@@ -361,6 +361,7 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
+ struct request_queue *q;
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
sector_t dev_size =
@@ -369,6 +370,22 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
limits->logical_block_size >> SECTOR_SHIFT;
char b[BDEVNAME_SIZE];
+ /*
+ * Some devices exist but have not yet request function defined
+ * (e.g. loop with not bounded backing file)
+ * Do not allow using such devices.
+ */
+ q = bdev_get_queue(bdev);
+ if (!q || !q->make_request_fn) {
+ DMWARN("%s: %s is not yet initialised: "
+ "start=%llu, len=%llu, dev_size=%llu",
+ dm_device_name(ti->table->md), bdevname(bdev, b),
+ (unsigned long long)start,
+ (unsigned long long)len,
+ (unsigned long long)dev_size);
+ return 1;
+ }
+
if (!dev_size)
return 0;