From 6edf1ad773206e5e1ec76b6b8492c83eecae031d Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Thu, 24 Aug 2017 00:03:43 -0700 Subject: UPSTREAM: loop: add ioctl for changing logical block size This is a different approach from the first attempt in f2c6df7dbf9a ("loop: support 4k physical blocksize"). Rather than extending LOOP_{GET,SET}_STATUS, add a separate ioctl just for setting the block size. Bug: 117823094 Change-Id: I8e69b8839d7fee3be564cbfce1797ce108e1aa1e Reviewed-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe (cherry picked from commit 89e4fdecb51cf5535867026274bc97de9480ade5) Signed-off-by: Martijn Coenen --- drivers/block/loop.c | 24 ++++++++++++++++++++++++ include/uapi/linux/loop.h | 1 + 2 files changed, 25 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index da3902ac16c8..b98797682fe7 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1070,6 +1070,7 @@ static int loop_clr_fd(struct loop_device *lo) memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); memset(lo->lo_file_name, 0, LO_NAME_SIZE); + blk_queue_logical_block_size(lo->lo_queue, 512); if (bdev) { bdput(bdev); invalidate_bdev(bdev); @@ -1355,6 +1356,24 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg) return error; } +static int loop_set_block_size(struct loop_device *lo, unsigned long arg) +{ + if (lo->lo_state != Lo_bound) + return -ENXIO; + + if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg)) + return -EINVAL; + + blk_mq_freeze_queue(lo->lo_queue); + + blk_queue_logical_block_size(lo->lo_queue, arg); + loop_update_dio(lo); + + blk_mq_unfreeze_queue(lo->lo_queue); + + return 0; +} + static int lo_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { @@ -1403,6 +1422,11 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) err = loop_set_dio(lo, arg); break; + case LOOP_SET_BLOCK_SIZE: + err = -EPERM; + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) + err = loop_set_block_size(lo, arg); + break; default: err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; } diff --git a/include/uapi/linux/loop.h b/include/uapi/linux/loop.h index c8125ec1f4f2..23158dbe2424 100644 --- a/include/uapi/linux/loop.h +++ b/include/uapi/linux/loop.h @@ -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 -- cgit v1.2.3