ISST-LTE: KVM:UBUNTU1804: BostonLC: fdisk -l shows the conflicting partitions name for the mpath

[bugproxy]

[Impact]
Any user of Ubuntu on multipath, where the default path separator has been changed to something else. This possibly affects other scenarios where the partition separator can be changed.

[Test case]
1) Install Ubuntu on multipath system
2) Change /etc/multipath.conf to set "path_separator" to "" or "p".
3) Reboot
4) Run 'sudo fdisk -l /dev/mapper/mpathX', to display a device's partitions where the path separator would be visible.

[Regression potential]
Minimal. This only affects display. Default separator on Ubuntu remains "-part". If the separator is not one of "", "p", or "-part", then "-part" would be used, as is already the case.

== Comment: #0 - Chanh H. Nguyen <email address hidden> - 2018-01-09 11:14:07 ==
We have the Ubuntu1804 installed on our BostonLC system. Create a SAN via the Emulex adapter to have the mpath disk.
Running the fdisk -l and ls -l showing the conflict name for the mpath.

:~# uname -a
Linux boslcp4 4.13.0-17-generic #20-Ubuntu SMP Mon Nov 6 10:03:08 UTC 2017 ppc64le ppc64le ppc64le GNU/Linux
root@boslcp4:~# cat /etc/os-release
NAME="Ubuntu"
VERSION="18.04 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu Bionic Beaver (development branch)"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

:~# fdisk -l /dev/mapper/mpatha
Disk /dev/mapper/mpatha: 600 GiB, 644245094400 bytes, 1258291200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 32768 bytes / 32768 bytes
Disklabel type: dos
Disk identifier: 0xa5be904b

Device Boot Start End Sectors Size Id Type
/dev/mapper/mpatha-part1 2048 419432447 419430400 200G 83 Linux
/dev/mapper/mpatha-part2 419432448 838862847 419430400 200G 83 Linux
/dev/mapper/mpatha-part3 838862848 1258291199 419428352 200G 83 Linux

:~# ls -l /dev/mapper/mpatha*
lrwxrwxrwx 1 root root 7 Jan 9 04:04 /dev/mapper/mpatha -> ../dm-0
lrwxrwxrwx 1 root root 7 Jan 9 04:03 /dev/mapper/mpatha1 -> ../dm-1
lrwxrwxrwx 1 root root 7 Jan 9 04:03 /dev/mapper/mpatha2 -> ../dm-2
lrwxrwxrwx 1 root root 7 Jan 9 04:03 /dev/mapper/mpatha3 -> ../dm-3

== Comment: #2 - Chanh H. Nguyen <email address hidden> - 2018-01-09 11:35:04 ==
I just modify the partitions and it is still showing the conflicting name on partitions.

:~# ls -l /dev/mapper/mpatha*
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha -> ../dm-0
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha1 -> ../dm-1
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha2 -> ../dm-2
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha3 -> ../dm-3
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha4 -> ../dm-4
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha5 -> ../dm-5
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha6 -> ../dm-6
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha7 -> ../dm-7
lrwxrwxrwx 1 root root 7 Jan 9 04:33 /dev/mapper/mpatha8 -> ../dm-8

:~# fdisk -l /dev/mapper/mpatha
Disk /dev/mapper/mpatha: 600 GiB, 644245094400 bytes, 1258291200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 32768 bytes / 32768 bytes
Disklabel type: dos
Disk identifier: 0xa5be904b

Device Boot Start End Sectors Size Id Type
/dev/mapper/mpatha-part1 2048 419432447 419430400 200G 83 Linux
/dev/mapper/mpatha-part2 419432448 838862847 419430400 200G 83 Linux
/dev/mapper/mpatha-part3 838862848 964691967 125829120 60G 83 Linux
/dev/mapper/mpatha-part4 964691968 1258291199 293599232 140G 5 Extended
/dev/mapper/mpatha-part5 964694016 1006637055 41943040 20G 83 Linux
/dev/mapper/mpatha-part6 1006639104 1048582143 41943040 20G 83 Linux
/dev/mapper/mpatha-part7 1048584192 1090527231 41943040 20G 83 Linux
/dev/mapper/mpatha-part8 1090529280 1132472319 41943040 20G 83 Linux

== Comment: #5 - Kyle Mahlkuch <email address hidden> - 2018-06-26 13:50:12 ==
I have created and submitted a patch that should help with this bug. I will update when/if the patch is accepted.

== Comment: #9 - Kyle Mahlkuch <email address hidden> - 2018-07-27 09:10:44 ==
Here is the patch:
https://github.com/karelzak/util-linux/commit/73775189767195f1d9f5b6b6f6a54e51f61c4356

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-08-08 15:47 EDT-------
Moving to submitted state, waiting for Canonical to pull in the requested patch.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-09-18 14:39 EDT-------
Are there any updates from Canonical on including this patch?

[Mathieu Trudel-Lapierre (cyphermox)]

I'm not convinced that this patch is necessarily what's the right thing to do -- in your examples, you have mpatha1, for instance -- using no sparator at all. In this case, fdisk would still display the device incorrectly.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-10-04 13:56 EDT-------
>156 asprintf(&res, "%.*s%zu", w, dev, partno);
>157 if (access(res, F_OK) == 0){
>158 p = "";

Given the example originally used to open the bug, dev=mpatha, partno=1 and so p is set to "" and that will display "mpatha1". Please correct me if I'm wrong.

[Mathieu Trudel-Lapierre (cyphermox)]

Correct, I hadn't noticed that part.

The issue I have with this patch still stands, nothing guarantees that the separator is "", "p", or "-part", but at least we're covering the most likely cases.

I'm sponsoring the patch now, we'll land this as SRU to 18.10 and 18.04.

[Adam Conrad (adconrad)]

Hello bugproxy, or anyone else affected,

Accepted util-linux into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/util-linux/2.31.1-0.4ubuntu3.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Launchpad Janitor (janitor)]

This bug was fixed in the package util-linux - 2.32-0.1ubuntu2

---------------
util-linux (2.32-0.1ubuntu2) cosmic; urgency=medium

  * debian/patches/support_alternate_partition_sep.patch: support alternate
    partition separators. Common cases of no separator, using "p" only, and
    "-part" (the only previously supported), are covered now, which should
    let fdisk show partitions in a way closer to reality on most systems.
    Patch from Kyle Mahlkuch, with changes by Karel Zak. (LP: #1784347)

 -- Mathieu Trudel-Lapierre <email address hidden> Mon, 15 Oct 2018 16:25:03 -0400

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-10-17 10:12 EDT-------
Thank you for for sponsoring the patch.
I agree that this is not the best fix as there may exist other partition separators but it's the best I could come up with. These were the most common three separators I found so it's at least "better" than the previous code.

[Mathieu Trudel-Lapierre (cyphermox)]

Hi Kyle,

Can you help with verifying the that patch works as expected on 18.04?

Thanks!

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-11-13 15:21 EDT-------
This works as expected in 18.04.

[Sebastien Bacher (seb128)]

the previous comment suggests it should be verification-done-bionic right?

[Łukasz Zemczak (sil2100)]

Kyle: which version of the package did you use during verification? We want to make sure that the correct -proposed package version has been tested. Could you provide us with apt-cache policy output?

[Mathieu Trudel-Lapierre (cyphermox)]

Please help to validate this SRU.

[Andrew Cloke (andrew-cloke)]

Update: IBM is working on the bionic verification.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-12-11 15:04 EDT-------
I've attached my apt-cache policy output. I enabled bionic-proposed but it looks like the patch has not been applied to the util-linux package.

When I said that the patch worked in Ubuntu 18.04 I had applied the patch to util-linux myself, I didn't use the bionic-proposed package package. Sorry for the confusion.

[bugproxy (bugproxy)]

------- Comment (attachment only) From <email address hidden> 2018-12-11 15:02 EDT-------

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-12-11 15:24 EDT-------
It looks like I did the update wrong. I have updated to the correct version and it looks like the patch was applied. Here is some console output showing two different partition separators:

root@ltc-briggs2:~# ls /dev/mapper/mpath*
/dev/mapper/mpatha /dev/mapper/mpatha-part1 /dev/mapper/mpatha-part2 /dev/mapper/mpathb /dev/mapper/mpathbp1

root@ltc-briggs2:~# fdisk -l | grep mpath
Disk /dev/mapper/mpatha: 30 GiB, 32212254720 bytes, 62914560 sectors
/dev/mapper/mpatha-part1 2048 16383 14336 7M PowerPC PReP boot
/dev/mapper/mpatha-part2 16384 62912511 62896128 30G Linux filesystem
Disk /dev/mapper/mpathb: 30 GiB, 32212254720 bytes, 62914560 sectors
/dev/mapper/mpathbp1 2048 62914559 62912512 30G 83 Linux

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-12-11 15:30 EDT-------
Output showing fdisk at v2.31.1-0.4ubuntu3.3:

root@ltc-briggs2:~/kmahlkuch# apt-get upgrade fdisk
Reading package lists... Done
Building dependency tree
Reading state information... Done
fdisk is already the newest version (2.31.1-0.4ubuntu3.3).

[Launchpad Janitor (janitor)]

This bug was fixed in the package util-linux - 2.31.1-0.4ubuntu3.3

---------------
util-linux (2.31.1-0.4ubuntu3.3) bionic; urgency=medium

  * debian/patches/support_alternate_partition_sep.patch: support alternate
    partition separators. Common cases of no separator, using "p" only, and
    "-part" (the only previously supported), are covered now, which should
    let fdisk show partitions in a way closer to reality on most systems.
    Patch from Kyle Mahlkuch, with changes by Karel Zak. (LP: #1784347)

 -- Mathieu Trudel-Lapierre <email address hidden> Mon, 15 Oct 2018 16:29:48 -0400

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for util-linux has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.