[PATCH 1/1] nfs41 do not allocate unused back channel pages

[PATCH 1/1] nfs41 do not allocate unused back channel pages

[andros]

From: Andy Adamson <andros@netapp.com>

Signed-off-by: Andy Adamson <andros@netapp.com>
---
 net/sunrpc/svc.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 538ca43..c9991e8 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -506,6 +506,12 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
 {
 	unsigned int pages, arghi;
 
+#if defined(CONFIG_NFS_V4_1)
+	/* bc_xprt uses fore channel allocated buffers */
+	if (rqstp->rq_server->bc_xprt)
+		return 1;
+#endif /* CONFIG_NFS_V4_1 */
+
 	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 				       * We assume one is at most one page
 				       */
-- 
1.6.6

Re: [PATCH 1/1] nfs41 do not allocate unused back channel pages

[Trond Myklebust]

On Tue, 2010-01-26 at 20:49 -0500, andros@netapp.com wrote: 
> From: Andy Adamson <andros@netapp.com>
> 
> Signed-off-by: Andy Adamson <andros@netapp.com>
> ---
>  net/sunrpc/svc.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> index 538ca43..c9991e8 100644
> --- a/net/sunrpc/svc.c
> +++ b/net/sunrpc/svc.c
> @@ -506,6 +506,12 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
>  {
>  	unsigned int pages, arghi;
>  
> +#if defined(CONFIG_NFS_V4_1)
> +	/* bc_xprt uses fore channel allocated buffers */
> +	if (rqstp->rq_server->bc_xprt)
> +		return 1;
> +#endif /* CONFIG_NFS_V4_1 */
> +
>  	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
>  				       * We assume one is at most one page
>  				       */

Can we replace this with a 'svc_is_backchannel(rqstp->rq_server)' type
of test? That would make it a bit easier on the eyes.

[PATCH 1/1] nfs41 do not allocate unused back channel pages

[andros]

From: Andy Adamson <andros@netapp.com>

Signed-off-by: Andy Adamson <andros@netapp.com>
---
 include/linux/sunrpc/svc.h |   12 ++++++++++++
 net/sunrpc/svc.c           |    4 ++++
 2 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 5a3085b..02329f4 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -281,6 +281,18 @@ struct svc_rqst {
 };
 
 /*
+ * Determine if a shared backchannel is in use
+ */
+static inline int svc_is_backchannel(const struct svc_rqst *rqstp)
+{
+#ifdef CONFIG_NFS_V4_1
+	if (rqstp->rq_server->bc_xprt)
+		return 1;
+#endif /* CONFIG_NFS_V4_1 */
+	return 0;
+}
+
+/*
  * Rigorous type checking on sockaddr type conversions
  */
 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 538ca43..6dcf8c9 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -506,6 +506,10 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
 {
 	unsigned int pages, arghi;
 
+	/* bc_xprt uses fore channel allocated buffers */
+	if (svc_is_backchannel(rqstp))
+		return 1;
+
 	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 				       * We assume one is at most one page
 				       */
-- 
1.6.6

[PATCH 1/1] nfs41 do not allocate unused back channel pages

[andros]

From: Andy Adamson <andros@netapp.com>

Signed-off-by: Andy Adamson <andros@netapp.com>
---
 net/sunrpc/svc.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 538ca43..984be52 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -506,6 +506,10 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
 {
 	unsigned int pages, arghi;
 
+	/* bc_xprt uses fore channel allocated buffers */
+	if (rqstp->rq_server->bc_xprt)
+		return 1;
+
 	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 				       * We assume one is at most one page
 				       */
-- 
1.6.6

Re: [PATCH 1/1] nfs41 do not allocate unused back channel pages

[Trond Myklebust]

On Tue, 2010-01-26 at 12:55 -0500, andros@netapp.com wrote: 
> From: Andy Adamson <andros@netapp.com>
> 
> Signed-off-by: Andy Adamson <andros@netapp.com>
> ---
>  net/sunrpc/svc.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> index 538ca43..984be52 100644
> --- a/net/sunrpc/svc.c
> +++ b/net/sunrpc/svc.c
> @@ -506,6 +506,10 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
>  {
>  	unsigned int pages, arghi;
>  
> +	/* bc_xprt uses fore channel allocated buffers */
> +	if (rqstp->rq_server->bc_xprt)
> +		return 1;
> +
>  	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
>  				       * We assume one is at most one page
>  				       */

Argh! This one too fails completely to compile ifndef CONFIG_NFS_V4_1

Trond