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Bug 1828180 - Multipath should blacklist Oracle ASM filter driver (AFD) devices by default
Summary: Multipath should blacklist Oracle ASM filter driver (AFD) devices by default
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: device-mapper-multipath
Version: 8.1
Hardware: Unspecified
OS: Unspecified
unspecified
medium
Target Milestone: rc
: 8.0
Assignee: Ben Marzinski
QA Contact: Lin Li
URL:
Whiteboard:
: 1859437 (view as bug list)
Depends On:
Blocks: 1799062
TreeView+ depends on / blocked
 
Reported: 2020-04-27 08:52 UTC by nikhil kshirsagar
Modified: 2023-09-07 22:58 UTC (History)
12 users (show)

Fixed In Version: device-mapper-multipath-0.8.4-2.el8
Doc Type: Enhancement
Doc Text:
Feature: Change multipath's default blacklist from blacklisting specific device types, to blacklisting all devices types except the ones that multipath supports (scsi, dasd, and nvme). Also users are now able to write inverse matching regexes in the blacklist and blacklist_exceptions sections of multipath.conf Reason: Previously, multipath's default blacklist specifically listed all the device types that were blacklisted. This cause a problem whenever users encountered a new device type. Multipath would attempt to use these devices, and they would need to be manually blacklisted until the default blacklist could be updated. Result: Multipath will now only accept the devices is was designed to support by default.
Clone Of:
Environment:
Last Closed: 2020-11-04 01:59:31 UTC
Type: Bug
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Knowledge Base (Solution) 29537 0 None None None 2020-07-20 14:54:24 UTC
Red Hat Product Errata RHEA-2020:4540 0 None None None 2020-11-04 01:59:59 UTC

Description nikhil kshirsagar 2020-04-27 08:52:27 UTC 
Description of problem:
multipath tried to claim paths from Oracle AFD devices ( This Oracle ASM filter driver is the replacement for the legacy asmlib kernel driver)

[root@pos-s-oradb01 ~]# multipathd show paths 
hcil    dev                dev_t  pri dm_st  chk_st dev_st  next_check     
0:0:0:1 sda                8:0    1   active ready  running XX........ 5/20
0:0:0:2 sdb                8:16   1   active ready  running XX........ 4/20
0:0:0:3 sdc                8:32   1   active ready  running XX........ 4/20
0:0:0:4 sdm                8:192  1   active ready  running XX........ 4/20
0:0:0:5 sdq                65:0   1   active ready  running XX........ 4/20
0:0:0:6 sdu                65:64  1   active ready  running XX........ 4/20
0:0:0:7 sdy                65:128 1   active ready  running XX........ 4/20
0:0:1:1 sdd                8:48   1   active ready  running XX........ 4/20
0:0:1:2 sde                8:64   1   active ready  running XX........ 4/20
0:0:1:3 sdf                8:80   1   active ready  running XX........ 4/20
0:0:1:4 sdn                8:208  1   active ready  running XX........ 4/20
0:0:1:5 sdr                65:16  1   active ready  running XX........ 4/20
0:0:1:6 sdv                65:80  1   active ready  running XX........ 4/20
0:0:1:7 sdz                65:144 1   active ready  running XX........ 4/20
1:0:0:1 sdg                8:96   1   active ready  running XX........ 4/20
1:0:0:2 sdh                8:112  1   active ready  running XX........ 4/20
1:0:0:3 sdi                8:128  1   active ready  running XX........ 4/20
1:0:0:4 sdo                8:224  1   active ready  running XX........ 4/20
1:0:0:5 sds                65:32  1   active ready  running XX........ 4/20
1:0:0:6 sdw                65:96  1   active ready  running XX........ 4/20
1:0:0:7 sdaa               65:160 1   active ready  running XX........ 4/20
1:0:1:1 sdj                8:144  1   active ready  running XX........ 5/20
1:0:1:2 sdk                8:160  1   active ready  running XX........ 4/20
1:0:1:3 sdl                8:176  1   active ready  running XX........ 4/20
1:0:1:4 sdp                8:240  1   active ready  running XX........ 4/20
1:0:1:5 sdt                65:48  1   active ready  running XX........ 4/20
1:0:1:6 sdx                65:112 1   active ready  running XX........ 4/20
1:0:1:7 sdab               65:176 1   active ready  running XX........ 4/20
#:#:#:# asm/.asm_ctl_spec  251:0  -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg0  251:10 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg1  251:11 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg2  251:12 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg3  251:13 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg4  251:14 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg5  251:15 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg6  251:16 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg7  251:17 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vbg8  251:18 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vdbg  251:1  -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio0  251:20 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio1  251:21 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio10 251:30 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio11 251:31 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio12 251:32 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio13 251:33 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio14 251:34 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio15 251:35 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio16 251:36 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio17 251:37 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio18 251:38 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio19 251:39 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio2  251:22 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio20 251:40 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio21 251:41 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio22 251:42 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio23 251:43 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio24 251:44 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio25 251:45 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio26 251:46 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio27 251:47 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio28 251:48 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio29 251:49 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio3  251:23 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio30 251:50 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio31 251:51 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio4  251:24 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio5  251:25 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio6  251:26 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio7  251:27 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio8  251:28 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vio9  251:29 -1  undef  undef  unknown orphan         
#:#:#:# asm/.asm_ctl_vmb   251:2  -1  undef  undef  unknown orphan         
#:#:#:# oracleafd/admin 252:0  -1  undef  undef  unknown orphan         
#:#:#:# ofsctl             250:0  -1  undef  undef  unknown orphan  

Changing the ruleset to this, and restarting multipathd removed these devices as expected:

[root@pos-s-oradb01 ~]# cat /etc/multipath.conf 
defaults {
	find_multipaths yes
	user_friendly_names yes
}

blacklist {
	devnode "^asm*|oracleafd*|ofsctl*" <--
} 

So the default blacklist in multipath should include these devices.


Additional info:
Since the C regex code doesn't allow negative lookahead, we cannot have a blacklist filter that blacklists anything that is *NOT* scsi/nvme/dasd.

the blacklist in the default multipath.conf in the multipath repo seems to be

#       devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
#       devnode "^hd[a-z]"

Is the required patch to change the multipath.conf in device-mapper-multipath/multipath-tools-0.8.3 like so?


#       devnode "^(asm|oracleafd|ofsctl|ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
Comment 1 Ben Marzinski 2020-06-10 15:24:36 UTC 
I actually did more work then was necessary to fix this, so that we don't have to keep dealing with this class of bugs going forwards.  The multipath blacklist and blacklist exceptions sections now treat their attribute values slightly differently.  If a value starts with an exclamation point, "!", it will invert the matching of the rest of the regex. So for instance

blacklist {
        devnode "!^sd[a-z]"
}

will now blacklist all devices whose device name doesn't start with "sd[a-z]".  The exclamation point can be escaped, "\!", to match a literal exclamation point at the start of the regex. This change will not cause any issues for existing values since, because of a bug, multipath previously didn't recognize quoted strings starting with an exclamation point.

With this new capability, the default blacklist has been changed to:

devnode "!^(sd[a-z]|dasd[a-z]|nvme[0-9])"

which only allows scsi, dasd, and nvme devices as multipath paths.  Other device types could be added using the blacklist_exceptions section. This change also should not cause any problems since these are the only device types that multipath currently has code to support, and the multipath udev rules already have the following line

KERNEL!="sd*|dasd*|nvme*", GOTO="end_mpath"

So other device types currently will not be correctly set up by udev.
Comment 14 Ben Marzinski 2020-10-07 16:41:09 UTC 
*** Bug 1859437 has been marked as a duplicate of this bug. ***
Comment 16 errata-xmlrpc 2020-11-04 01:59:31 UTC 
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 (device-mapper-multipath bug fix and enhancement update), 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://access.redhat.com/errata/RHEA-2020:4540
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