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Commit d16d4009 authored by Tom Tucker's avatar Tom Tucker
Browse files

svcrdma: Return error from rdma_read_xdr so caller knows to free context 



The rdma_read_xdr function did not discriminate between no read-list and
an error posting the read-list. This results in a leak of a page if there
is an error posting the read-list.

Signed-off-by: default avatarTom Tucker <tom@opengridcomputing.com>
parent 58e8f621

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

+16 −7
Original line number Diff line number Diff line
@@ -260,11 +260,16 @@ static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) 
 * On our side, we need to read into a pagelist. The first page immediately

 * follows the RPC header.

 *

 * This function returns 1 to indicate success. The data is not yet in

 * This function returns:

 * 0 - No error and no read-list found.

 *

 * 1 - Successful read-list processing. The data is not yet in

 * the pagelist and therefore the RPC request must be deferred. The

 * I/O completion will enqueue the transport again and

 * svc_rdma_recvfrom will complete the request.

 *

 * <0 - Error processing/posting read-list.

 *

 * NOTE: The ctxt must not be touched after the last WR has been posted

 * because the I/O completion processing may occur on another

 * processor and free / modify the context. Ne touche pas!
@@ -398,7 +403,7 @@ next_sge: 
			svc_rdma_put_context(head, 1);

			head = ctxt;

		}

		return 0;

		return err;

	}



	return 1;
@@ -532,14 +537,18 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp) 
		goto close_out;

	}



	/* Read read-list data. If we would need to wait, defer

	 * it. Not that in this case, we don't return the RQ credit

	 * until after the read completes.

	 */

	if (rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt)) {

	/* Read read-list data. */

	ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);

	if (ret > 0) {

		/* read-list posted, defer until data received from client. */

		svc_xprt_received(xprt);

		return 0;

	}

	if (ret < 0) {

		/* Post of read-list failed, free context. */

		svc_rdma_put_context(ctxt, 1);

		return 0;

	}



	ret = rqstp->rq_arg.head[0].iov_len

		+ rqstp->rq_arg.page_len