Failure to remove kernel partition mappings in yakkety (2.28.1-1ubuntu1)

[Robert C Jennings]

In the move from 2.28-5ubuntu2 and 2.28.1-1ubuntu1 of util-linux we see a regression when asking kpartx to remove kernel partition mappings where the appear to remain.

Context: We create and modify disk images heavily. The example recreate creates a 2GB disk image with a single partition. From that 2GB image we will resize it to 8GB and grow the partition/filesystem. This stopped working in yakkety with 2.28.1-1ubuntu1.

We do have a work-around which is call growpart on the file rather on the loopback device.

Recreate script is attached.

Related bugs:
 * bug 1619285: cc_growpart fails on yakkety

[Robert C Jennings (rcj)]

Running the recreate.sh script with util-linux 2.28-5ubuntu2 gives us a successful run.

[Robert C Jennings (rcj)]

Running the recreate.sh script with util-linux 2.28.1-1ubuntu1 results in a failure when growpart attempts to write the new partition table and update the kernel indicating that the partition table was not cleared from the kernel when we ran 'kpartx -s -v -d /dev/loop0'

In this case we have run:
kpartx -s -v -a file # create the loopback device for 'file' and add partition mappings
kpartx -s -v -d /dev/loop0 # delete the partition mappings, but keep the loopback device
growpart /dev/loop0 1 # grow the 1st partition on /dev/loop0

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Scott Moser (smoser)]

Seems likely to be a dupe / common cause of bug 1619285.