Bug 815469 - Floppy driver cause kernel panic in slow virtualized environment
Summary: Floppy driver cause kernel panic in slow virtualized environment
Keywords:
Status: CLOSED RAWHIDE
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: rawhide
Hardware: Unspecified
OS: Linux
unspecified
low
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: 815472
TreeView+ depends on / blocked
 
Reported: 2012-04-23 16:30 UTC by Pavel Hrdina
Modified: 2012-08-10 19:39 UTC (History)
5 users (show)

Fixed In Version:
Clone Of:
: 815472 (view as bug list)
Environment:
Last Closed: 2012-08-10 19:39:29 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)
backtrace-rhel6 (3.89 KB, text/plain)
2012-04-23 19:49 UTC, Pavel Hrdina
no flags Details
backtrace-fedora16 (7.35 KB, text/plain)
2012-04-23 20:02 UTC, Pavel Hrdina
no flags Details

Description Pavel Hrdina 2012-04-23 16:30:46 UTC
Description of problem:
Floppy driver cause kernel panic in slow virtualized environment.

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

How reproducible:
75%

Steps to Reproduce:
1. run qemu without kvm support and with floppy image inserted
2. in guest run "modprobe floppy" and then "mount /dev/fd0 /mnt"
3. mount command cause kernel panic, but not always
  
Actual results:
kenrel panic

Expected results:
mount floppy without kernel panic

Comment 1 Josh Boyer 2012-04-23 16:34:59 UTC
Can you attached the backtrace?  Also, which kernel version(s)?

Comment 2 Pavel Hrdina 2012-04-23 19:49:55 UTC
Created attachment 579675 [details]
backtrace-rhel6

Here is the backtrace on rhel6.3 you asked for and kernel version is 2.6.32-262.el6.x86_64

Comment 3 Josh Boyer 2012-04-23 20:00:34 UTC
(In reply to comment #2)
> Created attachment 579675 [details]
> backtrace
> 
> Here is the backtrace on rhel6.3 you asked for and kernel version is
> 2.6.32-262.el6.x86_64

You reported this against Fedora rawhide.  Does it happen there, or is this a RHEL-only bug?  If it happens in Fedora, can you attach the Fedora kernel backtrace?

Comment 4 Pavel Hrdina 2012-04-23 20:02:27 UTC
Created attachment 579681 [details]
backtrace-fedora16

Here is the backtrace on fedora16 and kernel version is 3.3.0-8.fc16.x86_64

Comment 5 Josh Boyer 2012-08-10 19:39:29 UTC
I tried this with the latest rawhide kernel on a non-KVM guest.  I ran:

modprobe floppy; mount /dev/fd0 /mnt; umount /mnt; modprobe -r floppy

several times and never got an oops.  There have been a number of block and floppy related changes since 3.3.

I'm going to close this bug out as fixed.  If you can recreate with the latest rawhide kernel, please reopen.

I do, however, question how much we care about this specific use case.  AFAIK, RHEL doesn't support non-KVM qemu and while Fedora might, it's use is rather limited particularly with floppy images.


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