Re: [PATCH net-next 1/5] RDS: Re-add pf/sol access via sysctl

[santosh.shilimkar@oracle.com]

On 8/14/19 8:56 AM, Doug Ledford wrote:
> On Tue, 2019-08-13 at 11:20 -0700, Gerd Rausch wrote:
>> From: Andy Grover <andy.grover@oracle.com>
>> Date: Tue, 24 Nov 2009 15:35:51 -0800
>>
>> Although RDS has an official PF_RDS value now, existing software
>> expects to look for rds sysctls to determine it. We need to maintain
>> these for now, for backwards compatibility.
>>
>> Signed-off-by: Andy Grover <andy.grover@oracle.com>
>> Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
>> ---
>>   net/rds/sysctl.c | 21 +++++++++++++++++++++
>>   1 file changed, 21 insertions(+)
>>
>> diff --git a/net/rds/sysctl.c b/net/rds/sysctl.c
>> index e381bbcd9cc1..9760292a0af4 100644
>> --- a/net/rds/sysctl.c
>> +++ b/net/rds/sysctl.c
>> @@ -49,6 +49,13 @@ unsigned int  rds_sysctl_max_unacked_bytes = (16 <<
>> 20);
>>   
>>   unsigned int rds_sysctl_ping_enable = 1;
>>   
>> +/*
>> + * We have official values, but must maintain the sysctl interface
>> for existing
>> + * software that expects to find these values here.
>> + */
>> +static int rds_sysctl_pf_rds = PF_RDS;
>> +static int rds_sysctl_sol_rds = SOL_RDS;
>> +
>>   static struct ctl_table rds_sysctl_rds_table[] = {
>>   	{
>>   		.procname       = "reconnect_min_delay_ms",
>> @@ -68,6 +75,20 @@ static struct ctl_table rds_sysctl_rds_table[] = {
>>   		.extra1		= &rds_sysctl_reconnect_min_jiffies,
>>   		.extra2		= &rds_sysctl_reconnect_max,
>>   	},
>> +	{
>> +		.procname       = "pf_rds",
>> +		.data		= &rds_sysctl_pf_rds,
>> +		.maxlen         = sizeof(int),
>> +		.mode           = 0444,
>> +		.proc_handler   = &proc_dointvec,
>> +	},
>> +	{
>> +		.procname       = "sol_rds",
>> +		.data		= &rds_sysctl_sol_rds,
>> +		.maxlen         = sizeof(int),
>> +		.mode           = 0444,
>> +		.proc_handler   = &proc_dointvec,
>> +	},
>>   	{
>>   		.procname	= "max_unacked_packets",
>>   		.data		= &rds_sysctl_max_unacked_packets,
> 
> Good Lord...RDS was taken into the kernel in Feb of 2009, so over 10
> years ago.  The patch to put PF_RDS/AF_RDS/SOL_RDS was taken into
> include/linux/socket.h Feb 26, 2009.  The RDS ports were allocated by
> IANA on Feb 27 and May 20, 2009.  And you *still* have software that
> needs this?  The only software that has ever used RDS was Oracle
> software.  I would have expected you guys to update your source code to
> do the right thing long before now.  In fact, I would expect you were
> ready to retire all of the legacy software that needs this by now.  As
> of today, does your current build of Oracle software still require this,
> or have you at least fixed it up in your modern builds?
> 
Some of the application software was released before 2009 and ended up
using these proc entries from downstream kernel. The newer lib/app
using RDS don't use these. Unfortunately lot of customer still use
Oracle 9, 10, 11 which were released before 2007 and run these apps
on modern kernels.

Regards,
Snatosh