NFS: Fix the XDR iovec calculation in nfs3_xdr_setaclargs

Commit ae46141ff0 (NFSv3: Fix posix ACL code)
introduces a bug in the calculation of the XDR header iovec. In the case
where we are inlining the acls, we need to adjust the length of the iovec
req->rq_svec, in addition to adjusting the total buffer length.

Tested-by: Leonardo Chiquitto <leonardo.lists@gmail.com>
Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nfs/nfs3xdr.c

@@ -713,7 +713,8 @@ nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p,
 	if (args->npages != 0)
 		xdr_encode_pages(buf, args->pages, 0, args->len);
 	else
-		req->rq_slen += args->len;
+		req->rq_slen = xdr_adjust_iovec(req->rq_svec,
+				p + XDR_QUADLEN(args->len));
 
 	err = nfsacl_encode(buf, base, args->inode,
 			    (args->mask & NFS_ACL) ?