[PATCH] Do not skip records with nonblocking connections

[PATCH] Do not skip records with nonblocking connections

[Steve Dickson]

With non-blocking connections, do not skip records when receiving
the streams since entire value messages can be ignored which
in cause the entire stream to become out of sync.

For example, two mounts simultaneously send two unmaps
commands. The first one is read, then the second thrown
away due to skipping the record. Skipping this record
will cause XDR error later in processing of the stream.

Signed-off-by: Steve Dickson <steved@redhat.com>
---
 src/svc_vc.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/src/svc_vc.c b/src/svc_vc.c
index aaaf2d7..15dac18 100644
--- a/src/svc_vc.c
+++ b/src/svc_vc.c
@@ -610,6 +610,11 @@ svc_vc_recv(xprt, msg)
 	}
 
 	xdrs->x_op = XDR_DECODE;
+	/*
+	 * No need skip records with nonblocking connections
+	 */
+	if (cd->nonblock == FALSE)
+		(void)xdrrec_skiprecord(xdrs);
 	(void)xdrrec_skiprecord(xdrs);
 	if (xdr_callmsg(xdrs, msg)) {
 		cd->x_id = msg->rm_xid;
-- 
1.7.4.4

Re: [Libtirpc-devel] [PATCH] Do not skip records with nonblocking connections

[Chuck Lever]

Sent from my iPad

On Jun 5, 2011, at 11:43 AM, Steve Dickson <steved@redhat.com> wrote:

> With non-blocking connections, do not skip records when receiving
> the streams since entire value messages can be ignored which
> in cause the entire stream to become out of sync.
> 
> For example, two mounts simultaneously send two unmaps
> commands. The first one is read, then the second thrown
> away due to skipping the record. Skipping this record
> will cause XDR error later in processing of the stream.
> 
> Signed-off-by: Steve Dickson <steved@redhat.com>
> ---
> src/svc_vc.c |    5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/src/svc_vc.c b/src/svc_vc.c
> index aaaf2d7..15dac18 100644
> --- a/src/svc_vc.c
> +++ b/src/svc_vc.c
> @@ -610,6 +610,11 @@ svc_vc_recv(xprt, msg)
>    }
> 
>    xdrs->x_op = XDR_DECODE;
> +    /*
> +     * No need skip records with nonblocking connections
> +     */
> +    if (cd->nonblock == FALSE)
> +        (void)xdrrec_skiprecord(xdrs);
>    (void)xdrrec_skiprecord(xdrs);

Do you want to delete the unconditional invocation of xdrrec_skiprecord() here?

>    if (xdr_callmsg(xdrs, msg)) {
>        cd->x_id = msg->rm_xid;
> -- 
> 1.7.4.4
> 
> 
> ------------------------------------------------------------------------------
> Simplify data backup and recovery for your virtual environment with vRanger.
> Installation's a snap, and flexible recovery options mean your data is safe,
> secure and there when you need it. Discover what all the cheering's about.
> Get your free trial download today. 
> http://p.sf.net/sfu/quest-dev2dev2 
> _______________________________________________
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> https://lists.sourceforge.net/lists/listinfo/libtirpc-devel

Re: [Libtirpc-devel] [PATCH] Do not skip records with nonblocking connections

[Steve Dickson]

On 06/05/2011 06:57 PM, Chuck Lever wrote:
> 
> 
> Sent from my iPad
> 
> On Jun 5, 2011, at 11:43 AM, Steve Dickson <steved@redhat.com> wrote:
> 
>> With non-blocking connections, do not skip records when receiving
>> the streams since entire value messages can be ignored which
>> in cause the entire stream to become out of sync.
>>
>> For example, two mounts simultaneously send two unmaps
>> commands. The first one is read, then the second thrown
>> away due to skipping the record. Skipping this record
>> will cause XDR error later in processing of the stream.
>>
>> Signed-off-by: Steve Dickson <steved@redhat.com>
>> ---
>> src/svc_vc.c |    5 +++++
>> 1 files changed, 5 insertions(+), 0 deletions(-)
>>
>> diff --git a/src/svc_vc.c b/src/svc_vc.c
>> index aaaf2d7..15dac18 100644
>> --- a/src/svc_vc.c
>> +++ b/src/svc_vc.c
>> @@ -610,6 +610,11 @@ svc_vc_recv(xprt, msg)
>>    }
>>
>>    xdrs->x_op = XDR_DECODE;
>> +    /*
>> +     * No need skip records with nonblocking connections
>> +     */
>> +    if (cd->nonblock == FALSE)
>> +        (void)xdrrec_skiprecord(xdrs);
>>    (void)xdrrec_skiprecord(xdrs);
> 
> Do you want to delete the unconditional invocation of xdrrec_skiprecord() here?
Yes I do... a small cut/past error... good catch!

steved.
> 
>>    if (xdr_callmsg(xdrs, msg)) {
>>        cd->x_id = msg->rm_xid;
>> -- 
>> 1.7.4.4
>>
>>
>> ------------------------------------------------------------------------------
>> Simplify data backup and recovery for your virtual environment with vRanger.
>> Installation's a snap, and flexible recovery options mean your data is safe,
>> secure and there when you need it. Discover what all the cheering's about.
>> Get your free trial download today. 
>> http://p.sf.net/sfu/quest-dev2dev2 
>> _______________________________________________
>> Libtirpc-devel mailing list
>> Libtirpc-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/libtirpc-devel