[Xen-devel] [PATCH 3/11] Test and fix acknowedge_watch from returning EINVAL.

[Rusty Russell <rusty@xxxxxxxxxxxxxxx>]

# HG changeset patch
# User Rusty Russell <rusty@xxxxxxxxxxxxxxx>
# Node ID 70ea61257cebc00212defe1dbed6de26c2edcf30
# Parent  e158ae50d2613b3e01d41c395b8dbc34c9766f73
Test and fix acknowedge_watch from returning EINVAL.
Also ensure that daemon re-xmits event if they ack wrong thing (otherwise 
confused clients get stuck, as we will send no more data while awaiting ack).

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

diff -r e158ae50d261 -r 70ea61257ceb tools/xenstore/xenstored_core.c
--- a/tools/xenstore/xenstored_core.c   Thu Aug  4 09:18:42 2005
+++ b/tools/xenstore/xenstored_core.c   Thu Aug  4 09:28:24 2005
@@ -1162,7 +1162,7 @@
        /* We might get a command while waiting for an ack: this means
         * the other end discarded it: we will re-transmit. */
        if (type != XS_WATCH_ACK)
-               conn->waiting_for_ack = false;
+               conn->waiting_for_ack = NULL;
 
        /* Careful: process_message may free connection.  We detach
         * "in" beforehand and allocate the new buffer to avoid
diff -r e158ae50d261 -r 70ea61257ceb tools/xenstore/xenstored_core.h
--- a/tools/xenstore/xenstored_core.h   Thu Aug  4 09:18:42 2005
+++ b/tools/xenstore/xenstored_core.h   Thu Aug  4 09:28:24 2005
@@ -64,7 +64,7 @@
        bool can_write;
 
        /* Are we waiting for a watch event ack? */
-       bool waiting_for_ack;
+       struct watch *waiting_for_ack;
 
        /* Buffered incoming data. */
        struct buffered_data *in;
diff -r e158ae50d261 -r 70ea61257ceb tools/xenstore/xenstored_watch.c
--- a/tools/xenstore/xenstored_watch.c  Thu Aug  4 09:18:42 2005
+++ b/tools/xenstore/xenstored_watch.c  Thu Aug  4 09:28:24 2005
@@ -102,7 +102,7 @@
        if (conn->waiting_reply) {
                conn->out = conn->waiting_reply;
                conn->waiting_reply = NULL;
-               conn->waiting_for_ack = false;
+               conn->waiting_for_ack = NULL;
                return;
        }
 
@@ -115,7 +115,7 @@
                return;
 
        /* If we decide to cancel, we will reset this. */
-       conn->waiting_for_ack = true;
+       conn->waiting_for_ack = event->watches[0];
 
        /* If we deleted /foo and they're watching /foo/bar, that's what we
         * tell them has changed. */
@@ -347,12 +347,17 @@
        if (!conn->waiting_for_ack)
                return send_error(conn, ENOENT);
 
-       event = get_first_event(conn);
-       if (!streq(event->watches[0]->token, token))
+       event = list_top(&conn->waiting_for_ack->events,
+                        struct watch_event, list);
+       assert(event->watches[0] == conn->waiting_for_ack);
+       if (!streq(conn->waiting_for_ack->token, token)) {
+               /* They're confused: this will cause us to send event again */
+               conn->waiting_for_ack = NULL;
                return send_error(conn, EINVAL);
+       }
 
        move_event_onwards(event);
-       conn->waiting_for_ack = false;
+       conn->waiting_for_ack = NULL;
        return send_ack(conn, XS_WATCH_ACK);
 }
 


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel