diff --git a/include/minix/ipc.h b/include/minix/ipc.h
index 609525f05..8555f149a 100644
--- a/include/minix/ipc.h
+++ b/include/minix/ipc.h
@@ -258,6 +258,19 @@ typedef struct {
 } mess_fs_vfs_lookup;
 _ASSERT_MSG_SIZE(mess_fs_vfs_lookup);
 
+typedef struct {
+	ino_t inode;
+
+	mode_t mode;
+	uid_t uid;
+	gid_t gid;
+	cp_grant_id_t grant;
+	size_t path_len;
+
+	uint8_t data[28];
+} mess_vfs_fs_mkdir;
+_ASSERT_MSG_SIZE(mess_vfs_fs_mkdir);
+
 typedef struct {
 	ino_t inode;
 
@@ -490,6 +503,7 @@ typedef struct {
 	mess_vfs_fs_link m_vfs_fs_link;
 	mess_vfs_fs_lookup m_vfs_fs_lookup;
 	mess_fs_vfs_lookup m_fs_vfs_lookup;
+	mess_vfs_fs_mkdir m_vfs_fs_mkdir;
 	mess_vfs_fs_mountpoint m_vfs_fs_mountpoint;
 	mess_vfs_fs_new_driver m_vfs_fs_new_driver;
 	mess_vfs_fs_putnode m_vfs_fs_putnode;
diff --git a/lib/libpuffs/open.c b/lib/libpuffs/open.c
index 5406fe838..2ea5ee56f 100644
--- a/lib/libpuffs/open.c
+++ b/lib/libpuffs/open.c
@@ -216,22 +216,22 @@ int fs_mkdir(void)
   }
 
   /* Copy the last component and set up caller's user and group id */
-  len = fs_m_in.REQ_PATH_LEN;
+  len = fs_m_in.m_vfs_fs_mkdir.path_len;
   pcn.pcn_namelen = len - 1;
   if (pcn.pcn_namelen > NAME_MAX)
 	return(ENAMETOOLONG);
 
-  err_code = sys_safecopyfrom(VFS_PROC_NR, (cp_grant_id_t) fs_m_in.REQ_GRANT,
+  err_code = sys_safecopyfrom(VFS_PROC_NR, fs_m_in.m_vfs_fs_mkdir.grant,
 			      (vir_bytes) 0, (vir_bytes) pcn.pcn_name,
 			      (phys_bytes) len);
   if (err_code != OK) return(err_code);
   NUL(pcn.pcn_name, len, sizeof(pcn.pcn_name));
 
-  caller_uid = (uid_t) fs_m_in.REQ_UID;
-  caller_gid = (gid_t) fs_m_in.REQ_GID;
+  caller_uid = fs_m_in.m_vfs_fs_mkdir.uid;
+  caller_gid = fs_m_in.m_vfs_fs_mkdir.gid;
 
   /* Get last directory pnode */
-  if ((pn_dir = puffs_pn_nodewalk(global_pu, 0, &fs_m_in.REQ_INODE_NR)) == NULL)
+  if ((pn_dir = puffs_pn_nodewalk(global_pu, 0, &fs_m_in.m_vfs_fs_mkdir.inode)) == NULL)
 	return(ENOENT);
   
   cur_time = clock_timespec();
@@ -241,7 +241,7 @@ int fs_mkdir(void)
 
   memset(&va, 0, sizeof(va));
   va.va_type = VDIR;
-  va.va_mode = (mode_t) fs_m_in.REQ_MODE;
+  va.va_mode = fs_m_in.m_vfs_fs_mkdir.mode;
   va.va_uid = caller_uid;
   va.va_gid = caller_gid;
   va.va_atime = va.va_mtime = va.va_ctime = cur_time;
diff --git a/lib/libsffs/link.c b/lib/libsffs/link.c
index d5d63b32f..11d89accd 100644
--- a/lib/libsffs/link.c
+++ b/lib/libsffs/link.c
@@ -140,19 +140,19 @@ int do_mkdir(void)
 	return EROFS;
 
   /* Get the path string and possibly an inode for the given path. */
-  if ((r = get_name(m_in.REQ_GRANT, m_in.REQ_PATH_LEN, name)) != OK)
+  if ((r = get_name(m_in.m_vfs_fs_mkdir.grant, m_in.m_vfs_fs_mkdir.path_len, name)) != OK)
 	return r;
 
   if (!strcmp(name, ".") || !strcmp(name, "..")) return EEXIST;
 
-  if ((parent = find_inode(m_in.REQ_INODE_NR)) == NULL)
+  if ((parent = find_inode(m_in.m_vfs_fs_mkdir.inode)) == NULL)
 	return EINVAL;
 
   if ((r = verify_dentry(parent, name, path, &ino)) != OK)
 	return r;
 
   /* Perform the actual mkdir call. */
-  r = sffs_table->t_mkdir(path, m_in.REQ_MODE);
+  r = sffs_table->t_mkdir(path, m_in.m_vfs_fs_mkdir.mode);
 
   if (r != OK) {
 	if (ino != NULL)
diff --git a/servers/ext2/open.c b/servers/ext2/open.c
index 2435f5355..01f942ca8 100644
--- a/servers/ext2/open.c
+++ b/servers/ext2/open.c
@@ -124,24 +124,24 @@ int fs_mkdir()
   phys_bytes len;
 
   /* Copy the last component and set up caller's user and group id */
-  len = fs_m_in.REQ_PATH_LEN; /* including trailing '\0' */
+  len = fs_m_in.m_vfs_fs_mkdir.path_len; /* including trailing '\0' */
   if (len > NAME_MAX + 1 || len > EXT2_NAME_MAX + 1)
 	return(ENAMETOOLONG);
 
-  err_code = sys_safecopyfrom(VFS_PROC_NR, (cp_grant_id_t) fs_m_in.REQ_GRANT,
+  err_code = sys_safecopyfrom(VFS_PROC_NR, fs_m_in.m_vfs_fs_mkdir.grant,
 			      (vir_bytes) 0, (vir_bytes) lastc, (phys_bytes) len);
   if(err_code != OK) return(err_code);
   NUL(lastc, len, sizeof(lastc));
 
-  caller_uid = (uid_t) fs_m_in.REQ_UID;
-  caller_gid = (gid_t) fs_m_in.REQ_GID;
+  caller_uid = fs_m_in.m_vfs_fs_mkdir.uid;
+  caller_gid = fs_m_in.m_vfs_fs_mkdir.gid;
 
   /* Get last directory inode */
-  if((ldirp = get_inode(fs_dev, (pino_t) fs_m_in.REQ_INODE_NR)) == NULL)
+  if((ldirp = get_inode(fs_dev, fs_m_in.m_vfs_fs_mkdir.inode)) == NULL)
       return(ENOENT);
 
   /* Next make the inode. If that fails, return error code. */
-  rip = new_node(ldirp, lastc, (pino_t) fs_m_in.REQ_MODE, (block_t) 0);
+  rip = new_node(ldirp, lastc, fs_m_in.m_vfs_fs_mkdir.mode, (block_t) 0);
 
   if(rip == NULL || err_code == EEXIST) {
 	  put_inode(rip);		/* can't make dir: it already exists */
@@ -155,7 +155,7 @@ int fs_mkdir()
 
   /* Now make dir entries for . and .. unless the disk is completely full. */
   /* Use dot1 and dot2, so the mode of the directory isn't important. */
-  rip->i_mode = (pmode_t) fs_m_in.REQ_MODE;	/* set mode */
+  rip->i_mode = fs_m_in.m_vfs_fs_mkdir.mode;	/* set mode */
   /* enter . in the new dir*/
   r1 = search_dir(rip, dot1, &dot, ENTER, IGN_PERM, I_DIRECTORY);
   /* enter .. in the new dir */
diff --git a/servers/mfs/open.c b/servers/mfs/open.c
index 3f780cf48..70fc05d30 100644
--- a/servers/mfs/open.c
+++ b/servers/mfs/open.c
@@ -112,21 +112,21 @@ int fs_mkdir()
   phys_bytes len;
 
   /* Copy the last component and set up caller's user and group id */
-  len = min( (unsigned) fs_m_in.REQ_PATH_LEN, sizeof(lastc));
-  err_code = sys_safecopyfrom(VFS_PROC_NR, (cp_grant_id_t) fs_m_in.REQ_GRANT,
+  len = min(fs_m_in.m_vfs_fs_mkdir.path_len, sizeof(lastc));
+  err_code = sys_safecopyfrom(VFS_PROC_NR, fs_m_in.m_vfs_fs_mkdir.grant,
   			   (vir_bytes) 0, (vir_bytes) lastc, (size_t) len);
   if(err_code != OK) return(err_code);
   NUL(lastc, len, sizeof(lastc));
 
-  caller_uid = (uid_t) fs_m_in.REQ_UID;
-  caller_gid = (gid_t) fs_m_in.REQ_GID;
+  caller_uid = fs_m_in.m_vfs_fs_mkdir.uid;
+  caller_gid = fs_m_in.m_vfs_fs_mkdir.gid;
   
   /* Get last directory inode */
-  if((ldirp = get_inode(fs_dev, (pino_t) fs_m_in.REQ_INODE_NR)) == NULL)
+  if((ldirp = get_inode(fs_dev, fs_m_in.m_vfs_fs_mkdir.inode)) == NULL)
       return(ENOENT);
   
   /* Next make the inode. If that fails, return error code. */
-  rip = new_node(ldirp, lastc, (pmode_t) fs_m_in.REQ_MODE, (zone_t) 0);
+  rip = new_node(ldirp, lastc, fs_m_in.m_vfs_fs_mkdir.mode, (zone_t) 0);
   
   if(rip == NULL || err_code == EEXIST) {
 	  put_inode(rip);		/* can't make dir: it already exists */
@@ -140,7 +140,7 @@ int fs_mkdir()
 
   /* Now make dir entries for . and .. unless the disk is completely full. */
   /* Use dot1 and dot2, so the mode of the directory isn't important. */
-  rip->i_mode = (pmode_t) fs_m_in.REQ_MODE;	/* set mode */
+  rip->i_mode = fs_m_in.m_vfs_fs_mkdir.mode;	/* set mode */
   r1 = search_dir(rip, dot1, &dot, ENTER, IGN_PERM);/* enter . in the new dir*/
   r2 = search_dir(rip, dot2, &dotdot, ENTER, IGN_PERM); /* enter .. in the new
 							 dir */
diff --git a/servers/vfs/request.c b/servers/vfs/request.c
index b209e2f52..0a6c97af9 100644
--- a/servers/vfs/request.c
+++ b/servers/vfs/request.c
@@ -542,12 +542,12 @@ int req_mkdir(
 
   /* Fill in request message */
   m.m_type = REQ_MKDIR;
-  m.REQ_INODE_NR = (pino_t) inode_nr;
-  m.REQ_MODE = (pmode_t) dmode;
-  m.REQ_UID = (puid_t) uid;
-  m.REQ_GID = (pgid_t) gid;
-  m.REQ_GRANT = grant_id;
-  m.REQ_PATH_LEN = len;
+  m.m_vfs_fs_mkdir.inode = inode_nr;
+  m.m_vfs_fs_mkdir.mode = dmode;
+  m.m_vfs_fs_mkdir.uid = uid;
+  m.m_vfs_fs_mkdir.gid = gid;
+  m.m_vfs_fs_mkdir.grant = grant_id;
+  m.m_vfs_fs_mkdir.path_len = len;
 
   /* Send/rec request */
   r = fs_sendrec(fs_e, &m);