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authorOmar Sandoval <osandov@fb.com>2017-08-24 00:03:43 -0700
committerJens Axboe <axboe@kernel.dk>2017-08-31 13:51:14 -0600
commit89e4fdecb51cf5535867026274bc97de9480ade5 (patch)
treee0cbe2e118ea5ac8ff05a3bb8323d4142545335c /drivers
parent6c6b6f28b3335fd85ec833ee0005d9c9dca6c003 (diff)
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. 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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/loop.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index e3f190016d4f..ac106b287d75 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1047,6 +1047,7 @@ 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);
@@ -1330,6 +1331,24 @@ 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)
{
@@ -1378,6 +1397,11 @@ 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;
}