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From:   schumaker.anna@gmail.com
To:     linux-nfs@vger.kernel.org
Cc:     Anna.Schumaker@Netapp.com
Subject: [PATCH v3 10/10] NFS: Decode a full READ_PLUS reply
Date:   Mon,  3 Aug 2020 13:00:13 -0400
Message-Id: <20200803170013.1348350-11-Anna.Schumaker@Netapp.com>
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From: Anna Schumaker <Anna.Schumaker@Netapp.com>

Decode multiple hole and data segments sent by the server, placing
everything directly where they need to go in the xdr pages.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
 fs/nfs/nfs42xdr.c | 50 +++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 791e90353bc2..c31c6fadee19 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -756,16 +756,15 @@ static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *re
 
 	p = xdr_decode_hyper(p, &offset);
 	count = be32_to_cpup(p);
-	recvd = xdr_read_pages(xdr, count);
+	recvd = xdr_align_data(xdr, res->count, count);
 	if (count > recvd) {
 		dprintk("NFS: server cheating in read reply: "
 				"count %u > recvd %u\n", count, recvd);
-		count = recvd;
 		*eof = 0;
 	}
 
-	res->count += count;
-	return 0;
+	res->count += recvd;
+	return count - recvd;
 }
 
 static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *res,
@@ -780,21 +779,18 @@ static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *re
 
 	p = xdr_decode_hyper(p, &offset);
 	p = xdr_decode_hyper(p, &length);
-
-	recvd = xdr_expand_hole(xdr, 0, length);
-	if (recvd < length) {
+	recvd = xdr_expand_hole(xdr, res->count, length);
+	if (recvd < length)
 		*eof = 0;
-		length = recvd;
-	}
 
-	res->count += length;
-	return 0;
+	res->count += recvd;
+	return length - recvd;
 }
 
 static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 {
 	uint32_t eof, segments, type;
-	int status;
+	int status, i;
 	__be32 *p;
 
 	status = decode_op_hdr(xdr, OP_READ_PLUS);
@@ -810,22 +806,24 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 	if (segments == 0)
 		goto out;
 
-	p = xdr_inline_decode(xdr, 4);
-	if (unlikely(!p))
-		return -EIO;
+	for (i = 0; i < segments; i++) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
 
-	type = be32_to_cpup(p++);
-	if (type == NFS4_CONTENT_DATA)
-		status = decode_read_plus_data(xdr, res, &eof);
-	else if (type == NFS4_CONTENT_HOLE)
-		status = decode_read_plus_hole(xdr, res, &eof);
-	else
-		return -EINVAL;
+		type = be32_to_cpup(p++);
+		if (type == NFS4_CONTENT_DATA)
+			status = decode_read_plus_data(xdr, res, &eof);
+		else if (type == NFS4_CONTENT_HOLE)
+			status = decode_read_plus_hole(xdr, res, &eof);
+		else
+			return -EINVAL;
 
-	if (status)
-		return status;
-	if (segments > 1)
-		eof = 0;
+		if (status < 0)
+			return status;
+		if (status > 0)
+			break;
+	}
 
 out:
 	res->eof = eof;
-- 
2.27.0