Commit a944209c authored by Chuck Lever's avatar Chuck Lever
Browse files

SUNRPC: Revert 57990067 ("svcrdma: Remove unused sc_pages field") 



Pre-requisite for releasing pages in the send completion handler.
Reverted by hand: patch -R would not apply cleanly.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 6be7afcd

include/linux/sunrpc/svc_rdma.h

+2 −1
Original line number Diff line number Diff line
@@ -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[];

};

net/sunrpc/xprtrdma/svc_rdma_sendto.c

+25 −0
Original line number Diff line number Diff line
@@ -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.