Patch "NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-update-the-nfsv3-pathconf3res-encoder-to-use-st.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 859ddcd96dfcb43b26a10e11baf01ad54c4456a1
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Fri Nov 6 13:15:09 2020 -0500

    NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream
    
    [ Upstream commit ded04a587f6ceaaba3caefad4021f2212b46c9ff ]
    
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 514f53ad73020..1467bba02e180 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -1501,25 +1501,47 @@ nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p)
 	return 1;
 }
 
+static bool
+svcxdr_encode_pathconf3resok(struct xdr_stream *xdr,
+			     const struct nfsd3_pathconfres *resp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 6);
+	if (!p)
+		return false;
+	*p++ = cpu_to_be32(resp->p_link_max);
+	*p++ = cpu_to_be32(resp->p_name_max);
+	p = xdr_encode_bool(p, resp->p_no_trunc);
+	p = xdr_encode_bool(p, resp->p_chown_restricted);
+	p = xdr_encode_bool(p, resp->p_case_insensitive);
+	xdr_encode_bool(p, resp->p_case_preserving);
+
+	return true;
+}
+
 /* PATHCONF */
 int
 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_res_stream;
 	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
 
-	*p++ = resp->status;
-	*p++ = xdr_zero;	/* no post_op_attr */
-
-	if (resp->status == 0) {
-		*p++ = htonl(resp->p_link_max);
-		*p++ = htonl(resp->p_name_max);
-		*p++ = htonl(resp->p_no_trunc);
-		*p++ = htonl(resp->p_chown_restricted);
-		*p++ = htonl(resp->p_case_insensitive);
-		*p++ = htonl(resp->p_case_preserving);
+	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
+		return 0;
+	switch (resp->status) {
+	case nfs_ok:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return 0;
+		if (!svcxdr_encode_pathconf3resok(xdr, resp))
+			return 0;
+		break;
+	default:
+		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &nfs3svc_null_fh))
+			return 0;
 	}
 
-	return xdr_ressize_check(rqstp, p);
+	return 1;
 }
 
 /* COMMIT */
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 237b78146c7d6..927f1458bcab9 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -395,7 +395,21 @@ static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
 }
 
 /**
- * xdr_stream_encode_bool - Encode a "not present" list item
+ * xdr_encode_bool - Encode a boolean item
+ * @p: address in a buffer into which to encode
+ * @n: boolean value to encode
+ *
+ * Return value:
+ *   Address of item following the encoded boolean
+ */
+static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
+{
+	*p = n ? xdr_one : xdr_zero;
+	return p++;
+}
+
+/**
+ * xdr_stream_encode_bool - Encode a boolean item
  * @xdr: pointer to xdr_stream
  * @n: boolean value to encode
  *
@@ -410,7 +424,7 @@ static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
 
 	if (unlikely(!p))
 		return -EMSGSIZE;
-	*p = n ? xdr_one : xdr_zero;
+	xdr_encode_bool(p, n);
 	return len;
 }