SUNRPC: Replace checksum construction in svcauth_gss_wrap_integ()

Replace finicky logic: Instead of trying to find scratch space in
the response buffer, use the scratch buffer from struct
gss_svc_data.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 8c4a442..4241f47 100644 (file)
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1797,15 +1797,8 @@ static int svcauth_gss_wrap_integ(struct svc_rqst *rqstp)
        *p++ = htonl(gc->gc_seq);
        if (xdr_buf_subsegment(buf, &databody_integ, offset, len))
                goto wrap_failed;
-       if (!buf->tail[0].iov_base) {
-               if (buf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
-                       goto wrap_failed;
-               buf->tail[0].iov_base = buf->head[0].iov_base
-                                               + buf->head[0].iov_len;
-               buf->tail[0].iov_len = 0;
-       }
-       resv = &buf->tail[0];
-       checksum.data = (u8 *)resv->iov_base + resv->iov_len + 4;
+
+       checksum.data = gsd->gsd_scratch;
        maj_stat = gss_get_mic(gsd->rsci->mechctx, &databody_integ, &checksum);
        if (maj_stat != GSS_S_COMPLETE)
                goto bad_mic;