fs: yaffs: Import yaffs from Thu Dec 23 13:31:37 2010 +1300
Arve Hjønnevåg [Wed, 19 May 2010 03:35:30 +0000 (20:35 -0700)]
commit ddf33fed15c2376bfb602d62dd018c63fce60df8
Author: Timothy Manning <tfhmanning@gmail.com>
Date:   Thu Dec 23 13:31:37 2010 +1300

    yaffs updated direct/timothy_tests/quick_tests
Signed-off-by: Timothy Manning <tfhmanning@gmail.com>

Change-Id: I5bbe5a05277bdf8a6fe188bbe4c77725b3fa2aae
Signed-off-by: Dima Zavin <dima@android.com>

45 files changed:
fs/Kconfig
fs/Makefile
fs/yaffs2/Kconfig [new file with mode: 0644]
fs/yaffs2/Makefile [new file with mode: 0644]
fs/yaffs2/yaffs_allocator.c [new file with mode: 0644]
fs/yaffs2/yaffs_allocator.h [new file with mode: 0644]
fs/yaffs2/yaffs_attribs.c [new file with mode: 0644]
fs/yaffs2/yaffs_attribs.h [new file with mode: 0644]
fs/yaffs2/yaffs_bitmap.c [new file with mode: 0644]
fs/yaffs2/yaffs_bitmap.h [new file with mode: 0644]
fs/yaffs2/yaffs_checkptrw.c [new file with mode: 0644]
fs/yaffs2/yaffs_checkptrw.h [new file with mode: 0644]
fs/yaffs2/yaffs_ecc.c [new file with mode: 0644]
fs/yaffs2/yaffs_ecc.h [new file with mode: 0644]
fs/yaffs2/yaffs_getblockinfo.h [new file with mode: 0644]
fs/yaffs2/yaffs_guts.c [new file with mode: 0644]
fs/yaffs2/yaffs_guts.h [new file with mode: 0644]
fs/yaffs2/yaffs_linux.h [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif.c [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif.h [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif1.c [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif1.h [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif2.c [new file with mode: 0644]
fs/yaffs2/yaffs_mtdif2.h [new file with mode: 0644]
fs/yaffs2/yaffs_nameval.c [new file with mode: 0644]
fs/yaffs2/yaffs_nameval.h [new file with mode: 0644]
fs/yaffs2/yaffs_nand.c [new file with mode: 0644]
fs/yaffs2/yaffs_nand.h [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags1.c [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags1.h [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags2.c [new file with mode: 0644]
fs/yaffs2/yaffs_packedtags2.h [new file with mode: 0644]
fs/yaffs2/yaffs_tagscompat.c [new file with mode: 0644]
fs/yaffs2/yaffs_tagscompat.h [new file with mode: 0644]
fs/yaffs2/yaffs_tagsvalidity.c [new file with mode: 0644]
fs/yaffs2/yaffs_tagsvalidity.h [new file with mode: 0644]
fs/yaffs2/yaffs_trace.h [new file with mode: 0644]
fs/yaffs2/yaffs_verify.c [new file with mode: 0644]
fs/yaffs2/yaffs_verify.h [new file with mode: 0644]
fs/yaffs2/yaffs_vfs.c [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs1.c [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs1.h [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs2.c [new file with mode: 0644]
fs/yaffs2/yaffs_yaffs2.h [new file with mode: 0644]
fs/yaffs2/yportenv.h [new file with mode: 0644]

index 9fe0b34..99453ba 100644 (file)
@@ -199,6 +199,10 @@ source "fs/hfsplus/Kconfig"
 source "fs/befs/Kconfig"
 source "fs/bfs/Kconfig"
 source "fs/efs/Kconfig"
+
+# Patched by YAFFS
+source "fs/yaffs2/Kconfig"
+
 source "fs/jffs2/Kconfig"
 # UBIFS File system configuration
 source "fs/ubifs/Kconfig"
index afc1096..a8bbb32 100644 (file)
@@ -123,3 +123,6 @@ obj-$(CONFIG_GFS2_FS)           += gfs2/
 obj-$(CONFIG_EXOFS_FS)          += exofs/
 obj-$(CONFIG_CEPH_FS)          += ceph/
 obj-$(CONFIG_PSTORE)           += pstore/
+
+# Patched by YAFFS
+obj-$(CONFIG_YAFFS_FS)         += yaffs2/
diff --git a/fs/yaffs2/Kconfig b/fs/yaffs2/Kconfig
new file mode 100644 (file)
index 0000000..6354140
--- /dev/null
@@ -0,0 +1,161 @@
+#
+# YAFFS file system configurations
+#
+
+config YAFFS_FS
+       tristate "YAFFS2 file system support"
+       default n
+       depends on MTD_BLOCK
+       select YAFFS_YAFFS1
+       select YAFFS_YAFFS2
+       help
+         YAFFS2, or Yet Another Flash Filing System, is a filing system
+         optimised for NAND Flash chips.
+
+         To compile the YAFFS2 file system support as a module, choose M
+         here: the module will be called yaffs2.
+
+         If unsure, say N.
+
+         Further information on YAFFS2 is available at
+         <http://www.aleph1.co.uk/yaffs/>.
+
+config YAFFS_YAFFS1
+       bool "512 byte / page devices"
+       depends on YAFFS_FS
+       default y
+       help
+         Enable YAFFS1 support -- yaffs for 512 byte / page devices
+
+         Not needed for 2K-page devices.
+
+         If unsure, say Y.
+
+config YAFFS_9BYTE_TAGS
+       bool "Use older-style on-NAND data format with pageStatus byte"
+       depends on YAFFS_YAFFS1
+       default n
+       help
+
+         Older-style on-NAND data format has a "pageStatus" byte to record
+         chunk/page state.  This byte is zero when the page is discarded.
+         Choose this option if you have existing on-NAND data using this
+         format that you need to continue to support.  New data written
+         also uses the older-style format.  Note: Use of this option
+         generally requires that MTD's oob layout be adjusted to use the
+         older-style format.  See notes on tags formats and MTD versions
+         in yaffs_mtdif1.c.
+
+         If unsure, say N.
+
+config YAFFS_DOES_ECC
+       bool "Lets Yaffs do its own ECC"
+       depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
+       default n
+       help
+         This enables Yaffs to use its own ECC functions instead of using
+         the ones from the generic MTD-NAND driver.
+
+         If unsure, say N.
+
+config YAFFS_ECC_WRONG_ORDER
+       bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
+       depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
+       default n
+       help
+         This makes yaffs_ecc.c use the same ecc byte order as Steven
+         Hill's nand_ecc.c. If not set, then you get the same ecc byte
+         order as SmartMedia.
+
+         If unsure, say N.
+
+config YAFFS_YAFFS2
+       bool "2048 byte (or larger) / page devices"
+       depends on YAFFS_FS
+       default y
+       help
+         Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices
+
+         If unsure, say Y.
+
+config YAFFS_AUTO_YAFFS2
+       bool "Autoselect yaffs2 format"
+       depends on YAFFS_YAFFS2
+       default y
+       help
+         Without this, you need to explicitely use yaffs2 as the file
+         system type. With this, you can say "yaffs" and yaffs or yaffs2
+         will be used depending on the device page size (yaffs on
+         512-byte page devices, yaffs2 on 2K page devices).
+
+         If unsure, say Y.
+
+config YAFFS_DISABLE_TAGS_ECC
+       bool "Disable YAFFS from doing ECC on tags by default"
+       depends on YAFFS_FS && YAFFS_YAFFS2
+       default n
+       help
+         This defaults Yaffs to using its own ECC calculations on tags instead of
+         just relying on the MTD.
+         This behavior can also be overridden with tags_ecc_on and
+         tags_ecc_off mount options.
+
+         If unsure, say N.
+
+config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+       bool "Force chunk erase check"
+       depends on YAFFS_FS
+       default n
+       help
+          Normally YAFFS only checks chunks before writing until an erased
+         chunk is found. This helps to detect any partially written
+         chunks that might have happened due to power loss.
+
+         Enabling this forces on the test that chunks are erased in flash
+         before writing to them. This takes more time but is potentially
+         a bit more secure.
+
+         Suggest setting Y during development and ironing out driver
+         issues etc. Suggest setting to N if you want faster writing.
+
+         If unsure, say Y.
+
+config YAFFS_EMPTY_LOST_AND_FOUND
+       bool "Empty lost and found on boot"
+       depends on YAFFS_FS
+       default n
+       help
+         If this is enabled then the contents of lost and found is
+         automatically dumped at mount.
+
+         If unsure, say N.
+
+config YAFFS_DISABLE_BLOCK_REFRESHING
+       bool "Disable yaffs2 block refreshing"
+       depends on YAFFS_FS
+       default n
+       help
+        If this is set, then block refreshing is disabled.
+        Block refreshing infrequently refreshes the oldest block in
+        a yaffs2 file system. This mechanism helps to refresh flash to
+        mitigate against data loss. This is particularly useful for MLC.
+
+         If unsure, say N.
+
+config YAFFS_DISABLE_BACKGROUND
+       bool "Disable yaffs2 background processing"
+       depends on YAFFS_FS
+       default n
+       help
+        If this is set, then background processing is disabled.
+        Background processing makes many foreground activities faster.
+
+        If unsure, say N.
+
+config YAFFS_XATTR
+       bool "Enable yaffs2 xattr support"
+       depends on YAFFS_FS
+       default y
+       help
+        If this is set then yaffs2 will provide xattr support.
+        If unsure, say Y.
diff --git a/fs/yaffs2/Makefile b/fs/yaffs2/Makefile
new file mode 100644 (file)
index 0000000..e63a28a
--- /dev/null
@@ -0,0 +1,17 @@
+#
+# Makefile for the linux YAFFS filesystem routines.
+#
+
+obj-$(CONFIG_YAFFS_FS) += yaffs.o
+
+yaffs-y := yaffs_ecc.o yaffs_vfs.o yaffs_guts.o yaffs_checkptrw.o
+yaffs-y += yaffs_packedtags1.o yaffs_packedtags2.o yaffs_nand.o
+yaffs-y += yaffs_tagscompat.o yaffs_tagsvalidity.o
+yaffs-y += yaffs_mtdif.o yaffs_mtdif1.o yaffs_mtdif2.o
+yaffs-y += yaffs_nameval.o yaffs_attribs.o
+yaffs-y += yaffs_allocator.o
+yaffs-y += yaffs_yaffs1.o
+yaffs-y += yaffs_yaffs2.o
+yaffs-y += yaffs_bitmap.o
+yaffs-y += yaffs_verify.o
+
diff --git a/fs/yaffs2/yaffs_allocator.c b/fs/yaffs2/yaffs_allocator.c
new file mode 100644 (file)
index 0000000..f9cd5be
--- /dev/null
@@ -0,0 +1,396 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_allocator.h"
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+#include "yportenv.h"
+
+#ifdef CONFIG_YAFFS_KMALLOC_ALLOCATOR
+
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
+{
+       return (struct yaffs_tnode *)kmalloc(dev->tnode_size, GFP_NOFS);
+}
+
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+       dev = dev;
+       kfree(tn);
+}
+
+void yaffs_init_raw_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
+{
+       dev = dev;
+}
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
+{
+       dev = dev;
+       return (struct yaffs_obj *)kmalloc(sizeof(struct yaffs_obj));
+}
+
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+
+       dev = dev;
+       kfree(obj);
+}
+
+#else
+
+struct yaffs_tnode_list {
+       struct yaffs_tnode_list *next;
+       struct yaffs_tnode *tnodes;
+};
+
+struct yaffs_obj_list {
+       struct yaffs_obj_list *next;
+       struct yaffs_obj *objects;
+};
+
+struct yaffs_allocator {
+       int n_tnodes_created;
+       struct yaffs_tnode *free_tnodes;
+       int n_free_tnodes;
+       struct yaffs_tnode_list *alloc_tnode_list;
+
+       int n_obj_created;
+       struct yaffs_obj *free_objs;
+       int n_free_objects;
+
+       struct yaffs_obj_list *allocated_obj_list;
+};
+
+static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
+{
+
+       struct yaffs_allocator *allocator =
+           (struct yaffs_allocator *)dev->allocator;
+
+       struct yaffs_tnode_list *tmp;
+
+       if (!allocator) {
+               YBUG();
+               return;
+       }
+
+       while (allocator->alloc_tnode_list) {
+               tmp = allocator->alloc_tnode_list->next;
+
+               kfree(allocator->alloc_tnode_list->tnodes);
+               kfree(allocator->alloc_tnode_list);
+               allocator->alloc_tnode_list = tmp;
+
+       }
+
+       allocator->free_tnodes = NULL;
+       allocator->n_free_tnodes = 0;
+       allocator->n_tnodes_created = 0;
+}
+
+static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (allocator) {
+               allocator->alloc_tnode_list = NULL;
+               allocator->free_tnodes = NULL;
+               allocator->n_free_tnodes = 0;
+               allocator->n_tnodes_created = 0;
+       } else {
+               YBUG();
+       }
+}
+
+static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
+{
+       struct yaffs_allocator *allocator =
+           (struct yaffs_allocator *)dev->allocator;
+       int i;
+       struct yaffs_tnode *new_tnodes;
+       u8 *mem;
+       struct yaffs_tnode *curr;
+       struct yaffs_tnode *next;
+       struct yaffs_tnode_list *tnl;
+
+       if (!allocator) {
+               YBUG();
+               return YAFFS_FAIL;
+       }
+
+       if (n_tnodes < 1)
+               return YAFFS_OK;
+
+       /* make these things */
+
+       new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
+       mem = (u8 *) new_tnodes;
+
+       if (!new_tnodes) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "yaffs: Could not allocate Tnodes");
+               return YAFFS_FAIL;
+       }
+
+       /* New hookup for wide tnodes */
+       for (i = 0; i < n_tnodes - 1; i++) {
+               curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size];
+               next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size];
+               curr->internal[0] = next;
+       }
+
+       curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size];
+       curr->internal[0] = allocator->free_tnodes;
+       allocator->free_tnodes = (struct yaffs_tnode *)mem;
+
+       allocator->n_free_tnodes += n_tnodes;
+       allocator->n_tnodes_created += n_tnodes;
+
+       /* Now add this bunch of tnodes to a list for freeing up.
+        * NB If we can't add this to the management list it isn't fatal
+        * but it just means we can't free this bunch of tnodes later.
+        */
+
+       tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
+       if (!tnl) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "Could not add tnodes to management list");
+               return YAFFS_FAIL;
+       } else {
+               tnl->tnodes = new_tnodes;
+               tnl->next = allocator->alloc_tnode_list;
+               allocator->alloc_tnode_list = tnl;
+       }
+
+       yaffs_trace(YAFFS_TRACE_ALLOCATE,"Tnodes added");
+
+       return YAFFS_OK;
+}
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator =
+           (struct yaffs_allocator *)dev->allocator;
+       struct yaffs_tnode *tn = NULL;
+
+       if (!allocator) {
+               YBUG();
+               return NULL;
+       }
+
+       /* If there are none left make more */
+       if (!allocator->free_tnodes)
+               yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES);
+
+       if (allocator->free_tnodes) {
+               tn = allocator->free_tnodes;
+               allocator->free_tnodes = allocator->free_tnodes->internal[0];
+               allocator->n_free_tnodes--;
+       }
+
+       return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (!allocator) {
+               YBUG();
+               return;
+       }
+
+       if (tn) {
+               tn->internal[0] = allocator->free_tnodes;
+               allocator->free_tnodes = tn;
+               allocator->n_free_tnodes++;
+       }
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+static void yaffs_init_raw_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (allocator) {
+               allocator->allocated_obj_list = NULL;
+               allocator->free_objs = NULL;
+               allocator->n_free_objects = 0;
+       } else {
+               YBUG();
+       }
+}
+
+static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+       struct yaffs_obj_list *tmp;
+
+       if (!allocator) {
+               YBUG();
+               return;
+       }
+
+       while (allocator->allocated_obj_list) {
+               tmp = allocator->allocated_obj_list->next;
+               kfree(allocator->allocated_obj_list->objects);
+               kfree(allocator->allocated_obj_list);
+
+               allocator->allocated_obj_list = tmp;
+       }
+
+       allocator->free_objs = NULL;
+       allocator->n_free_objects = 0;
+       allocator->n_obj_created = 0;
+}
+
+static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
+{
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       int i;
+       struct yaffs_obj *new_objs;
+       struct yaffs_obj_list *list;
+
+       if (!allocator) {
+               YBUG();
+               return YAFFS_FAIL;
+       }
+
+       if (n_obj < 1)
+               return YAFFS_OK;
+
+       /* make these things */
+       new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS);
+       list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
+
+       if (!new_objs || !list) {
+               if (new_objs) {
+                       kfree(new_objs);
+                       new_objs = NULL;
+               }
+               if (list) {
+                       kfree(list);
+                       list = NULL;
+               }
+               yaffs_trace(YAFFS_TRACE_ALLOCATE,
+                       "Could not allocate more objects");
+               return YAFFS_FAIL;
+       }
+
+       /* Hook them into the free list */
+       for (i = 0; i < n_obj - 1; i++) {
+               new_objs[i].siblings.next =
+                   (struct list_head *)(&new_objs[i + 1]);
+       }
+
+       new_objs[n_obj - 1].siblings.next = (void *)allocator->free_objs;
+       allocator->free_objs = new_objs;
+       allocator->n_free_objects += n_obj;
+       allocator->n_obj_created += n_obj;
+
+       /* Now add this bunch of Objects to a list for freeing up. */
+
+       list->objects = new_objs;
+       list->next = allocator->allocated_obj_list;
+       allocator->allocated_obj_list = list;
+
+       return YAFFS_OK;
+}
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj = NULL;
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (!allocator) {
+               YBUG();
+               return obj;
+       }
+
+       /* If there are none left make more */
+       if (!allocator->free_objs)
+               yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
+
+       if (allocator->free_objs) {
+               obj = allocator->free_objs;
+               allocator->free_objs =
+                   (struct yaffs_obj *)(allocator->free_objs->siblings.next);
+               allocator->n_free_objects--;
+       }
+
+       return obj;
+}
+
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+
+       struct yaffs_allocator *allocator = dev->allocator;
+
+       if (!allocator)
+               YBUG();
+       else {
+               /* Link into the free list. */
+               obj->siblings.next = (struct list_head *)(allocator->free_objs);
+               allocator->free_objs = obj;
+               allocator->n_free_objects++;
+       }
+}
+
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       if (dev->allocator) {
+               yaffs_deinit_raw_tnodes(dev);
+               yaffs_deinit_raw_objs(dev);
+
+               kfree(dev->allocator);
+               dev->allocator = NULL;
+       } else {
+               YBUG();
+       }
+}
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_allocator *allocator;
+
+       if (!dev->allocator) {
+               allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
+               if (allocator) {
+                       dev->allocator = allocator;
+                       yaffs_init_raw_tnodes(dev);
+                       yaffs_init_raw_objs(dev);
+               }
+       } else {
+               YBUG();
+       }
+}
+
+#endif
diff --git a/fs/yaffs2/yaffs_allocator.h b/fs/yaffs2/yaffs_allocator.h
new file mode 100644 (file)
index 0000000..4d5f2ae
--- /dev/null
@@ -0,0 +1,30 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_ALLOCATOR_H__
+#define __YAFFS_ALLOCATOR_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev);
+void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev);
+
+struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev);
+void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn);
+
+struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev);
+void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj);
+
+#endif
diff --git a/fs/yaffs2/yaffs_attribs.c b/fs/yaffs2/yaffs_attribs.c
new file mode 100644 (file)
index 0000000..9b47d37
--- /dev/null
@@ -0,0 +1,124 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_attribs.h"
+
+void yaffs_load_attribs(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh)
+{
+       obj->yst_uid = oh->yst_uid;
+       obj->yst_gid = oh->yst_gid;
+       obj->yst_atime = oh->yst_atime;
+       obj->yst_mtime = oh->yst_mtime;
+       obj->yst_ctime = oh->yst_ctime;
+       obj->yst_rdev = oh->yst_rdev;
+}
+
+void yaffs_load_attribs_oh(struct yaffs_obj_hdr *oh, struct yaffs_obj *obj)
+{
+       oh->yst_uid = obj->yst_uid;
+       oh->yst_gid = obj->yst_gid;
+       oh->yst_atime = obj->yst_atime;
+       oh->yst_mtime = obj->yst_mtime;
+       oh->yst_ctime = obj->yst_ctime;
+       oh->yst_rdev = obj->yst_rdev;
+
+}
+
+void yaffs_load_current_time(struct yaffs_obj *obj, int do_a, int do_c)
+{
+       obj->yst_mtime = Y_CURRENT_TIME;
+       if (do_a)
+               obj->yst_atime = obj->yst_mtime;
+       if (do_c)
+               obj->yst_ctime = obj->yst_mtime;
+}
+
+void yaffs_attribs_init(struct yaffs_obj *obj, u32 gid, u32 uid, u32 rdev)
+{
+       yaffs_load_current_time(obj, 1, 1);
+       obj->yst_rdev = rdev;
+       obj->yst_uid = uid;
+       obj->yst_gid = gid;
+}
+
+loff_t yaffs_get_file_size(struct yaffs_obj *obj)
+{
+       YCHAR *alias = NULL;
+       obj = yaffs_get_equivalent_obj(obj);
+
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               return obj->variant.file_variant.file_size;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               alias = obj->variant.symlink_variant.alias;
+               if (!alias)
+                       return 0;
+               return strnlen(alias, YAFFS_MAX_ALIAS_LENGTH);
+       default:
+               return 0;
+       }
+}
+
+int yaffs_set_attribs(struct yaffs_obj *obj, struct iattr *attr)
+{
+       unsigned int valid = attr->ia_valid;
+
+       if (valid & ATTR_MODE)
+               obj->yst_mode = attr->ia_mode;
+       if (valid & ATTR_UID)
+               obj->yst_uid = attr->ia_uid;
+       if (valid & ATTR_GID)
+               obj->yst_gid = attr->ia_gid;
+
+       if (valid & ATTR_ATIME)
+               obj->yst_atime = Y_TIME_CONVERT(attr->ia_atime);
+       if (valid & ATTR_CTIME)
+               obj->yst_ctime = Y_TIME_CONVERT(attr->ia_ctime);
+       if (valid & ATTR_MTIME)
+               obj->yst_mtime = Y_TIME_CONVERT(attr->ia_mtime);
+
+       if (valid & ATTR_SIZE)
+               yaffs_resize_file(obj, attr->ia_size);
+
+       yaffs_update_oh(obj, NULL, 1, 0, 0, NULL);
+
+       return YAFFS_OK;
+
+}
+
+int yaffs_get_attribs(struct yaffs_obj *obj, struct iattr *attr)
+{
+       unsigned int valid = 0;
+
+       attr->ia_mode = obj->yst_mode;
+       valid |= ATTR_MODE;
+       attr->ia_uid = obj->yst_uid;
+       valid |= ATTR_UID;
+       attr->ia_gid = obj->yst_gid;
+       valid |= ATTR_GID;
+
+       Y_TIME_CONVERT(attr->ia_atime) = obj->yst_atime;
+       valid |= ATTR_ATIME;
+       Y_TIME_CONVERT(attr->ia_ctime) = obj->yst_ctime;
+       valid |= ATTR_CTIME;
+       Y_TIME_CONVERT(attr->ia_mtime) = obj->yst_mtime;
+       valid |= ATTR_MTIME;
+
+       attr->ia_size = yaffs_get_file_size(obj);
+       valid |= ATTR_SIZE;
+
+       attr->ia_valid = valid;
+
+       return YAFFS_OK;
+}
diff --git a/fs/yaffs2/yaffs_attribs.h b/fs/yaffs2/yaffs_attribs.h
new file mode 100644 (file)
index 0000000..33d541d
--- /dev/null
@@ -0,0 +1,28 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_ATTRIBS_H__
+#define __YAFFS_ATTRIBS_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_load_attribs(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh);
+void yaffs_load_attribs_oh(struct yaffs_obj_hdr *oh, struct yaffs_obj *obj);
+void yaffs_attribs_init(struct yaffs_obj *obj, u32 gid, u32 uid, u32 rdev);
+void yaffs_load_current_time(struct yaffs_obj *obj, int do_a, int do_c);
+int yaffs_set_attribs(struct yaffs_obj *obj, struct iattr *attr);
+int yaffs_get_attribs(struct yaffs_obj *obj, struct iattr *attr);
+
+#endif
diff --git a/fs/yaffs2/yaffs_bitmap.c b/fs/yaffs2/yaffs_bitmap.c
new file mode 100644 (file)
index 0000000..7df42cd
--- /dev/null
@@ -0,0 +1,98 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_bitmap.h"
+#include "yaffs_trace.h"
+/*
+ * Chunk bitmap manipulations
+ */
+
+static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk)
+{
+       if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "BlockBits block %d is not valid",
+                       blk);
+               YBUG();
+       }
+       return dev->chunk_bits +
+           (dev->chunk_bit_stride * (blk - dev->internal_start_block));
+}
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk)
+{
+       if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
+           chunk < 0 || chunk >= dev->param.chunks_per_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "Chunk Id (%d:%d) invalid",
+                       blk, chunk);
+               YBUG();
+       }
+}
+
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+       memset(blk_bits, 0, dev->chunk_bit_stride);
+}
+
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+       yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+       blk_bits[chunk / 8] &= ~(1 << (chunk & 7));
+}
+
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+
+       yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+       blk_bits[chunk / 8] |= (1 << (chunk & 7));
+}
+
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+       yaffs_verify_chunk_bit_id(dev, blk, chunk);
+
+       return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
+}
+
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+       int i;
+       for (i = 0; i < dev->chunk_bit_stride; i++) {
+               if (*blk_bits)
+                       return 1;
+               blk_bits++;
+       }
+       return 0;
+}
+
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk)
+{
+       u8 *blk_bits = yaffs_block_bits(dev, blk);
+       int i;
+       int n = 0;
+
+       for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++)
+               n += hweight8(*blk_bits);
+
+       return n;
+}
diff --git a/fs/yaffs2/yaffs_bitmap.h b/fs/yaffs2/yaffs_bitmap.h
new file mode 100644 (file)
index 0000000..cf9ea58
--- /dev/null
@@ -0,0 +1,33 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * Chunk bitmap manipulations
+ */
+
+#ifndef __YAFFS_BITMAP_H__
+#define __YAFFS_BITMAP_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk);
+void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk);
+void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk);
+int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk);
+int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk);
+
+#endif
diff --git a/fs/yaffs2/yaffs_checkptrw.c b/fs/yaffs2/yaffs_checkptrw.c
new file mode 100644 (file)
index 0000000..4e40f43
--- /dev/null
@@ -0,0 +1,415 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_checkptrw.h"
+#include "yaffs_getblockinfo.h"
+
+static int yaffs2_checkpt_space_ok(struct yaffs_dev *dev)
+{
+       int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checkpt blocks_avail = %d", blocks_avail);
+
+       return (blocks_avail <= 0) ? 0 : 1;
+}
+
+static int yaffs_checkpt_erase(struct yaffs_dev *dev)
+{
+       int i;
+
+       if (!dev->param.erase_fn)
+               return 0;
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checking blocks %d to %d",
+               dev->internal_start_block, dev->internal_end_block);
+
+       for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+               struct yaffs_block_info *bi = yaffs_get_block_info(dev, i);
+               if (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT) {
+                       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                       "erasing checkpt block %d", i);
+
+                       dev->n_erasures++;
+
+                       if (dev->param.
+                           erase_fn(dev,
+                                    i - dev->block_offset /* realign */ )) {
+                               bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+                               dev->n_erased_blocks++;
+                               dev->n_free_chunks +=
+                                   dev->param.chunks_per_block;
+                       } else {
+                               dev->param.bad_block_fn(dev, i);
+                               bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+                       }
+               }
+       }
+
+       dev->blocks_in_checkpt = 0;
+
+       return 1;
+}
+
+static void yaffs2_checkpt_find_erased_block(struct yaffs_dev *dev)
+{
+       int i;
+       int blocks_avail = dev->n_erased_blocks - dev->param.n_reserved_blocks;
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "allocating checkpt block: erased %d reserved %d avail %d next %d ",
+               dev->n_erased_blocks, dev->param.n_reserved_blocks,
+               blocks_avail, dev->checkpt_next_block);
+
+       if (dev->checkpt_next_block >= 0 &&
+           dev->checkpt_next_block <= dev->internal_end_block &&
+           blocks_avail > 0) {
+
+               for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
+                    i++) {
+                       struct yaffs_block_info *bi =
+                           yaffs_get_block_info(dev, i);
+                       if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+                               dev->checkpt_next_block = i + 1;
+                               dev->checkpt_cur_block = i;
+                               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                       "allocating checkpt block %d", i);
+                               return;
+                       }
+               }
+       }
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT, "out of checkpt blocks");
+
+       dev->checkpt_next_block = -1;
+       dev->checkpt_cur_block = -1;
+}
+
+static void yaffs2_checkpt_find_block(struct yaffs_dev *dev)
+{
+       int i;
+       struct yaffs_ext_tags tags;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "find next checkpt block: start:  blocks %d next %d",
+               dev->blocks_in_checkpt, dev->checkpt_next_block);
+
+       if (dev->blocks_in_checkpt < dev->checkpt_max_blocks)
+               for (i = dev->checkpt_next_block; i <= dev->internal_end_block;
+                    i++) {
+                       int chunk = i * dev->param.chunks_per_block;
+                       int realigned_chunk = chunk - dev->chunk_offset;
+
+                       dev->param.read_chunk_tags_fn(dev, realigned_chunk,
+                                                     NULL, &tags);
+                       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                               "find next checkpt block: search: block %d oid %d seq %d eccr %d",
+                               i, tags.obj_id, tags.seq_number,
+                               tags.ecc_result);
+
+                       if (tags.seq_number == YAFFS_SEQUENCE_CHECKPOINT_DATA) {
+                               /* Right kind of block */
+                               dev->checkpt_next_block = tags.obj_id;
+                               dev->checkpt_cur_block = i;
+                               dev->checkpt_block_list[dev->
+                                                       blocks_in_checkpt] = i;
+                               dev->blocks_in_checkpt++;
+                               yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+                                       "found checkpt block %d", i);
+                               return;
+                       }
+               }
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT, "found no more checkpt blocks");
+
+       dev->checkpt_next_block = -1;
+       dev->checkpt_cur_block = -1;
+}
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
+{
+
+       dev->checkpt_open_write = writing;
+
+       /* Got the functions we need? */
+       if (!dev->param.write_chunk_tags_fn ||
+           !dev->param.read_chunk_tags_fn ||
+           !dev->param.erase_fn || !dev->param.bad_block_fn)
+               return 0;
+
+       if (writing && !yaffs2_checkpt_space_ok(dev))
+               return 0;
+
+       if (!dev->checkpt_buffer)
+               dev->checkpt_buffer =
+                   kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+       if (!dev->checkpt_buffer)
+               return 0;
+
+       dev->checkpt_page_seq = 0;
+       dev->checkpt_byte_count = 0;
+       dev->checkpt_sum = 0;
+       dev->checkpt_xor = 0;
+       dev->checkpt_cur_block = -1;
+       dev->checkpt_cur_chunk = -1;
+       dev->checkpt_next_block = dev->internal_start_block;
+
+       /* Erase all the blocks in the checkpoint area */
+       if (writing) {
+               memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
+               dev->checkpt_byte_offs = 0;
+               return yaffs_checkpt_erase(dev);
+       } else {
+               int i;
+               /* Set to a value that will kick off a read */
+               dev->checkpt_byte_offs = dev->data_bytes_per_chunk;
+               /* A checkpoint block list of 1 checkpoint block per 16 block is (hopefully)
+                * going to be way more than we need */
+               dev->blocks_in_checkpt = 0;
+               dev->checkpt_max_blocks =
+                   (dev->internal_end_block - dev->internal_start_block) / 16 +
+                   2;
+               dev->checkpt_block_list =
+                   kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
+               if (!dev->checkpt_block_list)
+                       return 0;
+
+               for (i = 0; i < dev->checkpt_max_blocks; i++)
+                       dev->checkpt_block_list[i] = -1;
+       }
+
+       return 1;
+}
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum)
+{
+       u32 composite_sum;
+       composite_sum = (dev->checkpt_sum << 8) | (dev->checkpt_xor & 0xFF);
+       *sum = composite_sum;
+       return 1;
+}
+
+static int yaffs2_checkpt_flush_buffer(struct yaffs_dev *dev)
+{
+       int chunk;
+       int realigned_chunk;
+
+       struct yaffs_ext_tags tags;
+
+       if (dev->checkpt_cur_block < 0) {
+               yaffs2_checkpt_find_erased_block(dev);
+               dev->checkpt_cur_chunk = 0;
+       }
+
+       if (dev->checkpt_cur_block < 0)
+               return 0;
+
+       tags.is_deleted = 0;
+       tags.obj_id = dev->checkpt_next_block;  /* Hint to next place to look */
+       tags.chunk_id = dev->checkpt_page_seq + 1;
+       tags.seq_number = YAFFS_SEQUENCE_CHECKPOINT_DATA;
+       tags.n_bytes = dev->data_bytes_per_chunk;
+       if (dev->checkpt_cur_chunk == 0) {
+               /* First chunk we write for the block? Set block state to
+                  checkpoint */
+               struct yaffs_block_info *bi =
+                   yaffs_get_block_info(dev, dev->checkpt_cur_block);
+               bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+               dev->blocks_in_checkpt++;
+       }
+
+       chunk =
+           dev->checkpt_cur_block * dev->param.chunks_per_block +
+           dev->checkpt_cur_chunk;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checkpoint wite buffer nand %d(%d:%d) objid %d chId %d",
+               chunk, dev->checkpt_cur_block, dev->checkpt_cur_chunk,
+               tags.obj_id, tags.chunk_id);
+
+       realigned_chunk = chunk - dev->chunk_offset;
+
+       dev->n_page_writes++;
+
+       dev->param.write_chunk_tags_fn(dev, realigned_chunk,
+                                      dev->checkpt_buffer, &tags);
+       dev->checkpt_byte_offs = 0;
+       dev->checkpt_page_seq++;
+       dev->checkpt_cur_chunk++;
+       if (dev->checkpt_cur_chunk >= dev->param.chunks_per_block) {
+               dev->checkpt_cur_chunk = 0;
+               dev->checkpt_cur_block = -1;
+       }
+       memset(dev->checkpt_buffer, 0, dev->data_bytes_per_chunk);
+
+       return 1;
+}
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
+{
+       int i = 0;
+       int ok = 1;
+
+       u8 *data_bytes = (u8 *) data;
+
+       if (!dev->checkpt_buffer)
+               return 0;
+
+       if (!dev->checkpt_open_write)
+               return -1;
+
+       while (i < n_bytes && ok) {
+               dev->checkpt_buffer[dev->checkpt_byte_offs] = *data_bytes;
+               dev->checkpt_sum += *data_bytes;
+               dev->checkpt_xor ^= *data_bytes;
+
+               dev->checkpt_byte_offs++;
+               i++;
+               data_bytes++;
+               dev->checkpt_byte_count++;
+
+               if (dev->checkpt_byte_offs < 0 ||
+                   dev->checkpt_byte_offs >= dev->data_bytes_per_chunk)
+                       ok = yaffs2_checkpt_flush_buffer(dev);
+       }
+
+       return i;
+}
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
+{
+       int i = 0;
+       int ok = 1;
+       struct yaffs_ext_tags tags;
+
+       int chunk;
+       int realigned_chunk;
+
+       u8 *data_bytes = (u8 *) data;
+
+       if (!dev->checkpt_buffer)
+               return 0;
+
+       if (dev->checkpt_open_write)
+               return -1;
+
+       while (i < n_bytes && ok) {
+
+               if (dev->checkpt_byte_offs < 0 ||
+                   dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
+
+                       if (dev->checkpt_cur_block < 0) {
+                               yaffs2_checkpt_find_block(dev);
+                               dev->checkpt_cur_chunk = 0;
+                       }
+
+                       if (dev->checkpt_cur_block < 0)
+                               ok = 0;
+                       else {
+                               chunk = dev->checkpt_cur_block *
+                                   dev->param.chunks_per_block +
+                                   dev->checkpt_cur_chunk;
+
+                               realigned_chunk = chunk - dev->chunk_offset;
+
+                               dev->n_page_reads++;
+
+                               /* read in the next chunk */
+                               dev->param.read_chunk_tags_fn(dev,
+                                                             realigned_chunk,
+                                                             dev->
+                                                             checkpt_buffer,
+                                                             &tags);
+
+                               if (tags.chunk_id != (dev->checkpt_page_seq + 1)
+                                   || tags.ecc_result > YAFFS_ECC_RESULT_FIXED
+                                   || tags.seq_number !=
+                                   YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                                       ok = 0;
+
+                               dev->checkpt_byte_offs = 0;
+                               dev->checkpt_page_seq++;
+                               dev->checkpt_cur_chunk++;
+
+                               if (dev->checkpt_cur_chunk >=
+                                   dev->param.chunks_per_block)
+                                       dev->checkpt_cur_block = -1;
+                       }
+               }
+
+               if (ok) {
+                       *data_bytes =
+                           dev->checkpt_buffer[dev->checkpt_byte_offs];
+                       dev->checkpt_sum += *data_bytes;
+                       dev->checkpt_xor ^= *data_bytes;
+                       dev->checkpt_byte_offs++;
+                       i++;
+                       data_bytes++;
+                       dev->checkpt_byte_count++;
+               }
+       }
+
+       return i;
+}
+
+int yaffs_checkpt_close(struct yaffs_dev *dev)
+{
+
+       if (dev->checkpt_open_write) {
+               if (dev->checkpt_byte_offs != 0)
+                       yaffs2_checkpt_flush_buffer(dev);
+       } else if (dev->checkpt_block_list) {
+               int i;
+               for (i = 0;
+                    i < dev->blocks_in_checkpt
+                    && dev->checkpt_block_list[i] >= 0; i++) {
+                       int blk = dev->checkpt_block_list[i];
+                       struct yaffs_block_info *bi = NULL;
+                       if (dev->internal_start_block <= blk
+                           && blk <= dev->internal_end_block)
+                               bi = yaffs_get_block_info(dev, blk);
+                       if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
+                               bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
+                       else {
+                               /* Todo this looks odd... */
+                       }
+               }
+               kfree(dev->checkpt_block_list);
+               dev->checkpt_block_list = NULL;
+       }
+
+       dev->n_free_chunks -=
+           dev->blocks_in_checkpt * dev->param.chunks_per_block;
+       dev->n_erased_blocks -= dev->blocks_in_checkpt;
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,"checkpoint byte count %d",
+               dev->checkpt_byte_count);
+
+       if (dev->checkpt_buffer) {
+               /* free the buffer */
+               kfree(dev->checkpt_buffer);
+               dev->checkpt_buffer = NULL;
+               return 1;
+       } else {
+               return 0;
+        }
+}
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)
+{
+       /* Erase the checkpoint data */
+
+       yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+               "checkpoint invalidate of %d blocks",
+               dev->blocks_in_checkpt);
+
+       return yaffs_checkpt_erase(dev);
+}
diff --git a/fs/yaffs2/yaffs_checkptrw.h b/fs/yaffs2/yaffs_checkptrw.h
new file mode 100644 (file)
index 0000000..361c606
--- /dev/null
@@ -0,0 +1,33 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_CHECKPTRW_H__
+#define __YAFFS_CHECKPTRW_H__
+
+#include "yaffs_guts.h"
+
+int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing);
+
+int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes);
+
+int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes);
+
+int yaffs2_get_checkpt_sum(struct yaffs_dev *dev, u32 * sum);
+
+int yaffs_checkpt_close(struct yaffs_dev *dev);
+
+int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev);
+
+#endif
diff --git a/fs/yaffs2/yaffs_ecc.c b/fs/yaffs2/yaffs_ecc.c
new file mode 100644 (file)
index 0000000..e95a806
--- /dev/null
@@ -0,0 +1,298 @@
+/*
+ * 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>
+ *
+ * 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 code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+/* Table generated by gen-ecc.c
+ * Using a table means we do not have to calculate p1..p4 and p1'..p4'
+ * for each byte of data. These are instead provided in a table in bits7..2.
+ * Bit 0 of each entry indicates whether the entry has an odd or even parity, and therefore
+ * this bytes influence on the line parity.
+ */
+
+#include "yportenv.h"
+
+#include "yaffs_ecc.h"
+
+static const unsigned char column_parity_table[] = {
+       0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+       0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+       0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+       0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+       0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+       0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+       0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+       0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+       0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+       0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+       0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+       0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+       0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+       0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+       0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+       0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+       0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+       0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+       0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+       0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+       0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+       0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+       0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+       0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+       0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+       0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+       0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+       0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+       0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+       0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+       0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+       0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+};
+
+
+/* Calculate the ECC for a 256-byte block of data */
+void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc)
+{
+       unsigned int i;
+
+       unsigned char col_parity = 0;
+       unsigned char line_parity = 0;
+       unsigned char line_parity_prime = 0;
+       unsigned char t;
+       unsigned char b;
+
+       for (i = 0; i < 256; i++) {
+               b = column_parity_table[*data++];
+               col_parity ^= b;
+
+               if (b & 0x01) { /* odd number of bits in the byte */
+                       line_parity ^= i;
+                       line_parity_prime ^= ~i;
+               }
+       }
+
+       ecc[2] = (~col_parity) | 0x03;
+
+       t = 0;
+       if (line_parity & 0x80)
+               t |= 0x80;
+       if (line_parity_prime & 0x80)
+               t |= 0x40;
+       if (line_parity & 0x40)
+               t |= 0x20;
+       if (line_parity_prime & 0x40)
+               t |= 0x10;
+       if (line_parity & 0x20)
+               t |= 0x08;
+       if (line_parity_prime & 0x20)
+               t |= 0x04;
+       if (line_parity & 0x10)
+               t |= 0x02;
+       if (line_parity_prime & 0x10)
+               t |= 0x01;
+       ecc[1] = ~t;
+
+       t = 0;
+       if (line_parity & 0x08)
+               t |= 0x80;
+       if (line_parity_prime & 0x08)
+               t |= 0x40;
+       if (line_parity & 0x04)
+               t |= 0x20;
+       if (line_parity_prime & 0x04)
+               t |= 0x10;
+       if (line_parity & 0x02)
+               t |= 0x08;
+       if (line_parity_prime & 0x02)
+               t |= 0x04;
+       if (line_parity & 0x01)
+               t |= 0x02;
+       if (line_parity_prime & 0x01)
+               t |= 0x01;
+       ecc[0] = ~t;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+       /* Swap the bytes into the wrong order */
+       t = ecc[0];
+       ecc[0] = ecc[1];
+       ecc[1] = t;
+#endif
+}
+
+/* Correct the ECC on a 256 byte block of data */
+
+int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
+                     const unsigned char *test_ecc)
+{
+       unsigned char d0, d1, d2;       /* deltas */
+
+       d0 = read_ecc[0] ^ test_ecc[0];
+       d1 = read_ecc[1] ^ test_ecc[1];
+       d2 = read_ecc[2] ^ test_ecc[2];
+
+       if ((d0 | d1 | d2) == 0)
+               return 0;       /* no error */
+
+       if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 &&
+           ((d1 ^ (d1 >> 1)) & 0x55) == 0x55 &&
+           ((d2 ^ (d2 >> 1)) & 0x54) == 0x54) {
+               /* Single bit (recoverable) error in data */
+
+               unsigned byte;
+               unsigned bit;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+               /* swap the bytes to correct for the wrong order */
+               unsigned char t;
+
+               t = d0;
+               d0 = d1;
+               d1 = t;
+#endif
+
+               bit = byte = 0;
+
+               if (d1 & 0x80)
+                       byte |= 0x80;
+               if (d1 & 0x20)
+                       byte |= 0x40;
+               if (d1 & 0x08)
+                       byte |= 0x20;
+               if (d1 & 0x02)
+                       byte |= 0x10;
+               if (d0 & 0x80)
+                       byte |= 0x08;
+               if (d0 & 0x20)
+                       byte |= 0x04;
+               if (d0 & 0x08)
+                       byte |= 0x02;
+               if (d0 & 0x02)
+                       byte |= 0x01;
+
+               if (d2 & 0x80)
+                       bit |= 0x04;
+               if (d2 & 0x20)
+                       bit |= 0x02;
+               if (d2 & 0x08)
+                       bit |= 0x01;
+
+               data[byte] ^= (1 << bit);
+
+               return 1;       /* Corrected the error */
+       }
+
+       if ((hweight8(d0) + hweight8(d1) + hweight8(d2)) == 1) {
+               /* Reccoverable error in ecc */
+
+               read_ecc[0] = test_ecc[0];
+               read_ecc[1] = test_ecc[1];
+               read_ecc[2] = test_ecc[2];
+
+               return 1;       /* Corrected the error */
+       }
+
+       /* Unrecoverable error */
+
+       return -1;
+
+}
+
+/*
+ * ECCxxxOther does ECC calcs on arbitrary n bytes of data
+ */
+void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+                         struct yaffs_ecc_other *ecc_other)
+{
+       unsigned int i;
+
+       unsigned char col_parity = 0;
+       unsigned line_parity = 0;
+       unsigned line_parity_prime = 0;
+       unsigned char b;
+
+       for (i = 0; i < n_bytes; i++) {
+               b = column_parity_table[*data++];
+               col_parity ^= b;
+
+               if (b & 0x01) {
+                       /* odd number of bits in the byte */
+                       line_parity ^= i;
+                       line_parity_prime ^= ~i;
+               }
+
+       }
+
+       ecc_other->col_parity = (col_parity >> 2) & 0x3f;
+       ecc_other->line_parity = line_parity;
+       ecc_other->line_parity_prime = line_parity_prime;
+}
+
+int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+                           struct yaffs_ecc_other *read_ecc,
+                           const struct yaffs_ecc_other *test_ecc)
+{
+       unsigned char delta_col;        /* column parity delta */
+       unsigned delta_line;    /* line parity delta */
+       unsigned delta_line_prime;      /* line parity delta */
+       unsigned bit;
+
+       delta_col = read_ecc->col_parity ^ test_ecc->col_parity;
+       delta_line = read_ecc->line_parity ^ test_ecc->line_parity;
+       delta_line_prime =
+           read_ecc->line_parity_prime ^ test_ecc->line_parity_prime;
+
+       if ((delta_col | delta_line | delta_line_prime) == 0)
+               return 0;       /* no error */
+
+       if (delta_line == ~delta_line_prime &&
+           (((delta_col ^ (delta_col >> 1)) & 0x15) == 0x15)) {
+               /* Single bit (recoverable) error in data */
+
+               bit = 0;
+
+               if (delta_col & 0x20)
+                       bit |= 0x04;
+               if (delta_col & 0x08)
+                       bit |= 0x02;
+               if (delta_col & 0x02)
+                       bit |= 0x01;
+
+               if (delta_line >= n_bytes)
+                       return -1;
+
+               data[delta_line] ^= (1 << bit);
+
+               return 1;       /* corrected */
+       }
+
+       if ((hweight32(delta_line) +
+            hweight32(delta_line_prime) +
+            hweight8(delta_col)) == 1) {
+               /* Reccoverable error in ecc */
+
+               *read_ecc = *test_ecc;
+               return 1;       /* corrected */
+       }
+
+       /* Unrecoverable error */
+
+       return -1;
+}
diff --git a/fs/yaffs2/yaffs_ecc.h b/fs/yaffs2/yaffs_ecc.h
new file mode 100644 (file)
index 0000000..b0c461d
--- /dev/null
@@ -0,0 +1,44 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * This code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+#ifndef __YAFFS_ECC_H__
+#define __YAFFS_ECC_H__
+
+struct yaffs_ecc_other {
+       unsigned char col_parity;
+       unsigned line_parity;
+       unsigned line_parity_prime;
+};
+
+void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc);
+int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
+                     const unsigned char *test_ecc);
+
+void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+                         struct yaffs_ecc_other *ecc);
+int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+                           struct yaffs_ecc_other *read_ecc,
+                           const struct yaffs_ecc_other *test_ecc);
+#endif
diff --git a/fs/yaffs2/yaffs_getblockinfo.h b/fs/yaffs2/yaffs_getblockinfo.h
new file mode 100644 (file)
index 0000000..d87acbd
--- /dev/null
@@ -0,0 +1,35 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GETBLOCKINFO_H__
+#define __YAFFS_GETBLOCKINFO_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_trace.h"
+
+/* Function to manipulate block info */
+static inline struct yaffs_block_info *yaffs_get_block_info(struct yaffs_dev
+                                                             *dev, int blk)
+{
+       if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "**>> yaffs: get_block_info block %d is not valid",
+                       blk);
+               YBUG();
+       }
+       return &dev->block_info[blk - dev->internal_start_block];
+}
+
+#endif
diff --git a/fs/yaffs2/yaffs_guts.c b/fs/yaffs2/yaffs_guts.c
new file mode 100644 (file)
index 0000000..f4ae9de
--- /dev/null
@@ -0,0 +1,5164 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yportenv.h"
+#include "yaffs_trace.h"
+
+#include "yaffs_guts.h"
+#include "yaffs_tagsvalidity.h"
+#include "yaffs_getblockinfo.h"
+
+#include "yaffs_tagscompat.h"
+
+#include "yaffs_nand.h"
+
+#include "yaffs_yaffs1.h"
+#include "yaffs_yaffs2.h"
+#include "yaffs_bitmap.h"
+#include "yaffs_verify.h"
+
+#include "yaffs_nand.h"
+#include "yaffs_packedtags2.h"
+
+#include "yaffs_nameval.h"
+#include "yaffs_allocator.h"
+
+#include "yaffs_attribs.h"
+
+/* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
+#define YAFFS_GC_GOOD_ENOUGH 2
+#define YAFFS_GC_PASSIVE_THRESHOLD 4
+
+#include "yaffs_ecc.h"
+
+/* Forward declarations */
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+                            const u8 * buffer, int n_bytes, int use_reserve);
+
+
+
+/* Function to calculate chunk and offset */
+
+static void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr,
+                               int *chunk_out, u32 * offset_out)
+{
+       int chunk;
+       u32 offset;
+
+       chunk = (u32) (addr >> dev->chunk_shift);
+
+       if (dev->chunk_div == 1) {
+               /* easy power of 2 case */
+               offset = (u32) (addr & dev->chunk_mask);
+       } else {
+               /* Non power-of-2 case */
+
+               loff_t chunk_base;
+
+               chunk /= dev->chunk_div;
+
+               chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk;
+               offset = (u32) (addr - chunk_base);
+       }
+
+       *chunk_out = chunk;
+       *offset_out = offset;
+}
+
+/* Function to return the number of shifts for a power of 2 greater than or
+ * equal to the given number
+ * Note we don't try to cater for all possible numbers and this does not have to
+ * be hellishly efficient.
+ */
+
+static u32 calc_shifts_ceiling(u32 x)
+{
+       int extra_bits;
+       int shifts;
+
+       shifts = extra_bits = 0;
+
+       while (x > 1) {
+               if (x & 1)
+                       extra_bits++;
+               x >>= 1;
+               shifts++;
+       }
+
+       if (extra_bits)
+               shifts++;
+
+       return shifts;
+}
+
+/* Function to return the number of shifts to get a 1 in bit 0
+ */
+
+static u32 calc_shifts(u32 x)
+{
+       u32 shifts;
+
+       shifts = 0;
+
+       if (!x)
+               return 0;
+
+       while (!(x & 1)) {
+               x >>= 1;
+               shifts++;
+       }
+
+       return shifts;
+}
+
+/*
+ * Temporary buffer manipulations.
+ */
+
+static int yaffs_init_tmp_buffers(struct yaffs_dev *dev)
+{
+       int i;
+       u8 *buf = (u8 *) 1;
+
+       memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer));
+
+       for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
+               dev->temp_buffer[i].line = 0;   /* not in use */
+               dev->temp_buffer[i].buffer = buf =
+                   kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+       }
+
+       return buf ? YAFFS_OK : YAFFS_FAIL;
+}
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev, int line_no)
+{
+       int i, j;
+
+       dev->temp_in_use++;
+       if (dev->temp_in_use > dev->max_temp)
+               dev->max_temp = dev->temp_in_use;
+
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->temp_buffer[i].line == 0) {
+                       dev->temp_buffer[i].line = line_no;
+                       if ((i + 1) > dev->max_temp) {
+                               dev->max_temp = i + 1;
+                               for (j = 0; j <= i; j++)
+                                       dev->temp_buffer[j].max_line =
+                                           dev->temp_buffer[j].line;
+                       }
+
+                       return dev->temp_buffer[i].buffer;
+               }
+       }
+
+       yaffs_trace(YAFFS_TRACE_BUFFERS,
+               "Out of temp buffers at line %d, other held by lines:",
+               line_no);
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+               yaffs_trace(YAFFS_TRACE_BUFFERS," %d", dev->temp_buffer[i].line);
+
+       /*
+        * If we got here then we have to allocate an unmanaged one
+        * This is not good.
+        */
+
+       dev->unmanaged_buffer_allocs++;
+       return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS);
+
+}
+
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no)
+{
+       int i;
+
+       dev->temp_in_use--;
+
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->temp_buffer[i].buffer == buffer) {
+                       dev->temp_buffer[i].line = 0;
+                       return;
+               }
+       }
+
+       if (buffer) {
+               /* assume it is an unmanaged one. */
+               yaffs_trace(YAFFS_TRACE_BUFFERS,
+                 "Releasing unmanaged temp buffer in line %d",
+                  line_no);
+               kfree(buffer);
+               dev->unmanaged_buffer_deallocs++;
+       }
+
+}
+
+/*
+ * Determine if we have a managed buffer.
+ */
+int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 * buffer)
+{
+       int i;
+
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->temp_buffer[i].buffer == buffer)
+                       return 1;
+       }
+
+       for (i = 0; i < dev->param.n_caches; i++) {
+               if (dev->cache[i].data == buffer)
+                       return 1;
+       }
+
+       if (buffer == dev->checkpt_buffer)
+               return 1;
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+         "yaffs: unmaged buffer detected.");
+       return 0;
+}
+
+/*
+ * Functions for robustisizing TODO
+ *
+ */
+
+static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk,
+                                    const u8 * data,
+                                    const struct yaffs_ext_tags *tags)
+{
+       dev = dev;
+       nand_chunk = nand_chunk;
+       data = data;
+       tags = tags;
+}
+
+static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk,
+                                     const struct yaffs_ext_tags *tags)
+{
+       dev = dev;
+       nand_chunk = nand_chunk;
+       tags = tags;
+}
+
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+                             struct yaffs_block_info *bi)
+{
+       if (!bi->gc_prioritise) {
+               bi->gc_prioritise = 1;
+               dev->has_pending_prioritised_gc = 1;
+               bi->chunk_error_strikes++;
+
+               if (bi->chunk_error_strikes > 3) {
+                       bi->needs_retiring = 1; /* Too many stikes, so retire this */
+                       yaffs_trace(YAFFS_TRACE_ALWAYS, "yaffs: Block struck out");
+
+               }
+       }
+}
+
+static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk,
+                                       int erased_ok)
+{
+       int flash_block = nand_chunk / dev->param.chunks_per_block;
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+       yaffs_handle_chunk_error(dev, bi);
+
+       if (erased_ok) {
+               /* Was an actual write failure, so mark the block for retirement  */
+               bi->needs_retiring = 1;
+               yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                 "**>> Block %d needs retiring", flash_block);
+       }
+
+       /* Delete the chunk */
+       yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+       yaffs_skip_rest_of_block(dev);
+}
+
+/*
+ * Verification code
+ */
+
+/*
+ *  Simple hash function. Needs to have a reasonable spread
+ */
+
+static inline int yaffs_hash_fn(int n)
+{
+       n = abs(n);
+       return n % YAFFS_NOBJECT_BUCKETS;
+}
+
+/*
+ * Access functions to useful fake objects.
+ * Note that root might have a presence in NAND if permissions are set.
+ */
+
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev)
+{
+       return dev->root_dir;
+}
+
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev)
+{
+       return dev->lost_n_found;
+}
+
+/*
+ *  Erased NAND checking functions
+ */
+
+int yaffs_check_ff(u8 * buffer, int n_bytes)
+{
+       /* Horrible, slow implementation */
+       while (n_bytes--) {
+               if (*buffer != 0xFF)
+                       return 0;
+               buffer++;
+       }
+       return 1;
+}
+
+static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk)
+{
+       int retval = YAFFS_OK;
+       u8 *data = yaffs_get_temp_buffer(dev, __LINE__);
+       struct yaffs_ext_tags tags;
+       int result;
+
+       result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags);
+
+       if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR)
+               retval = YAFFS_FAIL;
+
+       if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) ||
+               tags.chunk_used) {
+               yaffs_trace(YAFFS_TRACE_NANDACCESS, "Chunk %d not erased", nand_chunk);
+               retval = YAFFS_FAIL;
+       }
+
+       yaffs_release_temp_buffer(dev, data, __LINE__);
+
+       return retval;
+
+}
+
+static int yaffs_verify_chunk_written(struct yaffs_dev *dev,
+                                     int nand_chunk,
+                                     const u8 * data,
+                                     struct yaffs_ext_tags *tags)
+{
+       int retval = YAFFS_OK;
+       struct yaffs_ext_tags temp_tags;
+       u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+       int result;
+
+       result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags);
+       if (memcmp(buffer, data, dev->data_bytes_per_chunk) ||
+           temp_tags.obj_id != tags->obj_id ||
+           temp_tags.chunk_id != tags->chunk_id ||
+           temp_tags.n_bytes != tags->n_bytes)
+               retval = YAFFS_FAIL;
+
+       yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+       return retval;
+}
+
+
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks)
+{
+       int reserved_chunks;
+       int reserved_blocks = dev->param.n_reserved_blocks;
+       int checkpt_blocks;
+
+       checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev);
+
+       reserved_chunks =
+           ((reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block);
+
+       return (dev->n_free_chunks > (reserved_chunks + n_chunks));
+}
+
+static int yaffs_find_alloc_block(struct yaffs_dev *dev)
+{
+       int i;
+
+       struct yaffs_block_info *bi;
+
+       if (dev->n_erased_blocks < 1) {
+               /* Hoosterman we've got a problem.
+                * Can't get space to gc
+                */
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                 "yaffs tragedy: no more erased blocks" );
+
+               return -1;
+       }
+
+       /* Find an empty block. */
+
+       for (i = dev->internal_start_block; i <= dev->internal_end_block; i++) {
+               dev->alloc_block_finder++;
+               if (dev->alloc_block_finder < dev->internal_start_block
+                   || dev->alloc_block_finder > dev->internal_end_block) {
+                       dev->alloc_block_finder = dev->internal_start_block;
+               }
+
+               bi = yaffs_get_block_info(dev, dev->alloc_block_finder);
+
+               if (bi->block_state == YAFFS_BLOCK_STATE_EMPTY) {
+                       bi->block_state = YAFFS_BLOCK_STATE_ALLOCATING;
+                       dev->seq_number++;
+                       bi->seq_number = dev->seq_number;
+                       dev->n_erased_blocks--;
+                       yaffs_trace(YAFFS_TRACE_ALLOCATE,
+                         "Allocated block %d, seq  %d, %d left" ,
+                          dev->alloc_block_finder, dev->seq_number,
+                          dev->n_erased_blocks);
+                       return dev->alloc_block_finder;
+               }
+       }
+
+       yaffs_trace(YAFFS_TRACE_ALWAYS,
+               "yaffs tragedy: no more erased blocks, but there should have been %d",
+               dev->n_erased_blocks);
+
+       return -1;
+}
+
+static int yaffs_alloc_chunk(struct yaffs_dev *dev, int use_reserver,
+                            struct yaffs_block_info **block_ptr)
+{
+       int ret_val;
+       struct yaffs_block_info *bi;
+
+       if (dev->alloc_block < 0) {
+               /* Get next block to allocate off */
+               dev->alloc_block = yaffs_find_alloc_block(dev);
+               dev->alloc_page = 0;
+       }
+
+       if (!use_reserver && !yaffs_check_alloc_available(dev, 1)) {
+               /* Not enough space to allocate unless we're allowed to use the reserve. */
+               return -1;
+       }
+
+       if (dev->n_erased_blocks < dev->param.n_reserved_blocks
+           && dev->alloc_page == 0)
+               yaffs_trace(YAFFS_TRACE_ALLOCATE, "Allocating reserve");
+
+       /* Next page please.... */
+       if (dev->alloc_block >= 0) {
+               bi = yaffs_get_block_info(dev, dev->alloc_block);
+
+               ret_val = (dev->alloc_block * dev->param.chunks_per_block) +
+                   dev->alloc_page;
+               bi->pages_in_use++;
+               yaffs_set_chunk_bit(dev, dev->alloc_block, dev->alloc_page);
+
+               dev->alloc_page++;
+
+               dev->n_free_chunks--;
+
+               /* If the block is full set the state to full */
+               if (dev->alloc_page >= dev->param.chunks_per_block) {
+                       bi->block_state = YAFFS_BLOCK_STATE_FULL;
+                       dev->alloc_block = -1;
+               }
+
+               if (block_ptr)
+                       *block_ptr = bi;
+
+               return ret_val;
+       }
+
+       yaffs_trace(YAFFS_TRACE_ERROR, "!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" );
+
+       return -1;
+}
+
+static int yaffs_get_erased_chunks(struct yaffs_dev *dev)
+{
+       int n;
+
+       n = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+       if (dev->alloc_block > 0)
+               n += (dev->param.chunks_per_block - dev->alloc_page);
+
+       return n;
+
+}
+
+/*
+ * yaffs_skip_rest_of_block() skips over the rest of the allocation block
+ * if we don't want to write to it.
+ */
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev)
+{
+       if (dev->alloc_block > 0) {
+               struct yaffs_block_info *bi =
+                   yaffs_get_block_info(dev, dev->alloc_block);
+               if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                       bi->block_state = YAFFS_BLOCK_STATE_FULL;
+                       dev->alloc_block = -1;
+               }
+       }
+}
+
+static int yaffs_write_new_chunk(struct yaffs_dev *dev,
+                                const u8 * data,
+                                struct yaffs_ext_tags *tags, int use_reserver)
+{
+       int attempts = 0;
+       int write_ok = 0;
+       int chunk;
+
+       yaffs2_checkpt_invalidate(dev);
+
+       do {
+               struct yaffs_block_info *bi = 0;
+               int erased_ok = 0;
+
+               chunk = yaffs_alloc_chunk(dev, use_reserver, &bi);
+               if (chunk < 0) {
+                       /* no space */
+                       break;
+               }
+
+               /* First check this chunk is erased, if it needs
+                * checking.  The checking policy (unless forced
+                * always on) is as follows:
+                *
+                * Check the first page we try to write in a block.
+                * If the check passes then we don't need to check any
+                * more.        If the check fails, we check again...
+                * If the block has been erased, we don't need to check.
+                *
+                * However, if the block has been prioritised for gc,
+                * then we think there might be something odd about
+                * this block and stop using it.
+                *
+                * Rationale: We should only ever see chunks that have
+                * not been erased if there was a partially written
+                * chunk due to power loss.  This checking policy should
+                * catch that case with very few checks and thus save a
+                * lot of checks that are most likely not needed.
+                *
+                * Mods to the above
+                * If an erase check fails or the write fails we skip the 
+                * rest of the block.
+                */
+
+               /* let's give it a try */
+               attempts++;
+
+               if (dev->param.always_check_erased)
+                       bi->skip_erased_check = 0;
+
+               if (!bi->skip_erased_check) {
+                       erased_ok = yaffs_check_chunk_erased(dev, chunk);
+                       if (erased_ok != YAFFS_OK) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                 "**>> yaffs chunk %d was not erased",
+                                 chunk);
+
+                               /* If not erased, delete this one,
+                                * skip rest of block and
+                                * try another chunk */
+                               yaffs_chunk_del(dev, chunk, 1, __LINE__);
+                               yaffs_skip_rest_of_block(dev);
+                               continue;
+                       }
+               }
+
+               write_ok = yaffs_wr_chunk_tags_nand(dev, chunk, data, tags);
+
+               if (!bi->skip_erased_check)
+                       write_ok =
+                           yaffs_verify_chunk_written(dev, chunk, data, tags);
+
+               if (write_ok != YAFFS_OK) {
+                       /* Clean up aborted write, skip to next block and
+                        * try another chunk */
+                       yaffs_handle_chunk_wr_error(dev, chunk, erased_ok);
+                       continue;
+               }
+
+               bi->skip_erased_check = 1;
+
+               /* Copy the data into the robustification buffer */
+               yaffs_handle_chunk_wr_ok(dev, chunk, data, tags);
+
+       } while (write_ok != YAFFS_OK &&
+                (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
+
+       if (!write_ok)
+               chunk = -1;
+
+       if (attempts > 1) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "**>> yaffs write required %d attempts",
+                       attempts);
+               dev->n_retired_writes += (attempts - 1);
+       }
+
+       return chunk;
+}
+
+/*
+ * Block retiring for handling a broken block.
+ */
+
+static void yaffs_retire_block(struct yaffs_dev *dev, int flash_block)
+{
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block);
+
+       yaffs2_checkpt_invalidate(dev);
+
+       yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+       if (yaffs_mark_bad(dev, flash_block) != YAFFS_OK) {
+               if (yaffs_erase_block(dev, flash_block) != YAFFS_OK) {
+                       yaffs_trace(YAFFS_TRACE_ALWAYS,
+                               "yaffs: Failed to mark bad and erase block %d",
+                               flash_block);
+               } else {
+                       struct yaffs_ext_tags tags;
+                       int chunk_id =
+                           flash_block * dev->param.chunks_per_block;
+
+                       u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+                       memset(buffer, 0xff, dev->data_bytes_per_chunk);
+                       yaffs_init_tags(&tags);
+                       tags.seq_number = YAFFS_SEQUENCE_BAD_BLOCK;
+                       if (dev->param.write_chunk_tags_fn(dev, chunk_id -
+                                                          dev->chunk_offset,
+                                                          buffer,
+                                                          &tags) != YAFFS_OK)
+                               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                       "yaffs: Failed to write bad block marker to block %d",
+                                       flash_block);
+
+                       yaffs_release_temp_buffer(dev, buffer, __LINE__);
+               }
+       }
+
+       bi->block_state = YAFFS_BLOCK_STATE_DEAD;
+       bi->gc_prioritise = 0;
+       bi->needs_retiring = 0;
+
+       dev->n_retired_blocks++;
+}
+
+/*---------------- Name handling functions ------------*/
+
+static u16 yaffs_calc_name_sum(const YCHAR * name)
+{
+       u16 sum = 0;
+       u16 i = 1;
+
+       const YUCHAR *bname = (const YUCHAR *)name;
+       if (bname) {
+               while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH / 2))) {
+
+                       /* 0x1f mask is case insensitive */
+                       sum += ((*bname) & 0x1f) * i;
+                       i++;
+                       bname++;
+               }
+       }
+       return sum;
+}
+
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name)
+{
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+       memset(obj->short_name, 0, sizeof(obj->short_name));
+       if (name && 
+               strnlen(name, YAFFS_SHORT_NAME_LENGTH + 1) <=
+           YAFFS_SHORT_NAME_LENGTH)
+               strcpy(obj->short_name, name);
+       else
+               obj->short_name[0] = _Y('\0');
+#endif
+       obj->sum = yaffs_calc_name_sum(name);
+}
+
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+                               const struct yaffs_obj_hdr *oh)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+       YCHAR tmp_name[YAFFS_MAX_NAME_LENGTH + 1];
+       memset(tmp_name, 0, sizeof(tmp_name));
+       yaffs_load_name_from_oh(obj->my_dev, tmp_name, oh->name,
+                               YAFFS_MAX_NAME_LENGTH + 1);
+       yaffs_set_obj_name(obj, tmp_name);
+#else
+       yaffs_set_obj_name(obj, oh->name);
+#endif
+}
+
+/*-------------------- TNODES -------------------
+
+ * List of spare tnodes
+ * The list is hooked together using the first pointer
+ * in the tnode.
+ */
+
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev)
+{
+       struct yaffs_tnode *tn = yaffs_alloc_raw_tnode(dev);
+       if (tn) {
+               memset(tn, 0, dev->tnode_size);
+               dev->n_tnodes++;
+       }
+
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+
+       return tn;
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+static void yaffs_free_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
+{
+       yaffs_free_raw_tnode(dev, tn);
+       dev->n_tnodes--;
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+static void yaffs_deinit_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       yaffs_deinit_raw_tnodes_and_objs(dev);
+       dev->n_obj = 0;
+       dev->n_tnodes = 0;
+}
+
+void yaffs_load_tnode_0(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                       unsigned pos, unsigned val)
+{
+       u32 *map = (u32 *) tn;
+       u32 bit_in_map;
+       u32 bit_in_word;
+       u32 word_in_map;
+       u32 mask;
+
+       pos &= YAFFS_TNODES_LEVEL0_MASK;
+       val >>= dev->chunk_grp_bits;
+
+       bit_in_map = pos * dev->tnode_width;
+       word_in_map = bit_in_map / 32;
+       bit_in_word = bit_in_map & (32 - 1);
+
+       mask = dev->tnode_mask << bit_in_word;
+
+       map[word_in_map] &= ~mask;
+       map[word_in_map] |= (mask & (val << bit_in_word));
+
+       if (dev->tnode_width > (32 - bit_in_word)) {
+               bit_in_word = (32 - bit_in_word);
+               word_in_map++;;
+               mask =
+                   dev->tnode_mask >> ( /*dev->tnode_width - */ bit_in_word);
+               map[word_in_map] &= ~mask;
+               map[word_in_map] |= (mask & (val >> bit_in_word));
+       }
+}
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                        unsigned pos)
+{
+       u32 *map = (u32 *) tn;
+       u32 bit_in_map;
+       u32 bit_in_word;
+       u32 word_in_map;
+       u32 val;
+
+       pos &= YAFFS_TNODES_LEVEL0_MASK;
+
+       bit_in_map = pos * dev->tnode_width;
+       word_in_map = bit_in_map / 32;
+       bit_in_word = bit_in_map & (32 - 1);
+
+       val = map[word_in_map] >> bit_in_word;
+
+       if (dev->tnode_width > (32 - bit_in_word)) {
+               bit_in_word = (32 - bit_in_word);
+               word_in_map++;;
+               val |= (map[word_in_map] << bit_in_word);
+       }
+
+       val &= dev->tnode_mask;
+       val <<= dev->chunk_grp_bits;
+
+       return val;
+}
+
+/* ------------------- End of individual tnode manipulation -----------------*/
+
+/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
+ * The look up tree is represented by the top tnode and the number of top_level
+ * in the tree. 0 means only the level 0 tnode is in the tree.
+ */
+
+/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+                                      struct yaffs_file_var *file_struct,
+                                      u32 chunk_id)
+{
+       struct yaffs_tnode *tn = file_struct->top;
+       u32 i;
+       int required_depth;
+       int level = file_struct->top_level;
+
+       dev = dev;
+
+       /* Check sane level and chunk Id */
+       if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
+               return NULL;
+
+       if (chunk_id > YAFFS_MAX_CHUNK_ID)
+               return NULL;
+
+       /* First check we're tall enough (ie enough top_level) */
+
+       i = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+       required_depth = 0;
+       while (i) {
+               i >>= YAFFS_TNODES_INTERNAL_BITS;
+               required_depth++;
+       }
+
+       if (required_depth > file_struct->top_level)
+               return NULL;    /* Not tall enough, so we can't find it */
+
+       /* Traverse down to level 0 */
+       while (level > 0 && tn) {
+               tn = tn->internal[(chunk_id >>
+                                  (YAFFS_TNODES_LEVEL0_BITS +
+                                   (level - 1) *
+                                   YAFFS_TNODES_INTERNAL_BITS)) &
+                                 YAFFS_TNODES_INTERNAL_MASK];
+               level--;
+       }
+
+       return tn;
+}
+
+/* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
+ * This happens in two steps:
+ *  1. If the tree isn't tall enough, then make it taller.
+ *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
+ *
+ * Used when modifying the tree.
+ *
+ *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
+ *  be plugged into the ttree.
+ */
+
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+                                          struct yaffs_file_var *file_struct,
+                                          u32 chunk_id,
+                                          struct yaffs_tnode *passed_tn)
+{
+       int required_depth;
+       int i;
+       int l;
+       struct yaffs_tnode *tn;
+
+       u32 x;
+
+       /* Check sane level and page Id */
+       if (file_struct->top_level < 0
+           || file_struct->top_level > YAFFS_TNODES_MAX_LEVEL)
+               return NULL;
+
+       if (chunk_id > YAFFS_MAX_CHUNK_ID)
+               return NULL;
+
+       /* First check we're tall enough (ie enough top_level) */
+
+       x = chunk_id >> YAFFS_TNODES_LEVEL0_BITS;
+       required_depth = 0;
+       while (x) {
+               x >>= YAFFS_TNODES_INTERNAL_BITS;
+               required_depth++;
+       }
+
+       if (required_depth > file_struct->top_level) {
+               /* Not tall enough, gotta make the tree taller */
+               for (i = file_struct->top_level; i < required_depth; i++) {
+
+                       tn = yaffs_get_tnode(dev);
+
+                       if (tn) {
+                               tn->internal[0] = file_struct->top;
+                               file_struct->top = tn;
+                               file_struct->top_level++;
+                       } else {
+                               yaffs_trace(YAFFS_TRACE_ERROR, "yaffs: no more tnodes");
+                               return NULL;
+                       }
+               }
+       }
+
+       /* Traverse down to level 0, adding anything we need */
+
+       l = file_struct->top_level;
+       tn = file_struct->top;
+
+       if (l > 0) {
+               while (l > 0 && tn) {
+                       x = (chunk_id >>
+                            (YAFFS_TNODES_LEVEL0_BITS +
+                             (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
+                           YAFFS_TNODES_INTERNAL_MASK;
+
+                       if ((l > 1) && !tn->internal[x]) {
+                               /* Add missing non-level-zero tnode */
+                               tn->internal[x] = yaffs_get_tnode(dev);
+                               if (!tn->internal[x])
+                                       return NULL;
+                       } else if (l == 1) {
+                               /* Looking from level 1 at level 0 */
+                               if (passed_tn) {
+                                       /* If we already have one, then release it. */
+                                       if (tn->internal[x])
+                                               yaffs_free_tnode(dev,
+                                                                tn->
+                                                                internal[x]);
+                                       tn->internal[x] = passed_tn;
+
+                               } else if (!tn->internal[x]) {
+                                       /* Don't have one, none passed in */
+                                       tn->internal[x] = yaffs_get_tnode(dev);
+                                       if (!tn->internal[x])
+                                               return NULL;
+                               }
+                       }
+
+                       tn = tn->internal[x];
+                       l--;
+               }
+       } else {
+               /* top is level 0 */
+               if (passed_tn) {
+                       memcpy(tn, passed_tn,
+                              (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8);
+                       yaffs_free_tnode(dev, passed_tn);
+               }
+       }
+
+       return tn;
+}
+
+static int yaffs_tags_match(const struct yaffs_ext_tags *tags, int obj_id,
+                           int chunk_obj)
+{
+       return (tags->chunk_id == chunk_obj &&
+               tags->obj_id == obj_id && !tags->is_deleted) ? 1 : 0;
+
+}
+
+static int yaffs_find_chunk_in_group(struct yaffs_dev *dev, int the_chunk,
+                                    struct yaffs_ext_tags *tags, int obj_id,
+                                    int inode_chunk)
+{
+       int j;
+
+       for (j = 0; the_chunk && j < dev->chunk_grp_size; j++) {
+               if (yaffs_check_chunk_bit
+                   (dev, the_chunk / dev->param.chunks_per_block,
+                    the_chunk % dev->param.chunks_per_block)) {
+
+                       if (dev->chunk_grp_size == 1)
+                               return the_chunk;
+                       else {
+                               yaffs_rd_chunk_tags_nand(dev, the_chunk, NULL,
+                                                        tags);
+                               if (yaffs_tags_match(tags, obj_id, inode_chunk)) {
+                                       /* found it; */
+                                       return the_chunk;
+                               }
+                       }
+               }
+               the_chunk++;
+       }
+       return -1;
+}
+
+static int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                                   struct yaffs_ext_tags *tags)
+{
+       /*Get the Tnode, then get the level 0 offset chunk offset */
+       struct yaffs_tnode *tn;
+       int the_chunk = -1;
+       struct yaffs_ext_tags local_tags;
+       int ret_val = -1;
+
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (!tags) {
+               /* Passed a NULL, so use our own tags space */
+               tags = &local_tags;
+       }
+
+       tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+       if (tn) {
+               the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+               ret_val =
+                   yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+                                             inode_chunk);
+       }
+       return ret_val;
+}
+
+static int yaffs_find_del_file_chunk(struct yaffs_obj *in, int inode_chunk,
+                                    struct yaffs_ext_tags *tags)
+{
+       /* Get the Tnode, then get the level 0 offset chunk offset */
+       struct yaffs_tnode *tn;
+       int the_chunk = -1;
+       struct yaffs_ext_tags local_tags;
+
+       struct yaffs_dev *dev = in->my_dev;
+       int ret_val = -1;
+
+       if (!tags) {
+               /* Passed a NULL, so use our own tags space */
+               tags = &local_tags;
+       }
+
+       tn = yaffs_find_tnode_0(dev, &in->variant.file_variant, inode_chunk);
+
+       if (tn) {
+
+               the_chunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+               ret_val =
+                   yaffs_find_chunk_in_group(dev, the_chunk, tags, in->obj_id,
+                                             inode_chunk);
+
+               /* Delete the entry in the filestructure (if found) */
+               if (ret_val != -1)
+                       yaffs_load_tnode_0(dev, tn, inode_chunk, 0);
+       }
+
+       return ret_val;
+}
+
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                           int nand_chunk, int in_scan)
+{
+       /* NB in_scan is zero unless scanning.
+        * For forward scanning, in_scan is > 0;
+        * for backward scanning in_scan is < 0
+        *
+        * nand_chunk = 0 is a dummy insert to make sure the tnodes are there.
+        */
+
+       struct yaffs_tnode *tn;
+       struct yaffs_dev *dev = in->my_dev;
+       int existing_cunk;
+       struct yaffs_ext_tags existing_tags;
+       struct yaffs_ext_tags new_tags;
+       unsigned existing_serial, new_serial;
+
+       if (in->variant_type != YAFFS_OBJECT_TYPE_FILE) {
+               /* Just ignore an attempt at putting a chunk into a non-file during scanning
+                * If it is not during Scanning then something went wrong!
+                */
+               if (!in_scan) {
+                       yaffs_trace(YAFFS_TRACE_ERROR,
+                               "yaffs tragedy:attempt to put data chunk into a non-file"
+                               );
+                       YBUG();
+               }
+
+               yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+               return YAFFS_OK;
+       }
+
+       tn = yaffs_add_find_tnode_0(dev,
+                                   &in->variant.file_variant,
+                                   inode_chunk, NULL);
+       if (!tn)
+               return YAFFS_FAIL;
+
+       if (!nand_chunk)
+               /* Dummy insert, bail now */
+               return YAFFS_OK;
+
+       existing_cunk = yaffs_get_group_base(dev, tn, inode_chunk);
+
+       if (in_scan != 0) {
+               /* If we're scanning then we need to test for duplicates
+                * NB This does not need to be efficient since it should only ever
+                * happen when the power fails during a write, then only one
+                * chunk should ever be affected.
+                *
+                * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
+                * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
+                */
+
+               if (existing_cunk > 0) {
+                       /* NB Right now existing chunk will not be real chunk_id if the chunk group size > 1
+                        *    thus we have to do a FindChunkInFile to get the real chunk id.
+                        *
+                        * We have a duplicate now we need to decide which one to use:
+                        *
+                        * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
+                        * Forward scanning YAFFS2: The new one is what we use, dump the old one.
+                        * YAFFS1: Get both sets of tags and compare serial numbers.
+                        */
+
+                       if (in_scan > 0) {
+                               /* Only do this for forward scanning */
+                               yaffs_rd_chunk_tags_nand(dev,
+                                                        nand_chunk,
+                                                        NULL, &new_tags);
+
+                               /* Do a proper find */
+                               existing_cunk =
+                                   yaffs_find_chunk_in_file(in, inode_chunk,
+                                                            &existing_tags);
+                       }
+
+                       if (existing_cunk <= 0) {
+                               /*Hoosterman - how did this happen? */
+
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       "yaffs tragedy: existing chunk < 0 in scan"
+                                       );
+
+                       }
+
+                       /* NB The deleted flags should be false, otherwise the chunks will
+                        * not be loaded during a scan
+                        */
+
+                       if (in_scan > 0) {
+                               new_serial = new_tags.serial_number;
+                               existing_serial = existing_tags.serial_number;
+                       }
+
+                       if ((in_scan > 0) &&
+                           (existing_cunk <= 0 ||
+                            ((existing_serial + 1) & 3) == new_serial)) {
+                               /* Forward scanning.
+                                * Use new
+                                * Delete the old one and drop through to update the tnode
+                                */
+                               yaffs_chunk_del(dev, existing_cunk, 1,
+                                               __LINE__);
+                       } else {
+                               /* Backward scanning or we want to use the existing one
+                                * Use existing.
+                                * Delete the new one and return early so that the tnode isn't changed
+                                */
+                               yaffs_chunk_del(dev, nand_chunk, 1, __LINE__);
+                               return YAFFS_OK;
+                       }
+               }
+
+       }
+
+       if (existing_cunk == 0)
+               in->n_data_chunks++;
+
+       yaffs_load_tnode_0(dev, tn, inode_chunk, nand_chunk);
+
+       return YAFFS_OK;
+}
+
+static void yaffs_soft_del_chunk(struct yaffs_dev *dev, int chunk)
+{
+       struct yaffs_block_info *the_block;
+       unsigned block_no;
+
+       yaffs_trace(YAFFS_TRACE_DELETION, "soft delete chunk %d", chunk);
+
+       block_no = chunk / dev->param.chunks_per_block;
+       the_block = yaffs_get_block_info(dev, block_no);
+       if (the_block) {
+               the_block->soft_del_pages++;
+               dev->n_free_chunks++;
+               yaffs2_update_oldest_dirty_seq(dev, block_no, the_block);
+       }
+}
+
+/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
+ * All soft deleting does is increment the block's softdelete count and pulls the chunk out
+ * of the tnode.
+ * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
+ */
+
+static int yaffs_soft_del_worker(struct yaffs_obj *in, struct yaffs_tnode *tn,
+                                u32 level, int chunk_offset)
+{
+       int i;
+       int the_chunk;
+       int all_done = 1;
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = YAFFS_NTNODES_INTERNAL - 1; all_done && i >= 0;
+                            i--) {
+                               if (tn->internal[i]) {
+                                       all_done =
+                                           yaffs_soft_del_worker(in,
+                                                                 tn->internal
+                                                                 [i],
+                                                                 level - 1,
+                                                                 (chunk_offset
+                                                                  <<
+                                                                  YAFFS_TNODES_INTERNAL_BITS)
+                                                                 + i);
+                                       if (all_done) {
+                                               yaffs_free_tnode(dev,
+                                                                tn->internal
+                                                                [i]);
+                                               tn->internal[i] = NULL;
+                                       } else {
+                                               /* Hoosterman... how could this happen? */
+                                       }
+                               }
+                       }
+                       return (all_done) ? 1 : 0;
+               } else if (level == 0) {
+
+                       for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
+                               the_chunk = yaffs_get_group_base(dev, tn, i);
+                               if (the_chunk) {
+                                       /* Note this does not find the real chunk, only the chunk group.
+                                        * We make an assumption that a chunk group is not larger than
+                                        * a block.
+                                        */
+                                       yaffs_soft_del_chunk(dev, the_chunk);
+                                       yaffs_load_tnode_0(dev, tn, i, 0);
+                               }
+
+                       }
+                       return 1;
+
+               }
+
+       }
+
+       return 1;
+
+}
+
+static void yaffs_remove_obj_from_dir(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       struct yaffs_obj *parent;
+
+       yaffs_verify_obj_in_dir(obj);
+       parent = obj->parent;
+
+       yaffs_verify_dir(parent);
+
+       if (dev && dev->param.remove_obj_fn)
+               dev->param.remove_obj_fn(obj);
+
+       list_del_init(&obj->siblings);
+       obj->parent = NULL;
+
+       yaffs_verify_dir(parent);
+}
+
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj)
+{
+       if (!directory) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: Trying to add an object to a null pointer directory"
+                       );
+               YBUG();
+               return;
+       }
+       if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: Trying to add an object to a non-directory"
+                       );
+               YBUG();
+       }
+
+       if (obj->siblings.prev == NULL) {
+               /* Not initialised */
+               YBUG();
+       }
+
+       yaffs_verify_dir(directory);
+
+       yaffs_remove_obj_from_dir(obj);
+
+       /* Now add it */
+       list_add(&obj->siblings, &directory->variant.dir_variant.children);
+       obj->parent = directory;
+
+       if (directory == obj->my_dev->unlinked_dir
+           || directory == obj->my_dev->del_dir) {
+               obj->unlinked = 1;
+               obj->my_dev->n_unlinked_files++;
+               obj->rename_allowed = 0;
+       }
+
+       yaffs_verify_dir(directory);
+       yaffs_verify_obj_in_dir(obj);
+}
+
+static int yaffs_change_obj_name(struct yaffs_obj *obj,
+                                struct yaffs_obj *new_dir,
+                                const YCHAR * new_name, int force, int shadows)
+{
+       int unlink_op;
+       int del_op;
+
+       struct yaffs_obj *existing_target;
+
+       if (new_dir == NULL)
+               new_dir = obj->parent;  /* use the old directory */
+
+       if (new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: yaffs_change_obj_name: new_dir is not a directory"
+                       );
+               YBUG();
+       }
+
+       /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
+       if (obj->my_dev->param.is_yaffs2)
+               unlink_op = (new_dir == obj->my_dev->unlinked_dir);
+       else
+               unlink_op = (new_dir == obj->my_dev->unlinked_dir
+                            && obj->variant_type == YAFFS_OBJECT_TYPE_FILE);
+
+       del_op = (new_dir == obj->my_dev->del_dir);
+
+       existing_target = yaffs_find_by_name(new_dir, new_name);
+
+       /* If the object is a file going into the unlinked directory,
+        *   then it is OK to just stuff it in since duplicate names are allowed.
+        *   else only proceed if the new name does not exist and if we're putting
+        *   it into a directory.
+        */
+       if ((unlink_op ||
+            del_op ||
+            force ||
+            (shadows > 0) ||
+            !existing_target) &&
+           new_dir->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_set_obj_name(obj, new_name);
+               obj->dirty = 1;
+
+               yaffs_add_obj_to_dir(new_dir, obj);
+
+               if (unlink_op)
+                       obj->unlinked = 1;
+
+               /* If it is a deletion then we mark it as a shrink for gc purposes. */
+               if (yaffs_update_oh(obj, new_name, 0, del_op, shadows, NULL) >=
+                   0)
+                       return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+/*------------------------ Short Operations Cache ----------------------------------------
+ *   In many situations where there is no high level buffering  a lot of
+ *   reads might be short sequential reads, and a lot of writes may be short
+ *   sequential writes. eg. scanning/writing a jpeg file.
+ *   In these cases, a short read/write cache can provide a huge perfomance
+ *   benefit with dumb-as-a-rock code.
+ *   In Linux, the page cache provides read buffering and the short op cache 
+ *   provides write buffering.
+ *
+ *   There are a limited number (~10) of cache chunks per device so that we don't
+ *   need a very intelligent search.
+ */
+
+static int yaffs_obj_cache_dirty(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       int i;
+       struct yaffs_cache *cache;
+       int n_caches = obj->my_dev->param.n_caches;
+
+       for (i = 0; i < n_caches; i++) {
+               cache = &dev->cache[i];
+               if (cache->object == obj && cache->dirty)
+                       return 1;
+       }
+
+       return 0;
+}
+
+static void yaffs_flush_file_cache(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       int lowest = -99;       /* Stop compiler whining. */
+       int i;
+       struct yaffs_cache *cache;
+       int chunk_written = 0;
+       int n_caches = obj->my_dev->param.n_caches;
+
+       if (n_caches > 0) {
+               do {
+                       cache = NULL;
+
+                       /* Find the dirty cache for this object with the lowest chunk id. */
+                       for (i = 0; i < n_caches; i++) {
+                               if (dev->cache[i].object == obj &&
+                                   dev->cache[i].dirty) {
+                                       if (!cache
+                                           || dev->cache[i].chunk_id <
+                                           lowest) {
+                                               cache = &dev->cache[i];
+                                               lowest = cache->chunk_id;
+                                       }
+                               }
+                       }
+
+                       if (cache && !cache->locked) {
+                               /* Write it out and free it up */
+
+                               chunk_written =
+                                   yaffs_wr_data_obj(cache->object,
+                                                     cache->chunk_id,
+                                                     cache->data,
+                                                     cache->n_bytes, 1);
+                               cache->dirty = 0;
+                               cache->object = NULL;
+                       }
+
+               } while (cache && chunk_written > 0);
+
+               if (cache)
+                       /* Hoosterman, disk full while writing cache out. */
+                       yaffs_trace(YAFFS_TRACE_ERROR,
+                               "yaffs tragedy: no space during cache write");
+
+       }
+
+}
+
+/*yaffs_flush_whole_cache(dev)
+ *
+ *
+ */
+
+void yaffs_flush_whole_cache(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       int n_caches = dev->param.n_caches;
+       int i;
+
+       /* Find a dirty object in the cache and flush it...
+        * until there are no further dirty objects.
+        */
+       do {
+               obj = NULL;
+               for (i = 0; i < n_caches && !obj; i++) {
+                       if (dev->cache[i].object && dev->cache[i].dirty)
+                               obj = dev->cache[i].object;
+
+               }
+               if (obj)
+                       yaffs_flush_file_cache(obj);
+
+       } while (obj);
+
+}
+
+/* Grab us a cache chunk for use.
+ * First look for an empty one.
+ * Then look for the least recently used non-dirty one.
+ * Then look for the least recently used dirty one...., flush and look again.
+ */
+static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev)
+{
+       int i;
+
+       if (dev->param.n_caches > 0) {
+               for (i = 0; i < dev->param.n_caches; i++) {
+                       if (!dev->cache[i].object)
+                               return &dev->cache[i];
+               }
+       }
+
+       return NULL;
+}
+
+static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
+{
+       struct yaffs_cache *cache;
+       struct yaffs_obj *the_obj;
+       int usage;
+       int i;
+       int pushout;
+
+       if (dev->param.n_caches > 0) {
+               /* Try find a non-dirty one... */
+
+               cache = yaffs_grab_chunk_worker(dev);
+
+               if (!cache) {
+                       /* They were all dirty, find the last recently used object and flush
+                        * its cache, then  find again.
+                        * NB what's here is not very accurate, we actually flush the object
+                        * the last recently used page.
+                        */
+
+                       /* With locking we can't assume we can use entry zero */
+
+                       the_obj = NULL;
+                       usage = -1;
+                       cache = NULL;
+                       pushout = -1;
+
+                       for (i = 0; i < dev->param.n_caches; i++) {
+                               if (dev->cache[i].object &&
+                                   !dev->cache[i].locked &&
+                                   (dev->cache[i].last_use < usage
+                                    || !cache)) {
+                                       usage = dev->cache[i].last_use;
+                                       the_obj = dev->cache[i].object;
+                                       cache = &dev->cache[i];
+                                       pushout = i;
+                               }
+                       }
+
+                       if (!cache || cache->dirty) {
+                               /* Flush and try again */
+                               yaffs_flush_file_cache(the_obj);
+                               cache = yaffs_grab_chunk_worker(dev);
+                       }
+
+               }
+               return cache;
+       } else {
+               return NULL;
+        }
+}
+
+/* Find a cached chunk */
+static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj,
+                                                 int chunk_id)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+       int i;
+       if (dev->param.n_caches > 0) {
+               for (i = 0; i < dev->param.n_caches; i++) {
+                       if (dev->cache[i].object == obj &&
+                           dev->cache[i].chunk_id == chunk_id) {
+                               dev->cache_hits++;
+
+                               return &dev->cache[i];
+                       }
+               }
+       }
+       return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache,
+                           int is_write)
+{
+
+       if (dev->param.n_caches > 0) {
+               if (dev->cache_last_use < 0 || dev->cache_last_use > 100000000) {
+                       /* Reset the cache usages */
+                       int i;
+                       for (i = 1; i < dev->param.n_caches; i++)
+                               dev->cache[i].last_use = 0;
+
+                       dev->cache_last_use = 0;
+               }
+
+               dev->cache_last_use++;
+
+               cache->last_use = dev->cache_last_use;
+
+               if (is_write)
+                       cache->dirty = 1;
+       }
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id)
+{
+       if (object->my_dev->param.n_caches > 0) {
+               struct yaffs_cache *cache =
+                   yaffs_find_chunk_cache(object, chunk_id);
+
+               if (cache)
+                       cache->object = NULL;
+       }
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_invalidate_whole_cache(struct yaffs_obj *in)
+{
+       int i;
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (dev->param.n_caches > 0) {
+               /* Invalidate it. */
+               for (i = 0; i < dev->param.n_caches; i++) {
+                       if (dev->cache[i].object == in)
+                               dev->cache[i].object = NULL;
+               }
+       }
+}
+
+static void yaffs_unhash_obj(struct yaffs_obj *obj)
+{
+       int bucket;
+       struct yaffs_dev *dev = obj->my_dev;
+
+       /* If it is still linked into the bucket list, free from the list */
+       if (!list_empty(&obj->hash_link)) {
+               list_del_init(&obj->hash_link);
+               bucket = yaffs_hash_fn(obj->obj_id);
+               dev->obj_bucket[bucket].count--;
+       }
+}
+
+/*  FreeObject frees up a Object and puts it back on the free list */
+static void yaffs_free_obj(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev = obj->my_dev;
+
+       yaffs_trace(YAFFS_TRACE_OS, "FreeObject %p inode %p",
+               obj, obj->my_inode);
+
+       if (!obj)
+               YBUG();
+       if (obj->parent)
+               YBUG();
+       if (!list_empty(&obj->siblings))
+               YBUG();
+
+       if (obj->my_inode) {
+               /* We're still hooked up to a cached inode.
+                * Don't delete now, but mark for later deletion
+                */
+               obj->defered_free = 1;
+               return;
+       }
+
+       yaffs_unhash_obj(obj);
+
+       yaffs_free_raw_obj(dev, obj);
+       dev->n_obj--;
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+}
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj)
+{
+       if (obj->defered_free)
+               yaffs_free_obj(obj);
+}
+
+static int yaffs_generic_obj_del(struct yaffs_obj *in)
+{
+
+       /* First off, invalidate the file's data in the cache, without flushing. */
+       yaffs_invalidate_whole_cache(in);
+
+       if (in->my_dev->param.is_yaffs2 && (in->parent != in->my_dev->del_dir)) {
+               /* Move to the unlinked directory so we have a record that it was deleted. */
+               yaffs_change_obj_name(in, in->my_dev->del_dir, _Y("deleted"), 0,
+                                     0);
+
+       }
+
+       yaffs_remove_obj_from_dir(in);
+       yaffs_chunk_del(in->my_dev, in->hdr_chunk, 1, __LINE__);
+       in->hdr_chunk = 0;
+
+       yaffs_free_obj(in);
+       return YAFFS_OK;
+
+}
+
+static void yaffs_soft_del_file(struct yaffs_obj *obj)
+{
+       if (obj->deleted &&
+           obj->variant_type == YAFFS_OBJECT_TYPE_FILE && !obj->soft_del) {
+               if (obj->n_data_chunks <= 0) {
+                       /* Empty file with no duplicate object headers,
+                        * just delete it immediately */
+                       yaffs_free_tnode(obj->my_dev,
+                                        obj->variant.file_variant.top);
+                       obj->variant.file_variant.top = NULL;
+                       yaffs_trace(YAFFS_TRACE_TRACING,
+                               "yaffs: Deleting empty file %d",
+                               obj->obj_id);
+                       yaffs_generic_obj_del(obj);
+               } else {
+                       yaffs_soft_del_worker(obj,
+                                             obj->variant.file_variant.top,
+                                             obj->variant.
+                                             file_variant.top_level, 0);
+                       obj->soft_del = 1;
+               }
+       }
+}
+
+/* Pruning removes any part of the file structure tree that is beyond the
+ * bounds of the file (ie that does not point to chunks).
+ *
+ * A file should only get pruned when its size is reduced.
+ *
+ * Before pruning, the chunks must be pulled from the tree and the
+ * level 0 tnode entries must be zeroed out.
+ * Could also use this for file deletion, but that's probably better handled
+ * by a special case.
+ *
+ * This function is recursive. For levels > 0 the function is called again on
+ * any sub-tree. For level == 0 we just check if the sub-tree has data.
+ * If there is no data in a subtree then it is pruned.
+ */
+
+static struct yaffs_tnode *yaffs_prune_worker(struct yaffs_dev *dev,
+                                             struct yaffs_tnode *tn, u32 level,
+                                             int del0)
+{
+       int i;
+       int has_data;
+
+       if (tn) {
+               has_data = 0;
+
+               if (level > 0) {
+                       for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
+                               if (tn->internal[i]) {
+                                       tn->internal[i] =
+                                           yaffs_prune_worker(dev,
+                                                              tn->internal[i],
+                                                              level - 1,
+                                                              (i ==
+                                                               0) ? del0 : 1);
+                               }
+
+                               if (tn->internal[i])
+                                       has_data++;
+                       }
+               } else {
+                       int tnode_size_u32 = dev->tnode_size / sizeof(u32);
+                       u32 *map = (u32 *) tn;
+
+                       for (i = 0; !has_data && i < tnode_size_u32; i++) {
+                               if (map[i])
+                                       has_data++;
+                       }
+               }
+
+               if (has_data == 0 && del0) {
+                       /* Free and return NULL */
+
+                       yaffs_free_tnode(dev, tn);
+                       tn = NULL;
+               }
+
+       }
+
+       return tn;
+
+}
+
+static int yaffs_prune_tree(struct yaffs_dev *dev,
+                           struct yaffs_file_var *file_struct)
+{
+       int i;
+       int has_data;
+       int done = 0;
+       struct yaffs_tnode *tn;
+
+       if (file_struct->top_level > 0) {
+               file_struct->top =
+                   yaffs_prune_worker(dev, file_struct->top,
+                                      file_struct->top_level, 0);
+
+               /* Now we have a tree with all the non-zero branches NULL but the height
+                * is the same as it was.
+                * Let's see if we can trim internal tnodes to shorten the tree.
+                * We can do this if only the 0th element in the tnode is in use
+                * (ie all the non-zero are NULL)
+                */
+
+               while (file_struct->top_level && !done) {
+                       tn = file_struct->top;
+
+                       has_data = 0;
+                       for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
+                               if (tn->internal[i])
+                                       has_data++;
+                       }
+
+                       if (!has_data) {
+                               file_struct->top = tn->internal[0];
+                               file_struct->top_level--;
+                               yaffs_free_tnode(dev, tn);
+                       } else {
+                               done = 1;
+                       }
+               }
+       }
+
+       return YAFFS_OK;
+}
+
+/*-------------------- End of File Structure functions.-------------------*/
+
+/* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
+static struct yaffs_obj *yaffs_alloc_empty_obj(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj = yaffs_alloc_raw_obj(dev);
+
+       if (obj) {
+               dev->n_obj++;
+
+               /* Now sweeten it up... */
+
+               memset(obj, 0, sizeof(struct yaffs_obj));
+               obj->being_created = 1;
+
+               obj->my_dev = dev;
+               obj->hdr_chunk = 0;
+               obj->variant_type = YAFFS_OBJECT_TYPE_UNKNOWN;
+               INIT_LIST_HEAD(&(obj->hard_links));
+               INIT_LIST_HEAD(&(obj->hash_link));
+               INIT_LIST_HEAD(&obj->siblings);
+
+               /* Now make the directory sane */
+               if (dev->root_dir) {
+                       obj->parent = dev->root_dir;
+                       list_add(&(obj->siblings),
+                                &dev->root_dir->variant.dir_variant.children);
+               }
+
+               /* Add it to the lost and found directory.
+                * NB Can't put root or lost-n-found in lost-n-found so
+                * check if lost-n-found exists first
+                */
+               if (dev->lost_n_found)
+                       yaffs_add_obj_to_dir(dev->lost_n_found, obj);
+
+               obj->being_created = 0;
+       }
+
+       dev->checkpoint_blocks_required = 0;    /* force recalculation */
+
+       return obj;
+}
+
+static int yaffs_find_nice_bucket(struct yaffs_dev *dev)
+{
+       int i;
+       int l = 999;
+       int lowest = 999999;
+
+       /* Search for the shortest list or one that
+        * isn't too long.
+        */
+
+       for (i = 0; i < 10 && lowest > 4; i++) {
+               dev->bucket_finder++;
+               dev->bucket_finder %= YAFFS_NOBJECT_BUCKETS;
+               if (dev->obj_bucket[dev->bucket_finder].count < lowest) {
+                       lowest = dev->obj_bucket[dev->bucket_finder].count;
+                       l = dev->bucket_finder;
+               }
+
+       }
+
+       return l;
+}
+
+static int yaffs_new_obj_id(struct yaffs_dev *dev)
+{
+       int bucket = yaffs_find_nice_bucket(dev);
+
+       /* Now find an object value that has not already been taken
+        * by scanning the list.
+        */
+
+       int found = 0;
+       struct list_head *i;
+
+       u32 n = (u32) bucket;
+
+       /* yaffs_check_obj_hash_sane();  */
+
+       while (!found) {
+               found = 1;
+               n += YAFFS_NOBJECT_BUCKETS;
+               if (1 || dev->obj_bucket[bucket].count > 0) {
+                       list_for_each(i, &dev->obj_bucket[bucket].list) {
+                               /* If there is already one in the list */
+                               if (i && list_entry(i, struct yaffs_obj,
+                                                   hash_link)->obj_id == n) {
+                                       found = 0;
+                               }
+                       }
+               }
+       }
+
+       return n;
+}
+
+static void yaffs_hash_obj(struct yaffs_obj *in)
+{
+       int bucket = yaffs_hash_fn(in->obj_id);
+       struct yaffs_dev *dev = in->my_dev;
+
+       list_add(&in->hash_link, &dev->obj_bucket[bucket].list);
+       dev->obj_bucket[bucket].count++;
+}
+
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
+{
+       int bucket = yaffs_hash_fn(number);
+       struct list_head *i;
+       struct yaffs_obj *in;
+
+       list_for_each(i, &dev->obj_bucket[bucket].list) {
+               /* Look if it is in the list */
+               if (i) {
+                       in = list_entry(i, struct yaffs_obj, hash_link);
+                       if (in->obj_id == number) {
+
+                               /* Don't tell the VFS about this one if it is defered free */
+                               if (in->defered_free)
+                                       return NULL;
+
+                               return in;
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+struct yaffs_obj *yaffs_new_obj(struct yaffs_dev *dev, int number,
+                               enum yaffs_obj_type type)
+{
+       struct yaffs_obj *the_obj = NULL;
+       struct yaffs_tnode *tn = NULL;
+
+       if (number < 0)
+               number = yaffs_new_obj_id(dev);
+
+       if (type == YAFFS_OBJECT_TYPE_FILE) {
+               tn = yaffs_get_tnode(dev);
+               if (!tn)
+                       return NULL;
+       }
+
+       the_obj = yaffs_alloc_empty_obj(dev);
+       if (!the_obj) {
+               if (tn)
+                       yaffs_free_tnode(dev, tn);
+               return NULL;
+       }
+
+       if (the_obj) {
+               the_obj->fake = 0;
+               the_obj->rename_allowed = 1;
+               the_obj->unlink_allowed = 1;
+               the_obj->obj_id = number;
+               yaffs_hash_obj(the_obj);
+               the_obj->variant_type = type;
+               yaffs_load_current_time(the_obj, 1, 1);
+
+               switch (type) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       the_obj->variant.file_variant.file_size = 0;
+                       the_obj->variant.file_variant.scanned_size = 0;
+                       the_obj->variant.file_variant.shrink_size = ~0; /* max */
+                       the_obj->variant.file_variant.top_level = 0;
+                       the_obj->variant.file_variant.top = tn;
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       INIT_LIST_HEAD(&the_obj->variant.dir_variant.children);
+                       INIT_LIST_HEAD(&the_obj->variant.dir_variant.dirty);
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       /* No action required */
+                       break;
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* todo this should not happen */
+                       break;
+               }
+       }
+
+       return the_obj;
+}
+
+static struct yaffs_obj *yaffs_create_fake_dir(struct yaffs_dev *dev,
+                                              int number, u32 mode)
+{
+
+       struct yaffs_obj *obj =
+           yaffs_new_obj(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
+       if (obj) {
+               obj->fake = 1;  /* it is fake so it might have no NAND presence... */
+               obj->rename_allowed = 0;        /* ... and we're not allowed to rename it... */
+               obj->unlink_allowed = 0;        /* ... or unlink it */
+               obj->deleted = 0;
+               obj->unlinked = 0;
+               obj->yst_mode = mode;
+               obj->my_dev = dev;
+               obj->hdr_chunk = 0;     /* Not a valid chunk. */
+       }
+
+       return obj;
+
+}
+
+
+static void yaffs_init_tnodes_and_objs(struct yaffs_dev *dev)
+{
+       int i;
+
+       dev->n_obj = 0;
+       dev->n_tnodes = 0;
+
+       yaffs_init_raw_tnodes_and_objs(dev);
+
+       for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+               INIT_LIST_HEAD(&dev->obj_bucket[i].list);
+               dev->obj_bucket[i].count = 0;
+       }
+}
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+                                                int number,
+                                                enum yaffs_obj_type type)
+{
+       struct yaffs_obj *the_obj = NULL;
+
+       if (number > 0)
+               the_obj = yaffs_find_by_number(dev, number);
+
+       if (!the_obj)
+               the_obj = yaffs_new_obj(dev, number, type);
+
+       return the_obj;
+
+}
+
+YCHAR *yaffs_clone_str(const YCHAR * str)
+{
+       YCHAR *new_str = NULL;
+       int len;
+
+       if (!str)
+               str = _Y("");
+
+       len = strnlen(str, YAFFS_MAX_ALIAS_LENGTH);
+       new_str = kmalloc((len + 1) * sizeof(YCHAR), GFP_NOFS);
+       if (new_str) {
+               strncpy(new_str, str, len);
+               new_str[len] = 0;
+       }
+       return new_str;
+
+}
+/*
+ *yaffs_update_parent() handles fixing a directories mtime and ctime when a new
+ * link (ie. name) is created or deleted in the directory.
+ *
+ * ie.
+ *   create dir/a : update dir's mtime/ctime
+ *   rm dir/a:   update dir's mtime/ctime
+ *   modify dir/a: don't update dir's mtimme/ctime
+ *
+ * This can be handled immediately or defered. Defering helps reduce the number
+ * of updates when many files in a directory are changed within a brief period.
+ *
+ * If the directory updating is defered then yaffs_update_dirty_dirs must be
+ * called periodically.
+ */
+
+static void yaffs_update_parent(struct yaffs_obj *obj)
+{
+       struct yaffs_dev *dev;
+       if (!obj)
+               return;
+       dev = obj->my_dev;
+       obj->dirty = 1;
+       yaffs_load_current_time(obj, 0, 1);
+       if (dev->param.defered_dir_update) {
+               struct list_head *link = &obj->variant.dir_variant.dirty;
+
+               if (list_empty(link)) {
+                       list_add(link, &dev->dirty_dirs);
+                       yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                         "Added object %d to dirty directories",
+                          obj->obj_id);
+               }
+
+       } else {
+               yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+        }
+}
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev)
+{
+       struct list_head *link;
+       struct yaffs_obj *obj;
+       struct yaffs_dir_var *d_s;
+       union yaffs_obj_var *o_v;
+
+       yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update dirty directories");
+
+       while (!list_empty(&dev->dirty_dirs)) {
+               link = dev->dirty_dirs.next;
+               list_del_init(link);
+
+               d_s = list_entry(link, struct yaffs_dir_var, dirty);
+               o_v = list_entry(d_s, union yaffs_obj_var, dir_variant);
+               obj = list_entry(o_v, struct yaffs_obj, variant);
+
+               yaffs_trace(YAFFS_TRACE_BACKGROUND, "Update directory %d",
+                       obj->obj_id);
+
+               if (obj->dirty)
+                       yaffs_update_oh(obj, NULL, 0, 0, 0, NULL);
+       }
+}
+
+/*
+ * Mknod (create) a new object.
+ * equiv_obj only has meaning for a hard link;
+ * alias_str only has meaning for a symlink.
+ * rdev only has meaning for devices (a subset of special objects)
+ */
+
+static struct yaffs_obj *yaffs_create_obj(enum yaffs_obj_type type,
+                                         struct yaffs_obj *parent,
+                                         const YCHAR * name,
+                                         u32 mode,
+                                         u32 uid,
+                                         u32 gid,
+                                         struct yaffs_obj *equiv_obj,
+                                         const YCHAR * alias_str, u32 rdev)
+{
+       struct yaffs_obj *in;
+       YCHAR *str = NULL;
+
+       struct yaffs_dev *dev = parent->my_dev;
+
+       /* Check if the entry exists. If it does then fail the call since we don't want a dup. */
+       if (yaffs_find_by_name(parent, name))
+               return NULL;
+
+       if (type == YAFFS_OBJECT_TYPE_SYMLINK) {
+               str = yaffs_clone_str(alias_str);
+               if (!str)
+                       return NULL;
+       }
+
+       in = yaffs_new_obj(dev, -1, type);
+
+       if (!in) {
+               if (str)
+                       kfree(str);
+               return NULL;
+       }
+
+       if (in) {
+               in->hdr_chunk = 0;
+               in->valid = 1;
+               in->variant_type = type;
+
+               in->yst_mode = mode;
+
+               yaffs_attribs_init(in, gid, uid, rdev);
+
+               in->n_data_chunks = 0;
+
+               yaffs_set_obj_name(in, name);
+               in->dirty = 1;
+
+               yaffs_add_obj_to_dir(parent, in);
+
+               in->my_dev = parent->my_dev;
+
+               switch (type) {
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       in->variant.symlink_variant.alias = str;
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+                       in->variant.hardlink_variant.equiv_obj = equiv_obj;
+                       in->variant.hardlink_variant.equiv_id =
+                           equiv_obj->obj_id;
+                       list_add(&in->hard_links, &equiv_obj->hard_links);
+                       break;
+               case YAFFS_OBJECT_TYPE_FILE:
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* do nothing */
+                       break;
+               }
+
+               if (yaffs_update_oh(in, name, 0, 0, 0, NULL) < 0) {
+                       /* Could not create the object header, fail the creation */
+                       yaffs_del_obj(in);
+                       in = NULL;
+               }
+
+               yaffs_update_parent(parent);
+       }
+
+       return in;
+}
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+                                   const YCHAR * name, u32 mode, u32 uid,
+                                   u32 gid)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
+                               uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
+                                  u32 mode, u32 uid, u32 gid)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
+                               mode, uid, gid, NULL, NULL, 0);
+}
+
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, u32 rdev)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
+                               uid, gid, NULL, NULL, rdev);
+}
+
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, const YCHAR * alias)
+{
+       return yaffs_create_obj(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
+                               uid, gid, NULL, alias, 0);
+}
+
+/* yaffs_link_obj returns the object id of the equivalent object.*/
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+                                struct yaffs_obj *equiv_obj)
+{
+       /* Get the real object in case we were fed a hard link as an equivalent object */
+       equiv_obj = yaffs_get_equivalent_obj(equiv_obj);
+
+       if (yaffs_create_obj
+           (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
+            equiv_obj, NULL, 0)) {
+               return equiv_obj;
+       } else {
+               return NULL;
+       }
+
+}
+
+
+
+/*------------------------- Block Management and Page Allocation ----------------*/
+
+static int yaffs_init_blocks(struct yaffs_dev *dev)
+{
+       int n_blocks = dev->internal_end_block - dev->internal_start_block + 1;
+
+       dev->block_info = NULL;
+       dev->chunk_bits = NULL;
+
+       dev->alloc_block = -1;  /* force it to get a new one */
+
+       /* If the first allocation strategy fails, thry the alternate one */
+       dev->block_info =
+               kmalloc(n_blocks * sizeof(struct yaffs_block_info), GFP_NOFS);
+       if (!dev->block_info) {
+               dev->block_info =
+                   vmalloc(n_blocks * sizeof(struct yaffs_block_info));
+               dev->block_info_alt = 1;
+       } else {
+               dev->block_info_alt = 0;
+        }
+
+       if (dev->block_info) {
+               /* Set up dynamic blockinfo stuff. Round up bytes. */
+               dev->chunk_bit_stride = (dev->param.chunks_per_block + 7) / 8;
+               dev->chunk_bits =
+                       kmalloc(dev->chunk_bit_stride * n_blocks, GFP_NOFS);
+               if (!dev->chunk_bits) {
+                       dev->chunk_bits =
+                           vmalloc(dev->chunk_bit_stride * n_blocks);
+                       dev->chunk_bits_alt = 1;
+               } else {
+                       dev->chunk_bits_alt = 0;
+                }
+       }
+
+       if (dev->block_info && dev->chunk_bits) {
+               memset(dev->block_info, 0,
+                      n_blocks * sizeof(struct yaffs_block_info));
+               memset(dev->chunk_bits, 0, dev->chunk_bit_stride * n_blocks);
+               return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+static void yaffs_deinit_blocks(struct yaffs_dev *dev)
+{
+       if (dev->block_info_alt && dev->block_info)
+               vfree(dev->block_info);
+       else if (dev->block_info)
+               kfree(dev->block_info);
+
+       dev->block_info_alt = 0;
+
+       dev->block_info = NULL;
+
+       if (dev->chunk_bits_alt && dev->chunk_bits)
+               vfree(dev->chunk_bits);
+       else if (dev->chunk_bits)
+               kfree(dev->chunk_bits);
+       dev->chunk_bits_alt = 0;
+       dev->chunk_bits = NULL;
+}
+
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no)
+{
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, block_no);
+
+       int erased_ok = 0;
+
+       /* If the block is still healthy erase it and mark as clean.
+        * If the block has had a data failure, then retire it.
+        */
+
+       yaffs_trace(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
+               "yaffs_block_became_dirty block %d state %d %s",
+               block_no, bi->block_state,
+               (bi->needs_retiring) ? "needs retiring" : "");
+
+       yaffs2_clear_oldest_dirty_seq(dev, bi);
+
+       bi->block_state = YAFFS_BLOCK_STATE_DIRTY;
+
+       /* If this is the block being garbage collected then stop gc'ing this block */
+       if (block_no == dev->gc_block)
+               dev->gc_block = 0;
+
+       /* If this block is currently the best candidate for gc then drop as a candidate */
+       if (block_no == dev->gc_dirtiest) {
+               dev->gc_dirtiest = 0;
+               dev->gc_pages_in_use = 0;
+       }
+
+       if (!bi->needs_retiring) {
+               yaffs2_checkpt_invalidate(dev);
+               erased_ok = yaffs_erase_block(dev, block_no);
+               if (!erased_ok) {
+                       dev->n_erase_failures++;
+                       yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                         "**>> Erasure failed %d", block_no);
+               }
+       }
+
+       if (erased_ok &&
+           ((yaffs_trace_mask & YAFFS_TRACE_ERASE)
+            || !yaffs_skip_verification(dev))) {
+               int i;
+               for (i = 0; i < dev->param.chunks_per_block; i++) {
+                       if (!yaffs_check_chunk_erased
+                           (dev, block_no * dev->param.chunks_per_block + i)) {
+                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                       ">>Block %d erasure supposedly OK, but chunk %d not erased",
+                                       block_no, i);
+                       }
+               }
+       }
+
+       if (erased_ok) {
+               /* Clean it up... */
+               bi->block_state = YAFFS_BLOCK_STATE_EMPTY;
+               bi->seq_number = 0;
+               dev->n_erased_blocks++;
+               bi->pages_in_use = 0;
+               bi->soft_del_pages = 0;
+               bi->has_shrink_hdr = 0;
+               bi->skip_erased_check = 1;      /* Clean, so no need to check */
+               bi->gc_prioritise = 0;
+               yaffs_clear_chunk_bits(dev, block_no);
+
+               yaffs_trace(YAFFS_TRACE_ERASE,
+                       "Erased block %d", block_no);
+       } else {
+               /* We lost a block of free space */
+               dev->n_free_chunks -= dev->param.chunks_per_block;
+               yaffs_retire_block(dev, block_no);
+               yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                       "**>> Block %d retired", block_no);
+       }
+}
+
+
+
+static int yaffs_gc_block(struct yaffs_dev *dev, int block, int whole_block)
+{
+       int old_chunk;
+       int new_chunk;
+       int mark_flash;
+       int ret_val = YAFFS_OK;
+       int i;
+       int is_checkpt_block;
+       int matching_chunk;
+       int max_copies;
+
+       int chunks_before = yaffs_get_erased_chunks(dev);
+       int chunks_after;
+
+       struct yaffs_ext_tags tags;
+
+       struct yaffs_block_info *bi = yaffs_get_block_info(dev, block);
+
+       struct yaffs_obj *object;
+
+       is_checkpt_block = (bi->block_state == YAFFS_BLOCK_STATE_CHECKPOINT);
+
+       yaffs_trace(YAFFS_TRACE_TRACING,
+               "Collecting block %d, in use %d, shrink %d, whole_block %d",
+               block, bi->pages_in_use, bi->has_shrink_hdr,
+               whole_block);
+
+       /*yaffs_verify_free_chunks(dev); */
+
+       if (bi->block_state == YAFFS_BLOCK_STATE_FULL)
+               bi->block_state = YAFFS_BLOCK_STATE_COLLECTING;
+
+       bi->has_shrink_hdr = 0; /* clear the flag so that the block can erase */
+
+       dev->gc_disable = 1;
+
+       if (is_checkpt_block || !yaffs_still_some_chunks(dev, block)) {
+               yaffs_trace(YAFFS_TRACE_TRACING,
+                       "Collecting block %d that has no chunks in use",
+                       block);
+               yaffs_block_became_dirty(dev, block);
+       } else {
+
+               u8 *buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+               yaffs_verify_blk(dev, bi, block);
+
+               max_copies = (whole_block) ? dev->param.chunks_per_block : 5;
+               old_chunk = block * dev->param.chunks_per_block + dev->gc_chunk;
+
+               for ( /* init already done */ ;
+                    ret_val == YAFFS_OK &&
+                    dev->gc_chunk < dev->param.chunks_per_block &&
+                    (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) &&
+                    max_copies > 0; dev->gc_chunk++, old_chunk++) {
+                       if (yaffs_check_chunk_bit(dev, block, dev->gc_chunk)) {
+
+                               /* This page is in use and might need to be copied off */
+
+                               max_copies--;
+
+                               mark_flash = 1;
+
+                               yaffs_init_tags(&tags);
+
+                               yaffs_rd_chunk_tags_nand(dev, old_chunk,
+                                                        buffer, &tags);
+
+                               object = yaffs_find_by_number(dev, tags.obj_id);
+
+                               yaffs_trace(YAFFS_TRACE_GC_DETAIL,
+                                       "Collecting chunk in block %d, %d %d %d ",
+                                       dev->gc_chunk, tags.obj_id,
+                                       tags.chunk_id, tags.n_bytes);
+
+                               if (object && !yaffs_skip_verification(dev)) {
+                                       if (tags.chunk_id == 0)
+                                               matching_chunk =
+                                                   object->hdr_chunk;
+                                       else if (object->soft_del)
+                                               matching_chunk = old_chunk;     /* Defeat the test */
+                                       else
+                                               matching_chunk =
+                                                   yaffs_find_chunk_in_file
+                                                   (object, tags.chunk_id,
+                                                    NULL);
+
+                                       if (old_chunk != matching_chunk)
+                                               yaffs_trace(YAFFS_TRACE_ERROR,
+                                                       "gc: page in gc mismatch: %d %d %d %d",
+                                                       old_chunk,
+                                                       matching_chunk,
+                                                       tags.obj_id,
+                                                       tags.chunk_id);
+
+                               }
+
+                               if (!object) {
+                                       yaffs_trace(YAFFS_TRACE_ERROR,
+                                               "page %d in gc has no object: %d %d %d ",
+                                               old_chunk,
+                                               tags.obj_id, tags.chunk_id,
+                                               tags.n_bytes);
+                               }
+
+                               if (object &&
+                                   object->deleted &&
+                                   object->soft_del && tags.chunk_id != 0) {
+                                       /* Data chunk in a soft deleted file, throw it away
+                                        * It's a soft deleted data chunk,
+                                        * No need to copy this, just forget about it and
+                                        * fix up the object.
+                                        */
+
+                                       /* Free chunks already includes softdeleted chunks.
+                                        * How ever this chunk is going to soon be really deleted
+                                        * which will increment free chunks.
+                                        * We have to decrement free chunks so this works out properly.
+                                        */
+                                       dev->n_free_chunks--;
+                                       bi->soft_del_pages--;
+
+                                       object->n_data_chunks--;
+
+                                       if (object->n_data_chunks <= 0) {
+                                               /* remeber to clean up the object */
+                                               dev->gc_cleanup_list[dev->
+                                                                    n_clean_ups]
+                                                   = tags.obj_id;
+                                               dev->n_clean_ups++;
+                                       }
+                                       mark_flash = 0;
+                               } else if (0) {
+                                       /* Todo object && object->deleted && object->n_data_chunks == 0 */
+                                       /* Deleted object header with no data chunks.
+                                        * Can be discarded and the file deleted.
+                                        */
+                                       object->hdr_chunk = 0;
+                                       yaffs_free_tnode(object->my_dev,
+                                                        object->
+                                                        variant.file_variant.
+                                                        top);
+                                       object->variant.file_variant.top = NULL;
+                                       yaffs_generic_obj_del(object);
+
+                               } else if (object) {
+                                       /* It's either a data chunk in a live file or
+                                        * an ObjectHeader, so we're interested in it.
+                                        * NB Need to keep the ObjectHeaders of deleted files
+                                        * until the whole file has been deleted off
+                                        */
+                                       tags.serial_number++;
+
+                                       dev->n_gc_copies++;
+
+                                       if (tags.chunk_id == 0) {
+                                               /* It is an object Id,
+                                                * We need to nuke the shrinkheader flags first
+                                                * Also need to clean up shadowing.
+                                                * We no longer want the shrink_header flag since its work is done
+                                                * and if it is left in place it will mess up scanning.
+                                                */
+
+                                               struct yaffs_obj_hdr *oh;
+                                               oh = (struct yaffs_obj_hdr *)
+                                                   buffer;
+
+                                               oh->is_shrink = 0;
+                                               tags.extra_is_shrink = 0;
+
+                                               oh->shadows_obj = 0;
+                                               oh->inband_shadowed_obj_id = 0;
+                                               tags.extra_shadows = 0;
+
+                                               /* Update file size */
+                                               if (object->variant_type ==
+                                                   YAFFS_OBJECT_TYPE_FILE) {
+                                                       oh->file_size =
+                                                           object->variant.
+                                                           file_variant.
+                                                           file_size;
+                                                       tags.extra_length =
+                                                           oh->file_size;
+                                               }
+
+                                               yaffs_verify_oh(object, oh,
+                                                               &tags, 1);
+                                               new_chunk =
+                                                   yaffs_write_new_chunk(dev,
+                                                                         (u8 *)
+                                                                         oh,
+                                                                         &tags,
+                                                                         1);
+                                       } else {
+                                               new_chunk =
+                                                   yaffs_write_new_chunk(dev,
+                                                                         buffer,
+                                                                         &tags,
+                                                                         1);
+                                        }
+
+                                       if (new_chunk < 0) {
+                                               ret_val = YAFFS_FAIL;
+                                       } else {
+
+                                               /* Ok, now fix up the Tnodes etc. */
+
+                                               if (tags.chunk_id == 0) {
+                                                       /* It's a header */
+                                                       object->hdr_chunk =
+                                                           new_chunk;
+                                                       object->serial =
+                                                           tags.serial_number;
+                                               } else {
+                                                       /* It's a data chunk */
+                                                       int ok;
+                                                       ok = yaffs_put_chunk_in_file(object, tags.chunk_id, new_chunk, 0);
+                                               }
+                                       }
+                               }
+
+                               if (ret_val == YAFFS_OK)
+                                       yaffs_chunk_del(dev, old_chunk,
+                                                       mark_flash, __LINE__);
+
+                       }
+               }
+
+               yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+       }
+
+       yaffs_verify_collected_blk(dev, bi, block);
+
+       if (bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+               /*
+                * The gc did not complete. Set block state back to FULL
+                * because checkpointing does not restore gc.
+                */
+               bi->block_state = YAFFS_BLOCK_STATE_FULL;
+       } else {
+               /* The gc completed. */
+               /* Do any required cleanups */
+               for (i = 0; i < dev->n_clean_ups; i++) {
+                       /* Time to delete the file too */
+                       object =
+                           yaffs_find_by_number(dev, dev->gc_cleanup_list[i]);
+                       if (object) {
+                               yaffs_free_tnode(dev,
+                                                object->variant.
+                                                file_variant.top);
+                               object->variant.file_variant.top = NULL;
+                               yaffs_trace(YAFFS_TRACE_GC,
+                                       "yaffs: About to finally delete object %d",
+                                       object->obj_id);
+                               yaffs_generic_obj_del(object);
+                               object->my_dev->n_deleted_files--;
+                       }
+
+               }
+
+               chunks_after = yaffs_get_erased_chunks(dev);
+               if (chunks_before >= chunks_after)
+                       yaffs_trace(YAFFS_TRACE_GC,
+                               "gc did not increase free chunks before %d after %d",
+                               chunks_before, chunks_after);
+               dev->gc_block = 0;
+               dev->gc_chunk = 0;
+               dev->n_clean_ups = 0;
+       }
+
+       dev->gc_disable = 0;
+
+       return ret_val;
+}
+
+/*
+ * FindBlockForgarbageCollection is used to select the dirtiest block (or close enough)
+ * for garbage collection.
+ */
+
+static unsigned yaffs_find_gc_block(struct yaffs_dev *dev,
+                                   int aggressive, int background)
+{
+       int i;
+       int iterations;
+       unsigned selected = 0;
+       int prioritised = 0;
+       int prioritised_exist = 0;
+       struct yaffs_block_info *bi;
+       int threshold;
+
+       /* First let's see if we need to grab a prioritised block */
+       if (dev->has_pending_prioritised_gc && !aggressive) {
+               dev->gc_dirtiest = 0;
+               bi = dev->block_info;
+               for (i = dev->internal_start_block;
+                    i <= dev->internal_end_block && !selected; i++) {
+
+                       if (bi->gc_prioritise) {
+                               prioritised_exist = 1;
+                               if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+                                   yaffs_block_ok_for_gc(dev, bi)) {
+                                       selected = i;
+                                       prioritised = 1;
+                               }
+                       }
+                       bi++;
+               }
+
+               /*
+                * If there is a prioritised block and none was selected then
+                * this happened because there is at least one old dirty block gumming
+                * up the works. Let's gc the oldest dirty block.
+                */
+
+               if (prioritised_exist &&
+                   !selected && dev->oldest_dirty_block > 0)
+                       selected = dev->oldest_dirty_block;
+
+               if (!prioritised_exist) /* None found, so we can clear this */
+                       dev->has_pending_prioritised_gc = 0;
+       }
+
+       /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
+        * search harder.
+        * else (we're doing a leasurely gc), then we only bother to do this if the
+        * block has only a few pages in use.
+        */
+
+       if (!selected) {
+               int pages_used;
+               int n_blocks =
+                   dev->internal_end_block - dev->internal_start_block + 1;
+               if (aggressive) {
+                       threshold = dev->param.chunks_per_block;
+                       iterations = n_blocks;
+               } else {
+                       int max_threshold;
+
+                       if (background)
+                               max_threshold = dev->param.chunks_per_block / 2;
+                       else
+                               max_threshold = dev->param.chunks_per_block / 8;
+
+                       if (max_threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+                               max_threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+
+                       threshold = background ? (dev->gc_not_done + 2) * 2 : 0;
+                       if (threshold < YAFFS_GC_PASSIVE_THRESHOLD)
+                               threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+                       if (threshold > max_threshold)
+                               threshold = max_threshold;
+
+                       iterations = n_blocks / 16 + 1;
+                       if (iterations > 100)
+                               iterations = 100;
+               }
+
+               for (i = 0;
+                    i < iterations &&
+                    (dev->gc_dirtiest < 1 ||
+                     dev->gc_pages_in_use > YAFFS_GC_GOOD_ENOUGH); i++) {
+                       dev->gc_block_finder++;
+                       if (dev->gc_block_finder < dev->internal_start_block ||
+                           dev->gc_block_finder > dev->internal_end_block)
+                               dev->gc_block_finder =
+                                   dev->internal_start_block;
+
+                       bi = yaffs_get_block_info(dev, dev->gc_block_finder);
+
+                       pages_used = bi->pages_in_use - bi->soft_del_pages;
+
+                       if (bi->block_state == YAFFS_BLOCK_STATE_FULL &&
+                           pages_used < dev->param.chunks_per_block &&
+                           (dev->gc_dirtiest < 1
+                            || pages_used < dev->gc_pages_in_use)
+                           && yaffs_block_ok_for_gc(dev, bi)) {
+                               dev->gc_dirtiest = dev->gc_block_finder;
+                               dev->gc_pages_in_use = pages_used;
+                       }
+               }
+
+               if (dev->gc_dirtiest > 0 && dev->gc_pages_in_use <= threshold)
+                       selected = dev->gc_dirtiest;
+       }
+
+       /*
+        * If nothing has been selected for a while, try selecting the oldest dirty
+        * because that's gumming up the works.
+        */
+
+       if (!selected && dev->param.is_yaffs2 &&
+           dev->gc_not_done >= (background ? 10 : 20)) {
+               yaffs2_find_oldest_dirty_seq(dev);
+               if (dev->oldest_dirty_block > 0) {
+                       selected = dev->oldest_dirty_block;
+                       dev->gc_dirtiest = selected;
+                       dev->oldest_dirty_gc_count++;
+                       bi = yaffs_get_block_info(dev, selected);
+                       dev->gc_pages_in_use =
+                           bi->pages_in_use - bi->soft_del_pages;
+               } else {
+                       dev->gc_not_done = 0;
+                }
+       }
+
+       if (selected) {
+               yaffs_trace(YAFFS_TRACE_GC,
+                       "GC Selected block %d with %d free, prioritised:%d",
+                       selected,
+                       dev->param.chunks_per_block - dev->gc_pages_in_use,
+                       prioritised);
+
+               dev->n_gc_blocks++;
+               if (background)
+                       dev->bg_gcs++;
+
+               dev->gc_dirtiest = 0;
+               dev->gc_pages_in_use = 0;
+               dev->gc_not_done = 0;
+               if (dev->refresh_skip > 0)
+                       dev->refresh_skip--;
+       } else {
+               dev->gc_not_done++;
+               yaffs_trace(YAFFS_TRACE_GC,
+                       "GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s",
+                       dev->gc_block_finder, dev->gc_not_done, threshold,
+                       dev->gc_dirtiest, dev->gc_pages_in_use,
+                       dev->oldest_dirty_block, background ? " bg" : "");
+       }
+
+       return selected;
+}
+
+/* New garbage collector
+ * If we're very low on erased blocks then we do aggressive garbage collection
+ * otherwise we do "leasurely" garbage collection.
+ * Aggressive gc looks further (whole array) and will accept less dirty blocks.
+ * Passive gc only inspects smaller areas and will only accept more dirty blocks.
+ *
+ * The idea is to help clear out space in a more spread-out manner.
+ * Dunno if it really does anything useful.
+ */
+static int yaffs_check_gc(struct yaffs_dev *dev, int background)
+{
+       int aggressive = 0;
+       int gc_ok = YAFFS_OK;
+       int max_tries = 0;
+       int min_erased;
+       int erased_chunks;
+       int checkpt_block_adjust;
+
+       if (dev->param.gc_control && (dev->param.gc_control(dev) & 1) == 0)
+               return YAFFS_OK;
+
+       if (dev->gc_disable) {
+               /* Bail out so we don't get recursive gc */
+               return YAFFS_OK;
+       }
+
+       /* This loop should pass the first time.
+        * We'll only see looping here if the collection does not increase space.
+        */
+
+       do {
+               max_tries++;
+
+               checkpt_block_adjust = yaffs_calc_checkpt_blocks_required(dev);
+
+               min_erased =
+                   dev->param.n_reserved_blocks + checkpt_block_adjust + 1;
+               erased_chunks =
+                   dev->n_erased_blocks * dev->param.chunks_per_block;
+
+               /* If we need a block soon then do aggressive gc. */
+               if (dev->n_erased_blocks < min_erased)
+                       aggressive = 1;
+               else {
+                       if (!background
+                           && erased_chunks > (dev->n_free_chunks / 4))
+                               break;
+
+                       if (dev->gc_skip > 20)
+                               dev->gc_skip = 20;
+                       if (erased_chunks < dev->n_free_chunks / 2 ||
+                           dev->gc_skip < 1 || background)
+                               aggressive = 0;
+                       else {
+                               dev->gc_skip--;
+                               break;
+                       }
+               }
+
+               dev->gc_skip = 5;
+
+               /* If we don't already have a block being gc'd then see if we should start another */
+
+               if (dev->gc_block < 1 && !aggressive) {
+                       dev->gc_block = yaffs2_find_refresh_block(dev);
+                       dev->gc_chunk = 0;
+                       dev->n_clean_ups = 0;
+               }
+               if (dev->gc_block < 1) {
+                       dev->gc_block =
+                           yaffs_find_gc_block(dev, aggressive, background);
+                       dev->gc_chunk = 0;
+                       dev->n_clean_ups = 0;
+               }
+
+               if (dev->gc_block > 0) {
+                       dev->all_gcs++;
+                       if (!aggressive)
+                               dev->passive_gc_count++;
+
+                       yaffs_trace(YAFFS_TRACE_GC,
+                               "yaffs: GC n_erased_blocks %d aggressive %d",
+                               dev->n_erased_blocks, aggressive);
+
+                       gc_ok = yaffs_gc_block(dev, dev->gc_block, aggressive);
+               }
+
+               if (dev->n_erased_blocks < (dev->param.n_reserved_blocks)
+                   && dev->gc_block > 0) {
+                       yaffs_trace(YAFFS_TRACE_GC,
+                               "yaffs: GC !!!no reclaim!!! n_erased_blocks %d after try %d block %d",
+                               dev->n_erased_blocks, max_tries,
+                               dev->gc_block);
+               }
+       } while ((dev->n_erased_blocks < dev->param.n_reserved_blocks) &&
+                (dev->gc_block > 0) && (max_tries < 2));
+
+       return aggressive ? gc_ok : YAFFS_OK;
+}
+
+/*
+ * yaffs_bg_gc()
+ * Garbage collects. Intended to be called from a background thread.
+ * Returns non-zero if at least half the free chunks are erased.
+ */
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency)
+{
+       int erased_chunks = dev->n_erased_blocks * dev->param.chunks_per_block;
+
+       yaffs_trace(YAFFS_TRACE_BACKGROUND, "Background gc %u", urgency);
+
+       yaffs_check_gc(dev, 1);
+       return erased_chunks > dev->n_free_chunks / 2;
+}
+
+/*-------------------- Data file manipulation -----------------*/
+
+static int yaffs_rd_data_obj(struct yaffs_obj *in, int inode_chunk, u8 * buffer)
+{
+       int nand_chunk = yaffs_find_chunk_in_file(in, inode_chunk, NULL);
+
+       if (nand_chunk >= 0)
+               return yaffs_rd_chunk_tags_nand(in->my_dev, nand_chunk,
+                                               buffer, NULL);
+       else {
+               yaffs_trace(YAFFS_TRACE_NANDACCESS,
+                       "Chunk %d not found zero instead",
+                       nand_chunk);
+               /* get sane (zero) data if you read a hole */
+               memset(buffer, 0, in->my_dev->data_bytes_per_chunk);
+               return 0;
+       }
+
+}
+
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+                    int lyn)
+{
+       int block;
+       int page;
+       struct yaffs_ext_tags tags;
+       struct yaffs_block_info *bi;
+
+       if (chunk_id <= 0)
+               return;
+
+       dev->n_deletions++;
+       block = chunk_id / dev->param.chunks_per_block;
+       page = chunk_id % dev->param.chunks_per_block;
+
+       if (!yaffs_check_chunk_bit(dev, block, page))
+               yaffs_trace(YAFFS_TRACE_VERIFY,
+                       "Deleting invalid chunk %d", chunk_id);
+
+       bi = yaffs_get_block_info(dev, block);
+
+       yaffs2_update_oldest_dirty_seq(dev, block, bi);
+
+       yaffs_trace(YAFFS_TRACE_DELETION,
+               "line %d delete of chunk %d",
+               lyn, chunk_id);
+
+       if (!dev->param.is_yaffs2 && mark_flash &&
+           bi->block_state != YAFFS_BLOCK_STATE_COLLECTING) {
+
+               yaffs_init_tags(&tags);
+
+               tags.is_deleted = 1;
+
+               yaffs_wr_chunk_tags_nand(dev, chunk_id, NULL, &tags);
+               yaffs_handle_chunk_update(dev, chunk_id, &tags);
+       } else {
+               dev->n_unmarked_deletions++;
+       }
+
+       /* Pull out of the management area.
+        * If the whole block became dirty, this will kick off an erasure.
+        */
+       if (bi->block_state == YAFFS_BLOCK_STATE_ALLOCATING ||
+           bi->block_state == YAFFS_BLOCK_STATE_FULL ||
+           bi->block_state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+           bi->block_state == YAFFS_BLOCK_STATE_COLLECTING) {
+               dev->n_free_chunks++;
+
+               yaffs_clear_chunk_bit(dev, block, page);
+
+               bi->pages_in_use--;
+
+               if (bi->pages_in_use == 0 &&
+                   !bi->has_shrink_hdr &&
+                   bi->block_state != YAFFS_BLOCK_STATE_ALLOCATING &&
+                   bi->block_state != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       yaffs_block_became_dirty(dev, block);
+               }
+
+       }
+
+}
+
+static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk,
+                            const u8 * buffer, int n_bytes, int use_reserve)
+{
+       /* Find old chunk Need to do this to get serial number
+        * Write new one and patch into tree.
+        * Invalidate old tags.
+        */
+
+       int prev_chunk_id;
+       struct yaffs_ext_tags prev_tags;
+
+       int new_chunk_id;
+       struct yaffs_ext_tags new_tags;
+
+       struct yaffs_dev *dev = in->my_dev;
+
+       yaffs_check_gc(dev, 0);
+
+       /* Get the previous chunk at this location in the file if it exists.
+        * If it does not exist then put a zero into the tree. This creates
+        * the tnode now, rather than later when it is harder to clean up.
+        */
+       prev_chunk_id = yaffs_find_chunk_in_file(in, inode_chunk, &prev_tags);
+       if (prev_chunk_id < 1 &&
+           !yaffs_put_chunk_in_file(in, inode_chunk, 0, 0))
+               return 0;
+
+       /* Set up new tags */
+       yaffs_init_tags(&new_tags);
+
+       new_tags.chunk_id = inode_chunk;
+       new_tags.obj_id = in->obj_id;
+       new_tags.serial_number =
+           (prev_chunk_id > 0) ? prev_tags.serial_number + 1 : 1;
+       new_tags.n_bytes = n_bytes;
+
+       if (n_bytes < 1 || n_bytes > dev->param.total_bytes_per_chunk) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                 "Writing %d bytes to chunk!!!!!!!!!",
+                  n_bytes);
+               YBUG();
+       }
+
+       new_chunk_id =
+           yaffs_write_new_chunk(dev, buffer, &new_tags, use_reserve);
+
+       if (new_chunk_id > 0) {
+               yaffs_put_chunk_in_file(in, inode_chunk, new_chunk_id, 0);
+
+               if (prev_chunk_id > 0)
+                       yaffs_chunk_del(dev, prev_chunk_id, 1, __LINE__);
+
+               yaffs_verify_file_sane(in);
+       }
+       return new_chunk_id;
+
+}
+
+
+
+static int yaffs_do_xattrib_mod(struct yaffs_obj *obj, int set,
+                               const YCHAR * name, const void *value, int size,
+                               int flags)
+{
+       struct yaffs_xattr_mod xmod;
+
+       int result;
+
+       xmod.set = set;
+       xmod.name = name;
+       xmod.data = value;
+       xmod.size = size;
+       xmod.flags = flags;
+       xmod.result = -ENOSPC;
+
+       result = yaffs_update_oh(obj, NULL, 0, 0, 0, &xmod);
+
+       if (result > 0)
+               return xmod.result;
+       else
+               return -ENOSPC;
+}
+
+static int yaffs_apply_xattrib_mod(struct yaffs_obj *obj, char *buffer,
+                                  struct yaffs_xattr_mod *xmod)
+{
+       int retval = 0;
+       int x_offs = sizeof(struct yaffs_obj_hdr);
+       struct yaffs_dev *dev = obj->my_dev;
+       int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+
+       char *x_buffer = buffer + x_offs;
+
+       if (xmod->set)
+               retval =
+                   nval_set(x_buffer, x_size, xmod->name, xmod->data,
+                            xmod->size, xmod->flags);
+       else
+               retval = nval_del(x_buffer, x_size, xmod->name);
+
+       obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+       obj->xattr_known = 1;
+
+       xmod->result = retval;
+
+       return retval;
+}
+
+static int yaffs_do_xattrib_fetch(struct yaffs_obj *obj, const YCHAR * name,
+                                 void *value, int size)
+{
+       char *buffer = NULL;
+       int result;
+       struct yaffs_ext_tags tags;
+       struct yaffs_dev *dev = obj->my_dev;
+       int x_offs = sizeof(struct yaffs_obj_hdr);
+       int x_size = dev->data_bytes_per_chunk - sizeof(struct yaffs_obj_hdr);
+
+       char *x_buffer;
+
+       int retval = 0;
+
+       if (obj->hdr_chunk < 1)
+               return -ENODATA;
+
+       /* If we know that the object has no xattribs then don't do all the
+        * reading and parsing.
+        */
+       if (obj->xattr_known && !obj->has_xattr) {
+               if (name)
+                       return -ENODATA;
+               else
+                       return 0;
+       }
+
+       buffer = (char *)yaffs_get_temp_buffer(dev, __LINE__);
+       if (!buffer)
+               return -ENOMEM;
+
+       result =
+           yaffs_rd_chunk_tags_nand(dev, obj->hdr_chunk, (u8 *) buffer, &tags);
+
+       if (result != YAFFS_OK)
+               retval = -ENOENT;
+       else {
+               x_buffer = buffer + x_offs;
+
+               if (!obj->xattr_known) {
+                       obj->has_xattr = nval_hasvalues(x_buffer, x_size);
+                       obj->xattr_known = 1;
+               }
+
+               if (name)
+                       retval = nval_get(x_buffer, x_size, name, value, size);
+               else
+                       retval = nval_list(x_buffer, x_size, value, size);
+       }
+       yaffs_release_temp_buffer(dev, (u8 *) buffer, __LINE__);
+       return retval;
+}
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+                     const void *value, int size, int flags)
+{
+       return yaffs_do_xattrib_mod(obj, 1, name, value, size, flags);
+}
+
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name)
+{
+       return yaffs_do_xattrib_mod(obj, 0, name, NULL, 0, 0);
+}
+
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+                     int size)
+{
+       return yaffs_do_xattrib_fetch(obj, name, value, size);
+}
+
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size)
+{
+       return yaffs_do_xattrib_fetch(obj, NULL, buffer, size);
+}
+
+static void yaffs_check_obj_details_loaded(struct yaffs_obj *in)
+{
+       u8 *chunk_data;
+       struct yaffs_obj_hdr *oh;
+       struct yaffs_dev *dev;
+       struct yaffs_ext_tags tags;
+       int result;
+       int alloc_failed = 0;
+
+       if (!in)
+               return;
+
+       dev = in->my_dev;
+
+       if (in->lazy_loaded && in->hdr_chunk > 0) {
+               in->lazy_loaded = 0;
+               chunk_data = yaffs_get_temp_buffer(dev, __LINE__);
+
+               result =
+                   yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, chunk_data,
+                                            &tags);
+               oh = (struct yaffs_obj_hdr *)chunk_data;
+
+               in->yst_mode = oh->yst_mode;
+               yaffs_load_attribs(in, oh);
+               yaffs_set_obj_name_from_oh(in, oh);
+
+               if (in->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+                       in->variant.symlink_variant.alias =
+                           yaffs_clone_str(oh->alias);
+                       if (!in->variant.symlink_variant.alias)
+                               alloc_failed = 1;       /* Not returned to caller */
+               }
+
+               yaffs_release_temp_buffer(dev, chunk_data, __LINE__);
+       }
+}
+
+static void yaffs_load_name_from_oh(struct yaffs_dev *dev, YCHAR * name,
+                                   const YCHAR * oh_name, int buff_size)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+       if (dev->param.auto_unicode) {
+               if (*oh_name) {
+                       /* It is an ASCII name, do an ASCII to
+                        * unicode conversion */
+                       const char *ascii_oh_name = (const char *)oh_name;
+                       int n = buff_size - 1;
+                       while (n > 0 && *ascii_oh_name) {
+                               *name = *ascii_oh_name;
+                               name++;
+                               ascii_oh_name++;
+                               n--;
+                       }
+               } else {
+                       strncpy(name, oh_name + 1, buff_size - 1);
+                }
+       } else {
+#else
+        {
+#endif
+               strncpy(name, oh_name, buff_size - 1);
+        }
+}
+
+static void yaffs_load_oh_from_name(struct yaffs_dev *dev, YCHAR * oh_name,
+                                   const YCHAR * name)
+{
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+
+       int is_ascii;
+       YCHAR *w;
+
+       if (dev->param.auto_unicode) {
+
+               is_ascii = 1;
+               w = name;
+
+               /* Figure out if the name will fit in ascii character set */
+               while (is_ascii && *w) {
+                       if ((*w) & 0xff00)
+                               is_ascii = 0;
+                       w++;
+               }
+
+               if (is_ascii) {
+                       /* It is an ASCII name, so do a unicode to ascii conversion */
+                       char *ascii_oh_name = (char *)oh_name;
+                       int n = YAFFS_MAX_NAME_LENGTH - 1;
+                       while (n > 0 && *name) {
+                               *ascii_oh_name = *name;
+                               name++;
+                               ascii_oh_name++;
+                               n--;
+                       }
+               } else {
+                       /* It is a unicode name, so save starting at the second YCHAR */
+                       *oh_name = 0;
+                       strncpy(oh_name + 1, name,
+                                     YAFFS_MAX_NAME_LENGTH - 2);
+               }
+       } else {
+#else
+        {
+#endif
+               strncpy(oh_name, name, YAFFS_MAX_NAME_LENGTH - 1);
+        }
+
+}
+
+/* UpdateObjectHeader updates the header on NAND for an object.
+ * If name is not NULL, then that new name is used.
+ */
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name, int force,
+                   int is_shrink, int shadows, struct yaffs_xattr_mod *xmod)
+{
+
+       struct yaffs_block_info *bi;
+
+       struct yaffs_dev *dev = in->my_dev;
+
+       int prev_chunk_id;
+       int ret_val = 0;
+       int result = 0;
+
+       int new_chunk_id;
+       struct yaffs_ext_tags new_tags;
+       struct yaffs_ext_tags old_tags;
+       const YCHAR *alias = NULL;
+
+       u8 *buffer = NULL;
+       YCHAR old_name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       struct yaffs_obj_hdr *oh = NULL;
+
+       strcpy(old_name, _Y("silly old name"));
+
+       if (!in->fake || in == dev->root_dir ||
+           force || xmod) {
+
+               yaffs_check_gc(dev, 0);
+               yaffs_check_obj_details_loaded(in);
+
+               buffer = yaffs_get_temp_buffer(in->my_dev, __LINE__);
+               oh = (struct yaffs_obj_hdr *)buffer;
+
+               prev_chunk_id = in->hdr_chunk;
+
+               if (prev_chunk_id > 0) {
+                       result = yaffs_rd_chunk_tags_nand(dev, prev_chunk_id,
+                                                         buffer, &old_tags);
+
+                       yaffs_verify_oh(in, oh, &old_tags, 0);
+
+                       memcpy(old_name, oh->name, sizeof(oh->name));
+                       memset(buffer, 0xFF, sizeof(struct yaffs_obj_hdr));
+               } else {
+                       memset(buffer, 0xFF, dev->data_bytes_per_chunk);
+                }
+
+               oh->type = in->variant_type;
+               oh->yst_mode = in->yst_mode;
+               oh->shadows_obj = oh->inband_shadowed_obj_id = shadows;
+
+               yaffs_load_attribs_oh(oh, in);
+
+               if (in->parent)
+                       oh->parent_obj_id = in->parent->obj_id;
+               else
+                       oh->parent_obj_id = 0;
+
+               if (name && *name) {
+                       memset(oh->name, 0, sizeof(oh->name));
+                       yaffs_load_oh_from_name(dev, oh->name, name);
+               } else if (prev_chunk_id > 0) {
+                       memcpy(oh->name, old_name, sizeof(oh->name));
+               } else {
+                       memset(oh->name, 0, sizeof(oh->name));
+                }
+
+               oh->is_shrink = is_shrink;
+
+               switch (in->variant_type) {
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* Should not happen */
+                       break;
+               case YAFFS_OBJECT_TYPE_FILE:
+                       oh->file_size =
+                           (oh->parent_obj_id == YAFFS_OBJECTID_DELETED
+                            || oh->parent_obj_id ==
+                            YAFFS_OBJECTID_UNLINKED) ? 0 : in->
+                           variant.file_variant.file_size;
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+                       oh->equiv_id = in->variant.hardlink_variant.equiv_id;
+                       break;
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       /* Do nothing */
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       /* Do nothing */
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       alias = in->variant.symlink_variant.alias;
+                       if (!alias)
+                               alias = _Y("no alias");
+                       strncpy(oh->alias, alias, YAFFS_MAX_ALIAS_LENGTH);
+                       oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
+                       break;
+               }
+
+               /* process any xattrib modifications */
+               if (xmod)
+                       yaffs_apply_xattrib_mod(in, (char *)buffer, xmod);
+
+               /* Tags */
+               yaffs_init_tags(&new_tags);
+               in->serial++;
+               new_tags.chunk_id = 0;
+               new_tags.obj_id = in->obj_id;
+               new_tags.serial_number = in->serial;
+
+               /* Add extra info for file header */
+
+               new_tags.extra_available = 1;
+               new_tags.extra_parent_id = oh->parent_obj_id;
+               new_tags.extra_length = oh->file_size;
+               new_tags.extra_is_shrink = oh->is_shrink;
+               new_tags.extra_equiv_id = oh->equiv_id;
+               new_tags.extra_shadows = (oh->shadows_obj > 0) ? 1 : 0;
+               new_tags.extra_obj_type = in->variant_type;
+
+               yaffs_verify_oh(in, oh, &new_tags, 1);
+
+               /* Create new chunk in NAND */
+               new_chunk_id =
+                   yaffs_write_new_chunk(dev, buffer, &new_tags,
+                                         (prev_chunk_id > 0) ? 1 : 0);
+
+               if (new_chunk_id >= 0) {
+
+                       in->hdr_chunk = new_chunk_id;
+
+                       if (prev_chunk_id > 0) {
+                               yaffs_chunk_del(dev, prev_chunk_id, 1,
+                                               __LINE__);
+                       }
+
+                       if (!yaffs_obj_cache_dirty(in))
+                               in->dirty = 0;
+
+                       /* If this was a shrink, then mark the block that the chunk lives on */
+                       if (is_shrink) {
+                               bi = yaffs_get_block_info(in->my_dev,
+                                                         new_chunk_id /
+                                                         in->my_dev->param.
+                                                         chunks_per_block);
+                               bi->has_shrink_hdr = 1;
+                       }
+
+               }
+
+               ret_val = new_chunk_id;
+
+       }
+
+       if (buffer)
+               yaffs_release_temp_buffer(dev, buffer, __LINE__);
+
+       return ret_val;
+}
+
+/*--------------------- File read/write ------------------------
+ * Read and write have very similar structures.
+ * In general the read/write has three parts to it
+ * An incomplete chunk to start with (if the read/write is not chunk-aligned)
+ * Some complete chunks
+ * An incomplete chunk to end off with
+ *
+ * Curve-balls: the first chunk might also be the last chunk.
+ */
+
+int yaffs_file_rd(struct yaffs_obj *in, u8 * buffer, loff_t offset, int n_bytes)
+{
+
+       int chunk;
+       u32 start;
+       int n_copy;
+       int n = n_bytes;
+       int n_done = 0;
+       struct yaffs_cache *cache;
+
+       struct yaffs_dev *dev;
+
+       dev = in->my_dev;
+
+       while (n > 0) {
+               /* chunk = offset / dev->data_bytes_per_chunk + 1; */
+               /* start = offset % dev->data_bytes_per_chunk; */
+               yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+               chunk++;
+
+               /* OK now check for the curveball where the start and end are in
+                * the same chunk.
+                */
+               if ((start + n) < dev->data_bytes_per_chunk)
+                       n_copy = n;
+               else
+                       n_copy = dev->data_bytes_per_chunk - start;
+
+               cache = yaffs_find_chunk_cache(in, chunk);
+
+               /* If the chunk is already in the cache or it is less than a whole chunk
+                * or we're using inband tags then use the cache (if there is caching)
+                * else bypass the cache.
+                */
+               if (cache || n_copy != dev->data_bytes_per_chunk
+                   || dev->param.inband_tags) {
+                       if (dev->param.n_caches > 0) {
+
+                               /* If we can't find the data in the cache, then load it up. */
+
+                               if (!cache) {
+                                       cache =
+                                           yaffs_grab_chunk_cache(in->my_dev);
+                                       cache->object = in;
+                                       cache->chunk_id = chunk;
+                                       cache->dirty = 0;
+                                       cache->locked = 0;
+                                       yaffs_rd_data_obj(in, chunk,
+                                                         cache->data);
+                                       cache->n_bytes = 0;
+                               }
+
+                               yaffs_use_cache(dev, cache, 0);
+
+                               cache->locked = 1;
+
+                               memcpy(buffer, &cache->data[start], n_copy);
+
+                               cache->locked = 0;
+                       } else {
+                               /* Read into the local buffer then copy.. */
+
+                               u8 *local_buffer =
+                                   yaffs_get_temp_buffer(dev, __LINE__);
+                               yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                               memcpy(buffer, &local_buffer[start], n_copy);
+
+                               yaffs_release_temp_buffer(dev, local_buffer,
+                                                         __LINE__);
+                       }
+
+               } else {
+
+                       /* A full chunk. Read directly into the supplied buffer. */
+                       yaffs_rd_data_obj(in, chunk, buffer);
+
+               }
+
+               n -= n_copy;
+               offset += n_copy;
+               buffer += n_copy;
+               n_done += n_copy;
+
+       }
+
+       return n_done;
+}
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                    int n_bytes, int write_trhrough)
+{
+
+       int chunk;
+       u32 start;
+       int n_copy;
+       int n = n_bytes;
+       int n_done = 0;
+       int n_writeback;
+       int start_write = offset;
+       int chunk_written = 0;
+       u32 n_bytes_read;
+       u32 chunk_start;
+
+       struct yaffs_dev *dev;
+
+       dev = in->my_dev;
+
+       while (n > 0 && chunk_written >= 0) {
+               yaffs_addr_to_chunk(dev, offset, &chunk, &start);
+
+               if (chunk * dev->data_bytes_per_chunk + start != offset ||
+                   start >= dev->data_bytes_per_chunk) {
+                       yaffs_trace(YAFFS_TRACE_ERROR,
+                               "AddrToChunk of offset %d gives chunk %d start %d",
+                               (int)offset, chunk, start);
+               }
+               chunk++;        /* File pos to chunk in file offset */
+
+               /* OK now check for the curveball where the start and end are in
+                * the same chunk.
+                */
+
+               if ((start + n) < dev->data_bytes_per_chunk) {
+                       n_copy = n;
+
+                       /* Now folks, to calculate how many bytes to write back....
+                        * If we're overwriting and not writing to then end of file then
+                        * we need to write back as much as was there before.
+                        */
+
+                       chunk_start = ((chunk - 1) * dev->data_bytes_per_chunk);
+
+                       if (chunk_start > in->variant.file_variant.file_size)
+                               n_bytes_read = 0;       /* Past end of file */
+                       else
+                               n_bytes_read =
+                                   in->variant.file_variant.file_size -
+                                   chunk_start;
+
+                       if (n_bytes_read > dev->data_bytes_per_chunk)
+                               n_bytes_read = dev->data_bytes_per_chunk;
+
+                       n_writeback =
+                           (n_bytes_read >
+                            (start + n)) ? n_bytes_read : (start + n);
+
+                       if (n_writeback < 0
+                           || n_writeback > dev->data_bytes_per_chunk)
+                               YBUG();
+
+               } else {
+                       n_copy = dev->data_bytes_per_chunk - start;
+                       n_writeback = dev->data_bytes_per_chunk;
+               }
+
+               if (n_copy != dev->data_bytes_per_chunk
+                   || dev->param.inband_tags) {
+                       /* An incomplete start or end chunk (or maybe both start and end chunk),
+                        * or we're using inband tags, so we want to use the cache buffers.
+                        */
+                       if (dev->param.n_caches > 0) {
+                               struct yaffs_cache *cache;
+                               /* If we can't find the data in the cache, then load the cache */
+                               cache = yaffs_find_chunk_cache(in, chunk);
+
+                               if (!cache
+                                   && yaffs_check_alloc_available(dev, 1)) {
+                                       cache = yaffs_grab_chunk_cache(dev);
+                                       cache->object = in;
+                                       cache->chunk_id = chunk;
+                                       cache->dirty = 0;
+                                       cache->locked = 0;
+                                       yaffs_rd_data_obj(in, chunk,
+                                                         cache->data);
+                               } else if (cache &&
+                                          !cache->dirty &&
+                                          !yaffs_check_alloc_available(dev,
+                                                                       1)) {
+                                       /* Drop the cache if it was a read cache item and
+                                        * no space check has been made for it.
+                                        */
+                                       cache = NULL;
+                               }
+
+                               if (cache) {
+                                       yaffs_use_cache(dev, cache, 1);
+                                       cache->locked = 1;
+
+                                       memcpy(&cache->data[start], buffer,
+                                              n_copy);
+
+                                       cache->locked = 0;
+                                       cache->n_bytes = n_writeback;
+
+                                       if (write_trhrough) {
+                                               chunk_written =
+                                                   yaffs_wr_data_obj
+                                                   (cache->object,
+                                                    cache->chunk_id,
+                                                    cache->data,
+                                                    cache->n_bytes, 1);
+                                               cache->dirty = 0;
+                                       }
+
+                               } else {
+                                       chunk_written = -1;     /* fail the write */
+                               }
+                       } else {
+                               /* An incomplete start or end chunk (or maybe both start and end chunk)
+                                * Read into the local buffer then copy, then copy over and write back.
+                                */
+
+                               u8 *local_buffer =
+                                   yaffs_get_temp_buffer(dev, __LINE__);
+
+                               yaffs_rd_data_obj(in, chunk, local_buffer);
+
+                               memcpy(&local_buffer[start], buffer, n_copy);
+
+                               chunk_written =
+                                   yaffs_wr_data_obj(in, chunk,
+                                                     local_buffer,
+                                                     n_writeback, 0);
+
+                               yaffs_release_temp_buffer(dev, local_buffer,
+                                                         __LINE__);
+
+                       }
+
+               } else {
+                       /* A full chunk. Write directly from the supplied buffer. */
+
+                       chunk_written =
+                           yaffs_wr_data_obj(in, chunk, buffer,
+                                             dev->data_bytes_per_chunk, 0);
+
+                       /* Since we've overwritten the cached data, we better invalidate it. */
+                       yaffs_invalidate_chunk_cache(in, chunk);
+               }
+
+               if (chunk_written >= 0) {
+                       n -= n_copy;
+                       offset += n_copy;
+                       buffer += n_copy;
+                       n_done += n_copy;
+               }
+
+       }
+
+       /* Update file object */
+
+       if ((start_write + n_done) > in->variant.file_variant.file_size)
+               in->variant.file_variant.file_size = (start_write + n_done);
+
+       in->dirty = 1;
+
+       return n_done;
+}
+
+int yaffs_wr_file(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                 int n_bytes, int write_trhrough)
+{
+       yaffs2_handle_hole(in, offset);
+       return yaffs_do_file_wr(in, buffer, offset, n_bytes, write_trhrough);
+}
+
+/* ---------------------- File resizing stuff ------------------ */
+
+static void yaffs_prune_chunks(struct yaffs_obj *in, int new_size)
+{
+
+       struct yaffs_dev *dev = in->my_dev;
+       int old_size = in->variant.file_variant.file_size;
+
+       int last_del = 1 + (old_size - 1) / dev->data_bytes_per_chunk;
+
+       int start_del = 1 + (new_size + dev->data_bytes_per_chunk - 1) /
+           dev->data_bytes_per_chunk;
+       int i;
+       int chunk_id;
+
+       /* Delete backwards so that we don't end up with holes if
+        * power is lost part-way through the operation.
+        */
+       for (i = last_del; i >= start_del; i--) {
+               /* NB this could be optimised somewhat,
+                * eg. could retrieve the tags and write them without
+                * using yaffs_chunk_del
+                */
+
+               chunk_id = yaffs_find_del_file_chunk(in, i, NULL);
+               if (chunk_id > 0) {
+                       if (chunk_id <
+                           (dev->internal_start_block *
+                            dev->param.chunks_per_block)
+                           || chunk_id >=
+                           ((dev->internal_end_block +
+                             1) * dev->param.chunks_per_block)) {
+                               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                                       "Found daft chunk_id %d for %d",
+                                       chunk_id, i);
+                       } else {
+                               in->n_data_chunks--;
+                               yaffs_chunk_del(dev, chunk_id, 1, __LINE__);
+                       }
+               }
+       }
+
+}
+
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size)
+{
+       int new_full;
+       u32 new_partial;
+       struct yaffs_dev *dev = obj->my_dev;
+
+       yaffs_addr_to_chunk(dev, new_size, &new_full, &new_partial);
+
+       yaffs_prune_chunks(obj, new_size);
+
+       if (new_partial != 0) {
+               int last_chunk = 1 + new_full;
+               u8 *local_buffer = yaffs_get_temp_buffer(dev, __LINE__);
+
+               /* Rewrite the last chunk with its new size and zero pad */
+               yaffs_rd_data_obj(obj, last_chunk, local_buffer);
+               memset(local_buffer + new_partial, 0,
+                      dev->data_bytes_per_chunk - new_partial);
+
+               yaffs_wr_data_obj(obj, last_chunk, local_buffer,
+                                 new_partial, 1);
+
+               yaffs_release_temp_buffer(dev, local_buffer, __LINE__);
+       }
+
+       obj->variant.file_variant.file_size = new_size;
+
+       yaffs_prune_tree(dev, &obj->variant.file_variant);
+}
+
+int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size)
+{
+       struct yaffs_dev *dev = in->my_dev;
+       int old_size = in->variant.file_variant.file_size;
+
+       yaffs_flush_file_cache(in);
+       yaffs_invalidate_whole_cache(in);
+
+       yaffs_check_gc(dev, 0);
+
+       if (in->variant_type != YAFFS_OBJECT_TYPE_FILE)
+               return YAFFS_FAIL;
+
+       if (new_size == old_size)
+               return YAFFS_OK;
+
+       if (new_size > old_size) {
+               yaffs2_handle_hole(in, new_size);
+               in->variant.file_variant.file_size = new_size;
+       } else {
+               /* new_size < old_size */
+               yaffs_resize_file_down(in, new_size);
+       }
+
+       /* Write a new object header to reflect the resize.
+        * show we've shrunk the file, if need be
+        * Do this only if the file is not in the deleted directories
+        * and is not shadowed.
+        */
+       if (in->parent &&
+           !in->is_shadowed &&
+           in->parent->obj_id != YAFFS_OBJECTID_UNLINKED &&
+           in->parent->obj_id != YAFFS_OBJECTID_DELETED)
+               yaffs_update_oh(in, NULL, 0, 0, 0, NULL);
+
+       return YAFFS_OK;
+}
+
+int yaffs_flush_file(struct yaffs_obj *in, int update_time, int data_sync)
+{
+       int ret_val;
+       if (in->dirty) {
+               yaffs_flush_file_cache(in);
+               if (data_sync)  /* Only sync data */
+                       ret_val = YAFFS_OK;
+               else {
+                       if (update_time)
+                               yaffs_load_current_time(in, 0, 0);
+
+                       ret_val = (yaffs_update_oh(in, NULL, 0, 0, 0, NULL) >=
+                                  0) ? YAFFS_OK : YAFFS_FAIL;
+               }
+       } else {
+               ret_val = YAFFS_OK;
+       }
+
+       return ret_val;
+
+}
+
+
+/* yaffs_del_file deletes the whole file data
+ * and the inode associated with the file.
+ * It does not delete the links associated with the file.
+ */
+static int yaffs_unlink_file_if_needed(struct yaffs_obj *in)
+{
+
+       int ret_val;
+       int del_now = 0;
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (!in->my_inode)
+               del_now = 1;
+
+       if (del_now) {
+               ret_val =
+                   yaffs_change_obj_name(in, in->my_dev->del_dir,
+                                         _Y("deleted"), 0, 0);
+               yaffs_trace(YAFFS_TRACE_TRACING,
+                       "yaffs: immediate deletion of file %d",
+                       in->obj_id);
+               in->deleted = 1;
+               in->my_dev->n_deleted_files++;
+               if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+                       yaffs_resize_file(in, 0);
+               yaffs_soft_del_file(in);
+       } else {
+               ret_val =
+                   yaffs_change_obj_name(in, in->my_dev->unlinked_dir,
+                                         _Y("unlinked"), 0, 0);
+       }
+
+       return ret_val;
+}
+
+int yaffs_del_file(struct yaffs_obj *in)
+{
+       int ret_val = YAFFS_OK;
+       int deleted;            /* Need to cache value on stack if in is freed */
+       struct yaffs_dev *dev = in->my_dev;
+
+       if (dev->param.disable_soft_del || dev->param.is_yaffs2)
+               yaffs_resize_file(in, 0);
+
+       if (in->n_data_chunks > 0) {
+               /* Use soft deletion if there is data in the file.
+                * That won't be the case if it has been resized to zero.
+                */
+               if (!in->unlinked)
+                       ret_val = yaffs_unlink_file_if_needed(in);
+
+               deleted = in->deleted;
+
+               if (ret_val == YAFFS_OK && in->unlinked && !in->deleted) {
+                       in->deleted = 1;
+                       deleted = 1;
+                       in->my_dev->n_deleted_files++;
+                       yaffs_soft_del_file(in);
+               }
+               return deleted ? YAFFS_OK : YAFFS_FAIL;
+       } else {
+               /* The file has no data chunks so we toss it immediately */
+               yaffs_free_tnode(in->my_dev, in->variant.file_variant.top);
+               in->variant.file_variant.top = NULL;
+               yaffs_generic_obj_del(in);
+
+               return YAFFS_OK;
+       }
+}
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj)
+{
+       return (obj &&
+               obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY) &&
+               !(list_empty(&obj->variant.dir_variant.children));
+}
+
+static int yaffs_del_dir(struct yaffs_obj *obj)
+{
+       /* First check that the directory is empty. */
+       if (yaffs_is_non_empty_dir(obj))
+               return YAFFS_FAIL;
+
+       return yaffs_generic_obj_del(obj);
+}
+
+static int yaffs_del_symlink(struct yaffs_obj *in)
+{
+       if (in->variant.symlink_variant.alias)
+               kfree(in->variant.symlink_variant.alias);
+       in->variant.symlink_variant.alias = NULL;
+
+       return yaffs_generic_obj_del(in);
+}
+
+static int yaffs_del_link(struct yaffs_obj *in)
+{
+       /* remove this hardlink from the list assocaited with the equivalent
+        * object
+        */
+       list_del_init(&in->hard_links);
+       return yaffs_generic_obj_del(in);
+}
+
+int yaffs_del_obj(struct yaffs_obj *obj)
+{
+       int ret_val = -1;
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               ret_val = yaffs_del_file(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               if (!list_empty(&obj->variant.dir_variant.dirty)) {
+                       yaffs_trace(YAFFS_TRACE_BACKGROUND,
+                               "Remove object %d from dirty directories",
+                               obj->obj_id);
+                       list_del_init(&obj->variant.dir_variant.dirty);
+               }
+               return yaffs_del_dir(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               ret_val = yaffs_del_symlink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               ret_val = yaffs_del_link(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               ret_val = yaffs_generic_obj_del(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_UNKNOWN:
+               ret_val = 0;
+               break;          /* should not happen. */
+       }
+
+       return ret_val;
+}
+
+static int yaffs_unlink_worker(struct yaffs_obj *obj)
+{
+
+       int del_now = 0;
+
+       if (!obj->my_inode)
+               del_now = 1;
+
+       if (obj)
+               yaffs_update_parent(obj->parent);
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+               return yaffs_del_link(obj);
+       } else if (!list_empty(&obj->hard_links)) {
+               /* Curve ball: We're unlinking an object that has a hardlink.
+                *
+                * This problem arises because we are not strictly following
+                * The Linux link/inode model.
+                *
+                * We can't really delete the object.
+                * Instead, we do the following:
+                * - Select a hardlink.
+                * - Unhook it from the hard links
+                * - Move it from its parent directory (so that the rename can work)
+                * - Rename the object to the hardlink's name.
+                * - Delete the hardlink
+                */
+
+               struct yaffs_obj *hl;
+               struct yaffs_obj *parent;
+               int ret_val;
+               YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+               hl = list_entry(obj->hard_links.next, struct yaffs_obj,
+                               hard_links);
+
+               yaffs_get_obj_name(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
+               parent = hl->parent;
+
+               list_del_init(&hl->hard_links);
+
+               yaffs_add_obj_to_dir(obj->my_dev->unlinked_dir, hl);
+
+               ret_val = yaffs_change_obj_name(obj, parent, name, 0, 0);
+
+               if (ret_val == YAFFS_OK)
+                       ret_val = yaffs_generic_obj_del(hl);
+
+               return ret_val;
+
+       } else if (del_now) {
+               switch (obj->variant_type) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       return yaffs_del_file(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       list_del_init(&obj->variant.dir_variant.dirty);
+                       return yaffs_del_dir(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       return yaffs_del_symlink(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       return yaffs_generic_obj_del(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+               default:
+                       return YAFFS_FAIL;
+               }
+       } else if (yaffs_is_non_empty_dir(obj)) {
+               return YAFFS_FAIL;
+       } else {
+               return yaffs_change_obj_name(obj, obj->my_dev->unlinked_dir,
+                                            _Y("unlinked"), 0, 0);
+        }
+}
+
+static int yaffs_unlink_obj(struct yaffs_obj *obj)
+{
+
+       if (obj && obj->unlink_allowed)
+               return yaffs_unlink_worker(obj);
+
+       return YAFFS_FAIL;
+
+}
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name)
+{
+       struct yaffs_obj *obj;
+
+       obj = yaffs_find_by_name(dir, name);
+       return yaffs_unlink_obj(obj);
+}
+
+/* Note:
+ * If old_name is NULL then we take old_dir as the object to be renamed.
+ */
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
+                    struct yaffs_obj *new_dir, const YCHAR * new_name)
+{
+       struct yaffs_obj *obj = NULL;
+       struct yaffs_obj *existing_target = NULL;
+       int force = 0;
+       int result;
+       struct yaffs_dev *dev;
+
+       if (!old_dir || old_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+               YBUG();
+       if (!new_dir || new_dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+               YBUG();
+
+       dev = old_dir->my_dev;
+
+#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
+       /* Special case for case insemsitive systems.
+        * While look-up is case insensitive, the name isn't.
+        * Therefore we might want to change x.txt to X.txt
+        */
+       if (old_dir == new_dir && 
+               old_name && new_name && 
+               strcmp(old_name, new_name) == 0)
+               force = 1;
+#endif
+
+       if (strnlen(new_name, YAFFS_MAX_NAME_LENGTH + 1) >
+           YAFFS_MAX_NAME_LENGTH)
+               /* ENAMETOOLONG */
+               return YAFFS_FAIL;
+
+       if(old_name)
+               obj = yaffs_find_by_name(old_dir, old_name);
+       else{
+               obj = old_dir;
+               old_dir = obj->parent;
+       }
+
+
+       if (obj && obj->rename_allowed) {
+
+               /* Now do the handling for an existing target, if there is one */
+
+               existing_target = yaffs_find_by_name(new_dir, new_name);
+               if (yaffs_is_non_empty_dir(existing_target)){
+                       return YAFFS_FAIL;      /* ENOTEMPTY */
+               } else if (existing_target && existing_target != obj) {
+                       /* Nuke the target first, using shadowing,
+                        * but only if it isn't the same object.
+                        *
+                        * Note we must disable gc otherwise it can mess up the shadowing.
+                        *
+                        */
+                       dev->gc_disable = 1;
+                       yaffs_change_obj_name(obj, new_dir, new_name, force,
+                                             existing_target->obj_id);
+                       existing_target->is_shadowed = 1;
+                       yaffs_unlink_obj(existing_target);
+                       dev->gc_disable = 0;
+               }
+
+               result = yaffs_change_obj_name(obj, new_dir, new_name, 1, 0);
+
+               yaffs_update_parent(old_dir);
+               if (new_dir != old_dir)
+                       yaffs_update_parent(new_dir);
+
+               return result;
+       }
+       return YAFFS_FAIL;
+}
+
+/*----------------------- Initialisation Scanning ---------------------- */
+
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+                              int backward_scanning)
+{
+       struct yaffs_obj *obj;
+
+       if (!backward_scanning) {
+               /* Handle YAFFS1 forward scanning case
+                * For YAFFS1 we always do the deletion
+                */
+
+       } else {
+               /* Handle YAFFS2 case (backward scanning)
+                * If the shadowed object exists then ignore.
+                */
+               obj = yaffs_find_by_number(dev, obj_id);
+               if (obj)
+                       return;
+       }
+
+       /* Let's create it (if it does not exist) assuming it is a file so that it can do shrinking etc.
+        * We put it in unlinked dir to be cleaned up after the scanning
+        */
+       obj =
+           yaffs_find_or_create_by_number(dev, obj_id, YAFFS_OBJECT_TYPE_FILE);
+       if (!obj)
+               return;
+       obj->is_shadowed = 1;
+       yaffs_add_obj_to_dir(dev->unlinked_dir, obj);
+       obj->variant.file_variant.shrink_size = 0;
+       obj->valid = 1;         /* So that we don't read any other info for this file */
+
+}
+
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list)
+{
+       struct yaffs_obj *hl;
+       struct yaffs_obj *in;
+
+       while (hard_list) {
+               hl = hard_list;
+               hard_list = (struct yaffs_obj *)(hard_list->hard_links.next);
+
+               in = yaffs_find_by_number(dev,
+                                         hl->variant.
+                                         hardlink_variant.equiv_id);
+
+               if (in) {
+                       /* Add the hardlink pointers */
+                       hl->variant.hardlink_variant.equiv_obj = in;
+                       list_add(&hl->hard_links, &in->hard_links);
+               } else {
+                       /* Todo Need to report/handle this better.
+                        * Got a problem... hardlink to a non-existant object
+                        */
+                       hl->variant.hardlink_variant.equiv_obj = NULL;
+                       INIT_LIST_HEAD(&hl->hard_links);
+
+               }
+       }
+}
+
+static void yaffs_strip_deleted_objs(struct yaffs_dev *dev)
+{
+       /*
+        *  Sort out state of unlinked and deleted objects after scanning.
+        */
+       struct list_head *i;
+       struct list_head *n;
+       struct yaffs_obj *l;
+
+       if (dev->read_only)
+               return;
+
+       /* Soft delete all the unlinked files */
+       list_for_each_safe(i, n,
+                          &dev->unlinked_dir->variant.dir_variant.children) {
+               if (i) {
+                       l = list_entry(i, struct yaffs_obj, siblings);
+                       yaffs_del_obj(l);
+               }
+       }
+
+       list_for_each_safe(i, n, &dev->del_dir->variant.dir_variant.children) {
+               if (i) {
+                       l = list_entry(i, struct yaffs_obj, siblings);
+                       yaffs_del_obj(l);
+               }
+       }
+
+}
+
+/*
+ * This code iterates through all the objects making sure that they are rooted.
+ * Any unrooted objects are re-rooted in lost+found.
+ * An object needs to be in one of:
+ * - Directly under deleted, unlinked
+ * - Directly or indirectly under root.
+ *
+ * Note:
+ *  This code assumes that we don't ever change the current relationships between
+ *  directories:
+ *   root_dir->parent == unlinked_dir->parent == del_dir->parent == NULL
+ *   lost-n-found->parent == root_dir
+ *
+ * This fixes the problem where directories might have inadvertently been deleted
+ * leaving the object "hanging" without being rooted in the directory tree.
+ */
+
+static int yaffs_has_null_parent(struct yaffs_dev *dev, struct yaffs_obj *obj)
+{
+       return (obj == dev->del_dir ||
+               obj == dev->unlinked_dir || obj == dev->root_dir);
+}
+
+static void yaffs_fix_hanging_objs(struct yaffs_dev *dev)
+{
+       struct yaffs_obj *obj;
+       struct yaffs_obj *parent;
+       int i;
+       struct list_head *lh;
+       struct list_head *n;
+       int depth_limit;
+       int hanging;
+
+       if (dev->read_only)
+               return;
+
+       /* Iterate through the objects in each hash entry,
+        * looking at each object.
+        * Make sure it is rooted.
+        */
+
+       for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+               list_for_each_safe(lh, n, &dev->obj_bucket[i].list) {
+                       if (lh) {
+                               obj =
+                                   list_entry(lh, struct yaffs_obj, hash_link);
+                               parent = obj->parent;
+
+                               if (yaffs_has_null_parent(dev, obj)) {
+                                       /* These directories are not hanging */
+                                       hanging = 0;
+                               } else if (!parent
+                                          || parent->variant_type !=
+                                          YAFFS_OBJECT_TYPE_DIRECTORY) {
+                                       hanging = 1;
+                               } else if (yaffs_has_null_parent(dev, parent)) {
+                                       hanging = 0;
+                               } else {
+                                       /*
+                                        * Need to follow the parent chain to see if it is hanging.
+                                        */
+                                       hanging = 0;
+                                       depth_limit = 100;
+
+                                       while (parent != dev->root_dir &&
+                                              parent->parent &&
+                                              parent->parent->variant_type ==
+                                              YAFFS_OBJECT_TYPE_DIRECTORY
+                                              && depth_limit > 0) {
+                                               parent = parent->parent;
+                                               depth_limit--;
+                                       }
+                                       if (parent != dev->root_dir)
+                                               hanging = 1;
+                               }
+                               if (hanging) {
+                                       yaffs_trace(YAFFS_TRACE_SCAN,
+                                               "Hanging object %d moved to lost and found",
+                                               obj->obj_id);
+                                       yaffs_add_obj_to_dir(dev->lost_n_found,
+                                                            obj);
+                               }
+                       }
+               }
+       }
+}
+
+/*
+ * Delete directory contents for cleaning up lost and found.
+ */
+static void yaffs_del_dir_contents(struct yaffs_obj *dir)
+{
+       struct yaffs_obj *obj;
+       struct list_head *lh;
+       struct list_head *n;
+
+       if (dir->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY)
+               YBUG();
+
+       list_for_each_safe(lh, n, &dir->variant.dir_variant.children) {
+               if (lh) {
+                       obj = list_entry(lh, struct yaffs_obj, siblings);
+                       if (obj->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY)
+                               yaffs_del_dir_contents(obj);
+
+                       yaffs_trace(YAFFS_TRACE_SCAN,
+                               "Deleting lost_found object %d",
+                               obj->obj_id);
+
+                       /* Need to use UnlinkObject since Delete would not handle
+                        * hardlinked objects correctly.
+                        */
+                       yaffs_unlink_obj(obj);
+               }
+       }
+
+}
+
+static void yaffs_empty_l_n_f(struct yaffs_dev *dev)
+{
+       yaffs_del_dir_contents(dev->lost_n_found);
+}
+
+
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
+                                    const YCHAR * name)
+{
+       int sum;
+
+       struct list_head *i;
+       YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
+
+       struct yaffs_obj *l;
+
+       if (!name)
+               return NULL;
+
+       if (!directory) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: yaffs_find_by_name: null pointer directory"
+                       );
+               YBUG();
+               return NULL;
+       }
+       if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "tragedy: yaffs_find_by_name: non-directory"
+                       );
+               YBUG();
+       }
+
+       sum = yaffs_calc_name_sum(name);
+
+       list_for_each(i, &directory->variant.dir_variant.children) {
+               if (i) {
+                       l = list_entry(i, struct yaffs_obj, siblings);
+
+                       if (l->parent != directory)
+                               YBUG();
+
+                       yaffs_check_obj_details_loaded(l);
+
+                       /* Special case for lost-n-found */
+                       if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+                               if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
+                                       return l;
+                       } else if (l->sum == sum
+                                  || l->hdr_chunk <= 0) {
+                               /* LostnFound chunk called Objxxx
+                                * Do a real check
+                                */
+                               yaffs_get_obj_name(l, buffer,
+                                                  YAFFS_MAX_NAME_LENGTH + 1);
+                               if (strncmp
+                                   (name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
+                                       return l;
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+/* GetEquivalentObject dereferences any hard links to get to the
+ * actual object.
+ */
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj)
+{
+       if (obj && obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
+               /* We want the object id of the equivalent object, not this one */
+               obj = obj->variant.hardlink_variant.equiv_obj;
+               yaffs_check_obj_details_loaded(obj);
+       }
+       return obj;
+}
+
+/*
+ *  A note or two on object names.
+ *  * If the object name is missing, we then make one up in the form objnnn
+ *
+ *  * ASCII names are stored in the object header's name field from byte zero
+ *  * Unicode names are historically stored starting from byte zero.
+ *
+ * Then there are automatic Unicode names...
+ * The purpose of these is to save names in a way that can be read as
+ * ASCII or Unicode names as appropriate, thus allowing a Unicode and ASCII
+ * system to share files.
+ *
+ * These automatic unicode are stored slightly differently...
+ *  - If the name can fit in the ASCII character space then they are saved as 
+ *    ascii names as per above.
+ *  - If the name needs Unicode then the name is saved in Unicode
+ *    starting at oh->name[1].
+
+ */
+static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR * name,
+                               int buffer_size)
+{
+       /* Create an object name if we could not find one. */
+       if (strnlen(name, YAFFS_MAX_NAME_LENGTH) == 0) {
+               YCHAR local_name[20];
+               YCHAR num_string[20];
+               YCHAR *x = &num_string[19];
+               unsigned v = obj->obj_id;
+               num_string[19] = 0;
+               while (v > 0) {
+                       x--;
+                       *x = '0' + (v % 10);
+                       v /= 10;
+               }
+               /* make up a name */
+               strcpy(local_name, YAFFS_LOSTNFOUND_PREFIX);
+               strcat(local_name, x);
+               strncpy(name, local_name, buffer_size - 1);
+       }
+}
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size)
+{
+       memset(name, 0, buffer_size * sizeof(YCHAR));
+
+       yaffs_check_obj_details_loaded(obj);
+
+       if (obj->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+               strncpy(name, YAFFS_LOSTNFOUND_NAME, buffer_size - 1);
+       }
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+       else if (obj->short_name[0]) {
+               strcpy(name, obj->short_name);
+       }
+#endif
+       else if (obj->hdr_chunk > 0) {
+               int result;
+               u8 *buffer = yaffs_get_temp_buffer(obj->my_dev, __LINE__);
+
+               struct yaffs_obj_hdr *oh = (struct yaffs_obj_hdr *)buffer;
+
+               memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
+
+               if (obj->hdr_chunk > 0) {
+                       result = yaffs_rd_chunk_tags_nand(obj->my_dev,
+                                                         obj->hdr_chunk,
+                                                         buffer, NULL);
+               }
+               yaffs_load_name_from_oh(obj->my_dev, name, oh->name,
+                                       buffer_size);
+
+               yaffs_release_temp_buffer(obj->my_dev, buffer, __LINE__);
+       }
+
+       yaffs_fix_null_name(obj, name, buffer_size);
+
+       return strnlen(name, YAFFS_MAX_NAME_LENGTH);
+}
+
+int yaffs_get_obj_length(struct yaffs_obj *obj)
+{
+       /* Dereference any hard linking */
+       obj = yaffs_get_equivalent_obj(obj);
+
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_FILE)
+               return obj->variant.file_variant.file_size;
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK) {
+               if (!obj->variant.symlink_variant.alias)
+                       return 0;
+               return strnlen(obj->variant.symlink_variant.alias,
+                                    YAFFS_MAX_ALIAS_LENGTH);
+       } else {
+               /* Only a directory should drop through to here */
+               return obj->my_dev->data_bytes_per_chunk;
+       }
+}
+
+int yaffs_get_obj_link_count(struct yaffs_obj *obj)
+{
+       int count = 0;
+       struct list_head *i;
+
+       if (!obj->unlinked)
+               count++;        /* the object itself */
+
+       list_for_each(i, &obj->hard_links)
+           count++;            /* add the hard links; */
+
+       return count;
+}
+
+int yaffs_get_obj_inode(struct yaffs_obj *obj)
+{
+       obj = yaffs_get_equivalent_obj(obj);
+
+       return obj->obj_id;
+}
+
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj)
+{
+       obj = yaffs_get_equivalent_obj(obj);
+
+       switch (obj->variant_type) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               return DT_REG;
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               return DT_DIR;
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               return DT_LNK;
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               return DT_REG;
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               if (S_ISFIFO(obj->yst_mode))
+                       return DT_FIFO;
+               if (S_ISCHR(obj->yst_mode))
+                       return DT_CHR;
+               if (S_ISBLK(obj->yst_mode))
+                       return DT_BLK;
+               if (S_ISSOCK(obj->yst_mode))
+                       return DT_SOCK;
+       default:
+               return DT_REG;
+               break;
+       }
+}
+
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj)
+{
+       obj = yaffs_get_equivalent_obj(obj);
+       if (obj->variant_type == YAFFS_OBJECT_TYPE_SYMLINK)
+               return yaffs_clone_str(obj->variant.symlink_variant.alias);
+       else
+               return yaffs_clone_str(_Y(""));
+}
+
+/*--------------------------- Initialisation code -------------------------- */
+
+static int yaffs_check_dev_fns(const struct yaffs_dev *dev)
+{
+
+       /* Common functions, gotta have */
+       if (!dev->param.erase_fn || !dev->param.initialise_flash_fn)
+               return 0;
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+       /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
+       if (dev->param.write_chunk_tags_fn &&
+           dev->param.read_chunk_tags_fn &&
+           !dev->param.write_chunk_fn &&
+           !dev->param.read_chunk_fn &&
+           dev->param.bad_block_fn && dev->param.query_block_fn)
+               return 1;
+#endif
+
+       /* Can use the "spare" style interface for yaffs1 */
+       if (!dev->param.is_yaffs2 &&
+           !dev->param.write_chunk_tags_fn &&
+           !dev->param.read_chunk_tags_fn &&
+           dev->param.write_chunk_fn &&
+           dev->param.read_chunk_fn &&
+           !dev->param.bad_block_fn && !dev->param.query_block_fn)
+               return 1;
+
+       return 0;               /* bad */
+}
+
+static int yaffs_create_initial_dir(struct yaffs_dev *dev)
+{
+       /* Initialise the unlinked, deleted, root and lost and found directories */
+
+       dev->lost_n_found = dev->root_dir = NULL;
+       dev->unlinked_dir = dev->del_dir = NULL;
+
+       dev->unlinked_dir =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
+
+       dev->del_dir =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
+
+       dev->root_dir =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_ROOT,
+                                 YAFFS_ROOT_MODE | S_IFDIR);
+       dev->lost_n_found =
+           yaffs_create_fake_dir(dev, YAFFS_OBJECTID_LOSTNFOUND,
+                                 YAFFS_LOSTNFOUND_MODE | S_IFDIR);
+
+       if (dev->lost_n_found && dev->root_dir && dev->unlinked_dir
+           && dev->del_dir) {
+               yaffs_add_obj_to_dir(dev->root_dir, dev->lost_n_found);
+               return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+int yaffs_guts_initialise(struct yaffs_dev *dev)
+{
+       int init_failed = 0;
+       unsigned x;
+       int bits;
+
+       yaffs_trace(YAFFS_TRACE_TRACING, "yaffs: yaffs_guts_initialise()" );
+
+       /* Check stuff that must be set */
+
+       if (!dev) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "yaffs: Need a device"
+                       );
+               return YAFFS_FAIL;
+       }
+
+       dev->internal_start_block = dev->param.start_block;
+       dev->internal_end_block = dev->param.end_block;
+       dev->block_offset = 0;
+       dev->chunk_offset = 0;
+       dev->n_free_chunks = 0;
+
+       dev->gc_block = 0;
+
+       if (dev->param.start_block == 0) {
+               dev->internal_start_block = dev->param.start_block + 1;
+               dev->internal_end_block = dev->param.end_block + 1;
+               dev->block_offset = 1;
+               dev->chunk_offset = dev->param.chunks_per_block;
+       }
+
+       /* Check geometry parameters. */
+
+       if ((!dev->param.inband_tags && dev->param.is_yaffs2 &&
+               dev->param.total_bytes_per_chunk < 1024) ||
+               (!dev->param.is_yaffs2 &&
+                       dev->param.total_bytes_per_chunk < 512) ||
+               (dev->param.inband_tags && !dev->param.is_yaffs2) ||
+                dev->param.chunks_per_block < 2 ||
+                dev->param.n_reserved_blocks < 2 ||
+               dev->internal_start_block <= 0 || 
+               dev->internal_end_block <= 0 || 
+               dev->internal_end_block <= 
+               (dev->internal_start_block + dev->param.n_reserved_blocks + 2)
+               ) {
+               /* otherwise it is too small */
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "NAND geometry problems: chunk size %d, type is yaffs%s, inband_tags %d ",
+                       dev->param.total_bytes_per_chunk,
+                       dev->param.is_yaffs2 ? "2" : "",
+                       dev->param.inband_tags);
+               return YAFFS_FAIL;
+       }
+
+       if (yaffs_init_nand(dev) != YAFFS_OK) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "InitialiseNAND failed");
+               return YAFFS_FAIL;
+       }
+
+       /* Sort out space for inband tags, if required */
+       if (dev->param.inband_tags)
+               dev->data_bytes_per_chunk =
+                   dev->param.total_bytes_per_chunk -
+                   sizeof(struct yaffs_packed_tags2_tags_only);
+       else
+               dev->data_bytes_per_chunk = dev->param.total_bytes_per_chunk;
+
+       /* Got the right mix of functions? */
+       if (!yaffs_check_dev_fns(dev)) {
+               /* Function missing */
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "device function(s) missing or wrong");
+
+               return YAFFS_FAIL;
+       }
+
+       if (dev->is_mounted) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "device already mounted");
+               return YAFFS_FAIL;
+       }
+
+       /* Finished with most checks. One or two more checks happen later on too. */
+
+       dev->is_mounted = 1;
+
+       /* OK now calculate a few things for the device */
+
+       /*
+        *  Calculate all the chunk size manipulation numbers:
+        */
+       x = dev->data_bytes_per_chunk;
+       /* We always use dev->chunk_shift and dev->chunk_div */
+       dev->chunk_shift = calc_shifts(x);
+       x >>= dev->chunk_shift;
+       dev->chunk_div = x;
+       /* We only use chunk mask if chunk_div is 1 */
+       dev->chunk_mask = (1 << dev->chunk_shift) - 1;
+
+       /*
+        * Calculate chunk_grp_bits.
+        * We need to find the next power of 2 > than internal_end_block
+        */
+
+       x = dev->param.chunks_per_block * (dev->internal_end_block + 1);
+
+       bits = calc_shifts_ceiling(x);
+
+       /* Set up tnode width if wide tnodes are enabled. */
+       if (!dev->param.wide_tnodes_disabled) {
+               /* bits must be even so that we end up with 32-bit words */
+               if (bits & 1)
+                       bits++;
+               if (bits < 16)
+                       dev->tnode_width = 16;
+               else
+                       dev->tnode_width = bits;
+       } else {
+               dev->tnode_width = 16;
+        }
+
+       dev->tnode_mask = (1 << dev->tnode_width) - 1;
+
+       /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
+        * so if the bitwidth of the
+        * chunk range we're using is greater than 16 we need
+        * to figure out chunk shift and chunk_grp_size
+        */
+
+       if (bits <= dev->tnode_width)
+               dev->chunk_grp_bits = 0;
+       else
+               dev->chunk_grp_bits = bits - dev->tnode_width;
+
+       dev->tnode_size = (dev->tnode_width * YAFFS_NTNODES_LEVEL0) / 8;
+       if (dev->tnode_size < sizeof(struct yaffs_tnode))
+               dev->tnode_size = sizeof(struct yaffs_tnode);
+
+       dev->chunk_grp_size = 1 << dev->chunk_grp_bits;
+
+       if (dev->param.chunks_per_block < dev->chunk_grp_size) {
+               /* We have a problem because the soft delete won't work if
+                * the chunk group size > chunks per block.
+                * This can be remedied by using larger "virtual blocks".
+                */
+               yaffs_trace(YAFFS_TRACE_ALWAYS, "chunk group too large");
+
+               return YAFFS_FAIL;
+       }
+
+       /* OK, we've finished verifying the device, lets continue with initialisation */
+
+       /* More device initialisation */
+       dev->all_gcs = 0;
+       dev->passive_gc_count = 0;
+       dev->oldest_dirty_gc_count = 0;
+       dev->bg_gcs = 0;
+       dev->gc_block_finder = 0;
+       dev->buffered_block = -1;
+       dev->doing_buffered_block_rewrite = 0;
+       dev->n_deleted_files = 0;
+       dev->n_bg_deletions = 0;
+       dev->n_unlinked_files = 0;
+       dev->n_ecc_fixed = 0;
+       dev->n_ecc_unfixed = 0;
+       dev->n_tags_ecc_fixed = 0;
+       dev->n_tags_ecc_unfixed = 0;
+       dev->n_erase_failures = 0;
+       dev->n_erased_blocks = 0;
+       dev->gc_disable = 0;
+       dev->has_pending_prioritised_gc = 1;    /* Assume the worst for now, will get fixed on first GC */
+       INIT_LIST_HEAD(&dev->dirty_dirs);
+       dev->oldest_dirty_seq = 0;
+       dev->oldest_dirty_block = 0;
+
+       /* Initialise temporary buffers and caches. */
+       if (!yaffs_init_tmp_buffers(dev))
+               init_failed = 1;
+
+       dev->cache = NULL;
+       dev->gc_cleanup_list = NULL;
+
+       if (!init_failed && dev->param.n_caches > 0) {
+               int i;
+               void *buf;
+               int cache_bytes =
+                   dev->param.n_caches * sizeof(struct yaffs_cache);
+
+               if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES)
+                       dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES;
+
+               dev->cache = kmalloc(cache_bytes, GFP_NOFS);
+
+               buf = (u8 *) dev->cache;
+
+               if (dev->cache)
+                       memset(dev->cache, 0, cache_bytes);
+
+               for (i = 0; i < dev->param.n_caches && buf; i++) {
+                       dev->cache[i].object = NULL;
+                       dev->cache[i].last_use = 0;
+                       dev->cache[i].dirty = 0;
+                       dev->cache[i].data = buf =
+                           kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS);
+               }
+               if (!buf)
+                       init_failed = 1;
+
+               dev->cache_last_use = 0;
+       }
+
+       dev->cache_hits = 0;
+
+       if (!init_failed) {
+               dev->gc_cleanup_list =
+                   kmalloc(dev->param.chunks_per_block * sizeof(u32),
+                                       GFP_NOFS);
+               if (!dev->gc_cleanup_list)
+                       init_failed = 1;
+       }
+
+       if (dev->param.is_yaffs2)
+               dev->param.use_header_file_size = 1;
+
+       if (!init_failed && !yaffs_init_blocks(dev))
+               init_failed = 1;
+
+       yaffs_init_tnodes_and_objs(dev);
+
+       if (!init_failed && !yaffs_create_initial_dir(dev))
+               init_failed = 1;
+
+       if (!init_failed) {
+               /* Now scan the flash. */
+               if (dev->param.is_yaffs2) {
+                       if (yaffs2_checkpt_restore(dev)) {
+                               yaffs_check_obj_details_loaded(dev->root_dir);
+                               yaffs_trace(YAFFS_TRACE_CHECKPOINT | YAFFS_TRACE_MOUNT,
+                                       "yaffs: restored from checkpoint"
+                                       );
+                       } else {
+
+                               /* Clean up the mess caused by an aborted checkpoint load
+                                * and scan backwards.
+                                */
+                               yaffs_deinit_blocks(dev);
+
+                               yaffs_deinit_tnodes_and_objs(dev);
+
+                               dev->n_erased_blocks = 0;
+                               dev->n_free_chunks = 0;
+                               dev->alloc_block = -1;
+                               dev->alloc_page = -1;
+                               dev->n_deleted_files = 0;
+                               dev->n_unlinked_files = 0;
+                               dev->n_bg_deletions = 0;
+
+                               if (!init_failed && !yaffs_init_blocks(dev))
+                                       init_failed = 1;
+
+                               yaffs_init_tnodes_and_objs(dev);
+
+                               if (!init_failed
+                                   && !yaffs_create_initial_dir(dev))
+                                       init_failed = 1;
+
+                               if (!init_failed && !yaffs2_scan_backwards(dev))
+                                       init_failed = 1;
+                       }
+               } else if (!yaffs1_scan(dev)) {
+                       init_failed = 1;
+                }
+
+               yaffs_strip_deleted_objs(dev);
+               yaffs_fix_hanging_objs(dev);
+               if (dev->param.empty_lost_n_found)
+                       yaffs_empty_l_n_f(dev);
+       }
+
+       if (init_failed) {
+               /* Clean up the mess */
+               yaffs_trace(YAFFS_TRACE_TRACING,
+                 "yaffs: yaffs_guts_initialise() aborted.");
+
+               yaffs_deinitialise(dev);
+               return YAFFS_FAIL;
+       }
+
+       /* Zero out stats */
+       dev->n_page_reads = 0;
+       dev->n_page_writes = 0;
+       dev->n_erasures = 0;
+       dev->n_gc_copies = 0;
+       dev->n_retired_writes = 0;
+
+       dev->n_retired_blocks = 0;
+
+       yaffs_verify_free_chunks(dev);
+       yaffs_verify_blocks(dev);
+
+       /* Clean up any aborted checkpoint data */
+       if (!dev->is_checkpointed && dev->blocks_in_checkpt > 0)
+               yaffs2_checkpt_invalidate(dev);
+
+       yaffs_trace(YAFFS_TRACE_TRACING,
+         "yaffs: yaffs_guts_initialise() done.");
+       return YAFFS_OK;
+
+}
+
+void yaffs_deinitialise(struct yaffs_dev *dev)
+{
+       if (dev->is_mounted) {
+               int i;
+
+               yaffs_deinit_blocks(dev);
+               yaffs_deinit_tnodes_and_objs(dev);
+               if (dev->param.n_caches > 0 && dev->cache) {
+
+                       for (i = 0; i < dev->param.n_caches; i++) {
+                               if (dev->cache[i].data)
+                                       kfree(dev->cache[i].data);
+                               dev->cache[i].data = NULL;
+                       }
+
+                       kfree(dev->cache);
+                       dev->cache = NULL;
+               }
+
+               kfree(dev->gc_cleanup_list);
+
+               for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++)
+                       kfree(dev->temp_buffer[i].buffer);
+
+               dev->is_mounted = 0;
+
+               if (dev->param.deinitialise_flash_fn)
+                       dev->param.deinitialise_flash_fn(dev);
+       }
+}
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev)
+{
+       int n_free = 0;
+       int b;
+
+       struct yaffs_block_info *blk;
+
+       blk = dev->block_info;
+       for (b = dev->internal_start_block; b <= dev->internal_end_block; b++) {
+               switch (blk->block_state) {
+               case YAFFS_BLOCK_STATE_EMPTY:
+               case YAFFS_BLOCK_STATE_ALLOCATING:
+               case YAFFS_BLOCK_STATE_COLLECTING:
+               case YAFFS_BLOCK_STATE_FULL:
+                       n_free +=
+                           (dev->param.chunks_per_block - blk->pages_in_use +
+                            blk->soft_del_pages);
+                       break;
+               default:
+                       break;
+               }
+               blk++;
+       }
+
+       return n_free;
+}
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev)
+{
+       /* This is what we report to the outside world */
+
+       int n_free;
+       int n_dirty_caches;
+       int blocks_for_checkpt;
+       int i;
+
+       n_free = dev->n_free_chunks;
+       n_free += dev->n_deleted_files;
+
+       /* Now count the number of dirty chunks in the cache and subtract those */
+
+       for (n_dirty_caches = 0, i = 0; i < dev->param.n_caches; i++) {
+               if (dev->cache[i].dirty)
+                       n_dirty_caches++;
+       }
+
+       n_free -= n_dirty_caches;
+
+       n_free -=
+           ((dev->param.n_reserved_blocks + 1) * dev->param.chunks_per_block);
+
+       /* Now we figure out how much to reserve for the checkpoint and report that... */
+       blocks_for_checkpt = yaffs_calc_checkpt_blocks_required(dev);
+
+       n_free -= (blocks_for_checkpt * dev->param.chunks_per_block);
+
+       if (n_free < 0)
+               n_free = 0;
+
+       return n_free;
+
+}
diff --git a/fs/yaffs2/yaffs_guts.h b/fs/yaffs2/yaffs_guts.h
new file mode 100644 (file)
index 0000000..307eba2
--- /dev/null
@@ -0,0 +1,915 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GUTS_H__
+#define __YAFFS_GUTS_H__
+
+#include "yportenv.h"
+
+#define YAFFS_OK       1
+#define YAFFS_FAIL  0
+
+/* Give us a  Y=0x59,
+ * Give us an A=0x41,
+ * Give us an FF=0xFF
+ * Give us an S=0x53
+ * And what have we got...
+ */
+#define YAFFS_MAGIC                    0x5941FF53
+
+#define YAFFS_NTNODES_LEVEL0           16
+#define YAFFS_TNODES_LEVEL0_BITS       4
+#define YAFFS_TNODES_LEVEL0_MASK       0xf
+
+#define YAFFS_NTNODES_INTERNAL                 (YAFFS_NTNODES_LEVEL0 / 2)
+#define YAFFS_TNODES_INTERNAL_BITS     (YAFFS_TNODES_LEVEL0_BITS - 1)
+#define YAFFS_TNODES_INTERNAL_MASK     0x7
+#define YAFFS_TNODES_MAX_LEVEL         6
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+#define YAFFS_BYTES_PER_SPARE          16
+#define YAFFS_BYTES_PER_CHUNK          512
+#define YAFFS_CHUNK_SIZE_SHIFT         9
+#define YAFFS_CHUNKS_PER_BLOCK         32
+#define YAFFS_BYTES_PER_BLOCK          (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
+#endif
+
+#define YAFFS_MIN_YAFFS2_CHUNK_SIZE    1024
+#define YAFFS_MIN_YAFFS2_SPARE_SIZE    32
+
+#define YAFFS_MAX_CHUNK_ID             0x000FFFFF
+
+#define YAFFS_ALLOCATION_NOBJECTS      100
+#define YAFFS_ALLOCATION_NTNODES       100
+#define YAFFS_ALLOCATION_NLINKS                100
+
+#define YAFFS_NOBJECT_BUCKETS          256
+
+#define YAFFS_OBJECT_SPACE             0x40000
+#define YAFFS_MAX_OBJECT_ID            (YAFFS_OBJECT_SPACE -1)
+
+#define YAFFS_CHECKPOINT_VERSION       4
+
+#ifdef CONFIG_YAFFS_UNICODE
+#define YAFFS_MAX_NAME_LENGTH          127
+#define YAFFS_MAX_ALIAS_LENGTH         79
+#else
+#define YAFFS_MAX_NAME_LENGTH          255
+#define YAFFS_MAX_ALIAS_LENGTH         159
+#endif
+
+#define YAFFS_SHORT_NAME_LENGTH                15
+
+/* Some special object ids for pseudo objects */
+#define YAFFS_OBJECTID_ROOT            1
+#define YAFFS_OBJECTID_LOSTNFOUND      2
+#define YAFFS_OBJECTID_UNLINKED                3
+#define YAFFS_OBJECTID_DELETED         4
+
+/* Pseudo object ids for checkpointing */
+#define YAFFS_OBJECTID_SB_HEADER       0x10
+#define YAFFS_OBJECTID_CHECKPOINT_DATA 0x20
+#define YAFFS_SEQUENCE_CHECKPOINT_DATA  0x21
+
+#define YAFFS_MAX_SHORT_OP_CACHES      20
+
+#define YAFFS_N_TEMP_BUFFERS           6
+
+/* We limit the number attempts at sucessfully saving a chunk of data.
+ * Small-page devices have 32 pages per block; large-page devices have 64.
+ * Default to something in the order of 5 to 10 blocks worth of chunks.
+ */
+#define YAFFS_WR_ATTEMPTS              (5*64)
+
+/* Sequence numbers are used in YAFFS2 to determine block allocation order.
+ * The range is limited slightly to help distinguish bad numbers from good.
+ * This also allows us to perhaps in the future use special numbers for
+ * special purposes.
+ * EFFFFF00 allows the allocation of 8 blocks per second (~1Mbytes) for 15 years,
+ * and is a larger number than the lifetime of a 2GB device.
+ */
+#define YAFFS_LOWEST_SEQUENCE_NUMBER   0x00001000
+#define YAFFS_HIGHEST_SEQUENCE_NUMBER  0xEFFFFF00
+
+/* Special sequence number for bad block that failed to be marked bad */
+#define YAFFS_SEQUENCE_BAD_BLOCK       0xFFFF0000
+
+/* ChunkCache is used for short read/write operations.*/
+struct yaffs_cache {
+       struct yaffs_obj *object;
+       int chunk_id;
+       int last_use;
+       int dirty;
+       int n_bytes;            /* Only valid if the cache is dirty */
+       int locked;             /* Can't push out or flush while locked. */
+       u8 *data;
+};
+
+/* Tags structures in RAM
+ * NB This uses bitfield. Bitfields should not straddle a u32 boundary otherwise
+ * the structure size will get blown out.
+ */
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+struct yaffs_tags {
+       unsigned chunk_id:20;
+       unsigned serial_number:2;
+       unsigned n_bytes_lsb:10;
+       unsigned obj_id:18;
+       unsigned ecc:12;
+       unsigned n_bytes_msb:2;
+};
+
+union yaffs_tags_union {
+       struct yaffs_tags as_tags;
+       u8 as_bytes[8];
+};
+
+#endif
+
+/* Stuff used for extended tags in YAFFS2 */
+
+enum yaffs_ecc_result {
+       YAFFS_ECC_RESULT_UNKNOWN,
+       YAFFS_ECC_RESULT_NO_ERROR,
+       YAFFS_ECC_RESULT_FIXED,
+       YAFFS_ECC_RESULT_UNFIXED
+};
+
+enum yaffs_obj_type {
+       YAFFS_OBJECT_TYPE_UNKNOWN,
+       YAFFS_OBJECT_TYPE_FILE,
+       YAFFS_OBJECT_TYPE_SYMLINK,
+       YAFFS_OBJECT_TYPE_DIRECTORY,
+       YAFFS_OBJECT_TYPE_HARDLINK,
+       YAFFS_OBJECT_TYPE_SPECIAL
+};
+
+#define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
+
+struct yaffs_ext_tags {
+
+       unsigned validity0;
+       unsigned chunk_used;    /*  Status of the chunk: used or unused */
+       unsigned obj_id;        /* If 0 then this is not part of an object (unused) */
+       unsigned chunk_id;      /* If 0 then this is a header, else a data chunk */
+       unsigned n_bytes;       /* Only valid for data chunks */
+
+       /* The following stuff only has meaning when we read */
+       enum yaffs_ecc_result ecc_result;
+       unsigned block_bad;
+
+       /* YAFFS 1 stuff */
+       unsigned is_deleted;    /* The chunk is marked deleted */
+       unsigned serial_number; /* Yaffs1 2-bit serial number */
+
+       /* YAFFS2 stuff */
+       unsigned seq_number;    /* The sequence number of this block */
+
+       /* Extra info if this is an object header (YAFFS2 only) */
+
+       unsigned extra_available;       /* There is extra info available if this is not zero */
+       unsigned extra_parent_id;       /* The parent object */
+       unsigned extra_is_shrink;       /* Is it a shrink header? */
+       unsigned extra_shadows; /* Does this shadow another object? */
+
+       enum yaffs_obj_type extra_obj_type;     /* What object type? */
+
+       unsigned extra_length;  /* Length if it is a file */
+       unsigned extra_equiv_id;        /* Equivalent object Id if it is a hard link */
+
+       unsigned validity1;
+
+};
+
+/* Spare structure for YAFFS1 */
+struct yaffs_spare {
+       u8 tb0;
+       u8 tb1;
+       u8 tb2;
+       u8 tb3;
+       u8 page_status;         /* set to 0 to delete the chunk */
+       u8 block_status;
+       u8 tb4;
+       u8 tb5;
+       u8 ecc1[3];
+       u8 tb6;
+       u8 tb7;
+       u8 ecc2[3];
+};
+
+/*Special structure for passing through to mtd */
+struct yaffs_nand_spare {
+       struct yaffs_spare spare;
+       int eccres1;
+       int eccres2;
+};
+
+/* Block data in RAM */
+
+enum yaffs_block_state {
+       YAFFS_BLOCK_STATE_UNKNOWN = 0,
+
+       YAFFS_BLOCK_STATE_SCANNING,
+       /* Being scanned */
+
+       YAFFS_BLOCK_STATE_NEEDS_SCANNING,
+       /* The block might have something on it (ie it is allocating or full, perhaps empty)
+        * but it needs to be scanned to determine its true state.
+        * This state is only valid during scanning.
+        * NB We tolerate empty because the pre-scanner might be incapable of deciding
+        * However, if this state is returned on a YAFFS2 device, then we expect a sequence number
+        */
+
+       YAFFS_BLOCK_STATE_EMPTY,
+       /* This block is empty */
+
+       YAFFS_BLOCK_STATE_ALLOCATING,
+       /* This block is partially allocated.
+        * At least one page holds valid data.
+        * This is the one currently being used for page
+        * allocation. Should never be more than one of these.
+        * If a block is only partially allocated at mount it is treated as full.
+        */
+
+       YAFFS_BLOCK_STATE_FULL,
+       /* All the pages in this block have been allocated.
+        * If a block was only partially allocated when mounted we treat
+        * it as fully allocated.
+        */
+
+       YAFFS_BLOCK_STATE_DIRTY,
+       /* The block was full and now all chunks have been deleted.
+        * Erase me, reuse me.
+        */
+
+       YAFFS_BLOCK_STATE_CHECKPOINT,
+       /* This block is assigned to holding checkpoint data. */
+
+       YAFFS_BLOCK_STATE_COLLECTING,
+       /* This block is being garbage collected */
+
+       YAFFS_BLOCK_STATE_DEAD
+           /* This block has failed and is not in use */
+};
+
+#define        YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
+
+struct yaffs_block_info {
+
+       int soft_del_pages:10;  /* number of soft deleted pages */
+       int pages_in_use:10;    /* number of pages in use */
+       unsigned block_state:4; /* One of the above block states. NB use unsigned because enum is sometimes an int */
+       u32 needs_retiring:1;   /* Data has failed on this block, need to get valid data off */
+       /* and retire the block. */
+       u32 skip_erased_check:1;        /* If this is set we can skip the erased check on this block */
+       u32 gc_prioritise:1;    /* An ECC check or blank check has failed on this block.
+                                  It should be prioritised for GC */
+       u32 chunk_error_strikes:3;      /* How many times we've had ecc etc failures on this block and tried to reuse it */
+
+#ifdef CONFIG_YAFFS_YAFFS2
+       u32 has_shrink_hdr:1;   /* This block has at least one shrink object header */
+       u32 seq_number;         /* block sequence number for yaffs2 */
+#endif
+
+};
+
+/* -------------------------- Object structure -------------------------------*/
+/* This is the object structure as stored on NAND */
+
+struct yaffs_obj_hdr {
+       enum yaffs_obj_type type;
+
+       /* Apply to everything  */
+       int parent_obj_id;
+       u16 sum_no_longer_used; /* checksum of name. No longer used */
+       YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       /* The following apply to directories, files, symlinks - not hard links */
+       u32 yst_mode;           /* protection */
+
+       u32 yst_uid;
+       u32 yst_gid;
+       u32 yst_atime;
+       u32 yst_mtime;
+       u32 yst_ctime;
+
+       /* File size  applies to files only */
+       int file_size;
+
+       /* Equivalent object id applies to hard links only. */
+       int equiv_id;
+
+       /* Alias is for symlinks only. */
+       YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
+
+       u32 yst_rdev;           /* device stuff for block and char devices (major/min) */
+
+       u32 win_ctime[2];
+       u32 win_atime[2];
+       u32 win_mtime[2];
+
+       u32 inband_shadowed_obj_id;
+       u32 inband_is_shrink;
+
+       u32 reserved[2];
+       int shadows_obj;        /* This object header shadows the specified object if > 0 */
+
+       /* is_shrink applies to object headers written when we shrink the file (ie resize) */
+       u32 is_shrink;
+
+};
+
+/*--------------------------- Tnode -------------------------- */
+
+struct yaffs_tnode {
+       struct yaffs_tnode *internal[YAFFS_NTNODES_INTERNAL];
+};
+
+/*------------------------  Object -----------------------------*/
+/* An object can be one of:
+ * - a directory (no data, has children links
+ * - a regular file (data.... not prunes :->).
+ * - a symlink [symbolic link] (the alias).
+ * - a hard link
+ */
+
+struct yaffs_file_var {
+       u32 file_size;
+       u32 scanned_size;
+       u32 shrink_size;
+       int top_level;
+       struct yaffs_tnode *top;
+};
+
+struct yaffs_dir_var {
+       struct list_head children;      /* list of child links */
+       struct list_head dirty; /* Entry for list of dirty directories */
+};
+
+struct yaffs_symlink_var {
+       YCHAR *alias;
+};
+
+struct yaffs_hardlink_var {
+       struct yaffs_obj *equiv_obj;
+       u32 equiv_id;
+};
+
+union yaffs_obj_var {
+       struct yaffs_file_var file_variant;
+       struct yaffs_dir_var dir_variant;
+       struct yaffs_symlink_var symlink_variant;
+       struct yaffs_hardlink_var hardlink_variant;
+};
+
+struct yaffs_obj {
+       u8 deleted:1;           /* This should only apply to unlinked files. */
+       u8 soft_del:1;          /* it has also been soft deleted */
+       u8 unlinked:1;          /* An unlinked file. The file should be in the unlinked directory. */
+       u8 fake:1;              /* A fake object has no presence on NAND. */
+       u8 rename_allowed:1;    /* Some objects are not allowed to be renamed. */
+       u8 unlink_allowed:1;
+       u8 dirty:1;             /* the object needs to be written to flash */
+       u8 valid:1;             /* When the file system is being loaded up, this
+                                * object might be created before the data
+                                * is available (ie. file data records appear before the header).
+                                */
+       u8 lazy_loaded:1;       /* This object has been lazy loaded and is missing some detail */
+
+       u8 defered_free:1;      /* For Linux kernel. Object is removed from NAND, but is
+                                * still in the inode cache. Free of object is defered.
+                                * until the inode is released.
+                                */
+       u8 being_created:1;     /* This object is still being created so skip some checks. */
+       u8 is_shadowed:1;       /* This object is shadowed on the way to being renamed. */
+
+       u8 xattr_known:1;       /* We know if this has object has xattribs or not. */
+       u8 has_xattr:1;         /* This object has xattribs. Valid if xattr_known. */
+
+       u8 serial;              /* serial number of chunk in NAND. Cached here */
+       u16 sum;                /* sum of the name to speed searching */
+
+       struct yaffs_dev *my_dev;       /* The device I'm on */
+
+       struct list_head hash_link;     /* list of objects in this hash bucket */
+
+       struct list_head hard_links;    /* all the equivalent hard linked objects */
+
+       /* directory structure stuff */
+       /* also used for linking up the free list */
+       struct yaffs_obj *parent;
+       struct list_head siblings;
+
+       /* Where's my object header in NAND? */
+       int hdr_chunk;
+
+       int n_data_chunks;      /* Number of data chunks attached to the file. */
+
+       u32 obj_id;             /* the object id value */
+
+       u32 yst_mode;
+
+#ifndef CONFIG_YAFFS_NO_SHORT_NAMES
+       YCHAR short_name[YAFFS_SHORT_NAME_LENGTH + 1];
+#endif
+
+#ifdef CONFIG_YAFFS_WINCE
+       u32 win_ctime[2];
+       u32 win_mtime[2];
+       u32 win_atime[2];
+#else
+       u32 yst_uid;
+       u32 yst_gid;
+       u32 yst_atime;
+       u32 yst_mtime;
+       u32 yst_ctime;
+#endif
+
+       u32 yst_rdev;
+
+       void *my_inode;
+
+       enum yaffs_obj_type variant_type;
+
+       union yaffs_obj_var variant;
+
+};
+
+struct yaffs_obj_bucket {
+       struct list_head list;
+       int count;
+};
+
+/* yaffs_checkpt_obj holds the definition of an object as dumped
+ * by checkpointing.
+ */
+
+struct yaffs_checkpt_obj {
+       int struct_type;
+       u32 obj_id;
+       u32 parent_id;
+       int hdr_chunk;
+       enum yaffs_obj_type variant_type:3;
+       u8 deleted:1;
+       u8 soft_del:1;
+       u8 unlinked:1;
+       u8 fake:1;
+       u8 rename_allowed:1;
+       u8 unlink_allowed:1;
+       u8 serial;
+       int n_data_chunks;
+       u32 size_or_equiv_obj;
+};
+
+/*--------------------- Temporary buffers ----------------
+ *
+ * These are chunk-sized working buffers. Each device has a few
+ */
+
+struct yaffs_buffer {
+       u8 *buffer;
+       int line;               /* track from whence this buffer was allocated */
+       int max_line;
+};
+
+/*----------------- Device ---------------------------------*/
+
+struct yaffs_param {
+       const YCHAR *name;
+
+       /*
+        * Entry parameters set up way early. Yaffs sets up the rest.
+        * The structure should be zeroed out before use so that unused
+        * and defualt values are zero.
+        */
+
+       int inband_tags;        /* Use unband tags */
+       u32 total_bytes_per_chunk;      /* Should be >= 512, does not need to be a power of 2 */
+       int chunks_per_block;   /* does not need to be a power of 2 */
+       int spare_bytes_per_chunk;      /* spare area size */
+       int start_block;        /* Start block we're allowed to use */
+       int end_block;          /* End block we're allowed to use */
+       int n_reserved_blocks;  /* We want this tuneable so that we can reduce */
+       /* reserved blocks on NOR and RAM. */
+
+       int n_caches;           /* If <= 0, then short op caching is disabled, else
+                                * the number of short op caches (don't use too many).
+                                * 10 to 20 is a good bet.
+                                */
+       int use_nand_ecc;       /* Flag to decide whether or not to use NANDECC on data (yaffs1) */
+       int no_tags_ecc;        /* Flag to decide whether or not to do ECC on packed tags (yaffs2) */
+
+       int is_yaffs2;          /* Use yaffs2 mode on this device */
+
+       int empty_lost_n_found; /* Auto-empty lost+found directory on mount */
+
+       int refresh_period;     /* How often we should check to do a block refresh */
+
+       /* Checkpoint control. Can be set before or after initialisation */
+       u8 skip_checkpt_rd;
+       u8 skip_checkpt_wr;
+
+       int enable_xattr;       /* Enable xattribs */
+
+       /* NAND access functions (Must be set before calling YAFFS) */
+
+       int (*write_chunk_fn) (struct yaffs_dev * dev,
+                              int nand_chunk, const u8 * data,
+                              const struct yaffs_spare * spare);
+       int (*read_chunk_fn) (struct yaffs_dev * dev,
+                             int nand_chunk, u8 * data,
+                             struct yaffs_spare * spare);
+       int (*erase_fn) (struct yaffs_dev * dev, int flash_block);
+       int (*initialise_flash_fn) (struct yaffs_dev * dev);
+       int (*deinitialise_flash_fn) (struct yaffs_dev * dev);
+
+#ifdef CONFIG_YAFFS_YAFFS2
+       int (*write_chunk_tags_fn) (struct yaffs_dev * dev,
+                                   int nand_chunk, const u8 * data,
+                                   const struct yaffs_ext_tags * tags);
+       int (*read_chunk_tags_fn) (struct yaffs_dev * dev,
+                                  int nand_chunk, u8 * data,
+                                  struct yaffs_ext_tags * tags);
+       int (*bad_block_fn) (struct yaffs_dev * dev, int block_no);
+       int (*query_block_fn) (struct yaffs_dev * dev, int block_no,
+                              enum yaffs_block_state * state,
+                              u32 * seq_number);
+#endif
+
+       /* The remove_obj_fn function must be supplied by OS flavours that
+        * need it.
+        * yaffs direct uses it to implement the faster readdir.
+        * Linux uses it to protect the directory during unlocking.
+        */
+       void (*remove_obj_fn) (struct yaffs_obj * obj);
+
+       /* Callback to mark the superblock dirty */
+       void (*sb_dirty_fn) (struct yaffs_dev * dev);
+
+       /*  Callback to control garbage collection. */
+       unsigned (*gc_control) (struct yaffs_dev * dev);
+
+       /* Debug control flags. Don't use unless you know what you're doing */
+       int use_header_file_size;       /* Flag to determine if we should use file sizes from the header */
+       int disable_lazy_load;  /* Disable lazy loading on this device */
+       int wide_tnodes_disabled;       /* Set to disable wide tnodes */
+       int disable_soft_del;   /* yaffs 1 only: Set to disable the use of softdeletion. */
+
+       int defered_dir_update; /* Set to defer directory updates */
+
+#ifdef CONFIG_YAFFS_AUTO_UNICODE
+       int auto_unicode;
+#endif
+       int always_check_erased;        /* Force chunk erased check always on */
+};
+
+struct yaffs_dev {
+       struct yaffs_param param;
+
+       /* Context storage. Holds extra OS specific data for this device */
+
+       void *os_context;
+       void *driver_context;
+
+       struct list_head dev_list;
+
+       /* Runtime parameters. Set up by YAFFS. */
+       int data_bytes_per_chunk;
+
+       /* Non-wide tnode stuff */
+       u16 chunk_grp_bits;     /* Number of bits that need to be resolved if
+                                * the tnodes are not wide enough.
+                                */
+       u16 chunk_grp_size;     /* == 2^^chunk_grp_bits */
+
+       /* Stuff to support wide tnodes */
+       u32 tnode_width;
+       u32 tnode_mask;
+       u32 tnode_size;
+
+       /* Stuff for figuring out file offset to chunk conversions */
+       u32 chunk_shift;        /* Shift value */
+       u32 chunk_div;          /* Divisor after shifting: 1 for power-of-2 sizes */
+       u32 chunk_mask;         /* Mask to use for power-of-2 case */
+
+       int is_mounted;
+       int read_only;
+       int is_checkpointed;
+
+       /* Stuff to support block offsetting to support start block zero */
+       int internal_start_block;
+       int internal_end_block;
+       int block_offset;
+       int chunk_offset;
+
+       /* Runtime checkpointing stuff */
+       int checkpt_page_seq;   /* running sequence number of checkpoint pages */
+       int checkpt_byte_count;
+       int checkpt_byte_offs;
+       u8 *checkpt_buffer;
+       int checkpt_open_write;
+       int blocks_in_checkpt;
+       int checkpt_cur_chunk;
+       int checkpt_cur_block;
+       int checkpt_next_block;
+       int *checkpt_block_list;
+       int checkpt_max_blocks;
+       u32 checkpt_sum;
+       u32 checkpt_xor;
+
+       int checkpoint_blocks_required; /* Number of blocks needed to store current checkpoint set */
+
+       /* Block Info */
+       struct yaffs_block_info *block_info;
+       u8 *chunk_bits;         /* bitmap of chunks in use */
+       unsigned block_info_alt:1;      /* was allocated using alternative strategy */
+       unsigned chunk_bits_alt:1;      /* was allocated using alternative strategy */
+       int chunk_bit_stride;   /* Number of bytes of chunk_bits per block.
+                                * Must be consistent with chunks_per_block.
+                                */
+
+       int n_erased_blocks;
+       int alloc_block;        /* Current block being allocated off */
+       u32 alloc_page;
+       int alloc_block_finder; /* Used to search for next allocation block */
+
+       /* Object and Tnode memory management */
+       void *allocator;
+       int n_obj;
+       int n_tnodes;
+
+       int n_hardlinks;
+
+       struct yaffs_obj_bucket obj_bucket[YAFFS_NOBJECT_BUCKETS];
+       u32 bucket_finder;
+
+       int n_free_chunks;
+
+       /* Garbage collection control */
+       u32 *gc_cleanup_list;   /* objects to delete at the end of a GC. */
+       u32 n_clean_ups;
+
+       unsigned has_pending_prioritised_gc;    /* We think this device might have pending prioritised gcs */
+       unsigned gc_disable;
+       unsigned gc_block_finder;
+       unsigned gc_dirtiest;
+       unsigned gc_pages_in_use;
+       unsigned gc_not_done;
+       unsigned gc_block;
+       unsigned gc_chunk;
+       unsigned gc_skip;
+
+       /* Special directories */
+       struct yaffs_obj *root_dir;
+       struct yaffs_obj *lost_n_found;
+
+       /* Buffer areas for storing data to recover from write failures TODO
+        *      u8            buffered_data[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
+        *      struct yaffs_spare buffered_spare[YAFFS_CHUNKS_PER_BLOCK];
+        */
+
+       int buffered_block;     /* Which block is buffered here? */
+       int doing_buffered_block_rewrite;
+
+       struct yaffs_cache *cache;
+       int cache_last_use;
+
+       /* Stuff for background deletion and unlinked files. */
+       struct yaffs_obj *unlinked_dir; /* Directory where unlinked and deleted files live. */
+       struct yaffs_obj *del_dir;      /* Directory where deleted objects are sent to disappear. */
+       struct yaffs_obj *unlinked_deletion;    /* Current file being background deleted. */
+       int n_deleted_files;    /* Count of files awaiting deletion; */
+       int n_unlinked_files;   /* Count of unlinked files. */
+       int n_bg_deletions;     /* Count of background deletions. */
+
+       /* Temporary buffer management */
+       struct yaffs_buffer temp_buffer[YAFFS_N_TEMP_BUFFERS];
+       int max_temp;
+       int temp_in_use;
+       int unmanaged_buffer_allocs;
+       int unmanaged_buffer_deallocs;
+
+       /* yaffs2 runtime stuff */
+       unsigned seq_number;    /* Sequence number of currently allocating block */
+       unsigned oldest_dirty_seq;
+       unsigned oldest_dirty_block;
+
+       /* Block refreshing */
+       int refresh_skip;       /* A skip down counter. Refresh happens when this gets to zero. */
+
+       /* Dirty directory handling */
+       struct list_head dirty_dirs;    /* List of dirty directories */
+
+       /* Statistcs */
+       u32 n_page_writes;
+       u32 n_page_reads;
+       u32 n_erasures;
+       u32 n_erase_failures;
+       u32 n_gc_copies;
+       u32 all_gcs;
+       u32 passive_gc_count;
+       u32 oldest_dirty_gc_count;
+       u32 n_gc_blocks;
+       u32 bg_gcs;
+       u32 n_retired_writes;
+       u32 n_retired_blocks;
+       u32 n_ecc_fixed;
+       u32 n_ecc_unfixed;
+       u32 n_tags_ecc_fixed;
+       u32 n_tags_ecc_unfixed;
+       u32 n_deletions;
+       u32 n_unmarked_deletions;
+       u32 refresh_count;
+       u32 cache_hits;
+
+};
+
+/* The CheckpointDevice structure holds the device information that changes at runtime and
+ * must be preserved over unmount/mount cycles.
+ */
+struct yaffs_checkpt_dev {
+       int struct_type;
+       int n_erased_blocks;
+       int alloc_block;        /* Current block being allocated off */
+       u32 alloc_page;
+       int n_free_chunks;
+
+       int n_deleted_files;    /* Count of files awaiting deletion; */
+       int n_unlinked_files;   /* Count of unlinked files. */
+       int n_bg_deletions;     /* Count of background deletions. */
+
+       /* yaffs2 runtime stuff */
+       unsigned seq_number;    /* Sequence number of currently allocating block */
+
+};
+
+struct yaffs_checkpt_validity {
+       int struct_type;
+       u32 magic;
+       u32 version;
+       u32 head;
+};
+
+struct yaffs_shadow_fixer {
+       int obj_id;
+       int shadowed_id;
+       struct yaffs_shadow_fixer *next;
+};
+
+/* Structure for doing xattr modifications */
+struct yaffs_xattr_mod {
+       int set;                /* If 0 then this is a deletion */
+       const YCHAR *name;
+       const void *data;
+       int size;
+       int flags;
+       int result;
+};
+
+/*----------------------- YAFFS Functions -----------------------*/
+
+int yaffs_guts_initialise(struct yaffs_dev *dev);
+void yaffs_deinitialise(struct yaffs_dev *dev);
+
+int yaffs_get_n_free_chunks(struct yaffs_dev *dev);
+
+int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
+                    struct yaffs_obj *new_dir, const YCHAR * new_name);
+
+int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name);
+int yaffs_del_obj(struct yaffs_obj *obj);
+
+int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size);
+int yaffs_get_obj_length(struct yaffs_obj *obj);
+int yaffs_get_obj_inode(struct yaffs_obj *obj);
+unsigned yaffs_get_obj_type(struct yaffs_obj *obj);
+int yaffs_get_obj_link_count(struct yaffs_obj *obj);
+
+/* File operations */
+int yaffs_file_rd(struct yaffs_obj *obj, u8 * buffer, loff_t offset,
+                 int n_bytes);
+int yaffs_wr_file(struct yaffs_obj *obj, const u8 * buffer, loff_t offset,
+                 int n_bytes, int write_trhrough);
+int yaffs_resize_file(struct yaffs_obj *obj, loff_t new_size);
+
+struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
+                                   const YCHAR * name, u32 mode, u32 uid,
+                                   u32 gid);
+
+int yaffs_flush_file(struct yaffs_obj *obj, int update_time, int data_sync);
+
+/* Flushing and checkpointing */
+void yaffs_flush_whole_cache(struct yaffs_dev *dev);
+
+int yaffs_checkpoint_save(struct yaffs_dev *dev);
+int yaffs_checkpoint_restore(struct yaffs_dev *dev);
+
+/* Directory operations */
+struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR * name,
+                                  u32 mode, u32 uid, u32 gid);
+struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *the_dir,
+                                    const YCHAR * name);
+struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number);
+
+/* Link operations */
+struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR * name,
+                                struct yaffs_obj *equiv_obj);
+
+struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj);
+
+/* Symlink operations */
+struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, const YCHAR * alias);
+YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj);
+
+/* Special inodes (fifos, sockets and devices) */
+struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
+                                      const YCHAR * name, u32 mode, u32 uid,
+                                      u32 gid, u32 rdev);
+
+int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR * name,
+                     const void *value, int size, int flags);
+int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR * name, void *value,
+                     int size);
+int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size);
+int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR * name);
+
+/* Special directories */
+struct yaffs_obj *yaffs_root(struct yaffs_dev *dev);
+struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev);
+
+void yaffs_handle_defered_free(struct yaffs_obj *obj);
+
+void yaffs_update_dirty_dirs(struct yaffs_dev *dev);
+
+int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency);
+
+/* Debug dump  */
+int yaffs_dump_obj(struct yaffs_obj *obj);
+
+void yaffs_guts_test(struct yaffs_dev *dev);
+
+/* A few useful functions to be used within the core files*/
+void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
+                    int lyn);
+int yaffs_check_ff(u8 * buffer, int n_bytes);
+void yaffs_handle_chunk_error(struct yaffs_dev *dev,
+                             struct yaffs_block_info *bi);
+
+u8 *yaffs_get_temp_buffer(struct yaffs_dev *dev, int line_no);
+void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 * buffer, int line_no);
+
+struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
+                                                int number,
+                                                enum yaffs_obj_type type);
+int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
+                           int nand_chunk, int in_scan);
+void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR * name);
+void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
+                               const struct yaffs_obj_hdr *oh);
+void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj);
+YCHAR *yaffs_clone_str(const YCHAR * str);
+void yaffs_link_fixup(struct yaffs_dev *dev, struct yaffs_obj *hard_list);
+void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no);
+int yaffs_update_oh(struct yaffs_obj *in, const YCHAR * name,
+                   int force, int is_shrink, int shadows,
+                   struct yaffs_xattr_mod *xop);
+void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
+                              int backward_scanning);
+int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks);
+struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev);
+struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
+                                          struct yaffs_file_var *file_struct,
+                                          u32 chunk_id,
+                                          struct yaffs_tnode *passed_tn);
+
+int yaffs_do_file_wr(struct yaffs_obj *in, const u8 * buffer, loff_t offset,
+                    int n_bytes, int write_trhrough);
+void yaffs_resize_file_down(struct yaffs_obj *obj, loff_t new_size);
+void yaffs_skip_rest_of_block(struct yaffs_dev *dev);
+
+int yaffs_count_free_chunks(struct yaffs_dev *dev);
+
+struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
+                                      struct yaffs_file_var *file_struct,
+                                      u32 chunk_id);
+
+u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
+                        unsigned pos);
+
+int yaffs_is_non_empty_dir(struct yaffs_obj *obj);
+#endif
diff --git a/fs/yaffs2/yaffs_linux.h b/fs/yaffs2/yaffs_linux.h
new file mode 100644 (file)
index 0000000..3b508cb
--- /dev/null
@@ -0,0