loopdev: update block device size in loop_set_status()

Loop device driver sometimes fails to impose the size limit on the
device. Keep issuing following two commands:

losetup --offset 7517244416 --sizelimit 3224971264 /dev/loop0 backed_file
blockdev --getsize64 /dev/loop0

blockdev reports file size instead of sizelimit several out of 100 times.

The problems are:

	- losetup set up the device in two ioctl:
		  LOOP_SET_FD and LOOP_SET_STATUS64.

	- LOOP_SET_STATUS64 only update size of gendisk.

Block device size will be updated lazily when device comes to use. If udev
rushes in between the two ioctl, it will bring in a block device whose
size is backing file size. If the device is not released after
LOOP_SET_STATUS64 ioctl, blockdev will not see the updated size.

Update block size in LOOP_SET_STATUS64 ioctl.

Signed-off-by: Guo Chao <[email protected]>
Reported-by: M. Hindess <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Guo Chao <[email protected]>
Cc: Nikanth Karthikesan <[email protected]>
Cc: Jens Axboe <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions