xprtrdma: Replace rpcrdma_count_chunks()
Clean up chunk list decoding by using the xdr_stream set up in rpcrdma_reply_handler. This hardens decoding by checking for buffer overflow at every step while unmarshaling variable-length XDR objects. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever
Anna Schumaker
parent
07ff2dd510
commit
264b0cdbcb
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@ -792,48 +792,6 @@ out_err:
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return PTR_ERR(iptr);
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}
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/*
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* Chase down a received write or reply chunklist to get length
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* RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
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*/
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static int
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rpcrdma_count_chunks(struct rpcrdma_rep *rep, int wrchunk, __be32 **iptrp)
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{
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unsigned int i, total_len;
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struct rpcrdma_write_chunk *cur_wchunk;
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char *base = (char *)rdmab_to_msg(rep->rr_rdmabuf);
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i = be32_to_cpu(**iptrp);
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cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
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total_len = 0;
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while (i--) {
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struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
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ifdebug(FACILITY) {
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u64 off;
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xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
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dprintk("RPC: %s: chunk %d@0x%016llx:0x%08x\n",
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__func__,
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be32_to_cpu(seg->rs_length),
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(unsigned long long)off,
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be32_to_cpu(seg->rs_handle));
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}
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total_len += be32_to_cpu(seg->rs_length);
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++cur_wchunk;
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}
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/* check and adjust for properly terminated write chunk */
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if (wrchunk) {
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__be32 *w = (__be32 *) cur_wchunk;
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if (*w++ != xdr_zero)
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return -1;
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cur_wchunk = (struct rpcrdma_write_chunk *) w;
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}
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if ((char *)cur_wchunk > base + rep->rr_len)
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return -1;
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*iptrp = (__be32 *) cur_wchunk;
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return total_len;
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}
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/**
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* rpcrdma_inline_fixup - Scatter inline received data into rqst's iovecs
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* @rqst: controlling RPC request
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@ -1004,89 +962,164 @@ out_short:
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}
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#endif /* CONFIG_SUNRPC_BACKCHANNEL */
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static int decode_rdma_segment(struct xdr_stream *xdr, u32 *length)
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{
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__be32 *p;
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p = xdr_inline_decode(xdr, 4 * sizeof(*p));
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if (unlikely(!p))
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return -EIO;
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ifdebug(FACILITY) {
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u64 offset;
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u32 handle;
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handle = be32_to_cpup(p++);
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*length = be32_to_cpup(p++);
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xdr_decode_hyper(p, &offset);
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dprintk("RPC: %s: segment %u@0x%016llx:0x%08x\n",
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__func__, *length, (unsigned long long)offset,
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handle);
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} else {
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*length = be32_to_cpup(p + 1);
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}
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return 0;
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}
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static int decode_write_chunk(struct xdr_stream *xdr, u32 *length)
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{
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u32 segcount, seglength;
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__be32 *p;
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p = xdr_inline_decode(xdr, sizeof(*p));
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if (unlikely(!p))
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return -EIO;
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*length = 0;
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segcount = be32_to_cpup(p);
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while (segcount--) {
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if (decode_rdma_segment(xdr, &seglength))
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return -EIO;
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*length += seglength;
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}
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dprintk("RPC: %s: segcount=%u, %u bytes\n",
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__func__, be32_to_cpup(p), *length);
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return 0;
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}
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/* In RPC-over-RDMA Version One replies, a Read list is never
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* expected. This decoder is a stub that returns an error if
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* a Read list is present.
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*/
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static int decode_read_list(struct xdr_stream *xdr)
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{
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__be32 *p;
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p = xdr_inline_decode(xdr, sizeof(*p));
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if (unlikely(!p))
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return -EIO;
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if (unlikely(*p != xdr_zero))
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return -EIO;
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return 0;
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}
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/* Supports only one Write chunk in the Write list
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*/
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static int decode_write_list(struct xdr_stream *xdr, u32 *length)
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{
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u32 chunklen;
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bool first;
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__be32 *p;
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*length = 0;
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first = true;
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do {
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p = xdr_inline_decode(xdr, sizeof(*p));
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if (unlikely(!p))
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return -EIO;
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if (*p == xdr_zero)
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break;
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if (!first)
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return -EIO;
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if (decode_write_chunk(xdr, &chunklen))
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return -EIO;
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*length += chunklen;
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first = false;
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} while (true);
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return 0;
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}
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static int decode_reply_chunk(struct xdr_stream *xdr, u32 *length)
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{
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__be32 *p;
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p = xdr_inline_decode(xdr, sizeof(*p));
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if (unlikely(!p))
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return -EIO;
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*length = 0;
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if (*p != xdr_zero)
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if (decode_write_chunk(xdr, length))
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return -EIO;
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return 0;
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}
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static int
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rpcrdma_decode_msg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep,
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struct rpc_rqst *rqst)
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{
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struct xdr_stream *xdr = &rep->rr_stream;
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int rdmalen, status;
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__be32 *p;
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u32 writelist, replychunk, rpclen;
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char *base;
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p = xdr_inline_decode(xdr, 2 * sizeof(*p));
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if (unlikely(!p))
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/* Decode the chunk lists */
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if (decode_read_list(xdr))
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return -EIO;
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if (decode_write_list(xdr, &writelist))
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return -EIO;
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if (decode_reply_chunk(xdr, &replychunk))
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return -EIO;
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/* never expect read list */
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if (unlikely(*p++ != xdr_zero))
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/* RDMA_MSG sanity checks */
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if (unlikely(replychunk))
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return -EIO;
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/* Write list */
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if (*p != xdr_zero) {
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char *base = rep->rr_hdrbuf.head[0].iov_base;
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p++;
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rdmalen = rpcrdma_count_chunks(rep, 1, &p);
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if (rdmalen < 0 || *p++ != xdr_zero)
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return -EIO;
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rep->rr_len -= (char *)p - base;
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status = rep->rr_len + rdmalen;
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r_xprt->rx_stats.total_rdma_reply += rdmalen;
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/* special case - last segment may omit padding */
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rdmalen &= 3;
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if (rdmalen) {
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rdmalen = 4 - rdmalen;
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status += rdmalen;
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}
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} else {
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p = xdr_inline_decode(xdr, sizeof(*p));
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if (!p)
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return -EIO;
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/* never expect reply chunk */
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if (*p++ != xdr_zero)
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return -EIO;
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rdmalen = 0;
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rep->rr_len -= RPCRDMA_HDRLEN_MIN;
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status = rep->rr_len;
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}
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/* Build the RPC reply's Payload stream in rqst->rq_rcv_buf */
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base = (char *)xdr_inline_decode(xdr, 0);
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rpclen = xdr_stream_remaining(xdr);
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r_xprt->rx_stats.fixup_copy_count +=
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rpcrdma_inline_fixup(rqst, (char *)p, rep->rr_len,
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rdmalen);
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rpcrdma_inline_fixup(rqst, base, rpclen, writelist & 3);
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return status;
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r_xprt->rx_stats.total_rdma_reply += writelist;
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return rpclen + xdr_align_size(writelist);
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}
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static noinline int
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rpcrdma_decode_nomsg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep)
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{
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struct xdr_stream *xdr = &rep->rr_stream;
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int rdmalen;
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__be32 *p;
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u32 writelist, replychunk;
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p = xdr_inline_decode(xdr, 3 * sizeof(*p));
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if (unlikely(!p))
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/* Decode the chunk lists */
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if (decode_read_list(xdr))
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return -EIO;
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if (decode_write_list(xdr, &writelist))
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return -EIO;
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if (decode_reply_chunk(xdr, &replychunk))
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return -EIO;
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/* never expect Read chunks */
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if (unlikely(*p++ != xdr_zero))
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/* RDMA_NOMSG sanity checks */
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if (unlikely(writelist))
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return -EIO;
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/* never expect Write chunks */
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if (unlikely(*p++ != xdr_zero))
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return -EIO;
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/* always expect a Reply chunk */
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if (unlikely(*p++ == xdr_zero))
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if (unlikely(!replychunk))
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return -EIO;
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rdmalen = rpcrdma_count_chunks(rep, 0, &p);
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if (rdmalen < 0)
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return -EIO;
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r_xprt->rx_stats.total_rdma_reply += rdmalen;
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/* Reply chunk buffer already is the reply vector - no fixup. */
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return rdmalen;
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/* Reply chunk buffer already is the reply vector */
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r_xprt->rx_stats.total_rdma_reply += replychunk;
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return replychunk;
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}
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static noinline int
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