[PATCH] fs-back: terminate thread when domain gets destroyed

[Samuel Thibault <samuel.thibault@eu.citrix.com>]

fs-back: terminate thread when domain gets destroyed
by periodically checking that the frontend xenstore nodes still exist

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

diff -r 86e64b684fb2 tools/fs-back/fs-backend.c
--- a/tools/fs-back/fs-backend.c	Wed Mar 05 11:10:29 2008 +0000
+++ b/tools/fs-back/fs-backend.c	Tue Mar 11 13:47:40 2008 +0000
@@ -49,6 +49,7 @@ static void handle_aio_events(struct mou
     struct aiocb evtchn_cb;
     const struct aiocb * cb_list[mount->nr_entries];
     int request_ids[mount->nr_entries];
+    struct timespec timeout = { .tv_sec = 1, .tv_nsec = 0 };
 
     /* Prepare the AIO control block for evtchn */ 
     fd = xc_evtchn_fd(mount->evth); 
@@ -76,9 +77,11 @@ wait_again:
 
     /* Block till an AIO requset finishes, or we get an event */ 
     while(1) {
-	int ret = aio_suspend(cb_list, count, NULL);
+	int ret = aio_suspend(cb_list, count, &timeout);
 	if (!ret)
 	    break;
+        if (errno == EAGAIN)
+            return;
 	assert(errno == EINTR);
     }
     for(i=0; i<count; i++)
@@ -127,6 +130,9 @@ void* handle_mount(void *data)
 {
     int more, notify;
     struct mount *mount = (struct mount *)data;
+    char *state;
+    char node[1024];
+    sprintf(node, "%s/state", mount->frontend);
     
     printf("Starting a thread for mount: %d\n", mount->mount_id);
     allocate_request_array(mount);
@@ -172,14 +178,21 @@ moretodo:
 
             nr_consumed++;
         }
-        printf("Backend consumed: %d requests\n", nr_consumed);
+        if (nr_consumed)
+            printf("Backend consumed: %d requests\n", nr_consumed);
         RING_FINAL_CHECK_FOR_REQUESTS(&mount->ring, more);
         if(more) goto moretodo;
 
         RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&mount->ring, notify);
-        printf("Pushed responces and notify=%d\n", notify);
+        //printf("Pushed responces and notify=%d\n", notify);
         if(notify)
             xc_evtchn_notify(mount->evth, mount->local_evtchn);
+
+        state = xs_read(xsh, XBT_NULL, node, NULL);
+        if (!state)
+            /* domain destroyed */
+            break;
+        free(state);
     }
  
     printf("Destroying thread for mount: %d\n", mount->mount_id);