CIFS: Add writepage support for SMB2

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 23c569386f32..00dc45a7881c 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1501,3 +1501,64 @@ async_writev_out:
 	kfree(iov);
 	return rc;
 }
+
+/*
+ * SMB2_write function gets iov pointer to kvec array with n_vec as a length.
+ * The length field from io_parms must be at least 1 and indicates a number of
+ * elements with data to write that begins with position 1 in iov array. All
+ * data length is specified by count.
+ */
+int
+SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
+	   unsigned int *nbytes, struct kvec *iov, int n_vec)
+{
+	int rc = 0;
+	struct smb2_write_req *req = NULL;
+	struct smb2_write_rsp *rsp = NULL;
+	int resp_buftype;
+	*nbytes = 0;
+
+	if (n_vec < 1)
+		return rc;
+
+	rc = small_smb2_init(SMB2_WRITE, io_parms->tcon, (void **) &req);
+	if (rc)
+		return rc;
+
+	if (io_parms->tcon->ses->server == NULL)
+		return -ECONNABORTED;
+
+	req->hdr.ProcessId = cpu_to_le32(io_parms->pid);
+
+	req->PersistentFileId = io_parms->persistent_fid;
+	req->VolatileFileId = io_parms->volatile_fid;
+	req->WriteChannelInfoOffset = 0;
+	req->WriteChannelInfoLength = 0;
+	req->Channel = 0;
+	req->Length = cpu_to_le32(io_parms->length);
+	req->Offset = cpu_to_le64(io_parms->offset);
+	/* 4 for rfc1002 length field */
+	req->DataOffset = cpu_to_le16(
+				offsetof(struct smb2_write_req, Buffer) - 4);
+	req->RemainingBytes = 0;
+
+	iov[0].iov_base = (char *)req;
+	/* 4 for rfc1002 length field and 1 for Buffer */
+	iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;
+
+	/* length of entire message including data to be written */
+	inc_rfc1001_len(req, io_parms->length - 1 /* Buffer */);
+
+	rc = SendReceive2(xid, io_parms->tcon->ses, iov, n_vec + 1,
+			  &resp_buftype, 0);
+
+	if (rc) {
+		cifs_stats_fail_inc(io_parms->tcon, SMB2_WRITE_HE);
+		cERROR(1, "Send error in write = %d", rc);
+	} else {
+		rsp = (struct smb2_write_rsp *)iov[0].iov_base;
+		*nbytes = le32_to_cpu(rsp->DataLength);
+		free_rsp_buf(resp_buftype, rsp);
+	}
+	return rc;
+}