From 541c742a7559eb65f0e36d3e2338c2ca532a3e61 Mon Sep 17 00:00:00 2001 From: Guo Chao Date: Thu, 21 Feb 2013 15:16:46 -0800 Subject: 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 Reported-by: M. Hindess Cc: Alexander Viro Cc: Guo Chao Cc: Nikanth Karthikesan Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe --- drivers/block/loop.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 7f8065392064..ed850366f22d 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1092,8 +1092,13 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) if (lo->lo_offset != info->lo_offset || lo->lo_sizelimit != info->lo_sizelimit) { + struct block_device *bdev = lo->lo_device; + if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) return -EFBIG; + + bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9); + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } loop_config_discard(lo); -- cgit v1.2.3