[PATCH v2] cifs: use ALIGN() and round_up() macros

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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 <ematsumiya@xxxxxxx>
---
v2: drop performance claims, adjust commit title/message -- patch is the same

 fs/cifs/cifssmb.c   |  7 +++---
 fs/cifs/connect.c   | 11 ++++++--
 fs/cifs/sess.c      | 18 +++++--------
 fs/cifs/smb2inode.c |  4 +--
 fs/cifs/smb2misc.c  |  2 +-
 fs/cifs/smb2pdu.c   | 61 +++++++++++++++++++--------------------------
 6 files changed, 47 insertions(+), 56 deletions(-)

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 7aa91e272027..addf3fc62aef 100644
--- a/fs/cifs/cifssmb.c
+++ b/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;
@@ -2796,7 +2796,7 @@ CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
 		cifs_dbg(FYI, "Invalid return data count on get reparse info ioctl\n");
 		goto qreparse_out;
 	}
-	end_of_smb = 2 + get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
+	end_of_smb = sizeof(__le16) + get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
 	reparse_buf = (struct reparse_symlink_data *)
 				((char *)&pSMBr->hdr.Protocol + data_offset);
 	if ((char *)reparse_buf >= end_of_smb) {
@@ -3350,8 +3350,7 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
 	pSMBr = (struct smb_com_ntransact_rsp *)buf;
 
 	bcc = get_bcc(&pSMBr->hdr);
-	end_of_smb = 2 /* sizeof byte count */ + bcc +
-			(char *)&pSMBr->ByteCount;
+	end_of_smb = sizeof(__le16) + bcc + (char *)&pSMBr->ByteCount;
 
 	data_offset = le32_to_cpu(pSMBr->DataOffset);
 	data_count = le32_to_cpu(pSMBr->DataCount);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 7ae6f2c08153..8a26ba7fc707 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2831,9 +2831,12 @@ 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;
 
@@ -2869,8 +2872,12 @@ 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);
 		/*
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 3af3b05b6c74..951874928d70 100644
--- a/fs/cifs/sess.c
+++ b/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 */
@@ -1318,7 +1313,7 @@ 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++;
 		}
@@ -1358,7 +1353,7 @@ 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;
 		}
@@ -1442,8 +1437,7 @@ 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++;
 		}
@@ -1494,7 +1488,7 @@ 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;
 		}
@@ -1546,7 +1540,7 @@ _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++;
 	}
@@ -1747,7 +1741,7 @@ 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;
 		}
diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index b83f59051b26..4eefbe574b82 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -207,7 +207,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 		rqst[num_rqst].rq_iov = &vars->si_iov[0];
 		rqst[num_rqst].rq_nvec = 1;
 
-		size[0] = 1; /* sizeof __u8 See MS-FSCC section 2.4.11 */
+		size[0] = sizeof(u8); /* See MS-FSCC section 2.4.11 */
 		data[0] = &delete_pending[0];
 
 		rc = SMB2_set_info_init(tcon, server,
@@ -225,7 +225,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 		rqst[num_rqst].rq_iov = &vars->si_iov[0];
 		rqst[num_rqst].rq_nvec = 1;
 
-		size[0] = 8; /* sizeof __le64 */
+		size[0] = sizeof(__le64);
 		data[0] = ptr;
 
 		rc = SMB2_set_info_init(tcon, server,
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index d73e5672aac4..258b01306d85 100644
--- a/fs/cifs/smb2misc.c
+++ b/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;
 
 		/*
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 6352ab32c7e7..5da0b596c8a0 100644
--- a/fs/cifs/smb2pdu.c
+++ b/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;
 	}
@@ -2413,7 +2409,7 @@ 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 */
@@ -2487,7 +2483,7 @@ 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;
 }
@@ -2581,7 +2577,7 @@ 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;
@@ -2687,20 +2683,17 @@ int smb311_posix_mkdir(const unsigned int xid, struct inode *inode,
 		uni_path_len = (2 * UniStrnlen((wchar_t *)utf16_path, PATH_MAX)) + 2;
 		/* MUST set path len (NameLength) to 0 opening root of share */
 		req->NameLength = cpu_to_le16(uni_path_len - 2);
-		if (uni_path_len % 8 != 0) {
-			copy_size = roundup(uni_path_len, 8);
-			copy_path = kzalloc(copy_size, GFP_KERNEL);
-			if (!copy_path) {
-				rc = -ENOMEM;
-				goto err_free_req;
-			}
-			memcpy((char *)copy_path, (const char *)utf16_path,
-			       uni_path_len);
-			uni_path_len = copy_size;
-			/* free before overwriting resource */
-			kfree(utf16_path);
-			utf16_path = copy_path;
+		copy_size = round_up(uni_path_len, 8);
+		copy_path = kzalloc(copy_size, GFP_KERNEL);
+		if (!copy_path) {
+			rc = -ENOMEM;
+			goto err_free_req;
 		}
+		memcpy((char *)copy_path, (const char *)utf16_path, uni_path_len);
+		uni_path_len = copy_size;
+		/* free before overwriting resource */
+		kfree(utf16_path);
+		utf16_path = copy_path;
 	}
 
 	iov[1].iov_len = uni_path_len;
@@ -2826,9 +2819,7 @@ 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;
@@ -4090,7 +4081,7 @@ 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;
-- 
2.35.3




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