executable_name;
+
Sys.set_signal Sys.sighup (Sys.Signal_handle sighup_handler);
Sys.set_signal Sys.sigterm (Sys.Signal_handle (fun _ ->
info "Received SIGTERM";
@@ -483,18 +488,28 @@ let _ =
in

Systemd.sd_notify_ready ();
+ let live_update = ref false in
while not (!quit && Connections.prevents_quit cons = [])
do
try
- main_loop ()
+ main_loop ();
+ live_update := Process.LiveUpdate.should_run cons;
+ if !live_update || !quit then begin
+ (* don't initiate live update if saving state fails *)
+ DB.to_file store cons Disk.xs_daemon_database;
+ quit := true;
+ end
with exc ->
- error "caught exception %s" (Printexc.to_string exc);
+ let bt = Printexc.get_backtrace () in
+ error "caught exception %s: %s" (Printexc.to_string exc) bt;
if cf.reraise_top_level then
raise exc
done;
info "stopping xenstored";
- DB.to_file store cons Disk.xs_daemon_database;
- (* unlink pidfile so that launch-xenstore works again *)
- Unixext.unlink_safe pidfile;
- (match cf.pidfile with Some pidfile -> Unixext.unlink_safe pidfile | None -> ());
- ()
+ (* unlink pidfile so that launch-xenstore works again *)
+ Unixext.unlink_safe pidfile;
+ (match cf.pidfile with Some pidfile -> Unixext.unlink_safe pidfile | None -> ());
+ if !live_update then begin
+ Logging.live_update ();
+ Process.LiveUpdate.launch_exn !Process.LiveUpdate.state
+ end
--
2.29.2