Bug 52771 - Umount causes client hangs during I/O testing
Summary: Umount causes client hangs during I/O testing
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: kernel   
(Show other bugs)
Version: 7.1
Hardware: i686 Linux
Target Milestone: ---
Assignee: Arjan van de Ven
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2001-08-28 22:00 UTC by Aboubacar Diare
Modified: 2007-04-18 16:36 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2002-12-16 04:31:19 UTC
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
trace file from sysrq keys (78.34 KB, text/plain)
2001-08-28 22:02 UTC, Aboubacar Diare
no flags Details

Description Aboubacar Diare 2001-08-28 22:00:22 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)

Description of problem:
I am using 4 LP2000R (HP Netservers) loaded with Redhat Linux 7.1
Each LP2000R has dual 933MHZ and 512MB of RAM.  Additionally they
each carry an Emulex LP8000 fiber channel adapter card with v4.10l or 
later of the emulex driver.

The four clients above a connected to a brocade fiber channel switch
(SilkWorm 2800) which is connected to an XP48.  The switch is set to 
a fabric point-to-point mode and connected to an XP512 on a single port.

The I/O stress test we ran pretty much create ext2 file system on a
device on the array after mounting it, then reads/writes from it and later 
unmounts it.  This operation is performed over and over again for X number 
of hours.

Problem - Kernel 2.4.2-2 Redhat 7.1
 - The configuration described above runs for about 20-25hours before one 
of the clients stops I/O traffic because it is hung on a mount or umount.  
This problem exists in Redhat Linux 7.1 (Kernel 2.4.2-2).  This can always 
be duplicated.
I tried the raw 2.4.2 kernel from kernel.org.
That kernel does not appear to have the problem either. 
I also tried using Redhat's latest release 2.4.3 source rpm and the 
problem seemed to have been fixed in that kernel. However, other major 
things were not working for us in that kernel which kept us from making 
the transition.

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

How reproducible:

Steps to Reproduce:
1.Set up configuration as describe in description box.
2.Simulate heavy Fibre Channel I/O stress on all four clients

Actual Results:  Let the configuration ran for a while and eventually a 
client or more hang and stop I/O traffic.  Often the client completely 
hangs and sometimes it responds to keyboard inputs even though it is hang.

Expected Results:  This configuration should be able to run 96+ continous 
hours without interruption.  No server hang, data corruption, errors etc.

Additional info:

I selected the mount package to report this bug because it it was the 
closest match to our issue.  This bug doesn't really have to do with the 
mount package itself.  It's more the way the kernel handle locking of 
resources during such operations.  What we beleive is happening is a 
problem with some type of malprocessing of a spinlock in the 
file /fs/super.c that causes the umount operation to hang.  Since 
mount/umount are sequential this also hangs all subsequent umount and 

Comment 1 Aboubacar Diare 2001-08-28 22:02:43 UTC
Created attachment 29974 [details]
trace file from sysrq keys

Comment 2 Bernhard Rosenkraenzer 2001-08-30 14:51:12 UTC
If it's dependent on the kernel version, it's not a problem with the mount 

Comment 3 Arjan van de Ven 2001-08-30 14:54:08 UTC
I would be very interested why the 2.4.3-12 kernel is not working well for you.

Comment 4 Alan Cox 2002-12-16 04:31:19 UTC
no reply made

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