YAFFS2 import

Direct import of yaffs as a tarball as of 20071113 from their public
CVS-web at http://www.aleph1.co.uk/cgi-bin/viewcvs.cgi/yaffs2/

The code can also be imported on the command line with:
export CVSROOT=:pserver:anonymous@cvs.aleph1.co.uk:/home/aleph1/cvs cvs logon
(Hit return when asked for a password)
cvs checkout yaffs2

Signed-off-by: William Juul <william.juul@tandberg.com>
Signed-off-by: Stig Olsen <stig.olsen@tandberg.com>

1 files changed, 1505 insertions, 0 deletions

diff --git a/fs/yaffs2/direct/yaffsfs.c b/fs/yaffs2/direct/yaffsfs.c
new file mode 100644
index 0000000..a8519c2
--- /dev/null
+++ b/fs/yaffs2/direct/yaffsfs.c
@@ -0,0 +1,1505 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+ 
+#include "yaffsfs.h"
+#include "yaffs_guts.h"
+#include "yaffscfg.h"
+#include <string.h> // for memset
+#include "yportenv.h"
+
+#define YAFFSFS_MAX_SYMLINK_DEREFERENCES 5
+
+#ifndef NULL
+#define NULL ((void *)0)
+#endif
+
+
+const char *yaffsfs_c_version="$Id: yaffsfs.c,v 1.18 2007/07/18 19:40:38 charles Exp $";
+
+// configurationList is the list of devices that are supported
+static yaffsfs_DeviceConfiguration *yaffsfs_configurationList;
+
+
+/* Some forward references */
+static yaffs_Object *yaffsfs_FindObject(yaffs_Object *relativeDirectory, const char *path, int symDepth);
+static void yaffsfs_RemoveObjectCallback(yaffs_Object *obj);
+
+
+// Handle management.
+// 
+
+
+unsigned int yaffs_wr_attempts;
+
+typedef struct
+{
+	__u8  inUse:1;		// this handle is in use
+	__u8  readOnly:1;	// this handle is read only
+	__u8  append:1;		// append only
+	__u8  exclusive:1;	// exclusive
+	__u32 position;		// current position in file
+	yaffs_Object *obj;	// the object
+}yaffsfs_Handle;
+
+
+static yaffsfs_Handle yaffsfs_handle[YAFFSFS_N_HANDLES];
+
+// yaffsfs_InitHandle
+/// Inilitalise handles on start-up.
+//
+static int yaffsfs_InitHandles(void)
+{
+	int i;
+	for(i = 0; i < YAFFSFS_N_HANDLES; i++)
+	{
+		yaffsfs_handle[i].inUse = 0;
+		yaffsfs_handle[i].obj = NULL;
+	}
+	return 0;
+}
+
+yaffsfs_Handle *yaffsfs_GetHandlePointer(int h)
+{
+	if(h < 0 || h >= YAFFSFS_N_HANDLES)
+	{
+		return NULL;
+	}
+	
+	return &yaffsfs_handle[h];
+}
+
+yaffs_Object *yaffsfs_GetHandleObject(int handle)
+{
+	yaffsfs_Handle *h = yaffsfs_GetHandlePointer(handle);
+
+	if(h && h->inUse)
+	{
+		return h->obj;
+	}
+	
+	return NULL;
+}
+
+
+//yaffsfs_GetHandle
+// Grab a handle (when opening a file)
+//
+
+static int yaffsfs_GetHandle(void)
+{
+	int i;
+	yaffsfs_Handle *h;
+	
+	for(i = 0; i < YAFFSFS_N_HANDLES; i++)
+	{
+		h = yaffsfs_GetHandlePointer(i);
+		if(!h)
+		{
+			// todo bug: should never happen
+		}
+		if(!h->inUse)
+		{
+			memset(h,0,sizeof(yaffsfs_Handle));
+			h->inUse=1;
+			return i;
+		}
+	}
+	return -1;
+}
+
+// yaffs_PutHandle
+// Let go of a handle (when closing a file)
+//
+static int yaffsfs_PutHandle(int handle)
+{
+	yaffsfs_Handle *h = yaffsfs_GetHandlePointer(handle);
+	
+	if(h)
+	{
+		h->inUse = 0;
+		h->obj = NULL;
+	}
+	return 0;
+}
+
+
+
+// Stuff to search for a directory from a path
+
+
+int yaffsfs_Match(char a, char b)
+{
+	// case sensitive
+	return (a == b);
+}
+
+// yaffsfs_FindDevice
+// yaffsfs_FindRoot
+// Scan the configuration list to find the root.
+// Curveballs: Should match paths that end in '/' too
+// Curveball2 Might have "/x/ and "/x/y". Need to return the longest match
+static yaffs_Device *yaffsfs_FindDevice(const char *path, char **restOfPath)
+{
+	yaffsfs_DeviceConfiguration *cfg = yaffsfs_configurationList;
+	const char *leftOver;
+	const char *p;
+	yaffs_Device *retval = NULL;
+	int thisMatchLength;
+	int longestMatch = -1;
+	
+	// Check all configs, choose the one that:
+	// 1) Actually matches a prefix (ie /a amd /abc will not match
+	// 2) Matches the longest.
+	while(cfg && cfg->prefix && cfg->dev)
+	{
+		leftOver = path;
+		p = cfg->prefix;
+		thisMatchLength = 0;
+		
+		while(*p &&  //unmatched part of prefix 
+		      strcmp(p,"/") && // the rest of the prefix is not / (to catch / at end)
+		      *leftOver && 
+		      yaffsfs_Match(*p,*leftOver))
+		{
+			p++;
+			leftOver++;
+			thisMatchLength++;
+		}
+		if((!*p || strcmp(p,"/") == 0) &&      // end of prefix
+		   (!*leftOver || *leftOver == '/') && // no more in this path name part
+		   (thisMatchLength > longestMatch))
+		{
+			// Matched prefix
+			*restOfPath = (char *)leftOver;
+			retval = cfg->dev;
+			longestMatch = thisMatchLength;
+		}
+		cfg++;
+	}
+	return retval;
+}
+
+static yaffs_Object *yaffsfs_FindRoot(const char *path, char **restOfPath)
+{
+
+	yaffs_Device *dev;
+	
+	dev= yaffsfs_FindDevice(path,restOfPath);
+	if(dev && dev->isMounted)
+	{
+		return dev->rootDir;
+	}
+	return NULL;
+}
+
+static yaffs_Object *yaffsfs_FollowLink(yaffs_Object *obj,int symDepth)
+{
+
+	while(obj && obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK)
+	{
+		char *alias = obj->variant.symLinkVariant.alias;
+						
+		if(*alias == '/')
+		{
+			// Starts with a /, need to scan from root up
+			obj = yaffsfs_FindObject(NULL,alias,symDepth++);
+		}
+		else
+		{
+			// Relative to here, so use the parent of the symlink as a start
+			obj = yaffsfs_FindObject(obj->parent,alias,symDepth++);
+		}
+	}
+	return obj;
+}
+
+
+// yaffsfs_FindDirectory
+// Parse a path to determine the directory and the name within the directory.
+//
+// eg. "/data/xx/ff" --> puts name="ff" and returns the directory "/data/xx"
+static yaffs_Object *yaffsfs_DoFindDirectory(yaffs_Object *startDir,const char *path,char **name,int symDepth)
+{
+	yaffs_Object *dir;
+	char *restOfPath;
+	char str[YAFFS_MAX_NAME_LENGTH+1];
+	int i;
+	
+	if(symDepth > YAFFSFS_MAX_SYMLINK_DEREFERENCES)
+	{
+		return NULL;
+	}
+	
+	if(startDir)
+	{
+		dir = startDir;
+		restOfPath = (char *)path;
+	}
+	else
+	{
+		dir = yaffsfs_FindRoot(path,&restOfPath);
+	}
+	
+	while(dir)
+	{	
+		// parse off /.
+		// curve ball: also throw away surplus '/' 
+		// eg. "/ram/x////ff" gets treated the same as "/ram/x/ff"
+		while(*restOfPath == '/')
+		{
+			restOfPath++; // get rid of '/'
+		}
+		
+		*name = restOfPath;
+		i = 0;
+		
+		while(*restOfPath && *restOfPath != '/')
+		{
+			if (i < YAFFS_MAX_NAME_LENGTH)
+			{
+				str[i] = *restOfPath;
+				str[i+1] = '\0';
+				i++;
+			}
+			restOfPath++;
+		}
+		
+		if(!*restOfPath)
+		{
+			// got to the end of the string
+			return dir;
+		}
+		else
+		{
+			if(strcmp(str,".") == 0)
+			{
+				// Do nothing
+			}
+			else if(strcmp(str,"..") == 0)
+			{
+				dir = dir->parent;
+			}
+			else
+			{
+				dir = yaffs_FindObjectByName(dir,str);
+				
+				while(dir && dir->variantType == YAFFS_OBJECT_TYPE_SYMLINK)
+				{
+				
+					dir = yaffsfs_FollowLink(dir,symDepth);
+		
+				}
+				
+				if(dir && dir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
+				{
+					dir = NULL;
+				}
+			}
+		}
+	}
+	// directory did not exist.
+	return NULL;
+}
+
+static yaffs_Object *yaffsfs_FindDirectory(yaffs_Object *relativeDirectory,const char *path,char **name,int symDepth)
+{
+	return yaffsfs_DoFindDirectory(relativeDirectory,path,name,symDepth);
+}
+
+// yaffsfs_FindObject turns a path for an existing object into the object
+// 
+static yaffs_Object *yaffsfs_FindObject(yaffs_Object *relativeDirectory, const char *path,int symDepth)
+{
+	yaffs_Object *dir;
+	char *name;
+	
+	dir = yaffsfs_FindDirectory(relativeDirectory,path,&name,symDepth);
+	
+	if(dir && *name)
+	{
+		return yaffs_FindObjectByName(dir,name);
+	}
+	
+	return dir;
+}
+
+
+
+int yaffs_open(const char *path, int oflag, int mode)
+{
+	yaffs_Object *obj = NULL;
+	yaffs_Object *dir = NULL;
+	char *name;
+	int handle = -1;
+	yaffsfs_Handle *h = NULL;
+	int alreadyOpen = 0;
+	int alreadyExclusive = 0;
+	int openDenied = 0;
+	int symDepth = 0;
+	int errorReported = 0;
+	
+	int i;
+	
+	
+	// todo sanity check oflag (eg. can't have O_TRUNC without WRONLY or RDWR
+	
+	
+	yaffsfs_Lock();
+	
+	handle = yaffsfs_GetHandle();
+	
+	if(handle >= 0)
+	{
+
+		h = yaffsfs_GetHandlePointer(handle);
+	
+	
+		// try to find the exisiting object
+		obj = yaffsfs_FindObject(NULL,path,0);
+		
+		if(obj && obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK)
+		{
+		
+			obj = yaffsfs_FollowLink(obj,symDepth++);
+		}
+
+		if(obj)
+		{
+			// Check if the object is already in use
+			alreadyOpen = alreadyExclusive = 0;
+			
+			for(i = 0; i <= YAFFSFS_N_HANDLES; i++)
+			{
+				
+				if(i != handle &&
+				   yaffsfs_handle[i].inUse &&
+				    obj == yaffsfs_handle[i].obj)
+				 {
+				 	alreadyOpen = 1;
+					if(yaffsfs_handle[i].exclusive)
+					{
+						alreadyExclusive = 1;
+					}
+				 }
+			}
+
+			if(((oflag & O_EXCL) && alreadyOpen) || alreadyExclusive)
+			{
+				openDenied = 1;
+			}
+			
+			// Open should fail if O_CREAT and O_EXCL are specified
+			if((oflag & O_EXCL) && (oflag & O_CREAT))
+			{
+				openDenied = 1;
+				yaffsfs_SetError(-EEXIST);
+				errorReported = 1;
+			}
+			
+			// Check file permissions
+			if( (oflag & (O_RDWR | O_WRONLY)) == 0 &&     // ie O_RDONLY
+			   !(obj->yst_mode & S_IREAD))
+			{
+				openDenied = 1;
+			}
+
+			if( (oflag & O_RDWR) && 
+			   !(obj->yst_mode & S_IREAD))
+			{
+				openDenied = 1;
+			}
+
+			if( (oflag & (O_RDWR | O_WRONLY)) && 
+			   !(obj->yst_mode & S_IWRITE))
+			{
+				openDenied = 1;
+			}
+			
+		}
+		
+		else if((oflag & O_CREAT))
+		{
+			// Let's see if we can create this file
+			dir = yaffsfs_FindDirectory(NULL,path,&name,0);
+			if(dir)
+			{
+				obj = yaffs_MknodFile(dir,name,mode,0,0);	
+			}
+			else
+			{
+				yaffsfs_SetError(-ENOTDIR);
+			}
+		}
+		
+		if(obj && !openDenied)
+		{
+			h->obj = obj;
+			h->inUse = 1;
+	    	h->readOnly = (oflag & (O_WRONLY | O_RDWR)) ? 0 : 1;
+			h->append =  (oflag & O_APPEND) ? 1 : 0;
+			h->exclusive = (oflag & O_EXCL) ? 1 : 0;
+			h->position = 0;
+			
+			obj->inUse++;
+			if((oflag & O_TRUNC) && !h->readOnly)
+			{
+				//todo truncate
+				yaffs_ResizeFile(obj,0);
+			}
+			
+		}
+		else
+		{
+			yaffsfs_PutHandle(handle);
+			if(!errorReported)
+			{
+				yaffsfs_SetError(-EACCESS);
+				errorReported = 1;
+			}
+			handle = -1;
+		}
+		
+	}
+	
+	yaffsfs_Unlock();
+	
+	return handle;		
+}
+
+int yaffs_close(int fd)
+{
+	yaffsfs_Handle *h = NULL;
+	int retVal = 0;
+	
+	yaffsfs_Lock();
+
+	h = yaffsfs_GetHandlePointer(fd);
+	
+	if(h && h->inUse)
+	{
+		// clean up
+		yaffs_FlushFile(h->obj,1);
+		h->obj->inUse--;
+		if(h->obj->inUse <= 0 && h->obj->unlinked)
+		{
+			yaffs_DeleteFile(h->obj);
+		}
+		yaffsfs_PutHandle(fd);
+		retVal = 0;
+	}
+	else
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+		retVal = -1;
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+}
+
+int yaffs_read(int fd, void *buf, unsigned int nbyte)
+{
+	yaffsfs_Handle *h = NULL;
+	yaffs_Object *obj = NULL;
+	int pos = 0;
+	int nRead = -1;
+	int maxRead;
+	
+	yaffsfs_Lock();
+	h = yaffsfs_GetHandlePointer(fd);
+	obj = yaffsfs_GetHandleObject(fd);
+	
+	if(!h || !obj)
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+	}
+	else if( h && obj)
+	{
+		pos=  h->position;
+		if(yaffs_GetObjectFileLength(obj) > pos)
+		{
+			maxRead = yaffs_GetObjectFileLength(obj) - pos;
+		}
+		else
+		{
+			maxRead = 0;
+		}
+
+		if(nbyte > maxRead)
+		{
+			nbyte = maxRead;
+		}
+
+		
+		if(nbyte > 0)
+		{
+			nRead = yaffs_ReadDataFromFile(obj,buf,pos,nbyte);
+			if(nRead >= 0)
+			{
+				h->position = pos + nRead;
+			}
+			else
+			{
+				//todo error
+			}
+		}
+		else
+		{
+			nRead = 0;
+		}
+		
+	}
+	
+	yaffsfs_Unlock();
+	
+	
+	return (nRead >= 0) ? nRead : -1;
+		
+}
+
+int yaffs_write(int fd, const void *buf, unsigned int nbyte)
+{
+	yaffsfs_Handle *h = NULL;
+	yaffs_Object *obj = NULL;
+	int pos = 0;
+	int nWritten = -1;
+	int writeThrough = 0;
+	
+	yaffsfs_Lock();
+	h = yaffsfs_GetHandlePointer(fd);
+	obj = yaffsfs_GetHandleObject(fd);
+	
+	if(!h || !obj)
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+	}
+	else if( h && obj && h->readOnly)
+	{
+		// todo error
+	}
+	else if( h && obj)
+	{
+		if(h->append)
+		{
+			pos =  yaffs_GetObjectFileLength(obj);
+		}
+		else
+		{
+			pos = h->position;
+		}
+		
+		nWritten = yaffs_WriteDataToFile(obj,buf,pos,nbyte,writeThrough);
+		
+		if(nWritten >= 0)
+		{
+			h->position = pos + nWritten;
+		}
+		else
+		{
+			//todo error
+		}
+		
+	}
+	
+	yaffsfs_Unlock();
+	
+	
+	return (nWritten >= 0) ? nWritten : -1;
+
+}
+
+int yaffs_truncate(int fd, off_t newSize)
+{
+	yaffsfs_Handle *h = NULL;
+	yaffs_Object *obj = NULL;
+	int result = 0;
+	
+	yaffsfs_Lock();
+	h = yaffsfs_GetHandlePointer(fd);
+	obj = yaffsfs_GetHandleObject(fd);
+	
+	if(!h || !obj)
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+	}
+	else
+	{
+		// resize the file
+		result = yaffs_ResizeFile(obj,newSize);
+	}	
+	yaffsfs_Unlock();
+	
+	
+	return (result) ? 0 : -1;
+
+}
+
+off_t yaffs_lseek(int fd, off_t offset, int whence) 
+{
+	yaffsfs_Handle *h = NULL;
+	yaffs_Object *obj = NULL;
+	int pos = -1;
+	int fSize = -1;
+	
+	yaffsfs_Lock();
+	h = yaffsfs_GetHandlePointer(fd);
+	obj = yaffsfs_GetHandleObject(fd);
+	
+	if(!h || !obj)
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+	}
+	else if(whence == SEEK_SET)
+	{
+		if(offset >= 0)
+		{
+			pos = offset;
+		}
+	}
+	else if(whence == SEEK_CUR)
+	{
+		if( (h->position + offset) >= 0)
+		{
+			pos = (h->position + offset);
+		}
+	}
+	else if(whence == SEEK_END)
+	{
+		fSize = yaffs_GetObjectFileLength(obj);
+		if(fSize >= 0 && (fSize + offset) >= 0)
+		{
+			pos = fSize + offset;
+		}
+	}
+	
+	if(pos >= 0)
+	{
+		h->position = pos;
+	}
+	else
+	{
+		// todo error
+	}
+
+	
+	yaffsfs_Unlock();
+	
+	return pos;
+}
+
+
+int yaffsfs_DoUnlink(const char *path,int isDirectory) 
+{
+	yaffs_Object *dir = NULL;
+	yaffs_Object *obj = NULL;
+	char *name;
+	int result = YAFFS_FAIL;
+	
+	yaffsfs_Lock();
+
+	obj = yaffsfs_FindObject(NULL,path,0);
+	dir = yaffsfs_FindDirectory(NULL,path,&name,0);
+	if(!dir)
+	{
+		yaffsfs_SetError(-ENOTDIR);
+	}
+	else if(!obj)
+	{
+		yaffsfs_SetError(-ENOENT);
+	}
+	else if(!isDirectory && obj->variantType == YAFFS_OBJECT_TYPE_DIRECTORY)
+	{
+		yaffsfs_SetError(-EISDIR);
+	}
+	else if(isDirectory && obj->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
+	{
+		yaffsfs_SetError(-ENOTDIR);
+	}
+	else
+	{
+		result = yaffs_Unlink(dir,name);
+		
+		if(result == YAFFS_FAIL && isDirectory)
+		{
+			yaffsfs_SetError(-ENOTEMPTY);
+		}
+	}
+	
+	yaffsfs_Unlock();
+	
+	// todo error
+	
+	return (result == YAFFS_FAIL) ? -1 : 0;
+}
+int yaffs_rmdir(const char *path) 
+{
+	return yaffsfs_DoUnlink(path,1);
+}
+
+int yaffs_unlink(const char *path) 
+{
+	return yaffsfs_DoUnlink(path,0);
+}
+
+int yaffs_rename(const char *oldPath, const char *newPath)
+{
+	yaffs_Object *olddir = NULL;
+	yaffs_Object *newdir = NULL;
+	yaffs_Object *obj = NULL;
+	char *oldname;
+	char *newname;
+	int result= YAFFS_FAIL;
+	int renameAllowed = 1;
+	
+	yaffsfs_Lock();
+	
+	olddir = yaffsfs_FindDirectory(NULL,oldPath,&oldname,0);
+	newdir = yaffsfs_FindDirectory(NULL,newPath,&newname,0);
+	obj = yaffsfs_FindObject(NULL,oldPath,0);
+	
+	if(!olddir || !newdir || !obj)
+	{
+		// bad file
+		yaffsfs_SetError(-EBADF);	
+		renameAllowed = 0;	
+	}
+	else if(olddir->myDev != newdir->myDev)
+	{
+		// oops must be on same device
+		// todo error
+		yaffsfs_SetError(-EXDEV);
+		renameAllowed = 0;	
+	}
+	else if(obj && obj->variantType == YAFFS_OBJECT_TYPE_DIRECTORY)
+	{
+		// It is a directory, check that it is not being renamed to 
+		// being its own decendent.
+		// Do this by tracing from the new directory back to the root, checking for obj
+		
+		yaffs_Object *xx = newdir;
+		
+		while( renameAllowed && xx)
+		{
+			if(xx == obj)
+			{
+				renameAllowed = 0;
+			}
+			xx = xx->parent;
+		}
+		if(!renameAllowed) yaffsfs_SetError(-EACCESS);
+	}
+	
+	if(renameAllowed)
+	{
+		result = yaffs_RenameObject(olddir,oldname,newdir,newname);
+	}
+	
+	yaffsfs_Unlock();
+	
+	return (result == YAFFS_FAIL) ? -1 : 0;	
+}
+
+
+static int yaffsfs_DoStat(yaffs_Object *obj,struct yaffs_stat *buf)
+{
+	int retVal = -1;
+
+	if(obj)
+	{
+		obj = yaffs_GetEquivalentObject(obj);
+	}
+
+	if(obj && buf)
+	{
+    	buf->st_dev = (int)obj->myDev->genericDevice;
+    	buf->st_ino = obj->objectId;
+    	buf->st_mode = obj->yst_mode & ~S_IFMT; // clear out file type bits
+	
+		if(obj->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) 
+		{
+			buf->st_mode |= S_IFDIR;
+		}
+		else if(obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK) 
+		{
+			buf->st_mode |= S_IFLNK;
+		}
+		else if(obj->variantType == YAFFS_OBJECT_TYPE_FILE)
+		{
+			buf->st_mode |= S_IFREG;
+		}
+		
+    	buf->st_nlink = yaffs_GetObjectLinkCount(obj);
+    	buf->st_uid = 0;    
+    	buf->st_gid = 0;;     
+    	buf->st_rdev = obj->yst_rdev;
+    	buf->st_size = yaffs_GetObjectFileLength(obj);
+		buf->st_blksize = obj->myDev->nDataBytesPerChunk;
+    	buf->st_blocks = (buf->st_size + buf->st_blksize -1)/buf->st_blksize;
+    	buf->yst_atime = obj->yst_atime; 
+    	buf->yst_ctime = obj->yst_ctime; 
+    	buf->yst_mtime = obj->yst_mtime; 
+		retVal = 0;
+	}
+	return retVal;
+}
+
+static int yaffsfs_DoStatOrLStat(const char *path, struct yaffs_stat *buf,int doLStat)
+{
+	yaffs_Object *obj;
+	
+	int retVal = -1;
+	
+	yaffsfs_Lock();
+	obj = yaffsfs_FindObject(NULL,path,0);
+	
+	if(!doLStat && obj)
+	{
+		obj = yaffsfs_FollowLink(obj,0);
+	}
+	
+	if(obj)
+	{
+		retVal = yaffsfs_DoStat(obj,buf);
+	}
+	else
+	{
+		// todo error not found
+		yaffsfs_SetError(-ENOENT);
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+	
+}
+
+int yaffs_stat(const char *path, struct yaffs_stat *buf)
+{
+	return yaffsfs_DoStatOrLStat(path,buf,0);
+}
+
+int yaffs_lstat(const char *path, struct yaffs_stat *buf)
+{
+	return yaffsfs_DoStatOrLStat(path,buf,1);
+}
+
+int yaffs_fstat(int fd, struct yaffs_stat *buf)
+{
+	yaffs_Object *obj;
+	
+	int retVal = -1;
+	
+	yaffsfs_Lock();
+	obj = yaffsfs_GetHandleObject(fd);
+	
+	if(obj)
+	{
+		retVal = yaffsfs_DoStat(obj,buf);
+	}
+	else
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+}
+
+static int yaffsfs_DoChMod(yaffs_Object *obj,mode_t mode)
+{
+	int result;
+
+	if(obj)
+	{
+		obj = yaffs_GetEquivalentObject(obj);
+	}
+	
+	if(obj)
+	{
+		obj->yst_mode = mode;
+		obj->dirty = 1;
+		result = yaffs_FlushFile(obj,0);
+	}
+	
+	return result == YAFFS_OK ? 0 : -1;
+}
+
+
+int yaffs_chmod(const char *path, mode_t mode)
+{
+	yaffs_Object *obj;
+	
+	int retVal = -1;
+	
+	yaffsfs_Lock();
+	obj = yaffsfs_FindObject(NULL,path,0);
+	
+	if(obj)
+	{
+		retVal = yaffsfs_DoChMod(obj,mode);
+	}
+	else
+	{
+		// todo error not found
+		yaffsfs_SetError(-ENOENT);
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+	
+}
+
+
+int yaffs_fchmod(int fd, mode_t mode)
+{
+	yaffs_Object *obj;
+	
+	int retVal = -1;
+	
+	yaffsfs_Lock();
+	obj = yaffsfs_GetHandleObject(fd);
+	
+	if(obj)
+	{
+		retVal = yaffsfs_DoChMod(obj,mode);
+	}
+	else
+	{
+		// bad handle
+		yaffsfs_SetError(-EBADF);		
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+}
+
+
+int yaffs_mkdir(const char *path, mode_t mode)
+{
+	yaffs_Object *parent = NULL;
+	yaffs_Object *dir = NULL;
+	char *name;
+	int retVal= -1;
+	
+	yaffsfs_Lock();
+	parent = yaffsfs_FindDirectory(NULL,path,&name,0);
+	if(parent)
+		dir = yaffs_MknodDirectory(parent,name,mode,0,0);
+	if(dir)
+	{
+		retVal = 0;
+	}
+	else
+	{
+		yaffsfs_SetError(-ENOSPC); // just assume no space for now
+		retVal = -1;
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+}
+
+int yaffs_mount(const char *path)
+{
+	int retVal=-1;
+	int result=YAFFS_FAIL;
+	yaffs_Device *dev=NULL;
+	char *dummy;
+	
+	T(YAFFS_TRACE_ALWAYS,("yaffs: Mounting %s\n",path));
+	
+	yaffsfs_Lock();
+	dev = yaffsfs_FindDevice(path,&dummy);
+	if(dev)
+	{
+		if(!dev->isMounted)
+		{
+			result = yaffs_GutsInitialise(dev);
+			if(result == YAFFS_FAIL)
+			{
+				// todo error - mount failed
+				yaffsfs_SetError(-ENOMEM);
+			}
+			retVal = result ? 0 : -1;
+			
+		}
+		else
+		{
+			//todo error - already mounted.
+			yaffsfs_SetError(-EBUSY);
+		}
+	}
+	else
+	{
+		// todo error - no device
+		yaffsfs_SetError(-ENODEV);
+	}
+	yaffsfs_Unlock();
+	return retVal;
+	
+}
+
+int yaffs_unmount(const char *path)
+{
+	int retVal=-1;
+	yaffs_Device *dev=NULL;
+	char *dummy;
+	
+	yaffsfs_Lock();
+	dev = yaffsfs_FindDevice(path,&dummy);
+	if(dev)
+	{
+		if(dev->isMounted)
+		{
+			int i;
+			int inUse;
+			
+			yaffs_FlushEntireDeviceCache(dev);
+			yaffs_CheckpointSave(dev);
+			
+			for(i = inUse = 0; i < YAFFSFS_N_HANDLES && !inUse; i++)
+			{
+				if(yaffsfs_handle[i].inUse && yaffsfs_handle[i].obj->myDev == dev)
+				{
+					inUse = 1; // the device is in use, can't unmount
+				}
+			}
+			
+			if(!inUse)
+			{
+				yaffs_Deinitialise(dev);
+					
+				retVal = 0;
+			}
+			else
+			{
+				// todo error can't unmount as files are open
+				yaffsfs_SetError(-EBUSY);
+			}
+			
+		}
+		else
+		{
+			//todo error - not mounted.
+			yaffsfs_SetError(-EINVAL);
+			
+		}
+	}
+	else
+	{
+		// todo error - no device
+		yaffsfs_SetError(-ENODEV);
+	}	
+	yaffsfs_Unlock();
+	return retVal;
+	
+}
+
+loff_t yaffs_freespace(const char *path)
+{
+	loff_t retVal=-1;
+	yaffs_Device *dev=NULL;
+	char *dummy;
+	
+	yaffsfs_Lock();
+	dev = yaffsfs_FindDevice(path,&dummy);
+	if(dev  && dev->isMounted)
+	{
+		retVal = yaffs_GetNumberOfFreeChunks(dev);
+		retVal *= dev->nDataBytesPerChunk;
+		
+	}
+	else
+	{
+		yaffsfs_SetError(-EINVAL);
+	}
+	
+	yaffsfs_Unlock();
+	return retVal;	
+}
+
+
+
+void yaffs_initialise(yaffsfs_DeviceConfiguration *cfgList)
+{
+	
+	yaffsfs_DeviceConfiguration *cfg;
+	
+	yaffsfs_configurationList = cfgList;
+	
+	yaffsfs_InitHandles();
+	
+	cfg = yaffsfs_configurationList;
+	
+	while(cfg && cfg->prefix && cfg->dev)
+	{
+		cfg->dev->isMounted = 0;
+		cfg->dev->removeObjectCallback = yaffsfs_RemoveObjectCallback;
+		cfg++;
+	}
+	
+	
+}
+
+
+//
+// Directory search stuff.
+
+//
+// Directory search context
+//
+// NB this is an opaque structure.
+
+
+typedef struct
+{
+	__u32 magic;
+	yaffs_dirent de;		/* directory entry being used by this dsc */
+	char name[NAME_MAX+1];		/* name of directory being searched */
+	yaffs_Object *dirObj;		/* ptr to directory being searched */
+	yaffs_Object *nextReturn;	/* obj to be returned by next readddir */
+	int offset;
+	struct list_head others;	
+} yaffsfs_DirectorySearchContext;
+
+
+
+static struct list_head search_contexts;
+
+
+static void yaffsfs_SetDirRewound(yaffsfs_DirectorySearchContext *dsc)
+{
+	if(dsc &&
+	   dsc->dirObj &&
+	   dsc->dirObj->variantType == YAFFS_OBJECT_TYPE_DIRECTORY){
+	   
+	   dsc->offset = 0;
+	   
+	   if( list_empty(&dsc->dirObj->variant.directoryVariant.children)){
+	   	dsc->nextReturn = NULL;
+	   } else {
+	      	dsc->nextReturn = list_entry(dsc->dirObj->variant.directoryVariant.children.next,
+						yaffs_Object,siblings);
+	   }
+	} else {
+		/* Hey someone isn't playing nice! */
+	}
+}
+
+static void yaffsfs_DirAdvance(yaffsfs_DirectorySearchContext *dsc)
+{
+	if(dsc &&
+	   dsc->dirObj &&
+	   dsc->dirObj->variantType == YAFFS_OBJECT_TYPE_DIRECTORY){
+	   
+	   if( dsc->nextReturn == NULL ||
+	       list_empty(&dsc->dirObj->variant.directoryVariant.children)){
+	   	dsc->nextReturn = NULL;
+	   } else {
+		   struct list_head *next = dsc->nextReturn->siblings.next;
+   
+		   if( next == &dsc->dirObj->variant.directoryVariant.children)
+	   		dsc->nextReturn = NULL; /* end of list */
+	   	   else 
+		   	dsc->nextReturn = list_entry(next,yaffs_Object,siblings);
+	   }
+	} else {
+		/* Hey someone isn't playing nice! */
+	}
+}
+
+static void yaffsfs_RemoveObjectCallback(yaffs_Object *obj)
+{
+
+	struct list_head *i;
+	yaffsfs_DirectorySearchContext *dsc;
+	
+	/* if search contexts not initilised then skip */
+	if(!search_contexts.next)
+		return;
+		
+	/* Iteratethrough the directory search contexts.
+	 * If any are the one being removed, then advance the dsc to
+	 * the next one to prevent a hanging ptr.
+	 */
+	 list_for_each(i, &search_contexts) {
+		if (i) {
+			dsc = list_entry(i, yaffsfs_DirectorySearchContext,others);
+			if(dsc->nextReturn == obj)
+				yaffsfs_DirAdvance(dsc);
+		}
+	}
+				
+}
+
+yaffs_DIR *yaffs_opendir(const char *dirname)
+{
+	yaffs_DIR *dir = NULL;
+ 	yaffs_Object *obj = NULL;
+	yaffsfs_DirectorySearchContext *dsc = NULL;
+	
+	yaffsfs_Lock();
+	
+	obj = yaffsfs_FindObject(NULL,dirname,0);
+	
+	if(obj && obj->variantType == YAFFS_OBJECT_TYPE_DIRECTORY)
+	{
+		
+		dsc = YMALLOC(sizeof(yaffsfs_DirectorySearchContext));
+		dir = (yaffs_DIR *)dsc;
+		if(dsc)
+		{
+			memset(dsc,0,sizeof(yaffsfs_DirectorySearchContext));
+			dsc->magic = YAFFS_MAGIC;
+			dsc->dirObj = obj;
+			strncpy(dsc->name,dirname,NAME_MAX);
+			INIT_LIST_HEAD(&dsc->others);
+			
+			if(!search_contexts.next)
+				INIT_LIST_HEAD(&search_contexts);
+				
+			list_add(&dsc->others,&search_contexts);	
+			yaffsfs_SetDirRewound(dsc);		}
+	
+	}
+	
+	yaffsfs_Unlock();
+	
+	return dir;
+}
+
+struct yaffs_dirent *yaffs_readdir(yaffs_DIR *dirp)
+{
+	yaffsfs_DirectorySearchContext *dsc = (yaffsfs_DirectorySearchContext *)dirp;
+	struct yaffs_dirent *retVal = NULL;
+		
+	yaffsfs_Lock();
+	
+	if(dsc && dsc->magic == YAFFS_MAGIC){
+		yaffsfs_SetError(0);
+		if(dsc->nextReturn){
+			dsc->de.d_ino = yaffs_GetEquivalentObject(dsc->nextReturn)->objectId;
+			dsc->de.d_dont_use = (unsigned)dsc->nextReturn;
+			dsc->de.d_off = dsc->offset++;
+			yaffs_GetObjectName(dsc->nextReturn,dsc->de.d_name,NAME_MAX);
+			if(strlen(dsc->de.d_name) == 0)
+			{
+				// this should not happen!
+				strcpy(dsc->de.d_name,"zz");
+			}
+			dsc->de.d_reclen = sizeof(struct yaffs_dirent);
+			retVal = &dsc->de;
+			yaffsfs_DirAdvance(dsc);
+		} else
+			retVal = NULL;
+	}
+	else
+	{
+		yaffsfs_SetError(-EBADF);
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+	
+}
+
+
+void yaffs_rewinddir(yaffs_DIR *dirp)
+{
+	yaffsfs_DirectorySearchContext *dsc = (yaffsfs_DirectorySearchContext *)dirp;
+	
+	yaffsfs_Lock();
+	
+	yaffsfs_SetDirRewound(dsc);
+
+	yaffsfs_Unlock();
+}
+
+
+int yaffs_closedir(yaffs_DIR *dirp)
+{
+	yaffsfs_DirectorySearchContext *dsc = (yaffsfs_DirectorySearchContext *)dirp;
+		
+	yaffsfs_Lock();
+	dsc->magic = 0;
+	list_del(&dsc->others); /* unhook from list */
+	YFREE(dsc);
+	yaffsfs_Unlock();
+	return 0;
+}
+
+// end of directory stuff
+
+
+int yaffs_symlink(const char *oldpath, const char *newpath)
+{
+	yaffs_Object *parent = NULL;
+	yaffs_Object *obj;
+	char *name;
+	int retVal= -1;
+	int mode = 0; // ignore for now
+	
+	yaffsfs_Lock();
+	parent = yaffsfs_FindDirectory(NULL,newpath,&name,0);
+	obj = yaffs_MknodSymLink(parent,name,mode,0,0,oldpath);
+	if(obj)
+	{
+		retVal = 0;
+	}
+	else
+	{
+		yaffsfs_SetError(-ENOSPC); // just assume no space for now
+		retVal = -1;
+	}
+	
+	yaffsfs_Unlock();
+	
+	return retVal;
+	
+}
+
+int yaffs_readlink(const char *path, char *buf, int bufsiz)
+{
+	yaffs_Object *obj = NULL;
+	int retVal;
+
+		
+	yaffsfs_Lock();
+	
+	obj = yaffsfs_FindObject(NULL,path,0);
+	
+	if(!obj)
+	{
+		yaffsfs_SetError(-ENOENT);
+		retVal = -1;
+	}
+	else if(obj->variantType != YAFFS_OBJECT_TYPE_SYMLINK)
+	{
+		yaffsfs_SetError(-EINVAL);
+		retVal = -1;
+	}
+	else
+	{
+		char *alias = obj->variant.symLinkVariant.alias;
+		memset(buf,0,bufsiz);
+		strncpy(buf,alias,bufsiz - 1);
+		retVal = 0;
+	}
+	yaffsfs_Unlock();
+	return retVal;
+}
+
+int yaffs_link(const char *oldpath, const char *newpath)
+{
+	// Creates a link called newpath to existing oldpath
+	yaffs_Object *obj = NULL;
+	yaffs_Object *target = NULL;
+	int retVal = 0;
+
+		
+	yaffsfs_Lock();
+	
+	obj = yaffsfs_FindObject(NULL,oldpath,0);
+	target = yaffsfs_FindObject(NULL,newpath,0);
+	
+	if(!obj)
+	{
+		yaffsfs_SetError(-ENOENT);
+		retVal = -1;
+	}
+	else if(target)
+	{
+		yaffsfs_SetError(-EEXIST);
+		retVal = -1;
+	}
+	else	
+	{
+		yaffs_Object *newdir = NULL;
+		yaffs_Object *link = NULL;
+		
+		char *newname;
+		
+		newdir = yaffsfs_FindDirectory(NULL,newpath,&newname,0);
+		
+		if(!newdir)
+		{
+			yaffsfs_SetError(-ENOTDIR);
+			retVal = -1;
+		}
+		else if(newdir->myDev != obj->myDev)
+		{
+			yaffsfs_SetError(-EXDEV);
+			retVal = -1;
+		}
+		if(newdir && strlen(newname) > 0)
+		{
+			link = yaffs_Link(newdir,newname,obj);
+			if(link)
+				retVal = 0;
+			else
+			{
+				yaffsfs_SetError(-ENOSPC);
+				retVal = -1;
+			}
+
+		}
+	}
+	yaffsfs_Unlock();
+	
+	return retVal;
+}
+
+int yaffs_mknod(const char *pathname, mode_t mode, dev_t dev);
+
+int yaffs_DumpDevStruct(const char *path)
+{
+	char *rest;
+	
+	yaffs_Object *obj = yaffsfs_FindRoot(path,&rest);
+	
+	if(obj)
+	{
+		yaffs_Device *dev = obj->myDev;
+		
+		printf("\n"
+			   "nPageWrites.......... %d\n"
+			   "nPageReads........... %d\n"
+			   "nBlockErasures....... %d\n"
+			   "nGCCopies............ %d\n"
+			   "garbageCollections... %d\n"
+			   "passiveGarbageColl'ns %d\n"
+			   "\n",
+				dev->nPageWrites,
+				dev->nPageReads,
+				dev->nBlockErasures,
+				dev->nGCCopies,
+				dev->garbageCollections,
+				dev->passiveGarbageCollections
+		);
+		
+	}
+	return 0;
+}
+