discover: Check for devices with duplicate serial properties

If we have multipath devices present in the system, we'll end up with
duplicate mounts, parse results and boot options. This change adds a
check to see if we've encountered a device with this serial number
previously.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/discover/udev.c b/discover/udev.c
index 1c5cf71..e996e22 100644
--- a/discover/udev.c
+++ b/discover/udev.c
@@ -70,6 +70,7 @@ static int udev_handle_dev_add(struct pb_udev *udev, struct udev_device *dev)
 {
 	struct discover_device *ddev;
 	const char *typestr;
+	const char *serial;
 	const char *path;
 	const char *name;
 
@@ -104,6 +105,12 @@ static int udev_handle_dev_add(struct pb_udev *udev, struct udev_device *dev)
 		return -1;
 	}
 
+	/* we may also see multipath devices; same dev nodes (hence id), but
+	 * different serial numbers */
+	serial = udev_device_get_property_value(dev, "ID_SERIAL");
+	if (serial && device_lookup_by_serial(udev->handler, serial))
+		return -1;
+
 	ddev = discover_device_create(udev->handler, name);
 
 	ddev->device_path = udev_device_get_devnode(dev);