2007-12-12 22:13:28

by Tom Tucker

[permalink] [raw]
Subject: [PATCH 6/7] rdma: ONCRPC RDMA protocol marshalling


This logic parses the ONCRDMA protocol headers that
precede the actual RPC header. It is placed in a separate
file to keep all protocol aware code in a single place.

Signed-off-by: Tom Tucker <[email protected]>
---

net/sunrpc/xprtrdma/svc_rdma_marshal.c | 412 ++++++++++++++++++++++++++++++++
1 files changed, 412 insertions(+), 0 deletions(-)

diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c
new file mode 100644
index 0000000..9530ef2
--- /dev/null
+++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c
@@ -0,0 +1,412 @@
+/*
+ * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the BSD-type
+ * license below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * Neither the name of the Network Appliance, Inc. nor the names of
+ * its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Tom Tucker <[email protected]>
+ */
+
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/debug.h>
+#include <asm/unaligned.h>
+#include <linux/sunrpc/rpc_rdma.h>
+#include <linux/sunrpc/svc_rdma.h>
+
+#define RPCDBG_FACILITY RPCDBG_SVCXPRT
+
+/*
+ * Decodes a read chunk list. The expected format is as follows:
+ * descrim : xdr_one
+ * position : u32 offset into XDR stream
+ * handle : u32 RKEY
+ * . . .
+ * end-of-list: xdr_zero
+ */
+static u32 *decode_read_list(u32 *va, u32 *vaend)
+{
+ struct rpcrdma_read_chunk *ch = (struct rpcrdma_read_chunk *)va;
+
+ while (ch->rc_discrim != xdr_zero) {
+ u64 ch_offset;
+
+ if (((unsigned long)ch + sizeof(struct rpcrdma_read_chunk)) >
+ (unsigned long)vaend) {
+ dprintk("svcrdma: vaend=%p, ch=%p\n", vaend, ch);
+ return NULL;
+ }
+
+ ch->rc_discrim = ntohl(ch->rc_discrim);
+ ch->rc_position = ntohl(ch->rc_position);
+ ch->rc_target.rs_handle = ntohl(ch->rc_target.rs_handle);
+ ch->rc_target.rs_length = ntohl(ch->rc_target.rs_length);
+ va = (u32 *)&ch->rc_target.rs_offset;
+ xdr_decode_hyper(va, &ch_offset);
+ put_unaligned(ch_offset, (u64 *)va);
+ ch++;
+ }
+ return (u32 *)&ch->rc_position;
+}
+
+/*
+ * Determine number of chunks and total bytes in chunk list. The chunk
+ * list has already been verified to fit within the RPCRDMA header.
+ */
+void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch,
+ int *ch_count, int *byte_count)
+{
+ /* compute the number of bytes represented by read chunks */
+ *byte_count = 0;
+ *ch_count = 0;
+ for (; ch->rc_discrim != 0; ch++) {
+ *byte_count = *byte_count + ch->rc_target.rs_length;
+ *ch_count = *ch_count + 1;
+ }
+}
+
+/*
+ * Decodes a write chunk list. The expected format is as follows:
+ * descrim : xdr_one
+ * nchunks : <count>
+ * handle : u32 RKEY ---+
+ * length : u32 <len of segment> |
+ * offset : remove va + <count>
+ * . . . |
+ * ---+
+ */
+static u32 *decode_write_list(u32 *va, u32 *vaend)
+{
+ int ch_no;
+ struct rpcrdma_write_array *ary =
+ (struct rpcrdma_write_array *)va;
+
+ /* Check for not write-array */
+ if (ary->wc_discrim == xdr_zero)
+ return (u32 *)&ary->wc_nchunks;
+
+ if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
+ (unsigned long)vaend) {
+ dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
+ return NULL;
+ }
+ ary->wc_discrim = ntohl(ary->wc_discrim);
+ ary->wc_nchunks = ntohl(ary->wc_nchunks);
+ if (((unsigned long)&ary->wc_array[0] +
+ (sizeof(struct rpcrdma_write_chunk) * ary->wc_nchunks)) >
+ (unsigned long)vaend) {
+ dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
+ ary, ary->wc_nchunks, vaend);
+ return NULL;
+ }
+ for (ch_no = 0; ch_no < ary->wc_nchunks; ch_no++) {
+ u64 ch_offset;
+
+ ary->wc_array[ch_no].wc_target.rs_handle =
+ ntohl(ary->wc_array[ch_no].wc_target.rs_handle);
+ ary->wc_array[ch_no].wc_target.rs_length =
+ ntohl(ary->wc_array[ch_no].wc_target.rs_length);
+ va = (u32 *)&ary->wc_array[ch_no].wc_target.rs_offset;
+ xdr_decode_hyper(va, &ch_offset);
+ put_unaligned(ch_offset, (u64 *)va);
+ }
+
+ /*
+ * rs_length is the 2nd 4B field in wc_target and taking its
+ * address skips the list terminator
+ */
+ return (u32 *)&ary->wc_array[ch_no].wc_target.rs_length;
+}
+
+static u32 *decode_reply_array(u32 *va, u32 *vaend)
+{
+ int ch_no;
+ struct rpcrdma_write_array *ary =
+ (struct rpcrdma_write_array *)va;
+
+ /* Check for no reply-array */
+ if (ary->wc_discrim == xdr_zero)
+ return (u32 *)&ary->wc_nchunks;
+
+ if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
+ (unsigned long)vaend) {
+ dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
+ return NULL;
+ }
+ ary->wc_discrim = ntohl(ary->wc_discrim);
+ ary->wc_nchunks = ntohl(ary->wc_nchunks);
+ if (((unsigned long)&ary->wc_array[0] +
+ (sizeof(struct rpcrdma_write_chunk) * ary->wc_nchunks)) >
+ (unsigned long)vaend) {
+ dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
+ ary, ary->wc_nchunks, vaend);
+ return NULL;
+ }
+ for (ch_no = 0; ch_no < ary->wc_nchunks; ch_no++) {
+ u64 ch_offset;
+
+ ary->wc_array[ch_no].wc_target.rs_handle =
+ ntohl(ary->wc_array[ch_no].wc_target.rs_handle);
+ ary->wc_array[ch_no].wc_target.rs_length =
+ ntohl(ary->wc_array[ch_no].wc_target.rs_length);
+ va = (u32 *)&ary->wc_array[ch_no].wc_target.rs_offset;
+ xdr_decode_hyper(va, &ch_offset);
+ put_unaligned(ch_offset, (u64 *)va);
+ }
+
+ return (u32 *)&ary->wc_array[ch_no];
+}
+
+int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
+ struct svc_rqst *rqstp)
+{
+ struct rpcrdma_msg *rmsgp = NULL;
+ u32 *va;
+ u32 *vaend;
+ u32 hdr_len;
+
+ rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
+
+ /* Verify that there's enough bytes for header + something */
+ if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
+ dprintk("svcrdma: header too short = %d\n",
+ rqstp->rq_arg.len);
+ return -EINVAL;
+ }
+
+ /* Decode the header */
+ rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
+ rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
+ rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
+ rmsgp->rm_type = ntohl(rmsgp->rm_type);
+
+ if (rmsgp->rm_vers != RPCRDMA_VERSION)
+ return -ENOSYS;
+
+ /* Pull in the extra for the padded case and bump our pointer */
+ if (rmsgp->rm_type == RDMA_MSGP) {
+ int hdrlen;
+ rmsgp->rm_body.rm_padded.rm_align =
+ ntohl(rmsgp->rm_body.rm_padded.rm_align);
+ rmsgp->rm_body.rm_padded.rm_thresh =
+ ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
+
+ va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
+ rqstp->rq_arg.head[0].iov_base = va;
+ hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
+ rqstp->rq_arg.head[0].iov_len -= hdrlen;
+ if (hdrlen > rqstp->rq_arg.len)
+ return -EINVAL;
+ return hdrlen;
+ }
+
+ /* The chunk list may contain either a read chunk list or a write
+ * chunk list and a reply chunk list.
+ */
+ va = &rmsgp->rm_body.rm_chunks[0];
+ vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
+ va = decode_read_list(va, vaend);
+ if (!va)
+ return -EINVAL;
+ va = decode_write_list(va, vaend);
+ if (!va)
+ return -EINVAL;
+ va = decode_reply_array(va, vaend);
+ if (!va)
+ return -EINVAL;
+
+ rqstp->rq_arg.head[0].iov_base = va;
+ hdr_len = (unsigned long)va - (unsigned long)rmsgp;
+ rqstp->rq_arg.head[0].iov_len -= hdr_len;
+
+ *rdma_req = rmsgp;
+ return hdr_len;
+}
+
+int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
+{
+ struct rpcrdma_msg *rmsgp = NULL;
+ struct rpcrdma_read_chunk *ch;
+ struct rpcrdma_write_array *ary;
+ u32 *va;
+ u32 hdrlen;
+
+ dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
+ rqstp);
+ rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
+
+ /* Pull in the extra for the padded case and bump our pointer */
+ if (rmsgp->rm_type == RDMA_MSGP) {
+ va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
+ rqstp->rq_arg.head[0].iov_base = va;
+ hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
+ rqstp->rq_arg.head[0].iov_len -= hdrlen;
+ return hdrlen;
+ }
+
+ /*
+ * Skip all chunks to find RPC msg. These were previously processed
+ */
+ va = &rmsgp->rm_body.rm_chunks[0];
+
+ /* Skip read-list */
+ for (ch = (struct rpcrdma_read_chunk *)va;
+ ch->rc_discrim != xdr_zero; ch++);
+ va = (u32 *)&ch->rc_position;
+
+ /* Skip write-list */
+ ary = (struct rpcrdma_write_array *)va;
+ if (ary->wc_discrim == xdr_zero)
+ va = (u32 *)&ary->wc_nchunks;
+ else
+ /*
+ * rs_length is the 2nd 4B field in wc_target and taking its
+ * address skips the list terminator
+ */
+ va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
+
+ /* Skip reply-array */
+ ary = (struct rpcrdma_write_array *)va;
+ if (ary->wc_discrim == xdr_zero)
+ va = (u32 *)&ary->wc_nchunks;
+ else
+ va = (u32 *)&ary->wc_array[ary->wc_nchunks];
+
+ rqstp->rq_arg.head[0].iov_base = va;
+ hdrlen = (unsigned long)va - (unsigned long)rmsgp;
+ rqstp->rq_arg.head[0].iov_len -= hdrlen;
+
+ return hdrlen;
+}
+
+int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
+ struct rpcrdma_msg *rmsgp,
+ enum rpcrdma_errcode err, u32 *va)
+{
+ u32 *startp = va;
+
+ *va++ = htonl(rmsgp->rm_xid);
+ *va++ = htonl(rmsgp->rm_vers);
+ *va++ = htonl(xprt->sc_max_requests);
+ *va++ = htonl(RDMA_ERROR);
+ *va++ = htonl(err);
+ if (err == ERR_VERS) {
+ *va++ = htonl(RPCRDMA_VERSION);
+ *va++ = htonl(RPCRDMA_VERSION);
+ }
+
+ return (int)((unsigned long)va - (unsigned long)startp);
+}
+
+int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
+{
+ struct rpcrdma_write_array *wr_ary;
+
+ /* There is no read-list in a reply */
+
+ /* skip write list */
+ wr_ary = (struct rpcrdma_write_array *)
+ &rmsgp->rm_body.rm_chunks[1];
+ if (wr_ary->wc_discrim)
+ wr_ary = (struct rpcrdma_write_array *)
+ &wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
+ wc_target.rs_length;
+ else
+ wr_ary = (struct rpcrdma_write_array *)
+ &wr_ary->wc_nchunks;
+
+ /* skip reply array */
+ if (wr_ary->wc_discrim)
+ wr_ary = (struct rpcrdma_write_array *)
+ &wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
+ else
+ wr_ary = (struct rpcrdma_write_array *)
+ &wr_ary->wc_nchunks;
+
+ return (unsigned long) wr_ary - (unsigned long) rmsgp;
+}
+
+void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
+{
+ struct rpcrdma_write_array *ary;
+
+ /* no read-list */
+ rmsgp->rm_body.rm_chunks[0] = xdr_zero;
+
+ /* write-array discrim */
+ ary = (struct rpcrdma_write_array *)
+ &rmsgp->rm_body.rm_chunks[1];
+ ary->wc_discrim = xdr_one;
+ ary->wc_nchunks = htonl(chunks);
+
+ /* write-list terminator */
+ ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
+
+ /* reply-array discriminator */
+ ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
+}
+
+void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
+ int chunks)
+{
+ ary->wc_discrim = xdr_one;
+ ary->wc_nchunks = htonl(chunks);
+}
+
+void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
+ int chunk_no,
+ u32 rs_handle, u64 rs_offset,
+ u32 write_len)
+{
+ struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
+ seg->rs_handle = htonl(rs_handle);
+ seg->rs_length = htonl(write_len);
+ xdr_encode_hyper((u32 *) &seg->rs_offset, rs_offset);
+}
+
+void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
+ struct rpcrdma_msg *rdma_argp,
+ struct rpcrdma_msg *rdma_resp,
+ enum rpcrdma_proc rdma_type)
+{
+ rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
+ rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
+ rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
+ rdma_resp->rm_type = htonl(rdma_type);
+
+ /* Encode <nul> chunks lists */
+ rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
+ rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
+ rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
+}