2020-02-14 21:13:31

by Anna Schumaker

[permalink] [raw]
Subject: [PATCH v2 5/6] 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 | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index bf118ecabe2c..3407a3cf2e13 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -47,7 +47,7 @@
#define decode_deallocate_maxsz (op_decode_hdr_maxsz)
#define encode_read_plus_maxsz (op_encode_hdr_maxsz + \
encode_stateid_maxsz + 3)
-#define NFS42_READ_PLUS_SEGMENT_SIZE (1 /* data_content4 */ + \
+#define NFS42_READ_PLUS_SEGMENT_SIZE (2 /* data_content4 */ + \
2 /* data_info4.di_offset */ + \
2 /* data_info4.di_length */)
#define decode_read_plus_maxsz (op_decode_hdr_maxsz + \
@@ -771,6 +771,31 @@ static uint32_t decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_re
return count;
}

+static uint32_t decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *res,
+ uint32_t *eof)
+{
+ __be32 *p;
+ uint64_t offset, length;
+ size_t recvd;
+
+ p = xdr_inline_decode(xdr, 8 + 8);
+ if (unlikely(!p))
+ return -EIO;
+
+ p = xdr_decode_hyper(p, &offset);
+ p = xdr_decode_hyper(p, &length);
+ if (length == 0)
+ return 0;
+
+ recvd = xdr_expand_hole(xdr, 0, length);
+ if (recvd < length) {
+ *eof = 0;
+ length = recvd;
+ }
+
+ return length;
+}
+
static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
{
__be32 *p;
@@ -798,7 +823,10 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
if (type == NFS4_CONTENT_DATA)
count = decode_read_plus_data(xdr, res, &eof);
else
- return -EINVAL;
+ count = decode_read_plus_hole(xdr, res, &eof);
+
+ if (segments > 1)
+ eof = 0;

res->eof = eof;
res->count = count;
--
2.25.0