summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChuck Lever <chuck.lever@oracle.com>2016-05-04 10:52:55 -0400
committerJ. Bruce Fields <bfields@redhat.com>2016-05-13 15:53:05 -0400
commit6625d0913771df5f12b9531c8cb8414e55f1c21d (patch)
treefe2416c9d582062f42d1ac81a58e858a6e994382
parent696190eaf168e83fcbf0c9cf087995cdd15807e5 (diff)
svcrdma: Do not add XDR padding to xdr_buf page vector
An xdr_buf has a head, a vector of pages, and a tail. Each RPC request is presented to the NFS server contained in an xdr_buf. The RDMA transport would like to supply the NFS server with only the NFS WRITE payload bytes in the page vector. In some common cases, that would allow the NFS server to swap those pages right into the target file's page cache. Have the transport's RDMA Read logic put XDR pad bytes in the tail iovec, and not in the pages that hold the data payload. The NFSv3 WRITE XDR decoder is finicky about the lengths involved, so make sure it is looking in the correct places when computing the total length of the incoming NFS WRITE request. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--fs/nfsd/nfs3xdr.c2
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_recvfrom.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 2246454dec76..c5eff5fde11c 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -379,7 +379,7 @@ nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
*/
hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
- - hdr;
+ + rqstp->rq_arg.tail[0].iov_len - hdr;
/*
* Round the length of the data which was specified up to
* the next multiple of XDR units and then compare that
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 3b24a646eb46..234be9de6210 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -488,7 +488,7 @@ static int rdma_read_chunks(struct svcxprt_rdma *xprt,
if (page_offset & 3) {
u32 pad = 4 - (page_offset & 3);
- head->arg.page_len += pad;
+ head->arg.tail[0].iov_len += pad;
head->arg.len += pad;
head->arg.buflen += pad;
page_offset += pad;