[PATCH 4.4 19/20] nfsd4: minor NFSv2/v3 write decoding cleanup

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: J. Bruce Fields <bfie...@redhat.com>

commit db44bac41bbfc0c0d9dd943092d8bded3c9db19b upstream.

Use a couple shortcuts that will simplify a following bugfix.

(Minor backporting required to account for a change from f34b95689d2c
"The NFSv2/NFSv3 server does not handle zero length WRITE requests
correctly".)

Signed-off-by: J. Bruce Fields <bfie...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>


---
 fs/nfsd/nfs3xdr.c |    8 ++++----
 fs/nfsd/nfsxdr.c  |    8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -358,6 +358,7 @@ nfs3svc_decode_writeargs(struct svc_rqst
 {
        unsigned int len, v, hdr, dlen;
        u32 max_blocksize = svc_max_payload(rqstp);
+       struct kvec *head = rqstp->rq_arg.head;
 
        p = decode_fh(p, &args->fh);
        if (!p)
@@ -377,9 +378,8 @@ nfs3svc_decode_writeargs(struct svc_rqst
         * Check to make sure that we got the right number of
         * bytes.
         */
-       hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
-       dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
-               - hdr;
+       hdr = (void*)p - head->iov_base;
+       dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
        /*
         * Round the length of the data which was specified up to
         * the next multiple of XDR units and then compare that
@@ -396,7 +396,7 @@ nfs3svc_decode_writeargs(struct svc_rqst
                len = args->len = max_blocksize;
        }
        rqstp->rq_vec[0].iov_base = (void*)p;
-       rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
+       rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
        v = 0;
        while (len > rqstp->rq_vec[v].iov_len) {
                len -= rqstp->rq_vec[v].iov_len;
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -280,6 +280,7 @@ nfssvc_decode_writeargs(struct svc_rqst
                                        struct nfsd_writeargs *args)
 {
        unsigned int len, hdr, dlen;
+       struct kvec *head = rqstp->rq_arg.head;
        int v;
 
        p = decode_fh(p, &args->fh);
@@ -300,9 +301,8 @@ nfssvc_decode_writeargs(struct svc_rqst
         * Check to make sure that we got the right number of
         * bytes.
         */
-       hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
-       dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
-               - hdr;
+       hdr = (void*)p - head->iov_base;
+       dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
 
        /*
         * Round the length of the data which was specified up to
@@ -316,7 +316,7 @@ nfssvc_decode_writeargs(struct svc_rqst
                return 0;
 
        rqstp->rq_vec[0].iov_base = (void*)p;
-       rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
+       rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
        v = 0;
        while (len > rqstp->rq_vec[v].iov_len) {
                len -= rqstp->rq_vec[v].iov_len;