[xen staging-4.14] tools/ocaml/xenstored: ignore transaction id for [un]watch

[patchbot@xxxxxxx]

commit 228e5621ebdd3abd520fcdc712347f877880ee71
Author:     Edwin Török <edvin.torok@xxxxxxxxxx>
AuthorDate: Tue Dec 15 14:06:38 2020 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Dec 15 14:06:38 2020 +0100

    tools/ocaml/xenstored: ignore transaction id for [un]watch
    
    Instead of ignoring the transaction id for XS_WATCH and XS_UNWATCH
    commands as it is documented in docs/misc/xenstore.txt, it is tested
    for validity today.
    
    Really ignore the transaction id for XS_WATCH and XS_UNWATCH.
    
    This is part of XSA-115.
    
    Signed-off-by: Edwin Török <edvin.torok@xxxxxxxxxx>
    Acked-by: Christian Lindig <christian.lindig@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 tools/ocaml/xenstored/process.ml | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/ocaml/xenstored/process.ml b/tools/ocaml/xenstored/process.ml
index ff5c9484fc..2fa6798e3b 100644
--- a/tools/ocaml/xenstored/process.ml
+++ b/tools/ocaml/xenstored/process.ml
@@ -498,12 +498,19 @@ let retain_op_in_history ty =
        | Xenbus.Xb.Op.Reset_watches
        | Xenbus.Xb.Op.Invalid           -> false
 
+let maybe_ignore_transaction = function
+       | Xenbus.Xb.Op.Watch | Xenbus.Xb.Op.Unwatch -> fun tid ->
+               if tid <> Transaction.none then
+                       debug "Ignoring transaction ID %d for watch/unwatch" 
tid;
+               Transaction.none
+       | _ -> fun x -> x
+
 (**
  * Nothrow guarantee.
  *)
 let process_packet ~store ~cons ~doms ~con ~req =
        let ty = req.Packet.ty in
-       let tid = req.Packet.tid in
+       let tid = maybe_ignore_transaction ty req.Packet.tid in
        let rid = req.Packet.rid in
        try
                let fct = function_of_type ty in
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.14