Bug 1033971

Summary: mdadm --stop causes soft lockup and eventual crash
Product: [Fedora] Fedora Reporter: Richard W.M. Jones <rjones>
Component: kernelAssignee: LVM and device-mapper development team <lvm-team>
Status: CLOSED RAWHIDE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: rawhideCC: gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda
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Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Last Closed: 2013-11-30 19:17:53 UTC Type: Bug
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 910269    
Attachments:
Description Flags
build.log extract containing the multiple kernel stack traces that happen none

Description Richard W.M. Jones 2013-11-24 22:10:28 UTC 
Created attachment 828434 [details]
build.log extract containing the multiple kernel stack traces that happen

Description of problem:

The libguestfs test suite runs mdadm in various combinations.
Currently the mdadm --stop test causes a soft lockup and eventual
crash.  See the very long stack trace which I'll attach to
this bug.

This has just started happening in the Rawhide kernel, in the
last week.

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

kernel 3.13.0-0.rc1.git0.1.fc21
mdadm-3.3-4.fc21.x86_64

How reproducible:

Tested twice, reproduced the bug both times.

Steps to Reproduce:
1. See the build log for the exact commands.

Additional information:

Test source:
https://github.com/libguestfs/libguestfs/blob/master/tests/md/test-mdadm.sh
Comment 1 Richard W.M. Jones 2013-11-25 11:50:35 UTC 
Upstream: https://bugzilla.kernel.org/show_bug.cgi?id=65721
Comment 2 Richard W.M. Jones 2013-11-27 17:29:15 UTC 
Patch proposed, which I have tested and it fixes the problem.

https://bugzilla.kernel.org/show_bug.cgi?id=65721#c4
Comment 3 Josh Boyer 2013-11-30 19:17:53 UTC 
(In reply to Richard W.M. Jones from comment #2)
> Patch proposed, which I have tested and it fixes the problem.
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=65721#c4

Already in rawhide with 3.13-rc2.

Thanks much for reporting and following up with upstream, Richard.

(Worth noting the same fix is needed in 3.12 stable, so I'll add it there until upstream stable picks it up.)