2009-03-05 21:17:56

by Tom Talpey

[permalink] [raw]
Subject: [PATCH 2/4] 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 <[email protected]>
---

net/sunrpc/xprtrdma/rpc_rdma.c | 26 ++++++++++++++------------
1 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 14106d2..e5e28d1 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;