On Thu, Jun 11, 2015 at 08:44:35PM +0800, Tom Yan wrote: > I know `mkfs.btrfs -r $rootdir` copies whatever in $rootdir to the > newly created filesystem. > > When I try to use it for a block device, it creates a "minimal" > filesystem which can only be mounted read-only. > > When I use it for an (qemu raw) image, it seems to work but it also gives: > ERROR: device scan failed 'test.img' - Block device required > in the process. > > So what is it supposed to be used with? That's a bug (will be fixed in btrfs-progs 4.1). The device scan ioctl should not be called on a file. Otherwise it's harmless. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
