Bug 18115

Summary:	mounting an iso file increases load (loop device crash)
Product:	[Retired] Red Hat Linux	Reporter:	Jaanus J6gisman <jaanus>
Component:	kernel	Assignee:	Michael K. Johnson <johnsonm>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	7.0	CC:	alfredo.maria.ferrari, arjan, dowdle
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2000-10-28 11:01:45 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jaanus J6gisman 2000-10-02 17:55:05 UTC

When I mount an iso image using 
mount -t iso9660 -o loop file.iso /mnt/iso
the load will increase to >1.0 and all the memory becomes used.

also there will apear an process in the processlist that is not killable.
root 720 0.0 0.3 1568 752 ? D 01:25 0:00 /sbin/modprobe -s -k block-major-7

if I unmount the iso, the load will be still >1.0 and modprobe process 
keeps running.

this bug apeared on two servers with different configuration.

Comment 1 Alan Cox 2000-10-02 18:36:23 UTC

Transferred to kernel

Comment 2 Arjan van de Ven 2000-10-14 19:31:17 UTC

I made a provisional patch, see bug 19065 or
http://www.fenrus.demon.nl/loop.diff
Feel free to test; it is only a first draft though, and not finished, although
it solves the 
problem for me.

Comment 3 Scott Dowdle 2000-10-25 03:41:44 UTC

I've observed similiar behavior on two different machines... shortly after mounting an iso image my load will go up to 1.0 or greater.  If a machine is idle for a while, I login and check the load and w reports a 1.00 1.00 1.00.  I find it odd that it is a perfect 1.00 load for 15 minutes (or whatever) straight.  I even telinit 1 to stop everything and the load remains at 1 or greater.  In single user mode it was easier to spot the "loopd" process with a stat of "D" which according to the ps man page:  "D   uninterruptible sleep (usually IO)".  Until a new kernel or module fix is provided, I guess I'll not mount any iso images.

Comment 4 Arjan van de Ven 2000-10-28 11:01:41 UTC

I've put a kernel compiled with a fix up at
ftp://nl.linux.org/pub/people/arjan/rpm
This is the Red Hat 2.2.16-22 kernel with the fix for loop, as well as the fixes
for 19302 and 19072.
(Note: This is NOT an official Red Hat kernel, nor is it even looked at by Red
Hat employees !)

Comment 5 Arjan van de Ven 2001-02-09 20:16:38 UTC

fixed in errata kernel

Comment 6 Charles R. Anderson 2001-03-10 20:51:53 UTC

When installing the kernel-2.2.17-14 rpm (from a machine running 2.2.16-22)
which resides on an NFS mount, the next reboot fails to unmount the NFS mount
which causes the machine to hang with RPC failures after the network is stopped.
 This is due to the '/sbin/modprobe loop' process being in 'D' state, which
prevents the NFS mount from unmounting, even with umount -f.