Bug#782400: multipath-tools: libmultipath: fix discovery of devices with empty rev sysfs attribute

[Mauricio Faria de Oliveira]

Package: src:multipath-tools
Version: 0.5.0-6
Severity: serious
Tags: patch
Forwarded: https://www.redhat.com/archives/dm-devel/2015-April/msg00049.html

Hi Ritesh,

I noticed some IPR controllers with multipath support may have only
spaces in the rev sysfs attribute, which breaks a device's discovery
(example below got no paths at all).

May you please consider this (forwarded) patch for Jessie?

Thank you.


Example:
-------

The disks in this IPR controller:

	# grep . /sys/block/sda/device/{vendor,model,rev} | tr ' ' '#'
	/sys/block/sda/device/vendor:IBM#####
	/sys/block/sda/device/model:IPR-0###5EC99A00
	/sys/block/sda/device/rev:####

All of them (6 disks, 2 paths per disk):

	# grep . /sys/block/sd*/device/rev | tr ' ' '#'
	/sys/block/sda/device/rev:####
	/sys/block/sdb/device/rev:####
	/sys/block/sdc/device/rev:####
	/sys/block/sdd/device/rev:####
	/sys/block/sde/device/rev:####
	/sys/block/sdf/device/rev:####
	/sys/block/sdg/device/rev:####
	/sys/block/sdh/device/rev:####
	/sys/block/sdi/device/rev:####
	/sys/block/sdj/device/rev:####
	/sys/block/sdk/device/rev:####
	/sys/block/sdl/device/rev:####

Comparison of 'multipath -v3' without/with the patch
(notice 'no paths' vs. 'paths list')

	# diff -u multipath-v3.no-timestamp.{old,new}
	<...>
	  sda: vendor = IBM
	  sda: product = IPR-0   5EC99A00
	+ sda: rev =
	+ sda: h:b:t:l = 0:2:0:0
	+ sda: tgt_node_name =
	+ sda: path state = running
	+ sda: 4252 cyl, 128 heads, 32 sectors/track, start at 0
	<...>
	+ sda: alua prio = 50
	  sdb: <...>
	<...>
	-===== no paths =====
	+===== paths list =====
	+uuid                        hcil    dev dev_t pri dm_st chk_st 
vend/prod/rev
	+1IBM_IPR-0_5EC99A0000000410 0:2:0:0 sda 8:0   50  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A00000003F0 0:2:1:0 sdb 8:16  50  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A00000003D0 0:2:2:0 sdc 8:32  50  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A0000000430 0:2:3:0 sdd 8:48  50  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC9470000000060 0:2:4:0 sde 8:64  50  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC9470000000080 0:2:5:0 sdf 8:80  50  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A0000000410 1:2:0:0 sdg 8:96  10  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A00000003F0 1:2:1:0 sdh 8:112 10  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A00000003D0 1:2:2:0 sdi 8:128 10  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC9470000000080 1:2:3:0 sdj 8:144 10  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC9470000000060 1:2:4:0 sdk 8:160 10  undef ready 
IBM,IPR-0   5EC
	+1IBM_IPR-0_5EC99A0000000430 1:2:5:0 sdl 8:176 10  undef ready 
IBM,IPR-0   5EC
	<...>




-- 
Mauricio Faria de Oliveira
IBM Linux Technology Center