CIFS: Add SMB2 support for flush

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

fs/cifs/smb2ops.c

@@ -329,6 +329,13 @@ smb2_close_file(const unsigned int xid, struct cifs_tcon *tcon,
 	return SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
 }
 
+static int
+smb2_flush_file(const unsigned int xid, struct cifs_tcon *tcon,
+		struct cifs_fid *fid)
+{
+	return SMB2_flush(xid, tcon, fid->persistent_fid, fid->volatile_fid);
+}
+
 struct smb_version_operations smb21_operations = {
 	.setup_request = smb2_setup_request,
 	.setup_async_request = smb2_setup_async_request,
@@ -363,6 +370,7 @@ struct smb_version_operations smb21_operations = {
 	.open = smb2_open_file,
 	.set_fid = smb2_set_fid,
 	.close = smb2_close_file,
+	.flush = smb2_flush_file,
 };
 
 struct smb_version_values smb21_values = {

fs/cifs/smb2pdu.c

@@ -1152,3 +1152,41 @@ SMB2_echo(struct TCP_Server_Info *server)
 	cifs_small_buf_release(req);
 	return rc;
 }
+
+int
+SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
+	   u64 volatile_fid)
+{
+	struct smb2_flush_req *req;
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses = tcon->ses;
+	struct kvec iov[1];
+	int resp_buftype;
+	int rc = 0;
+
+	cFYI(1, "Flush");
+
+	if (ses && (ses->server))
+		server = ses->server;
+	else
+		return -EIO;
+
+	rc = small_smb2_init(SMB2_FLUSH, tcon, (void **) &req);
+	if (rc)
+		return rc;
+
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+
+	iov[0].iov_base = (char *)req;
+	/* 4 for rfc1002 length field */
+	iov[0].iov_len = get_rfc1002_length(req) + 4;
+
+	rc = SendReceive2(xid, ses, iov, 1, &resp_buftype, 0);
+
+	if ((rc != 0) && tcon)
+		cifs_stats_fail_inc(tcon, SMB2_FLUSH_HE);
+
+	free_rsp_buf(resp_buftype, iov[0].iov_base);
+	return rc;
+}

fs/cifs/smb2pdu.h

@@ -453,6 +453,21 @@ struct smb2_close_rsp {
 	__le32 Attributes;
 } __packed;
 
+struct smb2_flush_req {
+	struct smb2_hdr hdr;
+	__le16 StructureSize;	/* Must be 24 */
+	__le16 Reserved1;
+	__le32 Reserved2;
+	__u64  PersistentFileId; /* opaque endianness */
+	__u64  VolatileFileId; /* opaque endianness */
+} __packed;
+
+struct smb2_flush_rsp {
+	struct smb2_hdr hdr;
+	__le16 StructureSize;
+	__le16 Reserved;
+} __packed;
+
 struct smb2_echo_req {
 	struct smb2_hdr hdr;
 	__le16 StructureSize;	/* Must be 4 */

fs/cifs/smb2proto.h

@@ -89,6 +89,8 @@ extern int SMB2_open(const unsigned int xid, struct cifs_tcon *tcon,
 		     struct smb2_file_all_info *buf);
 extern int SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
 		      u64 persistent_file_id, u64 volatile_file_id);
+extern int SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon,
+		      u64 persistent_file_id, u64 volatile_file_id);
 extern int SMB2_query_info(const unsigned int xid, struct cifs_tcon *tcon,
 			   u64 persistent_file_id, u64 volatile_file_id,
 			   struct smb2_file_all_info *data);