diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 215e112d153eea64258aceac6805e07c39556eb0..451c3bb176d2953fcc8c5da8fccc42f34e83fc74 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -362,6 +362,7 @@ 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 = @@ -370,6 +371,22 @@ 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 without request functions, + * such as loop devices not yet bound to backing files. + * Forbid the use of 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;