Allow recovery from guest failure.

diff --git a/src/generator.ml b/src/generator.ml
index b7b1907..1e6c0bc 100755 (executable)
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -438,6 +438,16 @@ actions using the low-level API.
 
 For more information on states, see L<guestfs(3)>.");
 
+  ("end_busy", (RErr, []), -1, [NotInFish],
+   [],
+   "leave the busy state",
+   "\
+This sets the state to C<READY>, or if in C<CONFIG> then it leaves the
+state as is.  This is only used when implementing
+actions using the low-level API.
+
+For more information on states, see L<guestfs(3)>.");
+
 ]
 
 let daemon_functions = [
@@ -2824,7 +2834,7 @@ check_state (guestfs_h *g, const char *caller)
             name;
       );
       pr "  if (serial == -1) {\n";
-      pr "    guestfs_set_ready (g);\n";
+      pr "    guestfs_end_busy (g);\n";
       pr "    return %s;\n" error_code;
       pr "  }\n";
       pr "\n";
@@ -2839,7 +2849,7 @@ check_state (guestfs_h *g, const char *caller)
            pr "\n";
            pr "    r = guestfs__send_file_sync (g, %s);\n" n;
            pr "    if (r == -1) {\n";
-           pr "      guestfs_set_ready (g);\n";
+           pr "      guestfs_end_busy (g);\n";
            pr "      return %s;\n" error_code;
            pr "    }\n";
            pr "    if (r == -2) /* daemon cancelled */\n";
@@ -2859,21 +2869,21 @@ check_state (guestfs_h *g, const char *caller)
       pr "  guestfs_set_reply_callback (g, NULL, NULL);\n";
       pr "  if (ctx.cb_sequence != 1) {\n";
       pr "    error (g, \"%%s reply failed, see earlier error messages\", \"%s\");\n" name;
-      pr "    guestfs_set_ready (g);\n";
+      pr "    guestfs_end_busy (g);\n";
       pr "    return %s;\n" error_code;
       pr "  }\n";
       pr "\n";
 
       pr "  if (check_reply_header (g, &ctx.hdr, GUESTFS_PROC_%s, serial) == -1) {\n"
        (String.uppercase shortname);
-      pr "    guestfs_set_ready (g);\n";
+      pr "    guestfs_end_busy (g);\n";
       pr "    return %s;\n" error_code;
       pr "  }\n";
       pr "\n";
 
       pr "  if (ctx.hdr.status == GUESTFS_STATUS_ERROR) {\n";
       pr "    error (g, \"%%s\", ctx.err.error_message);\n";
-      pr "    guestfs_set_ready (g);\n";
+      pr "    guestfs_end_busy (g);\n";
       pr "    return %s;\n" error_code;
       pr "  }\n";
       pr "\n";
@@ -2883,14 +2893,14 @@ check_state (guestfs_h *g, const char *caller)
        function
        | FileOut n ->
            pr "  if (guestfs__receive_file_sync (g, %s) == -1) {\n" n;
-           pr "    guestfs_set_ready (g);\n";
+           pr "    guestfs_end_busy (g);\n";
            pr "    return %s;\n" error_code;
            pr "  }\n";
            pr "\n";
        | _ -> ()
       ) (snd style);
 
-      pr "  guestfs_set_ready (g);\n";
+      pr "  guestfs_end_busy (g);\n";
 
       (match fst style with
        | RErr -> pr "  return 0;\n"

diff --git a/src/guestfs.c b/src/guestfs.c
index 15111db..be7b0c7 100644 (file)
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -1095,6 +1095,25 @@ guestfs_set_busy (guestfs_h *g)
   return 0;
 }
 
+int
+guestfs_end_busy (guestfs_h *g)
+{
+  switch (g->state)
+    {
+    case BUSY:
+      g->state = READY;
+      break;
+    case CONFIG:
+    case READY:
+      break;
+    case LAUNCHING:
+    case NO_HANDLE:
+      error (g, "guestfs_end_busy: called when in state %d", g->state);
+      return -1;
+    }
+  return 0;
+}
+
 /* Structure-freeing functions.  These rely on the fact that the
  * structure format is identical to the XDR format.  See note in
  * generator.ml.
@@ -1126,6 +1145,39 @@ guestfs_free_lvm_lv_list (struct guestfs_lvm_lv_list *x)
   free (x);
 }
 
+/* We don't know if stdout_event or sock_read_event will be the
+ * first to receive EOF if the qemu process dies.  This function
+ * has the common cleanup code for both.
+ */
+static void
+child_cleanup (guestfs_h *g)
+{
+  if (g->verbose)
+    fprintf (stderr, "stdout_event: %p: child process died\n", g);
+  /*kill (g->pid, SIGTERM);*/
+  if (g->recoverypid > 0) kill (g->recoverypid, 9);
+  waitpid (g->pid, NULL, 0);
+  if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
+  if (g->stdout_watch >= 0)
+    g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch);
+  if (g->sock_watch >= 0)
+    g->main_loop->remove_handle (g->main_loop, g, g->sock_watch);
+  close (g->fd[0]);
+  close (g->fd[1]);
+  close (g->sock);
+  g->fd[0] = -1;
+  g->fd[1] = -1;
+  g->sock = -1;
+  g->pid = 0;
+  g->recoverypid = 0;
+  g->start_t = 0;
+  g->stdout_watch = -1;
+  g->sock_watch = -1;
+  g->state = CONFIG;
+  if (g->subprocess_quit_cb)
+    g->subprocess_quit_cb (g, g->subprocess_quit_cb_data);
+}
+
 /* This function is called whenever qemu prints something on stdout.
  * Qemu's stdout is also connected to the guest's serial console, so
  * we see kernel messages here too.
@@ -1152,30 +1204,7 @@ stdout_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
   n = read (fd, buf, sizeof buf);
   if (n == 0) {
     /* Hopefully this indicates the qemu child process has died. */
-    if (g->verbose)
-      fprintf (stderr, "stdout_event: %p: child process died\n", g);
-    /*kill (g->pid, SIGTERM);*/
-    if (g->recoverypid > 0) kill (g->recoverypid, 9);
-    waitpid (g->pid, NULL, 0);
-    if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
-    if (g->stdout_watch >= 0)
-      g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch);
-    if (g->sock_watch >= 0)
-      g->main_loop->remove_handle (g->main_loop, g, g->sock_watch);
-    close (g->fd[0]);
-    close (g->fd[1]);
-    close (g->sock);
-    g->fd[0] = -1;
-    g->fd[1] = -1;
-    g->sock = -1;
-    g->pid = 0;
-    g->recoverypid = 0;
-    g->start_t = 0;
-    g->stdout_watch = -1;
-    g->sock_watch = -1;
-    g->state = CONFIG;
-    if (g->subprocess_quit_cb)
-      g->subprocess_quit_cb (g, g->subprocess_quit_cb_data);
+    child_cleanup (g);
     return;
   }
 
@@ -1221,11 +1250,11 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
   }
   n = read (g->sock, g->msg_in + g->msg_in_size,
            g->msg_in_allocated - g->msg_in_size);
-  if (n == 0)
-    /* Disconnected?  Ignore it because stdout_watch will get called
-     * and will do the cleanup.
-     */
+  if (n == 0) {
+    /* Disconnected. */
+    child_cleanup (g);
     return;
+  }
 
   if (n == -1) {
     if (errno != EINTR && errno != EAGAIN)