2020-11-30 19:59:46

by Chuck Lever

Subject: [PATCH v2] SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall

There's no need to defer allocation of pages for the receive buffer.

- This upcall is quite infrequent
- gssp_alloc_receive_pages() can allocate the pages with GFP_KERNEL,
unlike the transport
- gssp_alloc_receive_pages() knows exactly how many pages are needed

Signed-off-by: Chuck Lever <[email protected]>
---
net/sunrpc/auth_gss/gss_rpc_upcall.c | 15 ++++++++++-----
net/sunrpc/auth_gss/gss_rpc_xdr.c | 1 -
2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
index af9c7f43859c..d1c003a25b0f 100644
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -200,7 +200,7 @@ static int gssp_call(struct net *net, struct rpc_message *msg)

static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
{
- int i;
+ unsigned int i;

for (i = 0; i < arg->npages && arg->pages[i]; i++)
__free_page(arg->pages[i]);
@@ -210,14 +210,19 @@ static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)

static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
{
+ unsigned int i;
+
arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
arg->pages = kcalloc(arg->npages, sizeof(struct page *), GFP_KERNEL);
- /*
- * XXX: actual pages are allocated by xdr layer in
- * xdr_partial_copy_from_skb.
- */
if (!arg->pages)
return -ENOMEM;
+ for (i = 0; i < arg->npages; i++) {
+ arg->pages[i] = alloc_page(GFP_KERNEL);
+ if (!arg->pages[i]) {
+ gssp_free_receive_pages(arg);
+ return -ENOMEM;
+ }
+ }
return 0;
}

diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index c636c648849b..d79f12c2550a 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -771,7 +771,6 @@ void gssx_enc_accept_sec_context(struct rpc_rqst *req,
xdr_inline_pages(&req->rq_rcv_buf,
PAGE_SIZE/2 /* pretty arbitrary */,
arg->pages, 0 /* page base */, arg->npages * PAGE_SIZE);
- req->rq_rcv_buf.flags |= XDRBUF_SPARSE_PAGES;
done:
if (err)
dprintk("RPC: gssx_enc_accept_sec_context: %d\n", err);

2020-11-30 23:04:06

by Olga Kornievskaia

Subject: Re: [PATCH v2] SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall

On Mon, Nov 30, 2020 at 2:59 PM Chuck Lever <[email protected]> wrote:
>
> There's no need to defer allocation of pages for the receive buffer.
>
> - This upcall is quite infrequent
> - gssp_alloc_receive_pages() can allocate the pages with GFP_KERNEL,
> unlike the transport
> - gssp_alloc_receive_pages() knows exactly how many pages are needed

Looks good to me now. Reviewed-by.

> Signed-off-by: Chuck Lever <[email protected]>
> ---
> net/sunrpc/auth_gss/gss_rpc_upcall.c | 15 ++++++++++-----
> net/sunrpc/auth_gss/gss_rpc_xdr.c | 1 -
> 2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/net/sunrpc/auth_gss/gss_rpc_upcall.c b/net/sunrpc/auth_gss/gss_rpc_upcall.c
> index af9c7f43859c..d1c003a25b0f 100644
> --- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
> +++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
> @@ -200,7 +200,7 @@ static int gssp_call(struct net *net, struct rpc_message *msg)
>
> static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
> {
> - int i;
> + unsigned int i;
>
> for (i = 0; i < arg->npages && arg->pages[i]; i++)
> __free_page(arg->pages[i]);
> @@ -210,14 +210,19 @@ static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
>
> static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
> {
> + unsigned int i;
> +
> arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
> arg->pages = kcalloc(arg->npages, sizeof(struct page *), GFP_KERNEL);
> - /*
> - * XXX: actual pages are allocated by xdr layer in
> - * xdr_partial_copy_from_skb.
> - */
> if (!arg->pages)
> return -ENOMEM;
> + for (i = 0; i < arg->npages; i++) {
> + arg->pages[i] = alloc_page(GFP_KERNEL);
> + if (!arg->pages[i]) {
> + gssp_free_receive_pages(arg);
> + return -ENOMEM;
> + }
> + }
> return 0;
> }
>
> diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
> index c636c648849b..d79f12c2550a 100644
> --- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
> +++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
> @@ -771,7 +771,6 @@ void gssx_enc_accept_sec_context(struct rpc_rqst *req,
> xdr_inline_pages(&req->rq_rcv_buf,
> PAGE_SIZE/2 /* pretty arbitrary */,
> arg->pages, 0 /* page base */, arg->npages * PAGE_SIZE);
> - req->rq_rcv_buf.flags |= XDRBUF_SPARSE_PAGES;
> done:
> if (err)
> dprintk("RPC: gssx_enc_accept_sec_context: %d\n", err);
>
>