Bug 654293

Created attachment 461072 [details]
SUNRPC: convert some sysctls into module parameters

There is a nasty hack to fix this at https://bugzilla.redhat.com/show_bug.cgi?id=189311 

the best way to fix this is either make the processing of sysctl.conf more intelligent.

but a nice and simple way is to have nfs modules load early in the boot process by dropping a script in /etc/sysconfig/modules/

this will avoid touching init scripts all together, and this file can be part of the nfs rpm's - therefore added and removed as needed.

for reference *this method is how kvm kernel modules are loaded in RHEL5 right now*

here is a sample of such a script

/etc/sysconfig/modules/nfs.sh
#!/bin/sh
if [ $(grep -c nfs /etc/fstab) -ne 0 ]; then
modprobe nfs >/dev/null 2>&1
fi

this little script is executed very early in init, before sysctl.conf is loaded. it greps /etc/fstab for nfs entries (granted it will be fooled if you mount /dev/sdXY as /something/nfs for some reason...) and pre-emptively loads nfs (which in turn loads sunrpc). sysctl.conf is loaded thereafter, so the values are applied correctly.

(In reply to comment #3)
> but a nice and simple way is to have nfs modules load early in the boot process
> by dropping a script in /etc/sysconfig/modules/

sunrpc is a kernel module where it can be removed and re-added.
Hence we need to utilise a mechanism where the kernel module parameters are applied anytime it is loaded, even well after boot.

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.

in kernel-2.6.18-245.el5
You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.

The bug is tested on 2.6.18-238.12.1.el5 and 2.6.18-262.el5.

1. Feature not implemented:
[root@intel-s3e36-01 ~]# uname -a
Linux intel-s3e36-01.rhts.eng.rdu.redhat.com 2.6.18-238.12.1.el5 #1 SMP Sat May 7 20:18:50 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
[root@intel-s3e36-01 ~]# modinfo sunrpc
filename:       /lib/modules/2.6.18-238.12.1.el5/kernel/net/sunrpc/sunrpc.ko
license:        GPL
srcversion:     4C59CA7104F920ED8BF33FD
depends:        
vermagic:       2.6.18-238.12.1.el5 SMP mod_unload gcc-4.1
module_sig:	883f3504dc5e5c12fa8482a4a8d9cf11275a40a0a0f0254efe18ee32e8cf33218b12331dbac89630a0a1c9a22df13ddf2b319f9a839891619a3a5d0fa

2. On 2.6.18-262.el5
[root@hp-dl360g6-01 ~]# uname -a
Linux hp-dl360g6-01.rhts.eng.brq.redhat.com 2.6.18-262.el5 #1 SMP Mon May 16 17:49:03 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
[root@hp-dl360g6-01 ~]# modprobe -r sunrpc
[root@hp-dl360g6-01 ~]# grep sunrpc /etc/modprobe.conf 
options sunrpc  min_resvport=110 max_resvport=11000 tcp_slot_table_entries=11
[root@hp-dl360g6-01 ~]# modprobe sunrpc
[root@hp-dl360g6-01 ~]# cat /proc/sys/sunrpc/{{max,min}_resvport,{tcp,udp}_slot_table_entries}
11000
110
11
16
[root@hp-dl360g6-01 ~]# sysctl -A | grep rpc
sunrpc.max_resvport = 11000
sunrpc.min_resvport = 110
sunrpc.tcp_slot_table_entries = 11
sunrpc.udp_slot_table_entries = 16
====snip

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-2011-1065.html