nodedev: dont rely on ignoring errors on missing properties

The udevProcessStorage method relies on udevGetIntProperty ignoring
errors about non-existant properties and instead setting the value to
zero. In theory when seeing ID_CDROM=1, you might expect that devices
which are not CDs will get ID_CDROM=0, but that's not what happens in
practice. Instead the property simply won't get set at all.

IOW, the code does not need to care about the value of the property,
merely whether it exists or not.

Reviewed-by: Laine Stump <laine@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
index 49c194bb5e5a67a2c4dedc2066d11d046229e099..a45a54938a764461180b10994753afb818fd65d5 100644 (file)
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -962,37 +962,16 @@ udevProcessStorage(struct udev_device *device,
 
     if (!storage->drive_type ||
         STREQ(def->caps->data.storage.drive_type, "generic")) {
-        int val = 0;
-        const char *str = NULL;
-
         /* All floppy drives have the ID_DRIVE_FLOPPY prop. This is
          * needed since legacy floppies don't have a drive_type */
-        if (udevGetIntProperty(device, "ID_DRIVE_FLOPPY", &val, 0) < 0)
+        if (udevHasDeviceProperty(device, "ID_DRIVE_FLOPPY"))
+            storage->drive_type = g_strdup("floppy");
+        else if (udevHasDeviceProperty(device, "ID_CDROM"))
+            storage->drive_type = g_strdup("cd");
+        else if (udevHasDeviceProperty(device, "ID_DRIVE_FLASH_SD"))
+            storage->drive_type = g_strdup("sd");
+        else if (udevKludgeStorageType(def) != 0)
             goto cleanup;
-        else if (val == 1)
-            str = "floppy";
-
-        if (!str) {
-            if (udevGetIntProperty(device, "ID_CDROM", &val, 0) < 0)
-                goto cleanup;
-            else if (val == 1)
-                str = "cd";
-        }
-
-        if (!str) {
-            if (udevGetIntProperty(device, "ID_DRIVE_FLASH_SD", &val, 0) < 0)
-                goto cleanup;
-            if (val == 1)
-                str = "sd";
-        }
-
-        if (str) {
-            storage->drive_type = g_strdup(str);
-        } else {
-            /* If udev doesn't have it, perhaps we can guess it. */
-            if (udevKludgeStorageType(def) != 0)
-                goto cleanup;
-        }
     }
 
     if (STREQ(def->caps->data.storage.drive_type, "cd")) {