So I assume this option is mainly used for preparation of an btrfs image? On 12 June 2015 at 01:09, David Sterba <dsterba@xxxxxxx> wrote: > 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
