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authorGuo Chao <yan@linux.vnet.ibm.com>2013-02-22 00:16:46 +0100
committerJens Axboe <axboe@kernel.dk>2013-02-22 10:43:22 +0100
commit541c742a7559eb65f0e36d3e2338c2ca532a3e61 (patch)
tree73ac23dda59eb39cc026bc3264e21abaa077328a /drivers/block/loop.c
parentloopdev: fix a deadlock (diff)
downloadlinux-541c742a7559eb65f0e36d3e2338c2ca532a3e61.tar.xz
linux-541c742a7559eb65f0e36d3e2338c2ca532a3e61.zip
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 <yan@linux.vnet.ibm.com> Reported-by: M. Hindess <hindessm@uk.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c5
1 files changed, 5 insertions, 0 deletions
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);