Clean out unneeded files

[people/ms/u-boot.git] / fs / yaffs2 / yaffsfs.c

/*
 * 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.
 */
 
/* XXX U-BOOT XXX */
#include <common.h>
#include <malloc.h>

#include "yaffsfs.h"
#include "yaffs_guts.h"
#include "yaffscfg.h"
#include "yportenv.h"

/* XXX U-BOOT XXX */
#if 0
#include <string.h> // for memset
#endif

#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 = YAFFS_FAIL;

        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;
}