loop: add ioctl for changing logical block size

This is a different approach from the first attempt in f2c6df7dbf
("loop: support 4k physical blocksize"). Rather than extending
LOOP_{GET,SET}_STATUS, add a separate ioctl just for setting the block
size.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Omar Sandoval 2017-08-24 00:03:43 -07:00 committed by Jens Axboe
parent 6c6b6f28b3
commit 89e4fdecb5
2 changed files with 25 additions and 0 deletions

View file

@ -88,6 +88,7 @@ struct loop_info64 {
#define LOOP_CHANGE_FD 0x4C06
#define LOOP_SET_CAPACITY 0x4C07
#define LOOP_SET_DIRECT_IO 0x4C08
#define LOOP_SET_BLOCK_SIZE 0x4C09
/* /dev/loop-control interface */
#define LOOP_CTL_ADD 0x4C80