Currently the loop driver just simulates 512-byte blocks. When creating bootable images for virtual machines it might be required to use a different physical blocksize (eg 4k for S/390 DASD), as the some bootloaders (like lilo or zipl for S/390) need to know the physical block addresses of the kernel and initrd.
With this patchset the loop driver will export the logical and physical blocksize and the current LOOP_SET_STATUS64 ioctl is extended to set the logical blocksize by re-using the existing 'init' fields, which are currently unused. As usual, comments and reviews are welcome. Changes to v1: - Move LO_FLAGS_BLOCKSIZE definition - Reshuffle patches Changes to v2: - Include reviews from Ming Lei Changes to v3: - Include reviews from Christoph - Merge patches Hannes Reinecke (2): loop: Remove unused 'bdev' argument from loop_set_capacity loop: support 4k physical blocksize drivers/block/loop.c | 40 +++++++++++++++++++++++++++++++++------- drivers/block/loop.h | 1 + include/uapi/linux/loop.h | 1 + 3 files changed, 35 insertions(+), 7 deletions(-) -- 2.6.6
