Public bug reported:

Release 16.04, kernel 4.4.0-124-generic

There's an issue in kernel's NBD module which prevents some larger images to be
correctly "connected" , largely described here:
https://github.com/NetworkBlockDevice/nbd/issues/44

There is a small patch here that was accepted into mainline 4.10:
https://www.spinics.net/lists/linux-block/msg07060.html

This is a regression from the previous LTS 3.13 kernel.

----

Here is a small example of the faulty behaviour:

# qemu-img create -f qcow2 test.img 1100G
Formatting 'test.img', fmt=qcow2 size=1181116006400 cluster_size=65536 
lazy_refcounts=off refcount_bits=16
# qemu-nbd -c /dev/nbd0 test.img
# blockdev --getsize64 /dev/nbd0
18446743055802302464

The correct response would be 1181116006400; this breaks most tools and
makes the image unusable, e.g.

# fdisk -l /dev/nbd0
fdisk: cannot open /dev/nbd0: Invalid argument

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1772575

Title:
  Kernel 4.4 NBD size overflow with image size exceeding 1TB

Status in linux package in Ubuntu:
  New

Bug description:
  Release 16.04, kernel 4.4.0-124-generic

  There's an issue in kernel's NBD module which prevents some larger images to 
be
  correctly "connected" , largely described here:
  https://github.com/NetworkBlockDevice/nbd/issues/44

  There is a small patch here that was accepted into mainline 4.10:
  https://www.spinics.net/lists/linux-block/msg07060.html

  This is a regression from the previous LTS 3.13 kernel.

  ----

  Here is a small example of the faulty behaviour:

  # qemu-img create -f qcow2 test.img 1100G
  Formatting 'test.img', fmt=qcow2 size=1181116006400 cluster_size=65536 
lazy_refcounts=off refcount_bits=16
  # qemu-nbd -c /dev/nbd0 test.img
  # blockdev --getsize64 /dev/nbd0
  18446743055802302464

  The correct response would be 1181116006400; this breaks most tools
  and makes the image unusable, e.g.

  # fdisk -l /dev/nbd0
  fdisk: cannot open /dev/nbd0: Invalid argument

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1772575/+subscriptions

-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to