1 files changed, 41 insertions, 3 deletions

diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index b6d5fff43d16..ba804f3d8278 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -50,6 +50,7 @@
 #include <xen/xenbus.h>
 #include <xen/xen.h>
 #include "xenbus_comms.h"
+#include "xenbus_probe.h"
 
 struct xs_stored_msg {
         struct list_head list;
@@ -139,6 +140,29 @@ static int get_error(const char *errorstring)
         return xsd_errors[i].errnum;
 }
 
+static bool xenbus_ok(void)
+{
+        switch (xen_store_domain_type) {
+        case XS_LOCAL:
+                switch (system_state) {
+                case SYSTEM_POWER_OFF:
+                case SYSTEM_RESTART:
+                case SYSTEM_HALT:
+                        return false;
+                default:
+                        break;
+                }
+                return true;
+        case XS_PV:
+        case XS_HVM:
+                /* FIXME: Could check that the remote domain is alive,
+                 * but it is normally initial domain. */
+                return true;
+        default:
+                break;
+        }
+        return false;
+}
 static void *read_reply(enum xsd_sockmsg_type *type, unsigned int *len)
 {
         struct xs_stored_msg *msg;
@@ -148,9 +172,20 @@ static void *read_reply(enum xsd_sockmsg_type *type, unsigned int *len)
 
         while (list_empty(&xs_state.reply_list)) {
                 spin_unlock(&xs_state.reply_lock);
-                /* XXX FIXME: Avoid synchronous wait for response here. */
-                wait_event(xs_state.reply_waitq,
-                           !list_empty(&xs_state.reply_list));
+                if (xenbus_ok())
+                        /* XXX FIXME: Avoid synchronous wait for response here. */
+                        wait_event_timeout(xs_state.reply_waitq,
+                                           !list_empty(&xs_state.reply_list),
+                                           msecs_to_jiffies(500));
+                else {
+                        /*
+                         * If we are in the process of being shut-down there is
+                         * no point of trying to contact XenBus - it is either
+                         * killed (xenstored application) or the other domain
+                         * has been killed or is unreachable.
+                         */
+                        return ERR_PTR(-EIO);
+                }
                 spin_lock(&xs_state.reply_lock);
         }
 
@@ -215,6 +250,9 @@ void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg)
 
         mutex_unlock(&xs_state.request_mutex);
 
+        if (IS_ERR(ret))
+                return ret;
+
         if ((msg->type == XS_TRANSACTION_END) ||
             ((req_msg.type == XS_TRANSACTION_START) &&
              (msg->type == XS_ERROR)))