2020-08-17 17:35:11

by Anna Schumaker

[permalink] [raw]
Subject: [PATCH v4 08/10] NFS: Add READ_PLUS hole segment decoding

From: Anna Schumaker <[email protected]>

We keep things simple for now by only decoding a single hole or data
segment returned by the server, even if they returned more to us.

Signed-off-by: Anna Schumaker <[email protected]>
---
fs/nfs/nfs42xdr.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 055a944d043d..90f415944b90 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 */ + \
@@ -769,6 +769,28 @@ static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *re
return 0;
}

+static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *res,
+ uint32_t *eof)
+{
+ uint64_t offset, length, recvd;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 8 + 8);
+ if (unlikely(!p))
+ return -EIO;
+
+ p = xdr_decode_hyper(p, &offset);
+ p = xdr_decode_hyper(p, &length);
+ recvd = xdr_expand_hole(xdr, 0, length);
+ res->count += recvd;
+
+ if (recvd < length) {
+ *eof = 0;
+ return 1;
+ }
+ return 0;
+}
+
static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
{
uint32_t eof, segments, type;
@@ -795,6 +817,8 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
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;

--
2.28.0