[6/7] NFS: Decode multiple READ_PLUS segments

Commit Message

Anna Schumaker Jan. 10, 2020, 10:34 p.m. UTC

From: Anna Schumaker <[e-mail]>

We now have everything we need to read holes and shift data to where
it's supposed to be. I switch over to using xdr_align_data() to put data
segments in the proper place.

Signed-off-by: Anna Schumaker <[e-mail]>
---
 fs/nfs/nfs42xdr.c | 43 +++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

Patch

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 3407a3cf2e13..b5c638bcab66 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -53,7 +53,7 @@ 
 #define decode_read_plus_maxsz		(op_decode_hdr_maxsz + \
 					 1 /* rpr_eof */ + \
 					 1 /* rpr_contents count */ + \
-					 NFS42_READ_PLUS_SEGMENT_SIZE)
+					 (2 * NFS42_READ_PLUS_SEGMENT_SIZE))
 #define encode_seek_maxsz		(op_encode_hdr_maxsz + \
 					 encode_stateid_maxsz + \
 					 2 /* offset */ + \
@@ -745,7 +745,7 @@  static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *re
 }
 
 static uint32_t decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *res,
-				      uint32_t *eof)
+				      uint32_t *eof, uint64_t total)
 {
 	__be32 *p;
 	uint32_t count, recvd;
@@ -760,7 +760,7 @@  static uint32_t decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_re
 	if (count == 0)
 		return 0;
 
-	recvd = xdr_read_pages(xdr, count);
+	recvd = xdr_align_data(xdr, total, count);
 	if (count > recvd) {
 		dprintk("NFS: server cheating in read reply: "
 				"count %u > recvd %u\n", count, recvd);
@@ -772,7 +772,7 @@  static uint32_t decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_re
 }
 
 static uint32_t decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *res,
-				      uint32_t *eof)
+				     uint32_t *eof, uint64_t total)
 {
 	__be32 *p;
 	uint64_t offset, length;
@@ -787,7 +787,7 @@  static uint32_t decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_re
 	if (length == 0)
 		return 0;
 
-	recvd = xdr_expand_hole(xdr, 0, length);
+	recvd = xdr_expand_hole(xdr, total, length);
 	if (recvd < length) {
 		*eof = 0;
 		length = recvd;
@@ -799,8 +799,9 @@  static uint32_t decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_re
 static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 {
 	__be32 *p;
-	uint32_t count, eof, segments, type;
-	int status;
+	uint32_t eof, segments, type, total;
+	int32_t count;
+	int status, i;
 
 	status = decode_op_hdr(xdr, OP_READ_PLUS);
 	if (status)
@@ -810,26 +811,28 @@  static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
 	if (unlikely(!p))
 		return -EIO;
 
+	total = 0;
 	eof = be32_to_cpup(p++);
 	segments = be32_to_cpup(p++);
-	if (segments == 0)
-		return 0;
 
-	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)
-		count = decode_read_plus_data(xdr, res, &eof);
-	else
-		count = decode_read_plus_hole(xdr, res, &eof);
+		type = be32_to_cpup(p);
+		if (type == NFS4_CONTENT_DATA)
+			count = decode_read_plus_data(xdr, res, &eof, total);
+		else
+			count = decode_read_plus_hole(xdr, res, &eof, total);
 
-	if (segments > 1)
-		eof = 0;
+		if (count < 0)
+			return count;
+		total += count;
+	}
 
 	res->eof = eof;
-	res->count = count;
+	res->count = total;
 	return 0;
 }