[PATCH v4 08/14] svcrdma: Adjust the number of entries in svc_rdma_recv_ctxt::rc_pages

cel
2025-04-28T19:37:14Z

From: Chuck Lever <chuck.lever@oracle.com>

Allow allocation of more entries in the rc_pages[] array when the
maximum size of an RPC message is increased.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
include/linux/sunrpc/svc_rdma.h | 3 ++-
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 8 ++++++--
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index 619fc0bd837a..1016f2feddc4 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -202,7 +202,8 @@ struct svc_rdma_recv_ctxt {
struct svc_rdma_pcl rc_reply_pcl;

unsigned int rc_page_count;
- struct page *rc_pages[RPCSVC_MAXPAGES];
+ unsigned long rc_maxpages;
+ struct page *rc_pages[] __counted_by(rc_maxpages);
};

/*
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 292022f0976e..e7e4a39ca6c6 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -120,12 +120,16 @@ svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
{
int node = ibdev_to_node(rdma->sc_cm_id->device);
struct svc_rdma_recv_ctxt *ctxt;
+ unsigned long pages;
dma_addr_t addr;
void *buffer;

- ctxt = kzalloc_node(sizeof(*ctxt), GFP_KERNEL, node);
+ pages = svc_serv_maxpages(rdma->sc_xprt.xpt_server);
+ ctxt = kzalloc_node(struct_size(ctxt, rc_pages, pages),
+ GFP_KERNEL, node);
if (!ctxt)
goto fail0;
+ ctxt->rc_maxpages = pages;
buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node);
if (!buffer)
goto fail1;
@@ -497,7 +501,7 @@ static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt)
* a computation, perform a simple range check. This is an
* arbitrary but sensible limit (ie, not architectural).
*/
- if (unlikely(segcount > RPCSVC_MAXPAGES))
+ if (unlikely(segcount > rctxt->rc_maxpages))
return false;

p = xdr_inline_decode(&rctxt->rc_stream,
--
2.49.0