yaffs-ecoscentric-gpl: packages/fs/yaffs/current/src/yaffs

comparison packages/fs/yaffs/current/src/yaffs_fs.c @ 425:dea4d7d250ad ecos

Move sources into packages/fs/yaffs/current/src/

author	Ross Younger <wry@ecoscentric.com>
date	Fri, 14 May 2010 16:03:09 +0100
parents	yaffs_fs.c@ff48885b11fb
children

comparison

equal deleted inserted replaced

-:d21d6fd33e63
+:dea4d7d250ad
+/*
+* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+*
+* Copyright (C) 2002-2010 Aleph One Ltd.
+*   for Toby Churchill Ltd and Brightstar Engineering
+*
+* Created by Charles Manning <charles@aleph1.co.uk>
+* Acknowledgements:
+* Luc van OostenRyck for numerous patches.
+* Nick Bane for numerous patches.
+* Nick Bane for 2.5/2.6 integration.
+* Andras Toth for mknod rdev issue.
+* Michael Fischer for finding the problem with inode inconsistency.
+* Some code bodily lifted from JFFS
+*
+* 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.
+*/
+/*
+*
+* This is the file system front-end to YAFFS that hooks it up to
+* the VFS.
+*
+* Special notes:
+* >> 2.4: sb->u.generic_sbp points to the yaffs_Device associated with
+*         this superblock
+* >> 2.6: sb->s_fs_info  points to the yaffs_Device associated with this
+*         superblock
+* >> inode->u.generic_ip points to the associated yaffs_Object.
+*/
+#include <linux/version.h>
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 10))
+#define YAFFS_COMPILE_BACKGROUND
+#endif
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,28))
+#define YAFFS_COMPILE_EXPORTFS
+#endif
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19))
+#include <linux/config.h>
+#endif
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/smp_lock.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#ifdef YAFFS_COMPILE_EXPORTFS
+#include <linux/exportfs.h>
+#endif
+#ifdef YAFFS_COMPILE_BACKGROUND
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#endif
+#include <asm/div64.h>
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+#include <linux/statfs.h>
+#define UnlockPage(p) unlock_page(p)
+#define Page_Uptodate(page)	test_bit(PG_uptodate, &(page)->flags)
+/* FIXME: use sb->s_id instead ? */
+#define yaffs_devname(sb, buf)	bdevname(sb->s_bdev, buf)
+#else
+#include <linux/locks.h>
+#define	BDEVNAME_SIZE		0
+#define	yaffs_devname(sb, buf)	kdevname(sb->s_dev)
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 0))
+/* added NCB 26/5/2006 for 2.4.25-vrs2-tcl1 kernel */
+#define __user
+#endif
+#endif
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 26))
+#define YPROC_ROOT  (&proc_root)
+#else
+#define YPROC_ROOT  NULL
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+#define WRITE_SIZE_STR "writesize"
+#define WRITE_SIZE(mtd) ((mtd)->writesize)
+#else
+#define WRITE_SIZE_STR "oobblock"
+#define WRITE_SIZE(mtd) ((mtd)->oobblock)
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 27))
+#define YAFFS_USE_WRITE_BEGIN_END 1
+#else
+#define YAFFS_USE_WRITE_BEGIN_END 0
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 28))
+static uint32_t YCALCBLOCKS(uint64_t partition_size, uint32_t block_size)
+{
+	uint64_t result = partition_size;
+	do_div(result, block_size);
+	return (uint32_t)result;
+}
+#else
+#define YCALCBLOCKS(s, b) ((s)/(b))
+#endif
+#include <linux/uaccess.h>
+#include <linux/mtd/mtd.h>
+#include "yportenv.h"
+#include "yaffs_trace.h"
+#include "yaffs_guts.h"
+#include "yaffs_linux.h"
+#include "yaffs_mtdif.h"
+#include "yaffs_mtdif1.h"
+#include "yaffs_mtdif2.h"
+unsigned int yaffs_traceMask = YAFFS_TRACE_BAD_BLOCKS | YAFFS_TRACE_ALWAYS;
+unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
+unsigned int yaffs_auto_checkpoint = 1;
+unsigned int yaffs_gc_control = 1;
+/* Module Parameters */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+module_param(yaffs_traceMask, uint, 0644);
+module_param(yaffs_wr_attempts, uint, 0644);
+module_param(yaffs_auto_checkpoint, uint, 0644);
+module_param(yaffs_gc_control, uint, 0644);
+#else
+MODULE_PARM(yaffs_traceMask, "i");
+MODULE_PARM(yaffs_wr_attempts, "i");
+MODULE_PARM(yaffs_auto_checkpoint, "i");
+MODULE_PARM(yaffs_gc_control, "i");
+#endif
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 25))
+/* use iget and read_inode */
+#define Y_IGET(sb, inum) iget((sb), (inum))
+static void yaffs_read_inode(struct inode *inode);
+#else
+/* Call local equivalent */
+#define YAFFS_USE_OWN_IGET
+#define Y_IGET(sb, inum) yaffs_iget((sb), (inum))
+static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino);
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 18))
+#define yaffs_InodeToObjectLV(iptr) ((iptr)->i_private)
+#else
+#define yaffs_InodeToObjectLV(iptr) ((iptr)->u.generic_ip)
+#endif
+#define yaffs_InodeToObject(iptr) ((yaffs_Object *)(yaffs_InodeToObjectLV(iptr)))
+#define yaffs_DentryToObject(dptr) yaffs_InodeToObject((dptr)->d_inode)
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+#define yaffs_SuperToDevice(sb)	((yaffs_Device *)sb->s_fs_info)
+#else
+#define yaffs_SuperToDevice(sb)	((yaffs_Device *)sb->u.generic_sbp)
+#endif
+#define update_dir_time(dir) do {\
+			(dir)->i_ctime = (dir)->i_mtime = CURRENT_TIME; \
+		} while(0)
+static void yaffs_put_super(struct super_block *sb);
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+				loff_t *pos);
+static ssize_t yaffs_hold_space(struct file *f);
+static void yaffs_release_space(struct file *f);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_file_flush(struct file *file, fl_owner_t id);
+#else
+static int yaffs_file_flush(struct file *file);
+#endif
+static int yaffs_sync_object(struct file *file, struct dentry *dentry,
+				int datasync);
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
+			struct nameidata *n);
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
+					struct nameidata *n);
+#else
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode);
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry);
+#endif
+static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
+			struct dentry *dentry);
+static int yaffs_unlink(struct inode *dir, struct dentry *dentry);
+static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
+			const char *symname);
+static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+			dev_t dev);
+#else
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+			int dev);
+#endif
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry);
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_sync_fs(struct super_block *sb, int wait);
+static void yaffs_write_super(struct super_block *sb);
+#else
+static int yaffs_sync_fs(struct super_block *sb);
+static int yaffs_write_super(struct super_block *sb);
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf);
+#elif (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_statfs(struct super_block *sb, struct kstatfs *buf);
+#else
+static int yaffs_statfs(struct super_block *sb, struct statfs *buf);
+#endif
+#ifdef YAFFS_HAS_PUT_INODE
+static void yaffs_put_inode(struct inode *inode);
+#endif
+static void yaffs_delete_inode(struct inode *);
+static void yaffs_clear_inode(struct inode *);
+static int yaffs_readpage(struct file *file, struct page *page);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_writepage(struct page *page, struct writeback_control *wbc);
+#else
+static int yaffs_writepage(struct page *page);
+#endif
+#if (YAFFS_USE_WRITE_BEGIN_END != 0)
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata);
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *pg, void *fsdadata);
+#else
+static int yaffs_prepare_write(struct file *f, struct page *pg,
+				unsigned offset, unsigned to);
+static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
+				unsigned to);
+#endif
+static int yaffs_readlink(struct dentry *dentry, char __user *buffer,
+				int buflen);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 13))
+static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd);
+#else
+static int yaffs_follow_link(struct dentry *dentry, struct nameidata *nd);
+#endif
+static loff_t yaffs_dir_llseek(struct file *file, loff_t offset, int origin);
+static struct address_space_operations yaffs_file_address_operations = {
+	.readpage = yaffs_readpage,
+	.writepage = yaffs_writepage,
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+	.write_begin = yaffs_write_begin,
+	.write_end = yaffs_write_end,
+#else
+	.prepare_write = yaffs_prepare_write,
+	.commit_write = yaffs_commit_write,
+#endif
+};
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 22))
+static const struct file_operations yaffs_file_operations = {
+	.read = do_sync_read,
+	.write = do_sync_write,
+	.aio_read = generic_file_aio_read,
+	.aio_write = generic_file_aio_write,
+	.mmap = generic_file_mmap,
+	.flush = yaffs_file_flush,
+	.fsync = yaffs_sync_object,
+	.splice_read = generic_file_splice_read,
+	.splice_write = generic_file_splice_write,
+	.llseek = generic_file_llseek,
+};
+#elif (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 18))
+static const struct file_operations yaffs_file_operations = {
+	.read = do_sync_read,
+	.write = do_sync_write,
+	.aio_read = generic_file_aio_read,
+	.aio_write = generic_file_aio_write,
+	.mmap = generic_file_mmap,
+	.flush = yaffs_file_flush,
+	.fsync = yaffs_sync_object,
+	.sendfile = generic_file_sendfile,
+};
+#else
+static const struct file_operations yaffs_file_operations = {
+	.read = generic_file_read,
+	.write = generic_file_write,
+	.mmap = generic_file_mmap,
+	.flush = yaffs_file_flush,
+	.fsync = yaffs_sync_object,
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+	.sendfile = generic_file_sendfile,
+#endif
+};
+#endif
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25))
+static void zero_user_segment(struct page *page, unsigned start, unsigned end)
+{
+	void * kaddr = kmap_atomic(page, KM_USER0);
+	memset(kaddr + start, 0, end - start);
+	kunmap_atomic(kaddr, KM_USER0);
+	flush_dcache_page(page);
+}
+#endif
+static const struct inode_operations yaffs_file_inode_operations = {
+	.setattr = yaffs_setattr,
+};
+static const struct inode_operations yaffs_symlink_inode_operations = {
+	.readlink = yaffs_readlink,
+	.follow_link = yaffs_follow_link,
+	.setattr = yaffs_setattr,
+};
+static const struct inode_operations yaffs_dir_inode_operations = {
+	.create = yaffs_create,
+	.lookup = yaffs_lookup,
+	.link = yaffs_link,
+	.unlink = yaffs_unlink,
+	.symlink = yaffs_symlink,
+	.mkdir = yaffs_mkdir,
+	.rmdir = yaffs_unlink,
+	.mknod = yaffs_mknod,
+	.rename = yaffs_rename,
+	.setattr = yaffs_setattr,
+};
+static const struct file_operations yaffs_dir_operations = {
+	.read = generic_read_dir,
+	.readdir = yaffs_readdir,
+	.fsync = yaffs_sync_object,
+	.llseek = yaffs_dir_llseek,
+};
+static const struct super_operations yaffs_super_ops = {
+	.statfs = yaffs_statfs,
+#ifndef YAFFS_USE_OWN_IGET
+	.read_inode = yaffs_read_inode,
+#endif
+#ifdef YAFFS_HAS_PUT_INODE
+	.put_inode = yaffs_put_inode,
+#endif
+	.put_super = yaffs_put_super,
+	.delete_inode = yaffs_delete_inode,
+	.clear_inode = yaffs_clear_inode,
+	.sync_fs = yaffs_sync_fs,
+	.write_super = yaffs_write_super,
+};
+static unsigned yaffs_gc_control_callback(yaffs_Device *dev)
+{
+	return yaffs_gc_control;
+}
+static void yaffs_GrossLock(yaffs_Device *dev)
+{
+	T(YAFFS_TRACE_LOCK, (TSTR("yaffs locking %p\n"), current));
+	down(&(yaffs_DeviceToContext(dev)->grossLock));
+	T(YAFFS_TRACE_LOCK, (TSTR("yaffs locked %p\n"), current));
+}
+static void yaffs_GrossUnlock(yaffs_Device *dev)
+{
+	T(YAFFS_TRACE_LOCK, (TSTR("yaffs unlocking %p\n"), current));
+	up(&(yaffs_DeviceToContext(dev)->grossLock));
+}
+#ifdef YAFFS_COMPILE_EXPORTFS
+static struct inode *
+yaffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, uint32_t generation)
+{
+	return Y_IGET(sb, ino);
+}
+static struct dentry *
+yaffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type, yaffs2_nfs_get_inode) ;
+}
+static struct dentry *
+yaffs2_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type, yaffs2_nfs_get_inode);
+}
+struct dentry *yaffs2_get_parent(struct dentry *dentry)
+{
+	struct super_block *sb = dentry->d_inode->i_sb;
+	struct dentry *parent = ERR_PTR(-ENOENT);
+	struct inode *inode;
+	unsigned long parent_ino;
+	yaffs_Object *d_obj;
+	yaffs_Object *parent_obj;
+	d_obj = yaffs_InodeToObject(dentry->d_inode);
+	if (d_obj) {
+		parent_obj = d_obj->parent;
+		if (parent_obj) {
+			parent_ino = yaffs_GetObjectInode(parent_obj);
+			inode = Y_IGET(sb, parent_ino);
+			if (IS_ERR(inode)) {
+				parent = ERR_CAST(inode);
+			} else {
+				parent = d_obtain_alias(inode);
+				if (!IS_ERR(parent)) {
+					parent = ERR_PTR(-ENOMEM);
+					iput(inode);
+				}
+			}
+		}
+	}
+	return parent;
+}
+/* Just declare a zero structure as a NULL value implies
+* using the default functions of exportfs.
+*/
+static struct export_operations yaffs_export_ops =
+{
+	.fh_to_dentry = yaffs2_fh_to_dentry,
+	.fh_to_parent = yaffs2_fh_to_parent,
+	.get_parent = yaffs2_get_parent,
+} ;
+#endif
+/*-----------------------------------------------------------------*/
+/* Directory search context allows us to unlock access to yaffs during
+* filldir without causing problems with the directory being modified.
+* This is similar to the tried and tested mechanism used in yaffs direct.
+*
+* A search context iterates along a doubly linked list of siblings in the
+* directory. If the iterating object is deleted then this would corrupt
+* the list iteration, likely causing a crash. The search context avoids
+* this by using the removeObjectCallback to move the search context to the
+* next object before the object is deleted.
+*
+* Many readdirs (and thus seach conexts) may be alive simulateously so
+* each yaffs_Device has a list of these.
+*
+* A seach context lives for the duration of a readdir.
+*
+* All these functions must be called while yaffs is locked.
+*/
+struct yaffs_SearchContext {
+	yaffs_Device *dev;
+	yaffs_Object *dirObj;
+	yaffs_Object *nextReturn;
+	struct ylist_head others;
+};
+/*
+* yaffs_NewSearch() creates a new search context, initialises it and
+* adds it to the device's search context list.
+*
+* Called at start of readdir.
+*/
+static struct yaffs_SearchContext * yaffs_NewSearch(yaffs_Object *dir)
+{
+	yaffs_Device *dev = dir->myDev;
+	struct yaffs_SearchContext *sc = YMALLOC(sizeof(struct yaffs_SearchContext));
+	if(sc){
+		sc->dirObj = dir;
+		sc->dev = dev;
+		if( ylist_empty(&sc->dirObj->variant.directoryVariant.children))
+			sc->nextReturn = NULL;
+		else
+			sc->nextReturn = ylist_entry(
+dir->variant.directoryVariant.children.next,
+				yaffs_Object,siblings);
+		YINIT_LIST_HEAD(&sc->others);
+		ylist_add(&sc->others,&(yaffs_DeviceToContext(dev)->searchContexts));
+	}
+	return sc;
+}
+/*
+* yaffs_EndSearch() disposes of a search context and cleans up.
+*/
+static void yaffs_EndSearch(struct yaffs_SearchContext * sc)
+{
+	if(sc){
+		ylist_del(&sc->others);
+		YFREE(sc);
+	}
+}
+/*
+* yaffs_SearchAdvance() moves a search context to the next object.
+* Called when the search iterates or when an object removal causes
+* the search context to be moved to the next object.
+*/
+static void yaffs_SearchAdvance(struct yaffs_SearchContext *sc)
+{
+if(!sc)
+return;
+if( sc->nextReturn == NULL ||
+ylist_empty(&sc->dirObj->variant.directoryVariant.children))
+sc->nextReturn = NULL;
+else {
+struct ylist_head *next = sc->nextReturn->siblings.next;
+if( next == &sc->dirObj->variant.directoryVariant.children)
+sc->nextReturn = NULL; /* end of list */
+else
+sc->nextReturn = ylist_entry(next,yaffs_Object,siblings);
+}
+}
+/*
+* yaffs_RemoveObjectCallback() is called when an object is unlinked.
+* We check open search contexts and advance any which are currently
+* on the object being iterated.
+*/
+static void yaffs_RemoveObjectCallback(yaffs_Object *obj)
+{
+struct ylist_head *i;
+struct yaffs_SearchContext *sc;
+struct ylist_head *search_contexts = &(yaffs_DeviceToContext(obj->myDev)->searchContexts);
+/* Iterate through the directory search contexts.
+* If any are currently on the object being removed, then advance
+* the search context to the next object to prevent a hanging pointer.
+*/
+ylist_for_each(i, search_contexts) {
+if (i) {
+sc = ylist_entry(i, struct yaffs_SearchContext,others);
+if(sc->nextReturn == obj)
+yaffs_SearchAdvance(sc);
+}
+	}
+}
+/*-----------------------------------------------------------------*/
+static int yaffs_readlink(struct dentry *dentry, char __user *buffer,
+			int buflen)
+{
+	unsigned char *alias;
+	int ret;
+	yaffs_Device *dev = yaffs_DentryToObject(dentry)->myDev;
+	yaffs_GrossLock(dev);
+	alias = yaffs_GetSymlinkAlias(yaffs_DentryToObject(dentry));
+	yaffs_GrossUnlock(dev);
+	if (!alias)
+		return -ENOMEM;
+	ret = vfs_readlink(dentry, buffer, buflen, alias);
+	kfree(alias);
+	return ret;
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 13))
+static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
+#else
+static int yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
+#endif
+{
+	unsigned char *alias;
+	int ret;
+	yaffs_Device *dev = yaffs_DentryToObject(dentry)->myDev;
+	yaffs_GrossLock(dev);
+	alias = yaffs_GetSymlinkAlias(yaffs_DentryToObject(dentry));
+	yaffs_GrossUnlock(dev);
+	if (!alias) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = vfs_follow_link(nd, alias);
+	kfree(alias);
+out:
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 13))
+	return ERR_PTR(ret);
+#else
+	return ret;
+#endif
+}
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
+				yaffs_Object *obj);
+/*
+* Lookup is used to find objects in the fs
+*/
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
+				struct nameidata *n)
+#else
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry)
+#endif
+{
+	yaffs_Object *obj;
+	struct inode *inode = NULL;	/* NCB 2.5/2.6 needs NULL here */
+	yaffs_Device *dev = yaffs_InodeToObject(dir)->myDev;
+	if(current != yaffs_DeviceToContext(dev)->readdirProcess)
+		yaffs_GrossLock(dev);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_lookup for %d:%s\n"),
+		yaffs_InodeToObject(dir)->objectId, dentry->d_name.name));
+	obj = yaffs_FindObjectByName(yaffs_InodeToObject(dir),
+					dentry->d_name.name);
+	obj = yaffs_GetEquivalentObject(obj);	/* in case it was a hardlink */
+	/* Can't hold gross lock when calling yaffs_get_inode() */
+	if(current != yaffs_DeviceToContext(dev)->readdirProcess)
+		yaffs_GrossUnlock(dev);
+	if (obj) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_lookup found %d\n"), obj->objectId));
+		inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+		if (inode) {
+			T(YAFFS_TRACE_OS,
+				(TSTR("yaffs_loookup dentry \n")));
+/* #if 0 asserted by NCB for 2.5/6 compatability - falls through to
+* d_add even if NULL inode */
+#if 0
+			/*dget(dentry); // try to solve directory bug */
+			d_add(dentry, inode);
+			/* return dentry; */
+			return NULL;
+#endif
+		}
+	} else {
+		T(YAFFS_TRACE_OS,(TSTR("yaffs_lookup not found\n")));
+	}
+/* added NCB for 2.5/6 compatability - forces add even if inode is
+* NULL which creates dentry hash */
+	d_add(dentry, inode);
+	return NULL;
+}
+#ifdef YAFFS_HAS_PUT_INODE
+/* For now put inode is just for debugging
+* Put inode is called when the inode **structure** is put.
+*/
+static void yaffs_put_inode(struct inode *inode)
+{
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_put_inode: ino %d, count %d\n"), (int)inode->i_ino,
+		atomic_read(&inode->i_count)));
+}
+#endif
+/* clear is called to tell the fs to release any per-inode data it holds */
+static void yaffs_clear_inode(struct inode *inode)
+{
+	yaffs_Object *obj;
+	yaffs_Device *dev;
+	obj = yaffs_InodeToObject(inode);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_clear_inode: ino %d, count %d %s\n"), (int)inode->i_ino,
+		atomic_read(&inode->i_count),
+		obj ? "object exists" : "null object"));
+	if (obj) {
+		dev = obj->myDev;
+		yaffs_GrossLock(dev);
+		/* Clear the association between the inode and
+		 * the yaffs_Object.
+		 */
+		obj->myInode = NULL;
+		yaffs_InodeToObjectLV(inode) = NULL;
+		/* If the object freeing was deferred, then the real
+		 * free happens now.
+		 * This should fix the inode inconsistency problem.
+		 */
+		yaffs_HandleDeferedFree(obj);
+		yaffs_GrossUnlock(dev);
+	}
+}
+/* delete is called when the link count is zero and the inode
+* is put (ie. nobody wants to know about it anymore, time to
+* delete the file).
+* NB Must call clear_inode()
+*/
+static void yaffs_delete_inode(struct inode *inode)
+{
+	yaffs_Object *obj = yaffs_InodeToObject(inode);
+	yaffs_Device *dev;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_delete_inode: ino %d, count %d %s\n"), (int)inode->i_ino,
+		atomic_read(&inode->i_count),
+		obj ? "object exists" : "null object"));
+	if (obj) {
+		dev = obj->myDev;
+		yaffs_GrossLock(dev);
+		yaffs_DeleteObject(obj);
+		yaffs_GrossUnlock(dev);
+	}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 13))
+	truncate_inode_pages(&inode->i_data, 0);
+#endif
+	clear_inode(inode);
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_file_flush(struct file *file, fl_owner_t id)
+#else
+static int yaffs_file_flush(struct file *file)
+#endif
+{
+	yaffs_Object *obj = yaffs_DentryToObject(file->f_dentry);
+	yaffs_Device *dev = obj->myDev;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_file_flush object %d (%s)\n"), obj->objectId,
+		obj->dirty ? "dirty" : "clean"));
+	yaffs_GrossLock(dev);
+	yaffs_FlushFile(obj, 1, 0);
+	yaffs_GrossUnlock(dev);
+	return 0;
+}
+static int yaffs_readpage_nolock(struct file *f, struct page *pg)
+{
+	/* Lifted from jffs2 */
+	yaffs_Object *obj;
+	unsigned char *pg_buf;
+	int ret;
+	yaffs_Device *dev;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_readpage_nolock at %08x, size %08x\n"),
+		(unsigned)(pg->index << PAGE_CACHE_SHIFT),
+		(unsigned)PAGE_CACHE_SIZE));
+	obj = yaffs_DentryToObject(f->f_dentry);
+	dev = obj->myDev;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+	BUG_ON(!PageLocked(pg));
+#else
+	if (!PageLocked(pg))
+		PAGE_BUG(pg);
+#endif
+	pg_buf = kmap(pg);
+	/* FIXME: Can kmap fail? */
+	yaffs_GrossLock(dev);
+	ret = yaffs_ReadDataFromFile(obj, pg_buf,
+				pg->index << PAGE_CACHE_SHIFT,
+				PAGE_CACHE_SIZE);
+	yaffs_GrossUnlock(dev);
+	if (ret >= 0)
+		ret = 0;
+	if (ret) {
+		ClearPageUptodate(pg);
+		SetPageError(pg);
+	} else {
+		SetPageUptodate(pg);
+		ClearPageError(pg);
+	}
+	flush_dcache_page(pg);
+	kunmap(pg);
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_readpage_nolock done\n")));
+	return ret;
+}
+static int yaffs_readpage_unlock(struct file *f, struct page *pg)
+{
+	int ret = yaffs_readpage_nolock(f, pg);
+	UnlockPage(pg);
+	return ret;
+}
+static int yaffs_readpage(struct file *f, struct page *pg)
+{
+	int ret;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_readpage\n")));
+	ret=yaffs_readpage_unlock(f, pg);
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_readpage done\n")));
+	return ret;
+}
+/* writepage inspired by/stolen from smbfs */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_writepage(struct page *page, struct writeback_control *wbc)
+#else
+static int yaffs_writepage(struct page *page)
+#endif
+{
+	struct address_space *mapping = page->mapping;
+	struct inode *inode;
+	unsigned long end_index;
+	char *buffer;
+	yaffs_Object *obj;
+	int nWritten = 0;
+	unsigned nBytes;
+	loff_t i_size;
+	if (!mapping)
+		BUG();
+	inode = mapping->host;
+	if (!inode)
+		BUG();
+	i_size = i_size_read(inode);
+	end_index = i_size >> PAGE_CACHE_SHIFT;
+	if(page->index < end_index)
+		nBytes = PAGE_CACHE_SIZE;
+	else {
+		nBytes = i_size & (PAGE_CACHE_SIZE -1);
+		if (page->index > end_index || !nBytes) {
+			T(YAFFS_TRACE_OS,
+				(TSTR("yaffs_writepage at %08x, inode size = %08x!!!\n"),
+				(unsigned)(page->index << PAGE_CACHE_SHIFT),
+				(unsigned)inode->i_size));
+			T(YAFFS_TRACE_OS,
+				(TSTR("                -> don't care!!\n")));
+			zero_user_segment(page,0,PAGE_CACHE_SIZE);
+			set_page_writeback(page);
+			unlock_page(page);
+			end_page_writeback(page);
+			return 0;
+		}
+	}
+	if(nBytes != PAGE_CACHE_SIZE)
+		zero_user_segment(page,nBytes,PAGE_CACHE_SIZE);
+	get_page(page);
+	buffer = kmap(page);
+	obj = yaffs_InodeToObject(inode);
+	yaffs_GrossLock(obj->myDev);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_writepage at %08x, size %08x\n"),
+		(unsigned)(page->index << PAGE_CACHE_SHIFT), nBytes));
+	T(YAFFS_TRACE_OS,
+		(TSTR("writepag0: obj = %05x, ino = %05x\n"),
+		(int)obj->variant.fileVariant.fileSize, (int)inode->i_size));
+	nWritten = yaffs_WriteDataToFile(obj, buffer,
+			page->index << PAGE_CACHE_SHIFT, nBytes, 0);
+	T(YAFFS_TRACE_OS,
+		(TSTR("writepag1: obj = %05x, ino = %05x\n"),
+		(int)obj->variant.fileVariant.fileSize, (int)inode->i_size));
+	yaffs_GrossUnlock(obj->myDev);
+	kunmap(page);
+	set_page_writeback(page);
+	unlock_page(page);
+	end_page_writeback(page);
+	put_page(page);
+	return (nWritten == nBytes) ? 0 : -ENOSPC;
+}
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata)
+{
+	struct page *pg = NULL;
+	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+	int ret = 0;
+	int space_held = 0;
+	/* Get a page */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 28)
+	pg = grab_cache_page_write_begin(mapping, index, flags);
+#else
+	pg = __grab_cache_page(mapping, index);
+#endif
+	*pagep = pg;
+	if (!pg) {
+		ret =  -ENOMEM;
+		goto out;
+	}
+	T(YAFFS_TRACE_OS,
+		(TSTR("start yaffs_write_begin index %d(%x) uptodate %d\n"),
+		(int)index,(int)index,Page_Uptodate(pg) ? 1 : 0));
+	/* Get fs space */
+	space_held = yaffs_hold_space(filp);
+	if (!space_held) {
+		ret = -ENOSPC;
+		goto out;
+	}
+	/* Update page if required */
+	if (!Page_Uptodate(pg))
+		ret = yaffs_readpage_nolock(filp, pg);
+	if (ret)
+		goto out;
+	/* Happy path return */
+	T(YAFFS_TRACE_OS, (TSTR("end yaffs_write_begin - ok\n")));
+	return 0;
+out:
+	T(YAFFS_TRACE_OS,
+		(TSTR("end yaffs_write_begin fail returning %d\n"), ret));
+	if (space_held)
+		yaffs_release_space(filp);
+	if (pg) {
+		unlock_page(pg);
+		page_cache_release(pg);
+	}
+	return ret;
+}
+#else
+static int yaffs_prepare_write(struct file *f, struct page *pg,
+				unsigned offset, unsigned to)
+{
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_prepair_write\n")));
+	if (!Page_Uptodate(pg))
+		return yaffs_readpage_nolock(f, pg);
+	return 0;
+}
+#endif
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *pg, void *fsdadata)
+{
+	int ret = 0;
+	void *addr, *kva;
+	uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE - 1);
+	kva = kmap(pg);
+	addr = kva + offset_into_page;
+	T(YAFFS_TRACE_OS,
+		("yaffs_write_end addr %p pos %x nBytes %d\n",
+		addr,(unsigned)pos, copied));
+	ret = yaffs_file_write(filp, addr, copied, &pos);
+	if (ret != copied) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_write_end not same size ret %d  copied %d\n"),
+			ret, copied));
+		SetPageError(pg);
+	} else {
+		/* Nothing */
+	}
+	kunmap(pg);
+	yaffs_release_space(filp);
+	unlock_page(pg);
+	page_cache_release(pg);
+	return ret;
+}
+#else
+static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
+				unsigned to)
+{
+	void *addr, *kva;
+	loff_t pos = (((loff_t) pg->index) << PAGE_CACHE_SHIFT) + offset;
+	int nBytes = to - offset;
+	int nWritten;
+	unsigned spos = pos;
+	unsigned saddr;
+	kva = kmap(pg);
+	addr = kva + offset;
+	saddr = (unsigned) addr;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_commit_write addr %x pos %x nBytes %d\n"),
+		saddr, spos, nBytes));
+	nWritten = yaffs_file_write(f, addr, nBytes, &pos);
+	if (nWritten != nBytes) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_commit_write not same size nWritten %d  nBytes %d\n"),
+			nWritten, nBytes));
+		SetPageError(pg);
+	} else {
+		/* Nothing */
+	}
+	kunmap(pg);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_commit_write returning %d\n"),
+		nWritten == nBytes ? 0 : nWritten));
+	return nWritten == nBytes ? 0 : nWritten;
+}
+#endif
+static void yaffs_FillInodeFromObject(struct inode *inode, yaffs_Object *obj)
+{
+	if (inode && obj) {
+		/* Check mode against the variant type and attempt to repair if broken. */
+		__u32 mode = obj->yst_mode;
+		switch (obj->variantType) {
+		case YAFFS_OBJECT_TYPE_FILE:
+			if (!S_ISREG(mode)) {
+				obj->yst_mode &= ~S_IFMT;
+				obj->yst_mode |= S_IFREG;
+			}
+			break;
+		case YAFFS_OBJECT_TYPE_SYMLINK:
+			if (!S_ISLNK(mode)) {
+				obj->yst_mode &= ~S_IFMT;
+				obj->yst_mode |= S_IFLNK;
+			}
+			break;
+		case YAFFS_OBJECT_TYPE_DIRECTORY:
+			if (!S_ISDIR(mode)) {
+				obj->yst_mode &= ~S_IFMT;
+				obj->yst_mode |= S_IFDIR;
+			}
+			break;
+		case YAFFS_OBJECT_TYPE_UNKNOWN:
+		case YAFFS_OBJECT_TYPE_HARDLINK:
+		case YAFFS_OBJECT_TYPE_SPECIAL:
+		default:
+			/* TODO? */
+			break;
+		}
+		inode->i_flags |= S_NOATIME;
+		inode->i_ino = obj->objectId;
+		inode->i_mode = obj->yst_mode;
+		inode->i_uid = obj->yst_uid;
+		inode->i_gid = obj->yst_gid;
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19))
+		inode->i_blksize = inode->i_sb->s_blocksize;
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+		inode->i_rdev = old_decode_dev(obj->yst_rdev);
+		inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
+		inode->i_atime.tv_nsec = 0;
+		inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
+		inode->i_mtime.tv_nsec = 0;
+		inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
+		inode->i_ctime.tv_nsec = 0;
+#else
+		inode->i_rdev = obj->yst_rdev;
+		inode->i_atime = obj->yst_atime;
+		inode->i_mtime = obj->yst_mtime;
+		inode->i_ctime = obj->yst_ctime;
+#endif
+		inode->i_size = yaffs_GetObjectFileLength(obj);
+		inode->i_blocks = (inode->i_size + 511) >> 9;
+		inode->i_nlink = yaffs_GetObjectLinkCount(obj);
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_FillInode mode %x uid %d gid %d size %d count %d\n"),
+			inode->i_mode, inode->i_uid, inode->i_gid,
+			(int)inode->i_size, atomic_read(&inode->i_count)));
+		switch (obj->yst_mode & S_IFMT) {
+		default:	/* fifo, device or socket */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+			init_special_inode(inode, obj->yst_mode,
+					old_decode_dev(obj->yst_rdev));
+#else
+			init_special_inode(inode, obj->yst_mode,
+					(dev_t) (obj->yst_rdev));
+#endif
+			break;
+		case S_IFREG:	/* file */
+			inode->i_op = &yaffs_file_inode_operations;
+			inode->i_fop = &yaffs_file_operations;
+			inode->i_mapping->a_ops =
+				&yaffs_file_address_operations;
+			break;
+		case S_IFDIR:	/* directory */
+			inode->i_op = &yaffs_dir_inode_operations;
+			inode->i_fop = &yaffs_dir_operations;
+			break;
+		case S_IFLNK:	/* symlink */
+			inode->i_op = &yaffs_symlink_inode_operations;
+			break;
+		}
+		yaffs_InodeToObjectLV(inode) = obj;
+		obj->myInode = inode;
+	} else {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_FileInode invalid parameters\n")));
+	}
+}
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
+				yaffs_Object *obj)
+{
+	struct inode *inode;
+	if (!sb) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_get_inode for NULL super_block!!\n")));
+		return NULL;
+	}
+	if (!obj) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_get_inode for NULL object!!\n")));
+		return NULL;
+	}
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_get_inode for object %d\n"), obj->objectId));
+	inode = Y_IGET(sb, obj->objectId);
+	if (IS_ERR(inode))
+		return NULL;
+	/* NB Side effect: iget calls back to yaffs_read_inode(). */
+	/* iget also increments the inode's i_count */
+	/* NB You can't be holding grossLock or deadlock will happen! */
+	return inode;
+}
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+				loff_t *pos)
+{
+	yaffs_Object *obj;
+	int nWritten, ipos;
+	struct inode *inode;
+	yaffs_Device *dev;
+	obj = yaffs_DentryToObject(f->f_dentry);
+	dev = obj->myDev;
+	yaffs_GrossLock(dev);
+	inode = f->f_dentry->d_inode;
+	if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND)
+		ipos = inode->i_size;
+	else
+		ipos = *pos;
+	if (!obj)
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_file_write: hey obj is null!\n")));
+	else
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_file_write about to write writing %u(%x) bytes"
+			"to object %d at %d(%x)\n"),
+			(unsigned) n, (unsigned) n, obj->objectId, ipos,ipos));
+	nWritten = yaffs_WriteDataToFile(obj, buf, ipos, n, 0);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_file_write: %d(%x) bytes written\n"),
+		(unsigned )n,(unsigned)n));
+	if (nWritten > 0) {
+		ipos += nWritten;
+		*pos = ipos;
+		if (ipos > inode->i_size) {
+			inode->i_size = ipos;
+			inode->i_blocks = (ipos + 511) >> 9;
+			T(YAFFS_TRACE_OS,
+				(TSTR("yaffs_file_write size updated to %d bytes, "
+				"%d blocks\n"),
+				ipos, (int)(inode->i_blocks)));
+		}
+	}
+	yaffs_GrossUnlock(dev);
+	return (nWritten == 0) && (n > 0) ? -ENOSPC : nWritten;
+}
+/* Space holding and freeing is done to ensure we have space available for write_begin/end */
+/* For now we just assume few parallel writes and check against a small number. */
+/* Todo: need to do this with a counter to handle parallel reads better */
+static ssize_t yaffs_hold_space(struct file *f)
+{
+	yaffs_Object *obj;
+	yaffs_Device *dev;
+	int nFreeChunks;
+	obj = yaffs_DentryToObject(f->f_dentry);
+	dev = obj->myDev;
+	yaffs_GrossLock(dev);
+	nFreeChunks = yaffs_GetNumberOfFreeChunks(dev);
+	yaffs_GrossUnlock(dev);
+	return (nFreeChunks > 20) ? 1 : 0;
+}
+static void yaffs_release_space(struct file *f)
+{
+	yaffs_Object *obj;
+	yaffs_Device *dev;
+	obj = yaffs_DentryToObject(f->f_dentry);
+	dev = obj->myDev;
+	yaffs_GrossLock(dev);
+	yaffs_GrossUnlock(dev);
+}
+static loff_t yaffs_dir_llseek(struct file *file, loff_t offset, int origin)
+{
+	long long retval;
+	lock_kernel();
+	switch (origin){
+	case 2:
+		offset += i_size_read(file->f_path.dentry->d_inode);
+		break;
+	case 1:
+		offset += file->f_pos;
+	}
+	retval = -EINVAL;
+	if (offset >= 0){
+		if (offset != file->f_pos)
+			file->f_pos = offset;
+		retval = offset;
+	}
+	unlock_kernel();
+	return retval;
+}
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
+{
+	yaffs_Object *obj;
+	yaffs_Device *dev;
+struct yaffs_SearchContext *sc;
+	struct inode *inode = f->f_dentry->d_inode;
+	unsigned long offset, curoffs;
+	yaffs_Object *l;
+int retVal = 0;
+	char name[YAFFS_MAX_NAME_LENGTH + 1];
+	obj = yaffs_DentryToObject(f->f_dentry);
+	dev = obj->myDev;
+	yaffs_GrossLock(dev);
+	yaffs_DeviceToContext(dev)->readdirProcess = current;
+	offset = f->f_pos;
+sc = yaffs_NewSearch(obj);
+if(!sc){
+retVal = -ENOMEM;
+goto unlock_out;
+}
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_readdir: starting at %d\n"), (int)offset));
+	if (offset == 0) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_readdir: entry . ino %d \n"),
+			(int)inode->i_ino));
+		yaffs_GrossUnlock(dev);
+		if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR) < 0)
+			goto out;
+		yaffs_GrossLock(dev);
+		offset++;
+		f->f_pos++;
+	}
+	if (offset == 1) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_readdir: entry .. ino %d \n"),
+			(int)f->f_dentry->d_parent->d_inode->i_ino));
+		yaffs_GrossUnlock(dev);
+		if (filldir(dirent, "..", 2, offset,
+			f->f_dentry->d_parent->d_inode->i_ino, DT_DIR) < 0)
+			goto out;
+		yaffs_GrossLock(dev);
+		offset++;
+		f->f_pos++;
+	}
+	curoffs = 1;
+	/* If the directory has changed since the open or last call to
+	   readdir, rewind to after the 2 canned entries. */
+	if (f->f_version != inode->i_version) {
+		offset = 2;
+		f->f_pos = offset;
+		f->f_version = inode->i_version;
+	}
+	while(sc->nextReturn){
+		curoffs++;
+l = sc->nextReturn;
+		if (curoffs >= offset) {
+int this_inode = yaffs_GetObjectInode(l);
+int this_type = yaffs_GetObjectType(l);
+			yaffs_GetObjectName(l, name,
+					    YAFFS_MAX_NAME_LENGTH + 1);
+			T(YAFFS_TRACE_OS,
+			  (TSTR("yaffs_readdir: %s inode %d\n"),
+			  name, yaffs_GetObjectInode(l)));
+yaffs_GrossUnlock(dev);
+			if (filldir(dirent,
+					name,
+					strlen(name),
+					offset,
+					this_inode,
+					this_type) < 0)
+				goto out;
+yaffs_GrossLock(dev);
+			offset++;
+			f->f_pos++;
+		}
+yaffs_SearchAdvance(sc);
+	}
+unlock_out:
+	yaffs_DeviceToContext(dev)->readdirProcess = NULL;
+	yaffs_GrossUnlock(dev);
+out:
+yaffs_EndSearch(sc);
+	return retVal;
+}
+/*
+* File creation. Allocate an inode, and we're done..
+*/
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
+#define YCRED(x) x
+#else
+#define YCRED(x) (x->cred)
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+			dev_t rdev)
+#else
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+			int rdev)
+#endif
+{
+	struct inode *inode;
+	yaffs_Object *obj = NULL;
+	yaffs_Device *dev;
+	yaffs_Object *parent = yaffs_InodeToObject(dir);
+	int error = -ENOSPC;
+	uid_t uid = YCRED(current)->fsuid;
+	gid_t gid = (dir->i_mode & S_ISGID) ? dir->i_gid : YCRED(current)->fsgid;
+	if ((dir->i_mode & S_ISGID) && S_ISDIR(mode))
+		mode |= S_ISGID;
+	if (parent) {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_mknod: parent object %d type %d\n"),
+			parent->objectId, parent->variantType));
+	} else {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_mknod: could not get parent object\n")));
+		return -EPERM;
+	}
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_mknod: making oject for %s, "
+			"mode %x dev %x\n"),
+			dentry->d_name.name, mode, rdev));
+	dev = parent->myDev;
+	yaffs_GrossLock(dev);
+	switch (mode & S_IFMT) {
+	default:
+		/* Special (socket, fifo, device...) */
+		T(YAFFS_TRACE_OS, (TSTR("yaffs_mknod: making special\n")));
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+		obj = yaffs_MknodSpecial(parent, dentry->d_name.name, mode, uid,
+				gid, old_encode_dev(rdev));
+#else
+		obj = yaffs_MknodSpecial(parent, dentry->d_name.name, mode, uid,
+				gid, rdev);
+#endif
+		break;
+	case S_IFREG:		/* file          */
+		T(YAFFS_TRACE_OS, (TSTR("yaffs_mknod: making file\n")));
+		obj = yaffs_MknodFile(parent, dentry->d_name.name, mode, uid,
+				gid);
+		break;
+	case S_IFDIR:		/* directory */
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_mknod: making directory\n")));
+		obj = yaffs_MknodDirectory(parent, dentry->d_name.name, mode,
+					uid, gid);
+		break;
+	case S_IFLNK:		/* symlink */
+		T(YAFFS_TRACE_OS, (TSTR("yaffs_mknod: making symlink\n")));
+		obj = NULL;	/* Do we ever get here? */
+		break;
+	}
+	/* Can not call yaffs_get_inode() with gross lock held */
+	yaffs_GrossUnlock(dev);
+	if (obj) {
+		inode = yaffs_get_inode(dir->i_sb, mode, rdev, obj);
+		d_instantiate(dentry, inode);
+		update_dir_time(dir);
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_mknod created object %d count = %d\n"),
+			obj->objectId, atomic_read(&inode->i_count)));
+		error = 0;
+		yaffs_FillInodeFromObject(dir,parent);
+	} else {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_mknod failed making object\n")));
+		error = -ENOMEM;
+	}
+	return error;
+}
+static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	int retVal;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_mkdir\n")));
+	retVal = yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
+	return retVal;
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
+			struct nameidata *n)
+#else
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode)
+#endif
+{
+	T(YAFFS_TRACE_OS,(TSTR("yaffs_create\n")));
+	return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+static int yaffs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	int retVal;
+	yaffs_Device *dev;
+	yaffs_Object *obj;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_unlink %d:%s\n"),
+		(int)(dir->i_ino),
+		dentry->d_name.name));
+	obj = yaffs_InodeToObject(dir);
+	dev = obj->myDev;
+	yaffs_GrossLock(dev);
+	retVal = yaffs_Unlink(obj, dentry->d_name.name);
+	if (retVal == YAFFS_OK) {
+		dentry->d_inode->i_nlink--;
+		dir->i_version++;
+		yaffs_GrossUnlock(dev);
+		mark_inode_dirty(dentry->d_inode);
+		update_dir_time(dir);
+		return 0;
+	}
+	yaffs_GrossUnlock(dev);
+	return -ENOTEMPTY;
+}
+/*
+* Create a link...
+*/
+static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
+			struct dentry *dentry)
+{
+	struct inode *inode = old_dentry->d_inode;
+	yaffs_Object *obj = NULL;
+	yaffs_Object *link = NULL;
+	yaffs_Device *dev;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_link\n")));
+	obj = yaffs_InodeToObject(inode);
+	dev = obj->myDev;
+	yaffs_GrossLock(dev);
+	if (!S_ISDIR(inode->i_mode))		/* Don't link directories */
+		link = yaffs_Link(yaffs_InodeToObject(dir), dentry->d_name.name,
+			obj);
+	if (link) {
+		old_dentry->d_inode->i_nlink = yaffs_GetObjectLinkCount(obj);
+		d_instantiate(dentry, old_dentry->d_inode);
+		atomic_inc(&old_dentry->d_inode->i_count);
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_link link count %d i_count %d\n"),
+			old_dentry->d_inode->i_nlink,
+			atomic_read(&old_dentry->d_inode->i_count)));
+	}
+	yaffs_GrossUnlock(dev);
+	if (link){
+		update_dir_time(dir);
+		return 0;
+	}
+	return -EPERM;
+}
+static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
+				const char *symname)
+{
+	yaffs_Object *obj;
+	yaffs_Device *dev;
+	uid_t uid = YCRED(current)->fsuid;
+	gid_t gid = (dir->i_mode & S_ISGID) ? dir->i_gid : YCRED(current)->fsgid;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_symlink\n")));
+	dev = yaffs_InodeToObject(dir)->myDev;
+	yaffs_GrossLock(dev);
+	obj = yaffs_MknodSymLink(yaffs_InodeToObject(dir), dentry->d_name.name,
+				S_IFLNK | S_IRWXUGO, uid, gid, symname);
+	yaffs_GrossUnlock(dev);
+	if (obj) {
+		struct inode *inode;
+		inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+		d_instantiate(dentry, inode);
+		update_dir_time(dir);
+		T(YAFFS_TRACE_OS, (TSTR("symlink created OK\n")));
+		return 0;
+	} else {
+		T(YAFFS_TRACE_OS, (TSTR("symlink not created\n")));
+	}
+	return -ENOMEM;
+}
+static int yaffs_sync_object(struct file *file, struct dentry *dentry,
+				int datasync)
+{
+	yaffs_Object *obj;
+	yaffs_Device *dev;
+	obj = yaffs_DentryToObject(dentry);
+	dev = obj->myDev;
+	T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
+		(TSTR("yaffs_sync_object\n")));
+	yaffs_GrossLock(dev);
+	yaffs_FlushFile(obj, 1, datasync);
+	yaffs_GrossUnlock(dev);
+	return 0;
+}
+/*
+* The VFS layer already does all the dentry stuff for rename.
+*
+* NB: POSIX says you can rename an object over an old object of the same name
+*/
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry)
+{
+	yaffs_Device *dev;
+	int retVal = YAFFS_FAIL;
+	yaffs_Object *target;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_rename\n")));
+	dev = yaffs_InodeToObject(old_dir)->myDev;
+	yaffs_GrossLock(dev);
+	/* Check if the target is an existing directory that is not empty. */
+	target = yaffs_FindObjectByName(yaffs_InodeToObject(new_dir),
+				new_dentry->d_name.name);
+	if (target && target->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
+		!ylist_empty(&target->variant.directoryVariant.children)) {
+		T(YAFFS_TRACE_OS, (TSTR("target is non-empty dir\n")));
+		retVal = YAFFS_FAIL;
+	} else {
+		/* Now does unlinking internally using shadowing mechanism */
+		T(YAFFS_TRACE_OS, (TSTR("calling yaffs_RenameObject\n")));
+		retVal = yaffs_RenameObject(yaffs_InodeToObject(old_dir),
+				old_dentry->d_name.name,
+				yaffs_InodeToObject(new_dir),
+				new_dentry->d_name.name);
+	}
+	yaffs_GrossUnlock(dev);
+	if (retVal == YAFFS_OK) {
+		if (target) {
+			new_dentry->d_inode->i_nlink--;
+			mark_inode_dirty(new_dentry->d_inode);
+		}
+		update_dir_time(old_dir);
+		if(old_dir != new_dir)
+			update_dir_time(new_dir);
+		return 0;
+	} else {
+		return -ENOTEMPTY;
+	}
+}
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = dentry->d_inode;
+	int error = 0;
+	yaffs_Device *dev;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_setattr of object %d\n"),
+		yaffs_InodeToObject(inode)->objectId));
+	/* Fail if a requested resize >= 2GB */
+	if (attr->ia_valid & ATTR_SIZE &&
+		(attr->ia_size >> 31))
+		error = -EINVAL;
+	if (error == 0)
+		error = inode_change_ok(inode, attr);
+	if (error == 0) {
+		int result;
+		if (!error){
+			error = inode_setattr(inode, attr);
+			T(YAFFS_TRACE_OS,(TSTR("inode_setattr called\n")));
+			if (attr->ia_valid & ATTR_SIZE)
+	truncate_inode_pages(&inode->i_data,attr->ia_size);
+		}
+		dev = yaffs_InodeToObject(inode)->myDev;
+		if (attr->ia_valid & ATTR_SIZE){
+			T(YAFFS_TRACE_OS,(TSTR("resize to %d(%x)\n"),
+				(int)(attr->ia_size),(int)(attr->ia_size)));
+		}
+		yaffs_GrossLock(dev);
+		result = yaffs_SetAttributes(yaffs_InodeToObject(inode), attr);
+		if(result == YAFFS_OK) {
+			error = 0;
+		} else {
+			error = -EPERM;
+		}
+		yaffs_GrossUnlock(dev);
+	}
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_setattr done returning %d\n"),error));
+	return error;
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	yaffs_Device *dev = yaffs_DentryToObject(dentry)->myDev;
+	struct super_block *sb = dentry->d_sb;
+#elif (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_statfs(struct super_block *sb, struct kstatfs *buf)
+{
+	yaffs_Device *dev = yaffs_SuperToDevice(sb);
+#else
+static int yaffs_statfs(struct super_block *sb, struct statfs *buf)
+{
+	yaffs_Device *dev = yaffs_SuperToDevice(sb);
+#endif
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_statfs\n")));
+	yaffs_GrossLock(dev);
+	buf->f_type = YAFFS_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_namelen = 255;
+	if (dev->nDataBytesPerChunk & (dev->nDataBytesPerChunk - 1)) {
+		/* Do this if chunk size is not a power of 2 */
+		uint64_t bytesInDev;
+		uint64_t bytesFree;
+		bytesInDev = ((uint64_t)((dev->param.endBlock - dev->param.startBlock + 1))) *
+			((uint64_t)(dev->param.nChunksPerBlock * dev->nDataBytesPerChunk));
+		do_div(bytesInDev, sb->s_blocksize); /* bytesInDev becomes the number of blocks */
+		buf->f_blocks = bytesInDev;
+		bytesFree  = ((uint64_t)(yaffs_GetNumberOfFreeChunks(dev))) *
+			((uint64_t)(dev->nDataBytesPerChunk));
+		do_div(bytesFree, sb->s_blocksize);
+		buf->f_bfree = bytesFree;
+	} else if (sb->s_blocksize > dev->nDataBytesPerChunk) {
+		buf->f_blocks =
+			(dev->param.endBlock - dev->param.startBlock + 1) *
+			dev->param.nChunksPerBlock /
+			(sb->s_blocksize / dev->nDataBytesPerChunk);
+		buf->f_bfree =
+			yaffs_GetNumberOfFreeChunks(dev) /
+			(sb->s_blocksize / dev->nDataBytesPerChunk);
+	} else {
+		buf->f_blocks =
+			(dev->param.endBlock - dev->param.startBlock + 1) *
+			dev->param.nChunksPerBlock *
+			(dev->nDataBytesPerChunk / sb->s_blocksize);
+		buf->f_bfree =
+			yaffs_GetNumberOfFreeChunks(dev) *
+			(dev->nDataBytesPerChunk / sb->s_blocksize);
+	}
+	buf->f_files = 0;
+	buf->f_ffree = 0;
+	buf->f_bavail = buf->f_bfree;
+	yaffs_GrossUnlock(dev);
+	return 0;
+}
+static void yaffs_FlushInodes(struct super_block *sb)
+{
+	struct inode *iptr;
+	yaffs_Object *obj;
+	list_for_each_entry(iptr,&sb->s_inodes, i_sb_list){
+		obj = yaffs_InodeToObject(iptr);
+		if(obj){
+			T(YAFFS_TRACE_OS, (TSTR("flushing obj %d\n"),
+				obj->objectId));
+			yaffs_FlushFile(obj,1,0);
+		}
+	}
+}
+static void yaffs_FlushSuperBlock(struct super_block *sb, int do_checkpoint)
+{
+	yaffs_Device *dev = yaffs_SuperToDevice(sb);
+	if(!dev)
+		return;
+	yaffs_FlushInodes(sb);
+	yaffs_UpdateDirtyDirectories(dev);
+	yaffs_FlushEntireDeviceCache(dev);
+	if(do_checkpoint)
+		yaffs_CheckpointSave(dev);
+}
+static unsigned yaffs_bg_gc_urgency(yaffs_Device *dev)
+{
+	unsigned erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
+	struct yaffs_LinuxContext *context = yaffs_DeviceToContext(dev);
+	unsigned scatteredFree = 0; /* Free chunks not in an erased block */
+	if(erasedChunks < dev->nFreeChunks)
+		scatteredFree = (dev->nFreeChunks - erasedChunks);
+	if(!context->bgRunning)
+		return 0;
+	else if(scatteredFree < (dev->param.nChunksPerBlock * 2))
+		return 0;
+	else if(erasedChunks > dev->nFreeChunks/2)
+		return 0;
+	else if(erasedChunks > dev->nFreeChunks/4)
+		return 1;
+	else
+		return 2;
+}
+static int yaffs_do_sync_fs(struct super_block *sb,
+				int request_checkpoint)
+{
+	yaffs_Device *dev = yaffs_SuperToDevice(sb);
+	unsigned int oneshot_checkpoint = (yaffs_auto_checkpoint & 4);
+	unsigned gc_urgent = yaffs_bg_gc_urgency(dev);
+	int do_checkpoint;
+	T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+		(TSTR("yaffs_do_sync_fs: gc-urgency %d %s %s%s\n"),
+		gc_urgent,
+		sb->s_dirt ? "dirty" : "clean",
+		request_checkpoint ? "checkpoint requested" : "no checkpoint",
+		oneshot_checkpoint ? " one-shot" : "" ));
+	yaffs_GrossLock(dev);
+	do_checkpoint = ((request_checkpoint && !gc_urgent) ||
+			oneshot_checkpoint) &&
+			!dev->isCheckpointed;
+	if (sb->s_dirt || do_checkpoint) {
+		yaffs_FlushSuperBlock(sb, !dev->isCheckpointed && do_checkpoint);
+		sb->s_dirt = 0;
+		if(oneshot_checkpoint)
+			yaffs_auto_checkpoint &= ~4;
+	}
+	yaffs_GrossUnlock(dev);
+	return 0;
+}
+/*
+* yaffs background thread functions .
+* yaffs_BackgroundThread() the thread function
+* yaffs_BackgroundStart() launches the background thread.
+* yaffs_BackgroundStop() cleans up the background thread.
+*
+* NB:
+* The thread should only run after the yaffs is initialised
+* The thread should be stopped before yaffs is unmounted.
+* The thread should not do any writing while the fs is in read only.
+*/
+#ifdef YAFFS_COMPILE_BACKGROUND
+void yaffs_background_waker(unsigned long data)
+{
+	wake_up_process((struct task_struct *)data);
+}
+static int yaffs_BackgroundThread(void *data)
+{
+	yaffs_Device *dev = (yaffs_Device *)data;
+	struct yaffs_LinuxContext *context = yaffs_DeviceToContext(dev);
+	unsigned long now = jiffies;
+	unsigned long next_dir_update = now;
+	unsigned long next_gc = now;
+	unsigned long expires;
+	unsigned int urgency;
+	int gcResult;
+	struct timer_list timer;
+	T(YAFFS_TRACE_BACKGROUND,
+		(TSTR("yaffs_background starting for dev %p\n"),
+		(void *)dev));
+	set_freezable();
+	while(context->bgRunning){
+		T(YAFFS_TRACE_BACKGROUND,
+			(TSTR("yaffs_background\n")));
+		if(kthread_should_stop())
+			break;
+		if(try_to_freeze())
+			continue;
+		yaffs_GrossLock(dev);
+		now = jiffies;
+		if(time_after(now, next_dir_update)){
+			yaffs_UpdateDirtyDirectories(dev);
+			next_dir_update = now + HZ;
+		}
+		if(time_after(now,next_gc)){
+			if(!dev->isCheckpointed){
+				urgency = yaffs_bg_gc_urgency(dev);
+				gcResult = yaffs_BackgroundGarbageCollect(dev, urgency);
+				if(urgency > 1)
+					next_gc = now + HZ/20+1;
+				else if(urgency > 0)
+					next_gc = now + HZ/10+1;
+				else
+					next_gc = now + HZ * 2;
+			} else /*
+				* gc not running so set to next_dir_update
+				* to cut down on wake ups
+				*/
+				next_gc = next_dir_update;
+		}
+		yaffs_GrossUnlock(dev);
+#if 1
+		expires = next_dir_update;
+		if (time_before(next_gc,expires))
+			expires = next_gc;
+		if(time_before(expires,now))
+			expires = now + HZ;
+		init_timer(&timer);
+		timer.expires = expires+1;
+		timer.data = (unsigned long) current;
+		timer.function = yaffs_background_waker;
+set_current_state(TASK_INTERRUPTIBLE);
+		add_timer(&timer);
+		schedule();
+		del_timer_sync(&timer);
+#else
+		msleep(10);
+#endif
+	}
+	return 0;
+}
+static int yaffs_BackgroundStart(yaffs_Device *dev)
+{
+	int retval = 0;
+	struct yaffs_LinuxContext *context = yaffs_DeviceToContext(dev);
+	context->bgRunning = 1;
+	context->bgThread = kthread_run(yaffs_BackgroundThread,
+	                        (void *)dev,"yaffs-bg");
+	if(IS_ERR(context->bgThread)){
+		retval = PTR_ERR(context->bgThread);
+		context->bgThread = NULL;
+		context->bgRunning = 0;
+	}
+	return retval;
+}
+static void yaffs_BackgroundStop(yaffs_Device *dev)
+{
+	struct yaffs_LinuxContext *ctxt = yaffs_DeviceToContext(dev);
+	ctxt->bgRunning = 0;
+	if( ctxt->bgThread){
+		kthread_stop(ctxt->bgThread);
+		ctxt->bgThread = NULL;
+	}
+}
+#else
+static int yaffs_BackgroundThread(void *data)
+{
+	return 0;
+}
+static int yaffs_BackgroundStart(yaffs_Device *dev)
+{
+	return 0;
+}
+static void yaffs_BackgroundStop(yaffs_Device *dev)
+{
+}
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static void yaffs_write_super(struct super_block *sb)
+#else
+static int yaffs_write_super(struct super_block *sb)
+#endif
+{
+	unsigned request_checkpoint = (yaffs_auto_checkpoint >= 2);
+	T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+		(TSTR("yaffs_write_super%s\n"),
+		request_checkpoint ? " checkpt" : ""));
+	yaffs_do_sync_fs(sb, request_checkpoint);
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 18))
+	return 0;
+#endif
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_sync_fs(struct super_block *sb, int wait)
+#else
+static int yaffs_sync_fs(struct super_block *sb)
+#endif
+{
+	unsigned request_checkpoint = (yaffs_auto_checkpoint >= 1);
+	T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
+		(TSTR("yaffs_sync_fs%s\n"),
+		request_checkpoint ? " checkpt" : ""));
+	yaffs_do_sync_fs(sb, request_checkpoint);
+	return 0;
+}
+#ifdef YAFFS_USE_OWN_IGET
+static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino)
+{
+	struct inode *inode;
+	yaffs_Object *obj;
+	yaffs_Device *dev = yaffs_SuperToDevice(sb);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_iget for %lu\n"), ino));
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+	/* NB This is called as a side effect of other functions, but
+	 * we had to release the lock to prevent deadlocks, so
+	 * need to lock again.
+	 */
+	yaffs_GrossLock(dev);
+	obj = yaffs_FindObjectByNumber(dev, inode->i_ino);
+	yaffs_FillInodeFromObject(inode, obj);
+	yaffs_GrossUnlock(dev);
+	unlock_new_inode(inode);
+	return inode;
+}
+#else
+static void yaffs_read_inode(struct inode *inode)
+{
+	/* NB This is called as a side effect of other functions, but
+	 * we had to release the lock to prevent deadlocks, so
+	 * need to lock again.
+	 */
+	yaffs_Object *obj;
+	yaffs_Device *dev = yaffs_SuperToDevice(inode->i_sb);
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_read_inode for %d\n"), (int)inode->i_ino));
+	if(current != yaffs_DeviceToContext(dev)->readdirProcess)
+		yaffs_GrossLock(dev);
+	obj = yaffs_FindObjectByNumber(dev, inode->i_ino);
+	yaffs_FillInodeFromObject(inode, obj);
+	if(current != yaffs_DeviceToContext(dev)->readdirProcess)
+		yaffs_GrossUnlock(dev);
+}
+#endif
+static YLIST_HEAD(yaffs_context_list);
+struct semaphore yaffs_context_lock;
+#if 0 /* not used */
+static int yaffs_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+	yaffs_Device    *dev = yaffs_SuperToDevice(sb);
+	if (*flags & MS_RDONLY) {
+		struct mtd_info *mtd = yaffs_SuperToDevice(sb)->genericDevice;
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_remount_fs: %s: RO\n"), dev->name));
+		yaffs_GrossLock(dev);
+		yaffs_FlushSuperBlock(sb,1);
+		if (mtd->sync)
+			mtd->sync(mtd);
+		yaffs_GrossUnlock(dev);
+	} else {
+		T(YAFFS_TRACE_OS,
+			(TSTR("yaffs_remount_fs: %s: RW\n"), dev->name));
+	}
+	return 0;
+}
+#endif
+static void yaffs_put_super(struct super_block *sb)
+{
+	yaffs_Device *dev = yaffs_SuperToDevice(sb);
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_put_super\n")));
+	T(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
+		(TSTR("Shutting down yaffs background thread\n")));
+	yaffs_BackgroundStop(dev);
+	T(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
+		(TSTR("yaffs background thread shut down\n")));
+	yaffs_GrossLock(dev);
+	yaffs_FlushSuperBlock(sb,1);
+	if (yaffs_DeviceToContext(dev)->putSuperFunc)
+		yaffs_DeviceToContext(dev)->putSuperFunc(sb);
+	yaffs_Deinitialise(dev);
+	yaffs_GrossUnlock(dev);
+	down(&yaffs_context_lock);
+	ylist_del_init(&(yaffs_DeviceToContext(dev)->contextList));
+	up(&yaffs_context_lock);
+	if (yaffs_DeviceToContext(dev)->spareBuffer) {
+		YFREE(yaffs_DeviceToContext(dev)->spareBuffer);
+		yaffs_DeviceToContext(dev)->spareBuffer = NULL;
+	}
+	kfree(dev);
+}
+static void yaffs_MTDPutSuper(struct super_block *sb)
+{
+	struct mtd_info *mtd = yaffs_DeviceToContext(yaffs_SuperToDevice(sb))->mtd;
+	if (mtd->sync)
+		mtd->sync(mtd);
+	put_mtd_device(mtd);
+}
+static void yaffs_MarkSuperBlockDirty(yaffs_Device *dev)
+{
+	struct super_block *sb = yaffs_DeviceToContext(dev)->superBlock;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_MarkSuperBlockDirty() sb = %p\n"), sb));
+	if (sb)
+		sb->s_dirt = 1;
+}
+typedef struct {
+	int inband_tags;
+	int skip_checkpoint_read;
+	int skip_checkpoint_write;
+	int no_cache;
+	int tags_ecc_on;
+	int tags_ecc_overridden;
+	int lazy_loading_enabled;
+	int lazy_loading_overridden;
+	int empty_lost_and_found;
+	int empty_lost_and_found_overridden;
+} yaffs_options;
+#define MAX_OPT_LEN 30
+static int yaffs_parse_options(yaffs_options *options, const char *options_str)
+{
+	char cur_opt[MAX_OPT_LEN + 1];
+	int p;
+	int error = 0;
+	/* Parse through the options which is a comma seperated list */
+	while (options_str && *options_str && !error) {
+		memset(cur_opt, 0, MAX_OPT_LEN + 1);
+		p = 0;
+		while(*options_str == ',')
+			options_str++;
+		while (*options_str && *options_str != ',') {
+			if (p < MAX_OPT_LEN) {
+				cur_opt[p] = *options_str;
+				p++;
+			}
+			options_str++;
+		}
+		if (!strcmp(cur_opt, "inband-tags"))
+			options->inband_tags = 1;
+		else if (!strcmp(cur_opt, "tags-ecc-off")){
+			options->tags_ecc_on = 0;
+			options->tags_ecc_overridden=1;
+		} else if (!strcmp(cur_opt, "tags-ecc-on")){
+			options->tags_ecc_on = 1;
+			options->tags_ecc_overridden = 1;
+		} else if (!strcmp(cur_opt, "lazy-loading-off")){
+			options->lazy_loading_enabled = 0;
+			options->lazy_loading_overridden=1;
+		} else if (!strcmp(cur_opt, "lazy-loading-on")){
+			options->lazy_loading_enabled = 1;
+			options->lazy_loading_overridden = 1;
+		} else if (!strcmp(cur_opt, "empty-lost-and-found-off")){
+			options->empty_lost_and_found = 0;
+			options->empty_lost_and_found_overridden=1;
+		} else if (!strcmp(cur_opt, "empty-lost-and-found-on")){
+			options->empty_lost_and_found = 1;
+			options->empty_lost_and_found_overridden=1;
+		} else if (!strcmp(cur_opt, "no-cache"))
+			options->no_cache = 1;
+		else if (!strcmp(cur_opt, "no-checkpoint-read"))
+			options->skip_checkpoint_read = 1;
+		else if (!strcmp(cur_opt, "no-checkpoint-write"))
+			options->skip_checkpoint_write = 1;
+		else if (!strcmp(cur_opt, "no-checkpoint")) {
+			options->skip_checkpoint_read = 1;
+			options->skip_checkpoint_write = 1;
+		} else {
+			printk(KERN_INFO "yaffs: Bad mount option \"%s\"\n",
+					cur_opt);
+			error = 1;
+		}
+	}
+	return error;
+}
+static struct super_block *yaffs_internal_read_super(int yaffsVersion,
+						struct super_block *sb,
+						void *data, int silent)
+{
+	int nBlocks;
+	struct inode *inode = NULL;
+	struct dentry *root;
+	yaffs_Device *dev = 0;
+	char devname_buf[BDEVNAME_SIZE + 1];
+	struct mtd_info *mtd;
+	int err;
+	char *data_str = (char *)data;
+	struct yaffs_LinuxContext *context = NULL;
+	yaffs_DeviceParam *param;
+	yaffs_options options;
+	sb->s_magic = YAFFS_MAGIC;
+	sb->s_op = &yaffs_super_ops;
+	sb->s_flags |= MS_NOATIME;
+#ifdef YAFFS_COMPILE_EXPORTFS
+	sb->s_export_op = &yaffs_export_ops;
+#endif
+	if (!sb)
+		printk(KERN_INFO "yaffs: sb is NULL\n");
+	else if (!sb->s_dev)
+		printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
+	else if (!yaffs_devname(sb, devname_buf))
+		printk(KERN_INFO "yaffs: devname is NULL\n");
+	else
+		printk(KERN_INFO "yaffs: dev is %d name is \"%s\"\n",
+		       sb->s_dev,
+		       yaffs_devname(sb, devname_buf));
+	if (!data_str)
+		data_str = "";
+	printk(KERN_INFO "yaffs: passed flags \"%s\"\n", data_str);
+	memset(&options, 0, sizeof(options));
+	if (yaffs_parse_options(&options, data_str)) {
+		/* Option parsing failed */
+		return NULL;
+	}
+	sb->s_blocksize = PAGE_CACHE_SIZE;
+	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_read_super: Using yaffs%d\n"), yaffsVersion));
+	T(YAFFS_TRACE_OS,
+		(TSTR("yaffs_read_super: block size %d\n"),
+		(int)(sb->s_blocksize)));
+	T(YAFFS_TRACE_ALWAYS,
+		(TSTR("yaffs: Attempting MTD mount of %u.%u,\"%s\"\n"),
+	       MAJOR(sb->s_dev), MINOR(sb->s_dev),
+	       yaffs_devname(sb, devname_buf)));
+	/* Check it's an mtd device..... */
+	if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR)
+		return NULL;	/* This isn't an mtd device */
+	/* Get the device */
+	mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+	if (!mtd) {
+		T(YAFFS_TRACE_ALWAYS,
+			(TSTR("yaffs: MTD device #%u doesn't appear to exist\n"),
+			MINOR(sb->s_dev)));
+		return NULL;
+	}
+	/* Check it's NAND */
+	if (mtd->type != MTD_NANDFLASH) {
+		T(YAFFS_TRACE_ALWAYS,
+			(TSTR("yaffs: MTD device is not NAND it's type %d\n"),
+			mtd->type));
+		return NULL;
+	}
+	T(YAFFS_TRACE_OS, (TSTR(" erase %p\n"), mtd->erase));
+	T(YAFFS_TRACE_OS, (TSTR(" read %p\n"), mtd->read));
+	T(YAFFS_TRACE_OS, (TSTR(" write %p\n"), mtd->write));
+	T(YAFFS_TRACE_OS, (TSTR(" readoob %p\n"), mtd->read_oob));
+	T(YAFFS_TRACE_OS, (TSTR(" writeoob %p\n"), mtd->write_oob));
+	T(YAFFS_TRACE_OS, (TSTR(" block_isbad %p\n"), mtd->block_isbad));
+	T(YAFFS_TRACE_OS, (TSTR(" block_markbad %p\n"), mtd->block_markbad));
+	T(YAFFS_TRACE_OS, (TSTR(" %s %d\n"), WRITE_SIZE_STR, WRITE_SIZE(mtd)));
+	T(YAFFS_TRACE_OS, (TSTR(" oobsize %d\n"), mtd->oobsize));
+	T(YAFFS_TRACE_OS, (TSTR(" erasesize %d\n"), mtd->erasesize));
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 29)
+	T(YAFFS_TRACE_OS, (TSTR(" size %u\n"), mtd->size));
+#else
+	T(YAFFS_TRACE_OS, (TSTR(" size %lld\n"), mtd->size));
+#endif
+#ifdef CONFIG_YAFFS_AUTO_YAFFS2
+	if (yaffsVersion == 1 && WRITE_SIZE(mtd) >= 2048) {
+		T(YAFFS_TRACE_ALWAYS,
+			(TSTR("yaffs: auto selecting yaffs2\n")));
+		yaffsVersion = 2;
+	}
+	/* Added NCB 26/5/2006 for completeness */
+	if (yaffsVersion == 2 && !options.inband_tags && WRITE_SIZE(mtd) == 512) {
+		T(YAFFS_TRACE_ALWAYS,
+			(TSTR("yaffs: auto selecting yaffs1\n")));
+		yaffsVersion = 1;
+	}
+#endif
+	if (yaffsVersion == 2) {
+		/* Check for version 2 style functions */
+		if (!mtd->erase ||
+		    !mtd->block_isbad ||
+		    !mtd->block_markbad ||
+		    !mtd->read ||
+		    !mtd->write ||
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+		    !mtd->read_oob || !mtd->write_oob) {
+#else
+		    !mtd->write_ecc ||
+		    !mtd->read_ecc || !mtd->read_oob || !mtd->write_oob) {
+#endif
+			T(YAFFS_TRACE_ALWAYS,
+			  (TSTR("yaffs: MTD device does not support required "
+			   "functions\n")));
+			return NULL;
+		}
+		if ((WRITE_SIZE(mtd) < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
+		    mtd->oobsize < YAFFS_MIN_YAFFS2_SPARE_SIZE) &&
+		    !options.inband_tags) {
+			T(YAFFS_TRACE_ALWAYS,
+			  (TSTR("yaffs: MTD device does not have the "
+			   "right page sizes\n")));
+			return NULL;
+		}
+	} else {
+		/* Check for V1 style functions */
+		if (!mtd->erase ||
+		    !mtd->read ||
+		    !mtd->write ||
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+		    !mtd->read_oob || !mtd->write_oob) {
+#else
+		    !mtd->write_ecc ||
+		    !mtd->read_ecc || !mtd->read_oob || !mtd->write_oob) {
+#endif
+			T(YAFFS_TRACE_ALWAYS,
+			  (TSTR("yaffs: MTD device does not support required "
+			   "functions\n")));
+			return NULL;
+		}
+		if (WRITE_SIZE(mtd) < YAFFS_BYTES_PER_CHUNK ||
+		    mtd->oobsize != YAFFS_BYTES_PER_SPARE) {
+			T(YAFFS_TRACE_ALWAYS,
+			  (TSTR("yaffs: MTD device does not support have the "
+			   "right page sizes\n")));
+			return NULL;
+		}
+	}
+	/* OK, so if we got here, we have an MTD that's NAND and looks
+	 * like it has the right capabilities
+	 * Set the yaffs_Device up for mtd
+	 */
+	dev = kmalloc(sizeof(yaffs_Device), GFP_KERNEL);
+	context = kmalloc(sizeof(struct yaffs_LinuxContext),GFP_KERNEL);
+	if(!dev || !context ){
+		if(dev)
+			kfree(dev);
+		if(context)
+			kfree(context);
+		dev = NULL;
+		context = NULL;
+	}
+	if (!dev) {
+		/* Deep shit could not allocate device structure */
+		T(YAFFS_TRACE_ALWAYS,
+		  (TSTR("yaffs_read_super: Failed trying to allocate "
+		   "yaffs_Device. \n")));
+		return NULL;
+	}
+	memset(dev, 0, sizeof(yaffs_Device));
+	param = &(dev->param);
+	memset(context,0,sizeof(struct yaffs_LinuxContext));
+	dev->context = context;
+	YINIT_LIST_HEAD(&(context->contextList));
+	context->dev = dev;
+	context->superBlock = sb;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+	sb->s_fs_info = dev;
+#else
+	sb->u.generic_sbp = dev;
+#endif
+	yaffs_DeviceToContext(dev)->mtd = mtd;
+	param->name = mtd->name;
+	/* Set up the memory size parameters.... */
+	nBlocks = YCALCBLOCKS(mtd->size, (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK));
+	param->startBlock = 0;
+	param->endBlock = nBlocks - 1;
+	param->nChunksPerBlock = YAFFS_CHUNKS_PER_BLOCK;
+	param->totalBytesPerChunk = YAFFS_BYTES_PER_CHUNK;
+	param->nReservedBlocks = 5;
+	param->nShortOpCaches = (options.no_cache) ? 0 : 10;
+	param->inbandTags = options.inband_tags;
+#ifdef CONFIG_YAFFS_DISABLE_LAZY_LOAD
+	param->disableLazyLoad = 1;
+#endif
+	if(options.lazy_loading_overridden)
+		param->disableLazyLoad = !options.lazy_loading_enabled;
+#ifdef CONFIG_YAFFS_DISABLE_TAGS_ECC
+	param->noTagsECC = 1;
+#endif
+#ifdef CONFIG_YAFFS_DISABLE_BACKGROUND
+#else
+	param->deferDirectoryUpdate = 1;
+#endif
+	if(options.tags_ecc_overridden)
+		param->noTagsECC = !options.tags_ecc_on;
+#ifdef CONFIG_YAFFS_EMPTY_LOST_AND_FOUND
+	param->emptyLostAndFound = 1;
+#endif
+#ifdef CONFIG_YAFFS_DISABLE_BLOCK_REFRESHING
+	param->refreshPeriod = 0;
+#else
+	param->refreshPeriod = 500;
+#endif
+	if(options.empty_lost_and_found_overridden)
+		param->emptyLostAndFound = options.empty_lost_and_found;
+	/* ... and the functions. */
+	if (yaffsVersion == 2) {
+		param->writeChunkWithTagsToNAND =
+		    nandmtd2_WriteChunkWithTagsToNAND;
+		param->readChunkWithTagsFromNAND =
+		    nandmtd2_ReadChunkWithTagsFromNAND;
+		param->markNANDBlockBad = nandmtd2_MarkNANDBlockBad;
+		param->queryNANDBlock = nandmtd2_QueryNANDBlock;
+		yaffs_DeviceToContext(dev)->spareBuffer = YMALLOC(mtd->oobsize);
+		param->isYaffs2 = 1;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+		param->totalBytesPerChunk = mtd->writesize;
+		param->nChunksPerBlock = mtd->erasesize / mtd->writesize;
+#else
+		param->totalBytesPerChunk = mtd->oobblock;
+		param->nChunksPerBlock = mtd->erasesize / mtd->oobblock;
+#endif
+		nBlocks = YCALCBLOCKS(mtd->size, mtd->erasesize);
+		param->startBlock = 0;
+		param->endBlock = nBlocks - 1;
+	} else {
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+		/* use the MTD interface in yaffs_mtdif1.c */
+		param->writeChunkWithTagsToNAND =
+			nandmtd1_WriteChunkWithTagsToNAND;
+		param->readChunkWithTagsFromNAND =
+			nandmtd1_ReadChunkWithTagsFromNAND;
+		param->markNANDBlockBad = nandmtd1_MarkNANDBlockBad;
+		param->queryNANDBlock = nandmtd1_QueryNANDBlock;
+#else
+		param->writeChunkToNAND = nandmtd_WriteChunkToNAND;
+		param->readChunkFromNAND = nandmtd_ReadChunkFromNAND;
+#endif
+		param->isYaffs2 = 0;
+	}
+	/* ... and common functions */
+	param->eraseBlockInNAND = nandmtd_EraseBlockInNAND;
+	param->initialiseNAND = nandmtd_InitialiseNAND;
+	yaffs_DeviceToContext(dev)->putSuperFunc = yaffs_MTDPutSuper;
+	param->markSuperBlockDirty = yaffs_MarkSuperBlockDirty;
+	param->gcControl = yaffs_gc_control_callback;
+	yaffs_DeviceToContext(dev)->superBlock= sb;
+#ifndef CONFIG_YAFFS_DOES_ECC
+	param->useNANDECC = 1;
+#endif
+#ifdef CONFIG_YAFFS_DISABLE_WIDE_TNODES
+	param->wideTnodesDisabled = 1;
+#endif
+	param->skipCheckpointRead = options.skip_checkpoint_read;
+	param->skipCheckpointWrite = options.skip_checkpoint_write;
+	/* we assume this is protected by lock_kernel() in mount/umount */
+	down(&yaffs_context_lock);
+	ylist_add_tail(&(yaffs_DeviceToContext(dev)->contextList), &yaffs_context_list);
+	up(&yaffs_context_lock);
+/* Directory search handling...*/
+YINIT_LIST_HEAD(&(yaffs_DeviceToContext(dev)->searchContexts));
+param->removeObjectCallback = yaffs_RemoveObjectCallback;
+	init_MUTEX(&(yaffs_DeviceToContext(dev)->grossLock));
+	yaffs_GrossLock(dev);
+	err = yaffs_GutsInitialise(dev);
+	T(YAFFS_TRACE_OS,
+	  (TSTR("yaffs_read_super: guts initialised %s\n"),
+	   (err == YAFFS_OK) ? "OK" : "FAILED"));
+	if(err == YAFFS_OK)
+		yaffs_BackgroundStart(dev);
+	if(!context->bgThread)
+		param->deferDirectoryUpdate = 0;
+	/* Release lock before yaffs_get_inode() */
+	yaffs_GrossUnlock(dev);
+	/* Create root inode */
+	if (err == YAFFS_OK)
+		inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0,
+					yaffs_Root(dev));
+	if (!inode)
+		return NULL;
+	inode->i_op = &yaffs_dir_inode_operations;
+	inode->i_fop = &yaffs_dir_operations;
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_read_super: got root inode\n")));
+	root = d_alloc_root(inode);
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_read_super: d_alloc_root done\n")));
+	if (!root) {
+		iput(inode);
+		return NULL;
+	}
+	sb->s_root = root;
+	sb->s_dirt = !dev->isCheckpointed;
+	T(YAFFS_TRACE_ALWAYS,
+		(TSTR("yaffs_read_super: isCheckpointed %d\n"),
+		dev->isCheckpointed));
+	T(YAFFS_TRACE_OS, (TSTR("yaffs_read_super: done\n")));
+	return sb;
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs_internal_read_super_mtd(struct super_block *sb, void *data,
+					 int silent)
+{
+	return yaffs_internal_read_super(1, sb, data, silent) ? 0 : -EINVAL;
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_read_super(struct file_system_type *fs,
+			    int flags, const char *dev_name,
+			    void *data, struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs, flags, dev_name, data,
+			   yaffs_internal_read_super_mtd, mnt);
+}
+#else
+static struct super_block *yaffs_read_super(struct file_system_type *fs,
+					    int flags, const char *dev_name,
+					    void *data)
+{
+	return get_sb_bdev(fs, flags, dev_name, data,
+			   yaffs_internal_read_super_mtd);
+}
+#endif
+static struct file_system_type yaffs_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "yaffs",
+	.get_sb = yaffs_read_super,
+	.kill_sb = kill_block_super,
+	.fs_flags = FS_REQUIRES_DEV,
+};
+#else
+static struct super_block *yaffs_read_super(struct super_block *sb, void *data,
+					    int silent)
+{
+	return yaffs_internal_read_super(1, sb, data, silent);
+}
+static DECLARE_FSTYPE(yaffs_fs_type, "yaffs", yaffs_read_super,
+		      FS_REQUIRES_DEV);
+#endif
+#ifdef CONFIG_YAFFS_YAFFS2
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0))
+static int yaffs2_internal_read_super_mtd(struct super_block *sb, void *data,
+					  int silent)
+{
+	return yaffs_internal_read_super(2, sb, data, silent) ? 0 : -EINVAL;
+}
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs2_read_super(struct file_system_type *fs,
+			int flags, const char *dev_name, void *data,
+			struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs, flags, dev_name, data,
+			yaffs2_internal_read_super_mtd, mnt);
+}
+#else
+static struct super_block *yaffs2_read_super(struct file_system_type *fs,
+					     int flags, const char *dev_name,
+					     void *data)
+{
+	return get_sb_bdev(fs, flags, dev_name, data,
+			   yaffs2_internal_read_super_mtd);
+}
+#endif
+static struct file_system_type yaffs2_fs_type = {
+	.owner = THIS_MODULE,
+	.name = "yaffs2",
+	.get_sb = yaffs2_read_super,
+	.kill_sb = kill_block_super,
+	.fs_flags = FS_REQUIRES_DEV,
+};
+#else
+static struct super_block *yaffs2_read_super(struct super_block *sb,
+					     void *data, int silent)
+{
+	return yaffs_internal_read_super(2, sb, data, silent);
+}
+static DECLARE_FSTYPE(yaffs2_fs_type, "yaffs2", yaffs2_read_super,
+		      FS_REQUIRES_DEV);
+#endif
+#endif				/* CONFIG_YAFFS_YAFFS2 */
+static struct proc_dir_entry *my_proc_entry;
+static struct proc_dir_entry *debug_proc_entry;
+static char *yaffs_dump_dev_part0(char *buf, yaffs_Device * dev)
+{
+	buf += sprintf(buf, "startBlock......... %d\n", dev->param.startBlock);
+	buf += sprintf(buf, "endBlock........... %d\n", dev->param.endBlock);
+	buf += sprintf(buf, "totalBytesPerChunk. %d\n", dev->param.totalBytesPerChunk);
+	buf += sprintf(buf, "useNANDECC......... %d\n", dev->param.useNANDECC);
+	buf += sprintf(buf, "noTagsECC.......... %d\n", dev->param.noTagsECC);
+	buf += sprintf(buf, "isYaffs2........... %d\n", dev->param.isYaffs2);
+	buf += sprintf(buf, "inbandTags......... %d\n", dev->param.inbandTags);
+	buf += sprintf(buf, "emptyLostAndFound.. %d\n", dev->param.emptyLostAndFound);
+	buf += sprintf(buf, "disableLazyLoad.... %d\n", dev->param.disableLazyLoad);
+	buf += sprintf(buf, "refreshPeriod...... %d\n", dev->param.refreshPeriod);
+	buf += sprintf(buf, "nShortOpCaches..... %d\n", dev->param.nShortOpCaches);
+	buf += sprintf(buf, "nReservedBlocks.... %d\n", dev->param.nReservedBlocks);
+	buf += sprintf(buf, "\n");
+	return buf;
+}
+static char *yaffs_dump_dev_part1(char *buf, yaffs_Device * dev)
+{
+	buf += sprintf(buf, "nDataBytesPerChunk. %d\n", dev->nDataBytesPerChunk);
+	buf += sprintf(buf, "chunkGroupBits..... %d\n", dev->chunkGroupBits);
+	buf += sprintf(buf, "chunkGroupSize..... %d\n", dev->chunkGroupSize);
+	buf += sprintf(buf, "nErasedBlocks...... %d\n", dev->nErasedBlocks);
+	buf += sprintf(buf, "blocksInCheckpoint. %d\n", dev->blocksInCheckpoint);
+	buf += sprintf(buf, "\n");
+	buf += sprintf(buf, "nTnodesCreated..... %d\n", dev->nTnodesCreated);
+	buf += sprintf(buf, "nFreeTnodes........ %d\n", dev->nFreeTnodes);
+	buf += sprintf(buf, "nObjectsCreated.... %d\n", dev->nObjectsCreated);
+	buf += sprintf(buf, "nFreeObjects....... %d\n", dev->nFreeObjects);
+	buf += sprintf(buf, "nFreeChunks........ %d\n", dev->nFreeChunks);
+	buf += sprintf(buf, "\n");
+	buf += sprintf(buf, "nPageWrites........ %u\n", dev->nPageWrites);
+	buf += sprintf(buf, "nPageReads......... %u\n", dev->nPageReads);
+	buf += sprintf(buf, "nBlockErasures..... %u\n", dev->nBlockErasures);
+	buf += sprintf(buf, "nGCCopies.......... %u\n", dev->nGCCopies);
+	buf += sprintf(buf, "allGCs............. %u\n", dev->allGCs);
+	buf += sprintf(buf, "passiveGCs......... %u\n", dev->passiveGCs);
+	buf += sprintf(buf, "oldestDirtyGCs..... %u\n", dev->oldestDirtyGCs);
+	buf += sprintf(buf, "backgroundGCs...... %u\n", dev->backgroundGCs);
+	buf += sprintf(buf, "nRetriedWrites..... %u\n", dev->nRetriedWrites);
+	buf += sprintf(buf, "nRetireBlocks...... %u\n", dev->nRetiredBlocks);
+	buf += sprintf(buf, "eccFixed........... %u\n", dev->eccFixed);
+	buf += sprintf(buf, "eccUnfixed......... %u\n", dev->eccUnfixed);
+	buf += sprintf(buf, "tagsEccFixed....... %u\n", dev->tagsEccFixed);
+	buf += sprintf(buf, "tagsEccUnfixed..... %u\n", dev->tagsEccUnfixed);
+	buf += sprintf(buf, "cacheHits.......... %u\n", dev->cacheHits);
+	buf += sprintf(buf, "nDeletedFiles...... %u\n", dev->nDeletedFiles);
+	buf += sprintf(buf, "nUnlinkedFiles..... %u\n", dev->nUnlinkedFiles);
+	buf += sprintf(buf, "refreshCount....... %u\n", dev->refreshCount);
+	buf +=
+	    sprintf(buf, "nBackgroudDeletions %u\n", dev->nBackgroundDeletions);
+	return buf;
+}
+static int yaffs_proc_read(char *page,
+			   char **start,
+			   off_t offset, int count, int *eof, void *data)
+{
+	struct ylist_head *item;
+	char *buf = page;
+	int step = offset;
+	int n = 0;
+	/* Get proc_file_read() to step 'offset' by one on each sucessive call.
+	 * We use 'offset' (*ppos) to indicate where we are in devList.
+	 * This also assumes the user has posted a read buffer large
+	 * enough to hold the complete output; but that's life in /proc.
+	 */
+	*(int *)start = 1;
+	/* Print header first */
+	if (step == 0)
+		buf += sprintf(buf, "YAFFS built:" __DATE__ " " __TIME__"\n");
+	else if (step == 1)
+		buf += sprintf(buf,"\n");
+	else {
+		step-=2;
+		down(&yaffs_context_lock);
+		/* Locate and print the Nth entry.  Order N-squared but N is small. */
+		ylist_for_each(item, &yaffs_context_list) {
+			struct yaffs_LinuxContext *dc = ylist_entry(item, struct yaffs_LinuxContext, contextList);
+			yaffs_Device *dev = dc->dev;
+			if (n < (step & ~1)) {
+				n+=2;
+				continue;
+			}
+			if((step & 1)==0){
+				buf += sprintf(buf, "\nDevice %d \"%s\"\n", n, dev->param.name);
+				buf = yaffs_dump_dev_part0(buf, dev);
+			} else
+				buf = yaffs_dump_dev_part1(buf, dev);
+			break;
+		}
+		up(&yaffs_context_lock);
+	}
+	return buf - page < count ? buf - page : count;
+}
+static int yaffs_stats_proc_read(char *page,
+				char **start,
+				off_t offset, int count, int *eof, void *data)
+{
+	struct ylist_head *item;
+	char *buf = page;
+	int n = 0;
+	down(&yaffs_context_lock);
+	/* Locate and print the Nth entry.  Order N-squared but N is small. */
+	ylist_for_each(item, &yaffs_context_list) {
+		struct yaffs_LinuxContext *dc = ylist_entry(item, struct yaffs_LinuxContext, contextList);
+		yaffs_Device *dev = dc->dev;
+		int erasedChunks;
+		int nObjects;
+		int nTnodes;
+		erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
+		nObjects = dev->nObjectsCreated -dev->nFreeObjects;
+		nTnodes = dev->nTnodesCreated - dev->nFreeTnodes;
+		buf += sprintf(buf,"%d, %d, %d, %u, %u, %d, %d\n",
+				n, dev->nFreeChunks, erasedChunks,
+				dev->backgroundGCs, dev->oldestDirtyGCs,
+				nObjects, nTnodes);
+	}
+	up(&yaffs_context_lock);
+	return buf - page < count ? buf - page : count;
+}
+/**
+* Set the verbosity of the warnings and error messages.
+*
+* Note that the names can only be a..z or _ with the current code.
+*/
+static struct {
+	char *mask_name;
+	unsigned mask_bitfield;
+} mask_flags[] = {
+	{"allocate", YAFFS_TRACE_ALLOCATE},
+	{"always", YAFFS_TRACE_ALWAYS},
+	{"background", YAFFS_TRACE_BACKGROUND},
+	{"bad_blocks", YAFFS_TRACE_BAD_BLOCKS},
+	{"buffers", YAFFS_TRACE_BUFFERS},
+	{"bug", YAFFS_TRACE_BUG},
+	{"checkpt", YAFFS_TRACE_CHECKPOINT},
+	{"deletion", YAFFS_TRACE_DELETION},
+	{"erase", YAFFS_TRACE_ERASE},
+	{"error", YAFFS_TRACE_ERROR},
+	{"gc_detail", YAFFS_TRACE_GC_DETAIL},
+	{"gc", YAFFS_TRACE_GC},
+	{"lock", YAFFS_TRACE_LOCK},
+	{"mtd", YAFFS_TRACE_MTD},
+	{"nandaccess", YAFFS_TRACE_NANDACCESS},
+	{"os", YAFFS_TRACE_OS},
+	{"scan_debug", YAFFS_TRACE_SCAN_DEBUG},
+	{"scan", YAFFS_TRACE_SCAN},
+	{"tracing", YAFFS_TRACE_TRACING},
+	{"sync", YAFFS_TRACE_SYNC},
+	{"write", YAFFS_TRACE_WRITE},
+	{"verify", YAFFS_TRACE_VERIFY},
+	{"verify_nand", YAFFS_TRACE_VERIFY_NAND},
+	{"verify_full", YAFFS_TRACE_VERIFY_FULL},
+	{"verify_all", YAFFS_TRACE_VERIFY_ALL},
+	{"all", 0xffffffff},
+	{"none", 0},
+	{NULL, 0},
+};
+#define MAX_MASK_NAME_LENGTH 40
+static int yaffs_proc_write_trace_options(struct file *file, const char *buf,
+					 unsigned long count, void *data)
+{
+	unsigned rg = 0, mask_bitfield;
+	char *end;
+	char *mask_name;
+	const char *x;
+	char substring[MAX_MASK_NAME_LENGTH + 1];
+	int i;
+	int done = 0;
+	int add, len = 0;
+	int pos = 0;
+	rg = yaffs_traceMask;
+	while (!done && (pos < count)) {
+		done = 1;
+		while ((pos < count) && isspace(buf[pos]))
+			pos++;
+		switch (buf[pos]) {
+		case '+':
+		case '-':
+		case '=':
+			add = buf[pos];
+			pos++;
+			break;
+		default:
+			add = ' ';
+			break;
+		}
+		mask_name = NULL;
+		mask_bitfield = simple_strtoul(buf + pos, &end, 0);
+		if (end > buf + pos) {
+			mask_name = "numeral";
+			len = end - (buf + pos);
+			pos += len;
+			done = 0;
+		} else {
+			for (x = buf + pos, i = 0;
+			    (*x == '_' || (*x >= 'a' && *x <= 'z')) &&
+			    i < MAX_MASK_NAME_LENGTH; x++, i++, pos++)
+				substring[i] = *x;
+			substring[i] = '\0';
+			for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+				if (strcmp(substring, mask_flags[i].mask_name) == 0) {
+					mask_name = mask_flags[i].mask_name;
+					mask_bitfield = mask_flags[i].mask_bitfield;
+					done = 0;
+					break;
+				}
+			}
+		}
+		if (mask_name != NULL) {
+			done = 0;
+			switch (add) {
+			case '-':
+				rg &= ~mask_bitfield;
+				break;
+			case '+':
+				rg |= mask_bitfield;
+				break;
+			case '=':
+				rg = mask_bitfield;
+				break;
+			default:
+				rg |= mask_bitfield;
+				break;
+			}
+		}
+	}
+	yaffs_traceMask = rg | YAFFS_TRACE_ALWAYS;
+	printk(KERN_DEBUG "new trace = 0x%08X\n", yaffs_traceMask);
+	if (rg & YAFFS_TRACE_ALWAYS) {
+		for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+			char flag;
+			flag = ((rg & mask_flags[i].mask_bitfield) ==
+				mask_flags[i].mask_bitfield) ? '+' : '-';
+			printk(KERN_DEBUG "%c%s\n", flag, mask_flags[i].mask_name);
+		}
+	}
+	return count;
+}
+static int yaffs_proc_write(struct file *file, const char *buf,
+					 unsigned long count, void *data)
+{
+return yaffs_proc_write_trace_options(file, buf, count, data);
+}
+/* Stuff to handle installation of file systems */
+struct file_system_to_install {
+	struct file_system_type *fst;
+	int installed;
+};
+static struct file_system_to_install fs_to_install[] = {
+	{&yaffs_fs_type, 0},
+	{&yaffs2_fs_type, 0},
+	{NULL, 0}
+};
+static int __init init_yaffs_fs(void)
+{
+	int error = 0;
+	struct file_system_to_install *fsinst;
+	T(YAFFS_TRACE_ALWAYS,
+	  (TSTR("yaffs built " __DATE__ " " __TIME__ " Installing. \n")));
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+	T(YAFFS_TRACE_ALWAYS,
+	  (TSTR(" \n\n\n\nYAFFS-WARNING CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED selected.\n\n\n\n")));
+#endif
+	init_MUTEX(&yaffs_context_lock);
+	/* Install the proc_fs entries */
+	my_proc_entry = create_proc_entry("yaffs",
+					       S_IRUGO | S_IFREG,
+					       YPROC_ROOT);
+	if (my_proc_entry) {
+		my_proc_entry->write_proc = yaffs_proc_write;
+		my_proc_entry->read_proc = yaffs_proc_read;
+		my_proc_entry->data = NULL;
+	} else
+		return -ENOMEM;
+	debug_proc_entry = create_proc_entry("yaffs_stats",
+					       S_IRUGO | S_IFREG,
+					       YPROC_ROOT);
+	if (debug_proc_entry) {
+		debug_proc_entry->write_proc = NULL;
+		debug_proc_entry->read_proc = yaffs_stats_proc_read;
+		debug_proc_entry->data = NULL;
+	} else
+		return -ENOMEM;
+	/* Now add the file system entries */
+	fsinst = fs_to_install;
+	while (fsinst->fst && !error) {
+		error = register_filesystem(fsinst->fst);
+		if (!error)
+			fsinst->installed = 1;
+		fsinst++;
+	}
+	/* Any errors? uninstall  */
+	if (error) {
+		fsinst = fs_to_install;
+		while (fsinst->fst) {
+			if (fsinst->installed) {
+				unregister_filesystem(fsinst->fst);
+				fsinst->installed = 0;
+			}
+			fsinst++;
+		}
+	}
+	return error;
+}
+static void __exit exit_yaffs_fs(void)
+{
+	struct file_system_to_install *fsinst;
+	T(YAFFS_TRACE_ALWAYS,
+		(TSTR("yaffs built " __DATE__ " " __TIME__ " removing. \n")));
+	remove_proc_entry("yaffs", YPROC_ROOT);
+	remove_proc_entry("yaffs_stats", YPROC_ROOT);
+	fsinst = fs_to_install;
+	while (fsinst->fst) {
+		if (fsinst->installed) {
+			unregister_filesystem(fsinst->fst);
+			fsinst->installed = 0;
+		}
+		fsinst++;
+	}
+}
+module_init(init_yaffs_fs)
+module_exit(exit_yaffs_fs)
+MODULE_DESCRIPTION("YAFFS2 - a NAND specific flash file system");
+MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002-2010");
+MODULE_LICENSE("GPL");

Mercurial > yaffs-ecoscentric-gpl

comparison packages/fs/yaffs/current/src/yaffs_fs.c @ 425:dea4d7d250ad ecos