From: Tom Talpey <tmtalpey@gmail.com>
Date: Wed, 11 Mar 2009 18:37:55 +0000 (-0400)
Subject: XPRTRDMA: correct an rpc/rdma inline send marshaling error
X-Git-Tag: firefly_0821_release~14990^2^2~43
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b38ab40ad58c1fc43ea590d6342f6a6763ac8fb6;p=firefly-linux-kernel-4.4.55.git

XPRTRDMA: correct an rpc/rdma inline send marshaling error

Certain client rpc's which contain both lengthy page-contained
metadata and a non-empty xdr_tail buffer require careful handling
to avoid overlapped memory copying. Rearranging of existing rpcrdma
marshaling code avoids it; this fixes an NFSv4 symlink creation error
detected with connectathon basic/test8 to multiple servers.

Signed-off-by: Tom Talpey <tmtalpey@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 14106d26bb95..e5e28d1946a4 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -310,6 +310,19 @@ rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
 		__func__, pad, destp, rqst->rq_slen, curlen);
 
 	copy_len = rqst->rq_snd_buf.page_len;
+
+	if (rqst->rq_snd_buf.tail[0].iov_len) {
+		curlen = rqst->rq_snd_buf.tail[0].iov_len;
+		if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) {
+			memmove(destp + copy_len,
+				rqst->rq_snd_buf.tail[0].iov_base, curlen);
+			r_xprt->rx_stats.pullup_copy_count += curlen;
+		}
+		dprintk("RPC:       %s: tail destp 0x%p len %d\n",
+			__func__, destp + copy_len, curlen);
+		rqst->rq_svec[0].iov_len += curlen;
+	}
+
 	r_xprt->rx_stats.pullup_copy_count += copy_len;
 	npages = PAGE_ALIGN(rqst->rq_snd_buf.page_base+copy_len) >> PAGE_SHIFT;
 	for (i = 0; copy_len && i < npages; i++) {
@@ -332,17 +345,6 @@ rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
 		destp += curlen;
 		copy_len -= curlen;
 	}
-	if (rqst->rq_snd_buf.tail[0].iov_len) {
-		curlen = rqst->rq_snd_buf.tail[0].iov_len;
-		if (destp != rqst->rq_snd_buf.tail[0].iov_base) {
-			memcpy(destp,
-				rqst->rq_snd_buf.tail[0].iov_base, curlen);
-			r_xprt->rx_stats.pullup_copy_count += curlen;
-		}
-		dprintk("RPC:       %s: tail destp 0x%p len %d curlen %d\n",
-			__func__, destp, copy_len, curlen);
-		rqst->rq_svec[0].iov_len += curlen;
-	}
 	/* header now contains entire send message */
 	return pad;
 }
@@ -656,7 +658,7 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
 		if (curlen > rqst->rq_rcv_buf.tail[0].iov_len)
 			curlen = rqst->rq_rcv_buf.tail[0].iov_len;
 		if (rqst->rq_rcv_buf.tail[0].iov_base != srcp)
-			memcpy(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
+			memmove(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
 		dprintk("RPC:       %s: tail srcp 0x%p len %d curlen %d\n",
 			__func__, srcp, copy_len, curlen);
 		rqst->rq_rcv_buf.tail[0].iov_len = curlen;