Description of problem:

With sg3_utils-1.28-8.el6 the rescan-scsi-bus.sh script could be run with the '-r' flag on systems without problems. Updating to sg3_utils-1.28-9.el6_7 this causes filesystems residing on the internal disk to go read-only.

Version-Release number of selected component (if applicable):

sg3_utils-1.28-9.el6_7

How reproducible:

Very, and it panicked my test VM twice, just running it.

Steps to Reproduce:
1. Install RHEL 6.7 and sg3_utils
2. Apply all errata
3. run "rescan-scsi-bus.sh -r"

Actual results:

Root filesystem goes read-only

Expected results:

System only removes and re-adds the LUNs that actually has changed.

Additional info:

Debugging this, I found that the fix from BZ#1291579 added double-quotes around two variables when comparing them. That creates a problem when the variable content have varying amount of leading or trailing whitespace.

The observation after putting a bit of debug in the script was the following:

~~~
"Host: scsi8 Channel: 00 Id: 01 Lun: 00
  Vendor:          Model: RHEL6x-2 SSD     Rev: F.5C
  Type:   Direct-Access                    ANSI SCSI revision: 05"
"Direct-Access                    "
"Direct-Access    "
~~~

Where the last two lines correspond to $TMPSTR and $TYPE. This meant the comparison failed and the script erroneously assumed the devices had changed, thus removing them and re-adding them.