cifs: Use help macro to get the header preamble size

It's better to use HEADER_PREAMBLE_SIZE because the unfolded expression
too long. No actual functional changes, minor readability improvement.
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsencrypt.c

@@ -32,7 +32,7 @@ int __cifs_calc_signature(struct smb_rqst *rqst,
 	int rc;
 	struct kvec *iov = rqst->rq_iov;
 	int n_vec = rqst->rq_nvec;
-	int is_smb2 = server->vals->header_preamble_size == 0;
+	bool is_smb2 = HEADER_PREAMBLE_SIZE(server) == 0;
 
 	/* iov[0] is actual data and not the rfc1002 length for SMB2+ */
 	if (is_smb2) {

fs/cifs/cifsglob.h

@@ -557,6 +557,7 @@ struct smb_version_values {
 
 #define HEADER_SIZE(server) (server->vals->header_size)
 #define MAX_HEADER_SIZE(server) (server->vals->max_header_size)
+#define HEADER_PREAMBLE_SIZE(server) (server->vals->header_preamble_size)
 
 /**
  * CIFS superblock mount flags (mnt_cifs_flags) to consider when

fs/cifs/connect.c

@@ -871,7 +871,7 @@ smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 	/*
 	 * SMB1 does not use credits.
 	 */
-	if (server->vals->header_preamble_size)
+	if (HEADER_PREAMBLE_SIZE(server))
 		return 0;
 
 	return le16_to_cpu(shdr->CreditRequest);
@@ -1050,7 +1050,7 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 
 	/* make sure this will fit in a large buffer */
 	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
-		server->vals->header_preamble_size) {
+	    HEADER_PREAMBLE_SIZE(server)) {
 		cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 		cifs_reconnect(server, true);
 		return -ECONNABORTED;
@@ -1065,8 +1065,8 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 
 	/* now read the rest */
 	length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
-				       pdu_length - HEADER_SIZE(server) + 1
-				       + server->vals->header_preamble_size);
+				       pdu_length - HEADER_SIZE(server) + 1 +
+				       HEADER_PREAMBLE_SIZE(server));
 
 	if (length < 0)
 		return length;
@@ -1122,7 +1122,7 @@ smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 	/*
 	 * SMB1 does not use credits.
 	 */
-	if (server->vals->header_preamble_size)
+	if (HEADER_PREAMBLE_SIZE(server))
 		return;
 
 	if (shdr->CreditRequest) {
@@ -1180,7 +1180,7 @@ cifs_demultiplex_thread(void *p)
 		if (length < 0)
 			continue;
 
-		if (server->vals->header_preamble_size == 0)
+		if (HEADER_PREAMBLE_SIZE(server) == 0)
 			server->total_read = 0;
 		else
 			server->total_read = length;
@@ -1199,7 +1199,7 @@ cifs_demultiplex_thread(void *p)
 
 		/* make sure we have enough to get to the MID */
 		if (server->pdu_size < HEADER_SIZE(server) - 1 -
-		    server->vals->header_preamble_size) {
+		    HEADER_PREAMBLE_SIZE(server)) {
 			cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
 				 server->pdu_size);
 			cifs_reconnect(server, true);
@@ -1208,9 +1208,9 @@ cifs_demultiplex_thread(void *p)
 
 		/* read down to the MID */
 		length = cifs_read_from_socket(server,
-			     buf + server->vals->header_preamble_size,
-			     HEADER_SIZE(server) - 1
-			     - server->vals->header_preamble_size);
+			     buf + HEADER_PREAMBLE_SIZE(server),
+			     HEADER_SIZE(server) - 1 -
+			     HEADER_PREAMBLE_SIZE(server));
 		if (length < 0)
 			continue;
 		server->total_read += length;

fs/cifs/transport.c

@@ -261,8 +261,8 @@ smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 	int nvec;
 	unsigned long buflen = 0;
 
-	if (server->vals->header_preamble_size == 0 &&
-	    rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
+	if (HEADER_PREAMBLE_SIZE(server) == 0 && rqst->rq_nvec >= 2 &&
+	    rqst->rq_iov[0].iov_len == 4) {
 		iov = &rqst->rq_iov[1];
 		nvec = rqst->rq_nvec - 1;
 	} else {
@@ -346,7 +346,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 	sigprocmask(SIG_BLOCK, &mask, &oldmask);
 
 	/* Generate a rfc1002 marker for SMB2+ */
-	if (server->vals->header_preamble_size == 0) {
+	if (HEADER_PREAMBLE_SIZE(server) == 0) {
 		struct kvec hiov = {
 			.iov_base = &rfc1002_marker,
 			.iov_len  = 4
@@ -1238,7 +1238,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		buf = (char *)midQ[i]->resp_buf;
 		resp_iov[i].iov_base = buf;
 		resp_iov[i].iov_len = midQ[i]->resp_buf_size +
-			server->vals->header_preamble_size;
+			HEADER_PREAMBLE_SIZE(server);
 
 		if (midQ[i]->large_buf)
 			resp_buf_type[i] = CIFS_LARGE_BUFFER;
@@ -1643,7 +1643,7 @@ int
 cifs_discard_remaining_data(struct TCP_Server_Info *server)
 {
 	unsigned int rfclen = server->pdu_size;
-	int remaining = rfclen + server->vals->header_preamble_size -
+	int remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
 		server->total_read;
 
 	while (remaining > 0) {
@@ -1689,8 +1689,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	unsigned int data_offset, data_len;
 	struct cifs_readdata *rdata = mid->callback_data;
 	char *buf = server->smallbuf;
-	unsigned int buflen = server->pdu_size +
-		server->vals->header_preamble_size;
+	unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server);
 	bool use_rdma_mr = false;
 
 	cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
@@ -1724,10 +1723,10 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 
 	/* set up first two iov for signature check and to get credits */
 	rdata->iov[0].iov_base = buf;
-	rdata->iov[0].iov_len = server->vals->header_preamble_size;
-	rdata->iov[1].iov_base = buf + server->vals->header_preamble_size;
+	rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server);
+	rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server);
 	rdata->iov[1].iov_len =
-		server->total_read - server->vals->header_preamble_size;
+		server->total_read - HEADER_PREAMBLE_SIZE(server);
 	cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
 		 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
 	cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
@@ -1752,7 +1751,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	}
 
 	data_offset = server->ops->read_data_offset(buf) +
-		server->vals->header_preamble_size;
+		HEADER_PREAMBLE_SIZE(server);
 	if (data_offset < server->total_read) {
 		/*
 		 * win2k8 sometimes sends an offset of 0 when the read