1 files changed, 53 insertions, 5 deletions

diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c
index 504d33aa91..dd18b2cde8 100644
--- a/storage-daemon/qemu-storage-daemon.c
+++ b/storage-daemon/qemu-storage-daemon.c
@@ -93,6 +93,9 @@ static void help(void)
 "  --chardev <options>    configure a character device backend\n"
 "                         (see the qemu(1) man page for possible options)\n"
 "\n"
+"  --daemonize            daemonize the process, and have the parent exit\n"
+"                         once startup is complete\n"
+"\n"
 "  --export [type=]nbd,id=<id>,node-name=<node-name>[,name=<export-name>]\n"
 "           [,writable=on|off][,bitmap=<name>]\n"
 "                         export the specified block node over NBD\n"
@@ -144,6 +147,7 @@ QEMU_HELP_BOTTOM "\n",
 enum {
     OPTION_BLOCKDEV = 256,
     OPTION_CHARDEV,
+    OPTION_DAEMONIZE,
     OPTION_EXPORT,
     OPTION_MONITOR,
     OPTION_NBD_SERVER,
@@ -177,13 +181,30 @@ static int getopt_set_loc(int argc, char **argv, const char *optstring,
     return c;
 }
 
-static void process_options(int argc, char *argv[])
+/**
+ * Process QSD command-line arguments.
+ *
+ * This is done in two passes:
+ *
+ * First (@pre_init_pass is true), we do a pass where all global
+ * arguments pertaining to the QSD process (like --help or --daemonize)
+ * are processed.  This pass is done before most of the QEMU-specific
+ * initialization steps (e.g. initializing the block layer or QMP), and
+ * so must only process arguments that are not really QEMU-specific.
+ *
+ * Second (@pre_init_pass is false), we (sequentially) process all
+ * QEMU/QSD-specific arguments.  Many of these arguments are effectively
+ * translated to QMP commands (like --blockdev for blockdev-add, or
+ * --export for block-export-add).
+ */
+static void process_options(int argc, char *argv[], bool pre_init_pass)
 {
     int c;
 
     static const struct option long_options[] = {
         {"blockdev", required_argument, NULL, OPTION_BLOCKDEV},
         {"chardev", required_argument, NULL, OPTION_CHARDEV},
+        {"daemonize", no_argument, NULL, OPTION_DAEMONIZE},
         {"export", required_argument, NULL, OPTION_EXPORT},
         {"help", no_argument, NULL, 'h'},
         {"monitor", required_argument, NULL, OPTION_MONITOR},
@@ -196,11 +217,27 @@ static void process_options(int argc, char *argv[])
     };
 
     /*
-     * In contrast to the system emulator, options are processed in the order
-     * they are given on the command lines. This means that things must be
-     * defined first before they can be referenced in another option.
+     * In contrast to the system emulator, QEMU-specific options are processed
+     * in the order they are given on the command lines. This means that things
+     * must be defined first before they can be referenced in another option.
      */
+    optind = 1;
     while ((c = getopt_set_loc(argc, argv, "-hT:V", long_options)) != -1) {
+        bool handle_option_pre_init;
+
+        /* Should this argument be processed in the pre-init pass? */
+        handle_option_pre_init =
+            c == '?' ||
+            c == 'h' ||
+            c == 'V' ||
+            c == OPTION_DAEMONIZE ||
+            c == OPTION_PIDFILE;
+
+        /* Process every option only in its respective pass */
+        if (pre_init_pass != handle_option_pre_init) {
+            continue;
+        }
+
         switch (c) {
         case '?':
             exit(EXIT_FAILURE);
@@ -246,6 +283,12 @@ static void process_options(int argc, char *argv[])
                 qemu_opts_del(opts);
                 break;
             }
+        case OPTION_DAEMONIZE:
+            if (os_set_daemonize(true) < 0) {
+                error_report("--daemonize not supported in this build");
+                exit(EXIT_FAILURE);
+            }
+            break;
         case OPTION_EXPORT:
             {
                 Visitor *v;
@@ -334,6 +377,10 @@ int main(int argc, char *argv[])
     qemu_init_exec_dir(argv[0]);
     os_setup_signal_handling();
 
+    process_options(argc, argv, true);
+
+    os_daemonize();
+
     module_call_init(MODULE_INIT_QOM);
     module_call_init(MODULE_INIT_TRACE);
     qemu_add_opts(&qemu_trace_opts);
@@ -348,7 +395,7 @@ int main(int argc, char *argv[])
     qemu_set_log(LOG_TRACE);
 
     qemu_init_main_loop(&error_fatal);
-    process_options(argc, argv);
+    process_options(argc, argv, false);
 
     /*
      * Write the pid file after creating chardevs, exports, and NBD servers but
@@ -356,6 +403,7 @@ int main(int argc, char *argv[])
      * it.
      */
     pid_file_init();
+    os_setup_post();
 
     while (!exit_requested) {
         main_loop_wait(false);