Bug 1310320

ioctl ERR:
==========

11 00000100111000 11111101 00000011
^^ ^^^^^^^^^^^^^^ ^^^^^^^^ ^^^^^^^^
|  |              |         ` function # 0x3    
|  |              | 
|  |              ` ASCI char 0xFD
|  |
|  ` Size of args 0x138
|  
`Read/Write

The no_partitions feature method of solving the problem of skipping kpartx running wasn't accepted upstream. The problem still needs to be solved, but it will most likely get solved with a multipath.conf parameter that sets a udev flag that skips kpartx running.  The effect will be the same.

Hi Ben,
Than you for info. Do you have the reject patch handy?
It's just my personal interest.

About the udev rules parameter, it's cool solution, do you any ETA?
Is there such a work already done in upstream?

Than you for the info.
Lukas

I don't currently have a patch, and nothing exists upstream for this. The device mapper udev cookies code has reserved bits that targets can use to set flags for use in udev processing.  multipath already uses DM_SUBSYSTEM_UDEV_FLAG0 to avoid executing rules when the device has just been reloaded because it has added or
removed paths. It's not too much work to make sure we set DM_SUBSYSTEM_UDEV_FLAG1 (for instance) whenever we would do a dm action that would otherwise cause kpartx to get run, and then check for this in the udev rules.

As for when this will get done. It's too late for this to make it into RHEL-6.8, so it will probably land first in RHEL-7.3 and upstream, and then go into RHEL-6.9.

Fix ported from RHEL7. It's pretty significantly different under the covers, since there were a lot of changes in this code from RHEL6 to RHEL7, but it should work exactly the same.

Verified on device-mapper-multipath-0.4.9-99.el6
1. # man multipath.conf
defaults section
       skip_kpartx      If set to yes , kpartx will not automatically create partitions on the device. The default is no

multipaths section
       The following attributes are optional; if not set the default values are taken from the defaults or devices section:
              skip_kpartx

devices section
       The following attributes are optional; if not set the default values are taken from the defaults section:
              skip_kpartx

2. edit /etc/multipath.conf
defaults {

        find_multipaths yes
        user_friendly_names yes
        skip_kpartx yes
}

3. # multipath -r
reload: mpatha (360fff19abdd9552f8a36e5355226ba27) undef EQLOGIC,100E-00
size=50G features='0' hwhandler='0' wp=undef
|-+- policy='round-robin 0' prio=1 status=undef
| `- 1:0:0:0 sda 8:0  active ready running
`-+- policy='round-robin 0' prio=1 status=undef
  `- 2:0:0:0 sdb 8:16 active ready running

4. edit /etc/multipath.conf
defaults {

        find_multipaths yes
        user_friendly_names yes
        skip_kpartx yes
}

multipaths {
        multipath {
                uid 0
                gid 0
                wwid "360fff19abdd9552f8a36e5355226ba27"
                mode 0600
                skip_kpartx yes
        }
}

5. # multipath -r
reload: mpatha (360fff19abdd9552f8a36e5355226ba27) undef EQLOGIC,100E-00
size=50G features='0' hwhandler='0' wp=undef
|-+- policy='round-robin 0' prio=1 status=undef
| `- 1:0:0:0 sda 8:0  active ready running
`-+- policy='round-robin 0' prio=1 status=undef
  `- 2:0:0:0 sdb 8:16 active ready running

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2017-0697.html