Bug 123852

Summary: scsi tape: hung "mt tell"
Product: [Fedora] Fedora Reporter: Konstantin Olchanski <olchansk>
Component: kernelAssignee: Arjan van de Ven <arjanv>
Status: CLOSED WONTFIX QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 1   
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2004-09-29 20:27:36 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
scsi errors from machine with hung "mt tell"
none
the real sysrq-T trace. The previous file was the dump of scsi errors. none

Description Konstantin Olchanski 2004-05-20 23:00:58 UTC 
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040116

Description of problem:
After a SCSI error, we cannot access the SCSI tape drive: there is a
hung "mt tell" process and any access to the tape drive reports
"Device or resource busy". The only known way to recover from this is
by rebooting the machine. Instead, "mt tell" should not hang forever,
but should report an error and exit. The currently hung machine is a
dual-opteron box running fedora-1, but we periodically see this
problem all machines with tape drives (and they all happen to be
dual-cpu boxes).

Version-Release number of selected component (if applicable):
kernel-smp-2.4.22-1.2174.nptl

How reproducible:
Sometimes

Additional info:

Attached is stack trace from alt-sysrq-t: the "mt" process is stuck in
"st_do_scsi->wait_for_completion". It looks like the SCSI error
recovery path failed to wakeup "mt" after the SCSI request failed.

Attached are the scsi errors from the system log (grep -i scsi
/var/log/messages).

K.O.
Comment 1 Konstantin Olchanski 2004-05-20 23:03:27 UTC 
Created attachment 100404 [details]
scsi errors from machine with hung "mt tell"
Comment 2 Konstantin Olchanski 2004-05-20 23:05:33 UTC 
Created attachment 100405 [details]
the real sysrq-T trace. The previous file was the dump of scsi errors.
Comment 3 David Lawrence 2004-09-29 20:27:36 UTC 
Thanks for the bug report. However, Red Hat no longer maintains this version of
the product. Please upgrade to the latest version and open a new bug if the problem
persists.

The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases, 
and if you believe this bug is interesting to them, please report the problem in
the bug tracker at: http://bugzilla.fedora.us/
Comment 4 Konstantin Olchanski 2004-09-30 00:09:54 UTC 
This problem no longer exists after we replaced the AMD64 FC1 kernel
(2.4 based) with the AMD64 FC2 kernel (2.6.8-1.521smp). Userland is
still FC1. K.O.