Patch "NFSD: Update the NFSv3 FSINFO3res 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 FSINFO3res 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-fsinfo3res-encoder-to-use-stru.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 df756f0ea3676bc5297648831e4eafd89c874621
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Thu Oct 22 13:42:13 2020 -0400

    NFSD: Update the NFSv3 FSINFO3res encoder to use struct xdr_stream
    
    [ Upstream commit 0a139d1b7f327010acc36e8162936d3108c7addb ]
    
    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 e4a569e7216d5..514f53ad73020 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -24,6 +24,15 @@ static const struct svc_fh nfs3svc_null_fh = {
 	.fh_no_wcc	= true,
 };
 
+/*
+ * time_delta. {1, 0} means the server is accurate only
+ * to the nearest second.
+ */
+static const struct timespec64 nfs3svc_time_delta = {
+	.tv_sec		= 1,
+	.tv_nsec	= 0,
+};
+
 /*
  * Mapping of S_IF* types to NFS file types
  */
@@ -1445,30 +1454,51 @@ nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p)
 	return 1;
 }
 
+static bool
+svcxdr_encode_fsinfo3resok(struct xdr_stream *xdr,
+			   const struct nfsd3_fsinfores *resp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 12);
+	if (!p)
+		return false;
+	*p++ = cpu_to_be32(resp->f_rtmax);
+	*p++ = cpu_to_be32(resp->f_rtpref);
+	*p++ = cpu_to_be32(resp->f_rtmult);
+	*p++ = cpu_to_be32(resp->f_wtmax);
+	*p++ = cpu_to_be32(resp->f_wtpref);
+	*p++ = cpu_to_be32(resp->f_wtmult);
+	*p++ = cpu_to_be32(resp->f_dtpref);
+	p = xdr_encode_hyper(p, resp->f_maxfilesize);
+	p = encode_nfstime3(p, &nfs3svc_time_delta);
+	*p = cpu_to_be32(resp->f_properties);
+
+	return true;
+}
+
 /* FSINFO */
 int
 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_res_stream;
 	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
 
-	*p++ = resp->status;
-	*p++ = xdr_zero;	/* no post_op_attr */
-
-	if (resp->status == 0) {
-		*p++ = htonl(resp->f_rtmax);
-		*p++ = htonl(resp->f_rtpref);
-		*p++ = htonl(resp->f_rtmult);
-		*p++ = htonl(resp->f_wtmax);
-		*p++ = htonl(resp->f_wtpref);
-		*p++ = htonl(resp->f_wtmult);
-		*p++ = htonl(resp->f_dtpref);
-		p = xdr_encode_hyper(p, resp->f_maxfilesize);
-		*p++ = xdr_one;
-		*p++ = xdr_zero;
-		*p++ = htonl(resp->f_properties);
+	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_fsinfo3resok(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;
 }
 
 /* PATHCONF */