1 files changed, 42 insertions, 2 deletions

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 62150ae2dc09..1dd48f269986 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -96,6 +96,42 @@ static bool rpcrdma_results_inline(struct rpc_rqst *rqst)
         return repsize <= RPCRDMA_INLINE_READ_THRESHOLD(rqst);
 }
 
+static int
+rpcrdma_tail_pullup(struct xdr_buf *buf)
+{
+        size_t tlen = buf->tail[0].iov_len;
+        size_t skip = tlen & 3;
+
+        /* Do not include the tail if it is only an XDR pad */
+        if (tlen < 4)
+                return 0;
+
+        /* xdr_write_pages() adds a pad at the beginning of the tail
+         * if the content in "buf->pages" is unaligned. Force the
+         * tail's actual content to land at the next XDR position
+         * after the head instead.
+         */
+        if (skip) {
+                unsigned char *src, *dst;
+                unsigned int count;
+
+                src = buf->tail[0].iov_base;
+                dst = buf->head[0].iov_base;
+                dst += buf->head[0].iov_len;
+
+                src += skip;
+                tlen -= skip;
+
+                dprintk("RPC:       %s: skip=%zu, memmove(%p, %p, %zu)\n",
+                        __func__, skip, dst, src, tlen);
+
+                for (count = tlen; count; count--)
+                        *dst++ = *src++;
+        }
+
+        return tlen;
+}
+
 /*
  * Chunk assembly from upper layer xdr_buf.
  *
@@ -147,6 +183,10 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
         if (len && n == nsegs)
                 return -EIO;
 
+        /* When encoding the read list, the tail is always sent inline */
+        if (type == rpcrdma_readch)
+                return n;
+
         if (xdrbuf->tail[0].iov_len) {
                 /* the rpcrdma protocol allows us to omit any trailing
                  * xdr pad bytes, saving the server an RDMA operation. */
@@ -476,8 +516,8 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
                 headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
                 /* new length after pullup */
                 rpclen = rqst->rq_svec[0].iov_len;
-        }
-
+        } else if (rtype == rpcrdma_readch)
+                rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf);
         if (rtype != rpcrdma_noch) {
                 hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_snd_buf,
                                                headerp, rtype);