cifs: Simplify SMB2_open_init()

We can point to the create contexts in just one place, we don't have
to do this in every add_*_context routine.
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2pdu.c

@@ -830,10 +830,6 @@ add_posix_context(struct kvec *iov, unsigned int *num_iovec, umode_t mode)
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = sizeof(struct create_posix);
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset = cpu_to_le32(
-				sizeof(struct smb2_create_req) +
-				iov[num - 1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_posix));
 	*num_iovec = num + 1;
 	return 0;
@@ -2183,10 +2179,6 @@ add_lease_context(struct TCP_Server_Info *server, struct kvec *iov,
 		return -ENOMEM;
 	iov[num].iov_len = server->vals->create_lease_size;
 	req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_LEASE;
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset = cpu_to_le32(
-				sizeof(struct smb2_create_req) +
-				iov[num - 1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength,
 		     server->vals->create_lease_size);
 	*num_iovec = num + 1;
@@ -2274,10 +2266,6 @@ add_durable_v2_context(struct kvec *iov, unsigned int *num_iovec,
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = sizeof(struct create_durable_v2);
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset =
-			cpu_to_le32(sizeof(struct smb2_create_req) +
-								iov[1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_durable_v2));
 	*num_iovec = num + 1;
 	return 0;
@@ -2297,10 +2285,6 @@ add_durable_reconnect_v2_context(struct kvec *iov, unsigned int *num_iovec,
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = sizeof(struct create_durable_handle_reconnect_v2);
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset =
-			cpu_to_le32(sizeof(struct smb2_create_req) +
-								iov[1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength,
 			sizeof(struct create_durable_handle_reconnect_v2));
 	*num_iovec = num + 1;
@@ -2331,10 +2315,6 @@ add_durable_context(struct kvec *iov, unsigned int *num_iovec,
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = sizeof(struct create_durable);
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset =
-			cpu_to_le32(sizeof(struct smb2_create_req) +
-								iov[1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_durable));
 	*num_iovec = num + 1;
 	return 0;
@@ -2376,10 +2356,6 @@ add_twarp_context(struct kvec *iov, unsigned int *num_iovec, __u64 timewarp)
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = sizeof(struct crt_twarp_ctxt);
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset = cpu_to_le32(
-				sizeof(struct smb2_create_req) +
-				iov[num - 1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength, sizeof(struct crt_twarp_ctxt));
 	*num_iovec = num + 1;
 	return 0;
@@ -2511,10 +2487,6 @@ add_sd_context(struct kvec *iov, unsigned int *num_iovec, umode_t mode, bool set
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = len;
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset = cpu_to_le32(
-				sizeof(struct smb2_create_req) +
-				iov[num - 1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength, len);
 	*num_iovec = num + 1;
 	return 0;
@@ -2553,10 +2525,6 @@ add_query_id_context(struct kvec *iov, unsigned int *num_iovec)
 	if (iov[num].iov_base == NULL)
 		return -ENOMEM;
 	iov[num].iov_len = sizeof(struct crt_query_id_ctxt);
-	if (!req->CreateContextsOffset)
-		req->CreateContextsOffset = cpu_to_le32(
-				sizeof(struct smb2_create_req) +
-				iov[num - 1].iov_len);
 	le32_add_cpu(&req->CreateContextsLength, sizeof(struct crt_query_id_ctxt));
 	*num_iovec = num + 1;
 	return 0;
@@ -2720,6 +2688,9 @@ int smb311_posix_mkdir(const unsigned int xid, struct inode *inode,
 		rc = add_posix_context(iov, &n_iov, mode);
 		if (rc)
 			goto err_free_req;
+		req->CreateContextsOffset = cpu_to_le32(
+			sizeof(struct smb2_create_req) +
+			iov[1].iov_len);
 		pc_buf = iov[n_iov-1].iov_base;
 	}
 
@@ -2943,6 +2914,16 @@ SMB2_open_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
 	}
 	add_query_id_context(iov, &n_iov);
 
+	if (n_iov > 2) {
+		/*
+		 * We have create contexts behind iov[1] (the file
+		 * name), point at them from the main create request
+		 */
+		req->CreateContextsOffset = cpu_to_le32(
+			sizeof(struct smb2_create_req) +
+			iov[1].iov_len);
+	}
+
 	rqst->rq_nvec = n_iov;
 	return 0;
 }