gss_krb5: Added and improved code comments
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 75602ec..d64a58b 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1316,15 +1316,21 @@
inpages = snd_buf->pages + first;
snd_buf->pages = rqstp->rq_enc_pages;
snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
- /* Give the tail its own page, in case we need extra space in the
- * head when wrapping: */
+ /*
+ * Give the tail its own page, in case we need extra space in the
+ * head when wrapping:
+ *
+ * call_allocate() allocates twice the slack space required
+ * by the authentication flavor to rq_callsize.
+ * For GSS, slack is GSS_CRED_SLACK.
+ */
if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
snd_buf->tail[0].iov_base = tmp;
}
maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
- /* RPC_SLACK_SPACE should prevent this ever happening: */
+ /* slack space should prevent this ever happening: */
BUG_ON(snd_buf->len > snd_buf->buflen);
status = -EIO;
/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was