From: Chuck Lever <chuck.lever@xxxxxxxxxx>
Pre-requisite for releasing pages in the send completion handler.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/svc_rdma.h | 3 ++-
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 25 +++++++++++++++++++++++++
2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index a0f3ea357977..8e654da55170 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -158,8 +158,9 @@ struct svc_rdma_send_ctxt {
struct xdr_buf sc_hdrbuf;
struct xdr_stream sc_stream;
void *sc_xprt_buf;
+ int sc_page_count;
int sc_cur_sge_no;
-
+ struct page *sc_pages[RPCSVC_MAXPAGES];
struct ib_sge sc_sges[];
};
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 8e7ccef74207..4c62bc41ea40 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -213,6 +213,7 @@ struct svc_rdma_send_ctxt *svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma)
ctxt->sc_send_wr.num_sge = 0;
ctxt->sc_cur_sge_no = 0;
+ ctxt->sc_page_count = 0;
return ctxt;
out_empty:
@@ -227,6 +228,8 @@ struct svc_rdma_send_ctxt *svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma)
* svc_rdma_send_ctxt_put - Return send_ctxt to free list
* @rdma: controlling svcxprt_rdma
* @ctxt: object to return to the free list
+ *
+ * Pages left in sc_pages are DMA unmapped and released.
*/
void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma,
struct svc_rdma_send_ctxt *ctxt)
@@ -234,6 +237,9 @@ void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma,
struct ib_device *device = rdma->sc_cm_id->device;
unsigned int i;
+ for (i = 0; i < ctxt->sc_page_count; ++i)
+ put_page(ctxt->sc_pages[i]);
+
/* The first SGE contains the transport header, which
* remains mapped until @ctxt is destroyed.
*/
@@ -798,6 +804,25 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
svc_rdma_xb_dma_map, &args);
}
+/* The svc_rqst and all resources it owns are released as soon as
+ * svc_rdma_sendto returns. Transfer pages under I/O to the ctxt
+ * so they are released by the Send completion handler.
+ */
+static inline void svc_rdma_save_io_pages(struct svc_rqst *rqstp,
+ struct svc_rdma_send_ctxt *ctxt)
+{
+ int i, pages = rqstp->rq_next_page - rqstp->rq_respages;
+
+ ctxt->sc_page_count += pages;
+ for (i = 0; i < pages; i++) {
+ ctxt->sc_pages[i] = rqstp->rq_respages[i];
+ rqstp->rq_respages[i] = NULL;
+ }
+
+ /* Prevent svc_xprt_release from releasing pages in rq_pages */
+ rqstp->rq_next_page = rqstp->rq_respages;
+}
+
/* Prepare the portion of the RPC Reply that will be transmitted
* via RDMA Send. The RPC-over-RDMA transport header is prepared
* in sc_sges[0], and the RPC xdr_buf is prepared in following sges.
