[xen staging] tools/oxenstored: Automatically resume when possible

[patchbot@xxxxxxx]

commit 4387b4c771feaf0455ea3dc9b4b199f51166c721
Author:     Edwin Török <edvin.torok@xxxxxxxxxx>
AuthorDate: Fri Jan 8 11:57:37 2021 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Fri Jan 22 15:22:42 2021 +0000

    tools/oxenstored: Automatically resume when possible
    
    When a `db` file exists use it to resume oxenstored.  It will contains a
    xenstore tree, domain reconnection info, and watches.
    
    It is currently missing data about all active socket connections, so a
    toolstack should ideally be stopped and restarted too.
    
    Tell systemd about oxenstored's PID and allow it to restart on success.
    
    This should make updating oxenstored as easy as: `systemctl stop -s SIGTERM
    xenstored` on a suitable xenstored version.
    
    Signed-off-by: Edwin Török <edvin.torok@xxxxxxxxxx>
    Reviewed-by: Pau Ruiz Safont <pau.safont@xxxxxxxxxx>
    Reviewed-by: Christian Lindig <christian.lindig@xxxxxxxxxx>
---
 tools/ocaml/xenstored/xenstored.ml | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/ocaml/xenstored/xenstored.ml 
b/tools/ocaml/xenstored/xenstored.ml
index 53d86618f2..a9894f0051 100644
--- a/tools/ocaml/xenstored/xenstored.ml
+++ b/tools/ocaml/xenstored/xenstored.ml
@@ -292,9 +292,8 @@ let _ =
        List.iter (fun path ->
                Store.write store Perms.Connection.full_rights path "") 
Store.Path.specials;
 
-       let filename = Paths.xen_run_stored ^ "/db" in
-       if cf.restart && Sys.file_exists filename then (
-               DB.from_file store domains cons filename;
+       if cf.restart && Sys.file_exists Disk.xs_daemon_database then (
+               DB.from_file store domains cons Disk.xs_daemon_database;
                Event.bind_dom_exc_virq eventchn
        ) else (
                if !Disk.enable then (
@@ -320,7 +319,7 @@ let _ =
        Sys.set_signal Sys.sigpipe Sys.Signal_ignore;
 
        if cf.activate_access_log then begin
-               let post_rotate () = DB.to_file store cons 
(Paths.xen_run_stored ^ "/db") in
+               let post_rotate () = DB.to_file store cons 
Disk.xs_daemon_database in
                Logging.init_access_log post_rotate
        end;
 
@@ -494,5 +493,8 @@ let _ =
                                raise exc
        done;
        info "stopping xenstored";
-       DB.to_file store cons (Paths.xen_run_stored ^ "/db");
+       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 -> ());
        ()
--
generated by git-patchbot for /home/xen/git/xen.git#staging