[Patch v2 16/19] CIFS: SMBD: Read correct returned data length for RDMA write (SMB READ) I/O

Long Li
2017-08-20T19:04:40Z

From: Long Li <longli@microsoft.com>

When RDMA write is used for SMB READ, the returned data length is returned in DataRemaining in the response packet. Reading it properly by adding a parameter to specifiy where the returned data length is.

Signed-off-by: Long Li <longli@microsoft.com>
---
fs/cifs/cifsglob.h | 10 ++++++++--
fs/cifs/cifssmb.c | 4 ++--
fs/cifs/smb1ops.c | 2 +-
fs/cifs/smb2ops.c | 8 ++++++--
4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index dcd2b63..d391767 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -231,8 +231,14 @@ struct smb_version_operations {
__u64 (*get_next_mid)(struct TCP_Server_Info *);
/* data offset from read response message */
unsigned int (*read_data_offset)(char *);
- /* data length from read response message */
- unsigned int (*read_data_length)(char *);
+ /*
+ * Data length from read response message
+ * When in_remaining is true, the returned data length is in
+ * message field DataRemaining for out-of-band data read (e.g through
+ * Memory Registration RDMA write in SMBD).
+ * Otherwise, the returned data length is in message field DataLength.
+ */
+ unsigned int (*read_data_length)(char *, bool in_remaining);
/* map smb to linux error */
int (*map_error)(char *, bool);
/* find mid corresponding to the response message */
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index fbb0d4c..9030fb5 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1523,8 +1523,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
rdata->iov[0].iov_base, server->total_read);

/* how much data is in the response? */
- data_len = server->ops->read_data_length(buf);
- if (data_offset + data_len > buflen) {
+ data_len = server->ops->read_data_length(buf, rdata->mr);
+ if (!rdata->mr && (data_offset + data_len > buflen)) {
/* data_len is corrupt -- discard frame */
rdata->result = -EIO;
return cifs_readv_discard(server, mid);
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index a723df3..27a8280 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -87,7 +87,7 @@ cifs_read_data_offset(char *buf)
}

static unsigned int
-cifs_read_data_length(char *buf)
+cifs_read_data_length(char *buf, bool in_remaining)
{
READ_RSP *rsp = (READ_RSP *)buf;
return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index e67f5f0..4067629 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -747,9 +747,13 @@ smb2_read_data_offset(char *buf)
}

static unsigned int
-smb2_read_data_length(char *buf)
+smb2_read_data_length(char *buf, bool in_remaining)
{
struct smb2_read_rsp *rsp = (struct smb2_read_rsp *)buf;
+
+ if (in_remaining)
+ return le32_to_cpu(rsp->DataRemaining);
+
return le32_to_cpu(rsp->DataLength);
}

@@ -2181,7 +2185,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
}

data_offset = server->ops->read_data_offset(buf) + 4;
- data_len = server->ops->read_data_length(buf);
+ data_len = server->ops->read_data_length(buf, rdata->mr);

if (data_offset < server->vals->read_rsp_size) {
/*
--
2.7.4