[Qemu-devel] [PATCH 14/14] usb: Proper error propagation for usb_device_attach errors

[Hans de Goede <hdegoede@redhat.com>]

---
 hw/usb-bus.c |   23 ++++++++++++-----------
 hw/usb-msd.c |    5 +++--
 usb-linux.c  |    6 +++++-
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index 0a49921..2ae2678 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -75,7 +75,7 @@ static int usb_qdev_init(DeviceState *qdev, DeviceInfo *base)
     QLIST_INIT(&dev->strings);
     rc = dev->info->init(dev);
     if (rc == 0 && dev->auto_attach)
-        usb_device_attach(dev);
+        rc = usb_device_attach(dev);
     return rc;
 }
 
@@ -171,20 +171,20 @@ void usb_unregister_port(USBBus *bus, USBPort *port)
     bus->nfree--;
 }
 
-static void do_attach(USBDevice *dev)
+static int do_attach(USBDevice *dev)
 {
     USBBus *bus = usb_bus_from_device(dev);
     USBPort *port;
 
     if (dev->attached) {
-        fprintf(stderr, "Warning: tried to attach usb device %s twice\n",
+        fprintf(stderr, "Error: tried to attach usb device %s twice\n",
                 dev->product_desc);
-        return;
+        return -1;
     }
     if (bus->nfree == 0) {
-        fprintf(stderr, "Warning: tried to attach usb device %s to a bus with no free ports\n",
+        fprintf(stderr, "Error: tried to attach usb device %s to a bus with no free ports\n",
                 dev->product_desc);
-        return;
+        return -1;
     }
     if (dev->port_path) {
         QTAILQ_FOREACH(port, &bus->free, next) {
@@ -193,9 +193,9 @@ static void do_attach(USBDevice *dev)
             }
         }
         if (port == NULL) {
-            fprintf(stderr, "Warning: usb port %s (bus %s) not found\n",
+            fprintf(stderr, "Error: usb port %s (bus %s) not found\n",
                     dev->port_path, bus->qbus.name);
-            return;
+            return -1;
         }
     } else {
         port = QTAILQ_FIRST(&bus->free);
@@ -209,6 +209,8 @@ static void do_attach(USBDevice *dev)
 
     QTAILQ_INSERT_TAIL(&bus->used, port, next);
     bus->nused++;
+
+    return 0;
 }
 
 int usb_device_attach(USBDevice *dev)
@@ -220,8 +222,7 @@ int usb_device_attach(USBDevice *dev)
            (unless a physical port location is specified). */
         usb_create_simple(bus, "usb-hub");
     }
-    do_attach(dev);
-    return 0;
+    return do_attach(dev);
 }
 
 int usb_device_detach(USBDevice *dev)
@@ -230,7 +231,7 @@ int usb_device_detach(USBDevice *dev)
     USBPort *port;
 
     if (!dev->attached) {
-        fprintf(stderr, "Warning: tried to detach unattached usb device %s\n",
+        fprintf(stderr, "Error: tried to detach unattached usb device %s\n",
                 dev->product_desc);
         return -1;
     }
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index c8b7d41..68b46fa 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -481,8 +481,9 @@ static void usb_msd_password_cb(void *opaque, int err)
     MSDState *s = opaque;
 
     if (!err)
-        usb_device_attach(&s->dev);
-    else
+        err = usb_device_attach(&s->dev);
+
+    if (err)
         qdev_unplug(&s->dev.qdev);
 }
 
diff --git a/usb-linux.c b/usb-linux.c
index 490c49f..fe21da1 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -1152,10 +1152,14 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
                 prod_name);
     }
 
+    ret = usb_device_attach(&dev->dev);
+    if (ret) {
+        goto fail;
+    }
+
     /* USB devio uses 'write' flag to check for async completions */
     qemu_set_fd_handler(dev->fd, NULL, async_complete, dev);
 
-    usb_device_attach(&dev->dev);
     return 0;
 
 fail:
-- 
1.7.5.1