cifs: use ALIGN() and round_up() macros

Improve code readability by using existing macros:

Replace hardcoded alignment computations (e.g. (len + 7) & ~0x7) by
ALIGN()/IS_ALIGNED() macros.

Also replace (DIV_ROUND_UP(len, 8) * 8) with ALIGN(len, 8), which, if
not optimized by the compiler, has the overhead of a multiplication
and a division. Do the same for roundup() by replacing it by round_up()
(division-less version, but requires the multiple to be a power of 2,
which is always the case for us).

And remove some unnecessary checks where !IS_ALIGNED() would fit, but
calling round_up() directly is fine as it's a no-op if the value is
already aligned.

Signed-off-by: Enzo Matsumiya <[email protected]>
Reviewed-by: Ronnie Sahlberg <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: ematsumiya

fs/cifs/cifssmb.c

@@ -2305,7 +2305,7 @@ int CIFSSMBRenameOpenFile(const unsigned int xid, struct cifs_tcon *pTcon,
 					remap);
 	}
 	rename_info->target_name_len = cpu_to_le32(2 * len_of_str);
-	count = 12 /* sizeof(struct set_file_rename) */ + (2 * len_of_str);
+	count = sizeof(struct set_file_rename) + (2 * len_of_str);
 	byte_count += count;
 	pSMB->DataCount = cpu_to_le16(count);
 	pSMB->TotalDataCount = pSMB->DataCount;

fs/cifs/connect.c

@@ -2832,9 +2832,12 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
 	 * sessinit is sent but no second negprot
 	 */
 	struct rfc1002_session_packet *ses_init_buf;
+	unsigned int req_noscope_len;
 	struct smb_hdr *smb_buf;
+
 	ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
 			       GFP_KERNEL);
+
 	if (ses_init_buf) {
 		ses_init_buf->trailer.session_req.called_len = 32;
 
@@ -2870,8 +2873,12 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
 		ses_init_buf->trailer.session_req.scope2 = 0;
 		smb_buf = (struct smb_hdr *)ses_init_buf;
 
-		/* sizeof RFC1002_SESSION_REQUEST with no scope */
-		smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
+		/* sizeof RFC1002_SESSION_REQUEST with no scopes */
+		req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
+
+		/* == cpu_to_be32(0x81000044) */
+		smb_buf->smb_buf_length =
+			cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
 		rc = smb_send(server, smb_buf, 0x44);
 		kfree(ses_init_buf);
 		/*

fs/cifs/sess.c

@@ -601,11 +601,6 @@ static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 	/* BB FIXME add check that strings total less
 	than 335 or will need to send them as arrays */
 
-	/* unicode strings, must be word aligned before the call */
-/*	if ((long) bcc_ptr % 2)	{
-		*bcc_ptr = 0;
-		bcc_ptr++;
-	} */
 	/* copy user */
 	if (ses->user_name == NULL) {
 		/* null user mount */
@@ -1324,7 +1319,7 @@ sess_auth_ntlmv2(struct sess_data *sess_data)
 	}
 
 	if (ses->capabilities & CAP_UNICODE) {
-		if (sess_data->iov[0].iov_len % 2) {
+		if (!IS_ALIGNED(sess_data->iov[0].iov_len, 2)) {
 			*bcc_ptr = 0;
 			bcc_ptr++;
 		}
@@ -1364,7 +1359,7 @@ sess_auth_ntlmv2(struct sess_data *sess_data)
 		/* no string area to decode, do nothing */
 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
 		/* unicode string area must be word-aligned */
-		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
 			++bcc_ptr;
 			--bytes_remaining;
 		}
@@ -1448,8 +1443,7 @@ sess_auth_kerberos(struct sess_data *sess_data)
 
 	if (ses->capabilities & CAP_UNICODE) {
 		/* unicode strings must be word aligned */
-		if ((sess_data->iov[0].iov_len
-			+ sess_data->iov[1].iov_len) % 2) {
+		if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
 			*bcc_ptr = 0;
 			bcc_ptr++;
 		}
@@ -1500,7 +1494,7 @@ sess_auth_kerberos(struct sess_data *sess_data)
 		/* no string area to decode, do nothing */
 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
 		/* unicode string area must be word-aligned */
-		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
 			++bcc_ptr;
 			--bytes_remaining;
 		}
@@ -1552,7 +1546,7 @@ _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
 
 	bcc_ptr = sess_data->iov[2].iov_base;
 	/* unicode strings must be word aligned */
-	if ((sess_data->iov[0].iov_len + sess_data->iov[1].iov_len) % 2) {
+	if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
 		*bcc_ptr = 0;
 		bcc_ptr++;
 	}
@@ -1753,7 +1747,7 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
 		/* no string area to decode, do nothing */
 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
 		/* unicode string area must be word-aligned */
-		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
 			++bcc_ptr;
 			--bytes_remaining;
 		}

fs/cifs/smb2misc.c

@@ -248,7 +248,7 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
 		 * Some windows servers (win2016) will pad also the final
 		 * PDU in a compound to 8 bytes.
 		 */
-		if (((calc_len + 7) & ~7) == len)
+		if (ALIGN(calc_len, 8) == len)
 			return 0;
 
 		/*

fs/cifs/smb2pdu.c

@@ -466,15 +466,14 @@ build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt)
 	/*
 	 * Context Data length must be rounded to multiple of 8 for some servers
 	 */
-	pneg_ctxt->DataLength = cpu_to_le16(DIV_ROUND_UP(
-				sizeof(struct smb2_signing_capabilities) -
-				sizeof(struct smb2_neg_context) +
-				(num_algs * 2 /* sizeof u16 */), 8) * 8);
+	pneg_ctxt->DataLength = cpu_to_le16(ALIGN(sizeof(struct smb2_signing_capabilities) -
+					    sizeof(struct smb2_neg_context) +
+					    (num_algs * sizeof(u16)), 8));
 	pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(num_algs);
 	pneg_ctxt->SigningAlgorithms[0] = cpu_to_le16(SIGNING_ALG_AES_CMAC);
 
-	ctxt_len += 2 /* sizeof le16 */ * num_algs;
-	ctxt_len = DIV_ROUND_UP(ctxt_len, 8) * 8;
+	ctxt_len += sizeof(__le16) * num_algs;
+	ctxt_len = ALIGN(ctxt_len, 8);
 	return ctxt_len;
 	/* TBD add SIGNING_ALG_AES_GMAC and/or SIGNING_ALG_HMAC_SHA256 */
 }
@@ -511,8 +510,7 @@ build_netname_ctxt(struct smb2_netname_neg_context *pneg_ctxt, char *hostname)
 	/* copy up to max of first 100 bytes of server name to NetName field */
 	pneg_ctxt->DataLength = cpu_to_le16(2 * cifs_strtoUTF16(pneg_ctxt->NetName, hostname, 100, cp));
 	/* context size is DataLength + minimal smb2_neg_context */
-	return DIV_ROUND_UP(le16_to_cpu(pneg_ctxt->DataLength) +
-			sizeof(struct smb2_neg_context), 8) * 8;
+	return ALIGN(le16_to_cpu(pneg_ctxt->DataLength) + sizeof(struct smb2_neg_context), 8);
 }
 
 static void
@@ -557,18 +555,18 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	 * round up total_len of fixed part of SMB3 negotiate request to 8
 	 * byte boundary before adding negotiate contexts
 	 */
-	*total_len = roundup(*total_len, 8);
+	*total_len = ALIGN(*total_len, 8);
 
 	pneg_ctxt = (*total_len) + (char *)req;
 	req->NegotiateContextOffset = cpu_to_le32(*total_len);
 
 	build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
-	ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
+	ctxt_len = ALIGN(sizeof(struct smb2_preauth_neg_context), 8);
 	*total_len += ctxt_len;
 	pneg_ctxt += ctxt_len;
 
 	build_encrypt_ctxt((struct smb2_encryption_neg_context *)pneg_ctxt);
-	ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_encryption_neg_context), 8) * 8;
+	ctxt_len = ALIGN(sizeof(struct smb2_encryption_neg_context), 8);
 	*total_len += ctxt_len;
 	pneg_ctxt += ctxt_len;
 
@@ -595,9 +593,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	if (server->compress_algorithm) {
 		build_compression_ctxt((struct smb2_compression_capabilities_context *)
 				pneg_ctxt);
-		ctxt_len = DIV_ROUND_UP(
-			sizeof(struct smb2_compression_capabilities_context),
-				8) * 8;
+		ctxt_len = ALIGN(sizeof(struct smb2_compression_capabilities_context), 8);
 		*total_len += ctxt_len;
 		pneg_ctxt += ctxt_len;
 		neg_context_count++;
@@ -780,7 +776,7 @@ static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
 		if (rc)
 			break;
 		/* offsets must be 8 byte aligned */
-		clen = (clen + 7) & ~0x7;
+		clen = ALIGN(clen, 8);
 		offset += clen + sizeof(struct smb2_neg_context);
 		len_of_ctxts -= clen;
 	}
@@ -2426,7 +2422,7 @@ create_sd_buf(umode_t mode, bool set_owner, unsigned int *len)
 	unsigned int group_offset = 0;
 	struct smb3_acl acl;
 
-	*len = roundup(sizeof(struct crt_sd_ctxt) + (sizeof(struct cifs_ace) * 4), 8);
+	*len = round_up(sizeof(struct crt_sd_ctxt) + (sizeof(struct cifs_ace) * 4), 8);
 
 	if (set_owner) {
 		/* sizeof(struct owner_group_sids) is already multiple of 8 so no need to round */
@@ -2500,7 +2496,7 @@ create_sd_buf(umode_t mode, bool set_owner, unsigned int *len)
 	memcpy(aclptr, &acl, sizeof(struct smb3_acl));
 
 	buf->ccontext.DataLength = cpu_to_le32(ptr - (__u8 *)&buf->sd);
-	*len = roundup(ptr - (__u8 *)buf, 8);
+	*len = round_up((unsigned int)(ptr - (__u8 *)buf), 8);
 
 	return buf;
 }
@@ -2594,7 +2590,7 @@ alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
 	 * final path needs to be 8-byte aligned as specified in
 	 * MS-SMB2 2.2.13 SMB2 CREATE Request.
 	 */
-	*out_size = roundup(*out_len * sizeof(__le16), 8);
+	*out_size = round_up(*out_len * sizeof(__le16), 8);
 	*out_path = kzalloc(*out_size + sizeof(__le16) /* null */, GFP_KERNEL);
 	if (!*out_path)
 		return -ENOMEM;
@@ -2839,9 +2835,7 @@ SMB2_open_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
 		uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
 		/* MUST set path len (NameLength) to 0 opening root of share */
 		req->NameLength = cpu_to_le16(uni_path_len - 2);
-		copy_size = uni_path_len;
-		if (copy_size % 8 != 0)
-			copy_size = roundup(copy_size, 8);
+		copy_size = round_up(uni_path_len, 8);
 		copy_path = kzalloc(copy_size, GFP_KERNEL);
 		if (!copy_path)
 			return -ENOMEM;
@@ -4103,7 +4097,7 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
 	if (request_type & CHAINED_REQUEST) {
 		if (!(request_type & END_OF_CHAIN)) {
 			/* next 8-byte aligned request */
-			*total_len = DIV_ROUND_UP(*total_len, 8) * 8;
+			*total_len = ALIGN(*total_len, 8);
 			shdr->NextCommand = cpu_to_le32(*total_len);
 		} else /* END_OF_CHAIN */
 			shdr->NextCommand = 0;