Bug 443627

Summary: kernel dm snapshot: PPC64: kernel OOPS during activation of snapshot with small chunksize
Product: Red Hat Enterprise Linux 5 Reporter: Milan Broz <mbroz>
Component: kernelAssignee: Milan Broz <mbroz>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.2CC: agk, mgahagan, mpatocka, pvrabec
Target Milestone: rc   
Target Release: ---   
Hardware: ppc64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
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Story Points: ---
Clone Of: Environment:
Last Closed: 2009-01-20 20:16:13 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
Zero number of pages none

Description Milan Broz 2008-04-22 16:00:08 UTC
PPC64 architecture cannot initialize snapshot with chunksize smaller than
pagesize (here 64K page)

Setting up Logical Volume Management: kernel BUG in mempool_resize at
mm/mempool.c:121!
cpu 0x1: Vector: 700 (Program Check) at [c0000001633f3250]
    pc: c0000000000b8a10: .mempool_resize+0x3c/0x254
    lr: d000000000627d3c: .dm_io_client_resize+0x24/0x38 [dm_mod]
    sp: c0000001633f34d0
   msr: 8000000000029032
  current = 0xc0000001645764f0
  paca    = 0xc000000000475000
    pid   = 1854, comm = lvm.static
kernel BUG in mempool_resize at mm/mempool.c:121!

Volume group was created on i386 this way:
DEV=/dev/sdc1
VG=vg_tst

pvcreate $DEV
vgcreate $VG $DEV

lvcreate -L 100M -n lv $VG

for i in 4 8 16 32 64 128 256 512 ; do
        lvcreate -s -c $i -L 12M -n "snap"$i vg_tst/lv
done

Simple vgscan; vgchange -a y is enough to rerproduce it.

Kernel version:
Linux ppc-powerv 2.6.18-53.1.14.el5 #1 SMP Tue Feb 19 07:22:57 EST 2008 ppc64
ppc64 ppc64 GNU/Linux

Comment 1 Mikuláš Patočka 2008-04-22 18:26:25 UTC
Created attachment 303351 [details]
Zero number of pages

What about this patch? I can't check that it fixes the bug (don't have PPC),
but it looks like a place where "0" count of pages was created.

Comment 2 Milan Broz 2008-04-23 11:12:16 UTC
(In reply to comment #1)
> What about this patch? I can't check that it fixes the bug (don't have PPC),
> but it looks like a place where "0" count of pages was created.

yep, this helps:-)


Comment 3 RHEL Program Management 2008-04-23 11:20:31 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 7 Don Zickus 2008-07-23 18:55:11 UTC
in kernel-2.6.18-99.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Comment 11 Mikuláš Patočka 2008-09-29 04:24:23 UTC
*** Bug 461506 has been marked as a duplicate of this bug. ***

Comment 13 errata-xmlrpc 2009-01-20 20:16:13 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2009-0225.html