Bug 676337

Summary: [tgt-setup-lun] - adding inaccurate LUN to existing target will remove the target itself
Product: Red Hat Enterprise Linux 6 Reporter: Max Benenson <mbenenso>
Component: scsi-target-utilsAssignee: Andy Grover <agrover>
Status: CLOSED ERRATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: urgent Docs Contact:
Priority: medium    
Version: 6.0CC: agrover, bdonahue, erezz, mchristi, syeghiay
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Providing an existing target name to tgt-setup-lun when attempting to add a new LUN based on a nonexistant device correctly resulted in failure because a target with the same name already existed. If the user then followed the utility's suggestion to add the new LUN to the existing target, the operation failed (again, correctly) because the device did not exist. However, the rollback action associated with this second failure resulted in the target being removed. The rollback action now checks whether the target pre-existed the failed actions, so the target is not removed in this circumstance.
 Story Points: ---
Clone Of:
: 695867 (view as bug list) Environment:
Last Closed: 2011-05-19 14:15:02 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 695867    
Attachments:
Description Flags
fix
none
revised fix none

Description Max Benenson 2011-02-09 15:06:23 UTC 
Description of problem:
If you try to add a new LUN based on non existing device and provide the target name that already exists, the operation will fail since the target with the same name already exists. Then the utility will suggest to the user to add new LUN to this existing target and if the user will select to proceed it will fail since the device does not exist and as the result, the rollback action will remove the target itself.

Version-Release number of selected component (if applicable):
scsi-target-utils-1.0.4-3.el6.x86_64

How reproducible:
Always

Steps to Reproduce (/dev/vg_autofiler01/max_lv02 doesn't exist):
1. lvcreate -L 10G -n /dev/vg_autofiler01/max_lv01
2. tgt-setup-lun -n target1 -d /dev/vg_autofiler01/max_lv01 -t iscsi
3. tgt-setup-lun -n target1 -d /dev/vg_autofiler01/max_lv02 -t iscsi
  
Actual results:
Using transport: iscsi
Error: target named iqn.2001-04.com.auto-filer01-target1 already exists
Add a new lun to the existing target? (yes/NO): yes
Adding a logical unit (/dev/vg_autofiler01/max_lv02) to target, tid=1
tgtadm: invalid request
Error: failed to add a logical unit (/dev/vg_autofiler01/max_lv02) to target, tid=1
Deleting new target, tid=1
The target with id 1 was removed from the targets.conf file.

Expected results:
The rollback action should consider the presence of existing target and should NOT remove it.

Additional info:
[root@auto-filer01 tgt]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.0 (Santiago)
[root@auto-filer01 tgt]# rpm -qa | grep kernel
dracut-kernel-004-33.2.el6_0.noarch
abrt-addon-kerneloops-1.1.13-4.el6.x86_64
kernel-firmware-2.6.32-71.14.1.el6.noarch
kernel-2.6.32-71.14.1.el6.x86_64
kernel-2.6.32-71.el6.x86_64
[root@auto-filer01 tgt]# rpm -qa | grep lvm
lvm2-2.02.72-8.el6_0.4.x86_64
lvm2-libs-2.02.72-8.el6_0.4.x86_64
[root@auto-filer01 tgt]# less /var/log/messages
Jan 31 17:43:09 auto-filer01 tgtd: backed_file_open(92) Could not open /dev/vg_autofiler01/max_lv02, No such file or directory

IMHO, there are few fixes:
1. Add new function that validates if a target is empty
2. Fix err_exit() function to use the function from 1 above before remove any target
3. Remove the validation if target already exists during 'add new LUN' sequence
Comment 2 Mike Christie 2011-02-14 21:09:05 UTC 
Did you send some patches to the upstream tgt list for this?
Comment 3 Max Benenson 2011-02-15 19:00:04 UTC 
(In reply to comment #2)
> Did you send some patches to the upstream tgt list for this?
No, I did not.
Comment 4 Andy Grover 2011-03-08 19:24:56 UTC 
Created attachment 482991 [details]
fix

proposed fix attached.
Comment 5 Mike Christie 2011-03-08 20:37:36 UTC 
Hey, I do not think Erez works at Voltaire anymore.
Comment 6 Andy Grover 2011-03-08 21:00:48 UTC 
Created attachment 483013 [details]
revised fix
Comment 7 Andy Grover 2011-03-17 22:21:34 UTC 
fix in upstream git.
Comment 9 Barry Donahue 2011-04-19 19:46:33 UTC 
Verified on 2.6.32-131.0.1.el6.x86_64.
Comment 10 Laura Bailey 2011-05-05 05:11:17 UTC 
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Providing an existing target name to tgt-setup-lun when attempting to add a new LUN based on a nonexistant device correctly resulted in failure because a target with the same name already existed. If the user then followed the utility's suggestion to add the new LUN to the existing target, the operation failed (again, correctly) because the device did not exist. However, the rollback action associated with this second failure resulted in the target being removed. The rollback action now checks whether the target pre-existed the failed actions, so the target is not removed in this circumstance.
Comment 11 errata-xmlrpc 2011-05-19 14:15:02 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0734.html