Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 3457 insertions, 0 deletions

diff --git a/fs/jffs/intrep.c b/fs/jffs/intrep.c
new file mode 100644
index 00000000000..8cc6893fc56
--- /dev/null
+++ b/fs/jffs/intrep.c
@@ -0,0 +1,3457 @@
+/*
+ * JFFS -- Journaling Flash File System, Linux implementation.
+ *
+ * Copyright (C) 1999, 2000  Axis Communications, Inc.
+ *
+ * Created by Finn Hakansson <finn@axis.com>.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * $Id: intrep.c,v 1.102 2001/09/23 23:28:36 dwmw2 Exp $
+ *
+ * Ported to Linux 2.3.x and MTD:
+ * Copyright (C) 2000  Alexander Larsson (alex@cendio.se), Cendio Systems AB
+ *
+ */
+
+/* This file contains the code for the internal structure of the
+   Journaling Flash File System, JFFS.  */
+
+/*
+ * Todo list:
+ *
+ * memcpy_to_flash() and memcpy_from_flash() functions.
+ *
+ * Implementation of hard links.
+ *
+ * Organize the source code in a better way. Against the VFS we could
+ * have jffs_ext.c, and against the block device jffs_int.c.
+ * A better file-internal organization too.
+ *
+ * A better checksum algorithm.
+ *
+ * Consider endianness stuff. ntohl() etc.
+ *
+ * Are we handling the atime, mtime, ctime members of the inode right?
+ *
+ * Remove some duplicated code. Take a look at jffs_write_node() and
+ * jffs_rewrite_data() for instance.
+ *
+ * Implement more meaning of the nlink member in various data structures.
+ * nlink could be used in conjunction with hard links for instance.
+ *
+ * Better memory management. Allocate data structures in larger chunks
+ * if possible.
+ *
+ * If too much meta data is stored, a garbage collect should be issued.
+ * We have experienced problems with too much meta data with for instance
+ * log files.
+ *
+ * Improve the calls to jffs_ioctl(). We would like to retrieve more
+ * information to be able to debug (or to supervise) JFFS during run-time.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/jffs.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/pagemap.h>
+#include <asm/semaphore.h>
+#include <asm/byteorder.h>
+#include <linux/smp_lock.h>
+#include <linux/time.h>
+#include <linux/ctype.h>
+
+#include "intrep.h"
+#include "jffs_fm.h"
+
+long no_jffs_node = 0;
+static long no_jffs_file = 0;
+#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
+long no_jffs_control = 0;
+long no_jffs_raw_inode = 0;
+long no_jffs_node_ref = 0;
+long no_jffs_fm = 0;
+long no_jffs_fmcontrol = 0;
+long no_hash = 0;
+long no_name = 0;
+#endif
+
+static int jffs_scan_flash(struct jffs_control *c);
+static int jffs_update_file(struct jffs_file *f, struct jffs_node *node);
+static int jffs_build_file(struct jffs_file *f);
+static int jffs_free_file(struct jffs_file *f);
+static int jffs_free_node_list(struct jffs_file *f);
+static int jffs_garbage_collect_now(struct jffs_control *c);
+static int jffs_insert_file_into_hash(struct jffs_file *f);
+static int jffs_remove_redundant_nodes(struct jffs_file *f);
+
+/* Is there enough space on the flash?  */
+static inline int JFFS_ENOUGH_SPACE(struct jffs_control *c, __u32 space)
+{
+	struct jffs_fmcontrol *fmc = c->fmc;
+
+	while (1) {
+		if ((fmc->flash_size - (fmc->used_size + fmc->dirty_size))
+			>= fmc->min_free_size + space) {
+			return 1;
+		}
+		if (fmc->dirty_size < fmc->sector_size)
+			return 0;
+
+		if (jffs_garbage_collect_now(c)) {
+		  D1(printk("JFFS_ENOUGH_SPACE: jffs_garbage_collect_now() failed.\n"));
+		  return 0;
+		}
+	}
+}
+
+#if CONFIG_JFFS_FS_VERBOSE > 0
+static __u8
+flash_read_u8(struct mtd_info *mtd, loff_t from)
+{
+	size_t retlen;
+	__u8 ret;
+	int res;
+
+	res = MTD_READ(mtd, from, 1, &retlen, &ret);
+	if (retlen != 1) {
+		printk("Didn't read a byte in flash_read_u8(). Returned %d\n", res);
+		return 0;
+	}
+
+	return ret;
+}
+
+static void
+jffs_hexdump(struct mtd_info *mtd, loff_t pos, int size)
+{
+	char line[16];
+	int j = 0;
+
+	while (size > 0) {
+		int i;
+
+		printk("%ld:", (long) pos);
+		for (j = 0; j < 16; j++) {
+			line[j] = flash_read_u8(mtd, pos++);
+		}
+		for (i = 0; i < j; i++) {
+			if (!(i & 1)) {
+				printk(" %.2x", line[i] & 0xff);
+			}
+			else {
+				printk("%.2x", line[i] & 0xff);
+			}
+		}
+
+		/* Print empty space */
+		for (; i < 16; i++) {
+			if (!(i & 1)) {
+				printk("   ");
+			}
+			else {
+				printk("  ");
+			}
+		}
+		printk("  ");
+
+		for (i = 0; i < j; i++) {
+			if (isgraph(line[i])) {
+				printk("%c", line[i]);
+			}
+			else {
+				printk(".");
+			}
+		}
+		printk("\n");
+		size -= 16;
+	}
+}
+
+#endif
+
+#define flash_safe_acquire(arg)
+#define flash_safe_release(arg)
+
+
+static int
+flash_safe_read(struct mtd_info *mtd, loff_t from,
+		u_char *buf, size_t count)
+{
+	size_t retlen;
+	int res;
+
+	D3(printk(KERN_NOTICE "flash_safe_read(%p, %08x, %p, %08x)\n",
+		  mtd, (unsigned int) from, buf, count));
+
+	res = MTD_READ(mtd, from, count, &retlen, buf);
+	if (retlen != count) {
+		panic("Didn't read all bytes in flash_safe_read(). Returned %d\n", res);
+	}
+	return res?res:retlen;
+}
+
+
+static __u32
+flash_read_u32(struct mtd_info *mtd, loff_t from)
+{
+	size_t retlen;
+	__u32 ret;
+	int res;
+
+	res = MTD_READ(mtd, from, 4, &retlen, (unsigned char *)&ret);
+	if (retlen != 4) {
+		printk("Didn't read all bytes in flash_read_u32(). Returned %d\n", res);
+		return 0;
+	}
+
+	return ret;
+}
+
+
+static int
+flash_safe_write(struct mtd_info *mtd, loff_t to,
+		 const u_char *buf, size_t count)
+{
+	size_t retlen;
+	int res;
+
+	D3(printk(KERN_NOTICE "flash_safe_write(%p, %08x, %p, %08x)\n",
+		  mtd, (unsigned int) to, buf, count));
+
+	res = MTD_WRITE(mtd, to, count, &retlen, buf);
+	if (retlen != count) {
+		printk("Didn't write all bytes in flash_safe_write(). Returned %d\n", res);
+	}
+	return res?res:retlen;
+}
+
+
+static int
+flash_safe_writev(struct mtd_info *mtd, const struct kvec *vecs,
+			unsigned long iovec_cnt, loff_t to)
+{
+	size_t retlen, retlen_a;
+	int i;
+	int res;
+
+	D3(printk(KERN_NOTICE "flash_safe_writev(%p, %08x, %p)\n",
+		  mtd, (unsigned int) to, vecs));
+	
+	if (mtd->writev) {
+		res = MTD_WRITEV(mtd, vecs, iovec_cnt, to, &retlen);
+		return res ? res : retlen;
+	}
+	/* Not implemented writev. Repeatedly use write - on the not so
+	   unreasonable assumption that the mtd driver doesn't care how
+	   many write cycles we use. */
+	res=0;
+	retlen=0;
+
+	for (i=0; !res && i<iovec_cnt; i++) {
+		res = MTD_WRITE(mtd, to, vecs[i].iov_len, &retlen_a, vecs[i].iov_base);
+		if (retlen_a != vecs[i].iov_len) {
+			printk("Didn't write all bytes in flash_safe_writev(). Returned %d\n", res);
+			if (i != iovec_cnt-1)
+				return -EIO;
+		}
+		/* If res is non-zero, retlen_a is undefined, but we don't
+		   care because in that case it's not going to be 
+		   returned anyway.
+		*/
+		to += retlen_a;
+		retlen += retlen_a;
+	}
+	return res?res:retlen;
+}
+
+
+static int
+flash_memset(struct mtd_info *mtd, loff_t to,
+	     const u_char c, size_t size)
+{
+	static unsigned char pattern[64];
+	int i;
+
+	/* fill up pattern */
+
+	for(i = 0; i < 64; i++)
+		pattern[i] = c;
+
+	/* write as many 64-byte chunks as we can */
+
+	while (size >= 64) {
+		flash_safe_write(mtd, to, pattern, 64);
+		size -= 64;
+		to += 64;
+	}
+
+	/* and the rest */
+
+	if(size)
+		flash_safe_write(mtd, to, pattern, size);
+
+	return size;
+}
+
+
+static void
+intrep_erase_callback(struct erase_info *done)
+{
+	wait_queue_head_t *wait_q;
+
+	wait_q = (wait_queue_head_t *)done->priv;
+
+	wake_up(wait_q);
+}
+
+
+static int
+flash_erase_region(struct mtd_info *mtd, loff_t start,
+		   size_t size)
+{
+	struct erase_info *erase;
+	DECLARE_WAITQUEUE(wait, current);
+	wait_queue_head_t wait_q;
+
+	erase = kmalloc(sizeof(struct erase_info), GFP_KERNEL);
+	if (!erase)
+		return -ENOMEM;
+
+	init_waitqueue_head(&wait_q);
+
+	erase->mtd = mtd;
+	erase->callback = intrep_erase_callback;
+	erase->addr = start;
+	erase->len = size;
+	erase->priv = (u_long)&wait_q;
+
+	/* FIXME: Use TASK_INTERRUPTIBLE and deal with being interrupted */
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	add_wait_queue(&wait_q, &wait);
+
+	if (MTD_ERASE(mtd, erase) < 0) {
+		set_current_state(TASK_RUNNING);
+		remove_wait_queue(&wait_q, &wait);
+		kfree(erase);
+
+		printk(KERN_WARNING "flash: erase of region [0x%lx, 0x%lx] "
+		       "totally failed\n", (long)start, (long)start + size);
+
+		return -1;
+	}
+
+	schedule(); /* Wait for flash to finish. */
+	remove_wait_queue(&wait_q, &wait);
+
+	kfree(erase);
+
+	return 0;
+}
+
+/* This routine calculates checksums in JFFS.  */
+static __u32
+jffs_checksum(const void *data, int size)
+{
+	__u32 sum = 0;
+	__u8 *ptr = (__u8 *)data;
+	while (size-- > 0) {
+		sum += *ptr++;
+	}
+	D3(printk(", result: 0x%08x\n", sum));
+	return sum;
+}
+
+
+static int
+jffs_checksum_flash(struct mtd_info *mtd, loff_t start, int size, __u32 *result)
+{
+	__u32 sum = 0;
+	loff_t ptr = start;
+	__u8 *read_buf;
+	int i, length;
+
+	/* Allocate read buffer */
+	read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL);
+	if (!read_buf) {
+		printk(KERN_NOTICE "kmalloc failed in jffs_checksum_flash()\n");
+		return -ENOMEM;
+	}
+	/* Loop until checksum done */
+	while (size) {
+		/* Get amount of data to read */
+		if (size < 4096)
+			length = size;
+		else
+			length = 4096;
+
+		/* Perform flash read */
+		D3(printk(KERN_NOTICE "jffs_checksum_flash\n"));
+		flash_safe_read(mtd, ptr, &read_buf[0], length);
+
+		/* Compute checksum */
+		for (i=0; i < length ; i++)
+			sum += read_buf[i];
+
+		/* Update pointer and size */
+		size -= length;
+		ptr += length;
+	}
+
+	/* Free read buffer */
+	kfree (read_buf);
+
+	/* Return result */
+	D3(printk("checksum result: 0x%08x\n", sum));
+	*result = sum;
+	return 0;
+}
+
+static __inline__ void jffs_fm_write_lock(struct jffs_fmcontrol *fmc)
+{
+  //	down(&fmc->wlock);
+}
+
+static __inline__ void jffs_fm_write_unlock(struct jffs_fmcontrol *fmc)
+{
+  //	up(&fmc->wlock);
+}
+
+
+/* Create and initialize a new struct jffs_file.  */
+static struct jffs_file *
+jffs_create_file(struct jffs_control *c,
+		 const struct jffs_raw_inode *raw_inode)
+{
+	struct jffs_file *f;
+
+	if (!(f = (struct jffs_file *)kmalloc(sizeof(struct jffs_file),
+					      GFP_KERNEL))) {
+		D(printk("jffs_create_file(): Failed!\n"));
+		return NULL;
+	}
+	no_jffs_file++;
+	memset(f, 0, sizeof(struct jffs_file));
+	f->ino = raw_inode->ino;
+	f->pino = raw_inode->pino;
+	f->nlink = raw_inode->nlink;
+	f->deleted = raw_inode->deleted;
+	f->c = c;
+
+	return f;
+}
+
+
+/* Build a control block for the file system.  */
+static struct jffs_control *
+jffs_create_control(struct super_block *sb)
+{
+	struct jffs_control *c;
+	register int s = sizeof(struct jffs_control);
+	int i;
+	D(char *t = 0);
+
+	D2(printk("jffs_create_control()\n"));
+
+	if (!(c = (struct jffs_control *)kmalloc(s, GFP_KERNEL))) {
+		goto fail_control;
+	}
+	DJM(no_jffs_control++);
+	c->root = NULL;
+	c->gc_task = NULL;
+	c->hash_len = JFFS_HASH_SIZE;
+	s = sizeof(struct list_head) * c->hash_len;
+	if (!(c->hash = (struct list_head *)kmalloc(s, GFP_KERNEL))) {
+		goto fail_hash;
+	}
+	DJM(no_hash++);
+	for (i = 0; i < c->hash_len; i++)
+		INIT_LIST_HEAD(&c->hash[i]);
+	if (!(c->fmc = jffs_build_begin(c, MINOR(sb->s_dev)))) {
+		goto fail_fminit;
+	}
+	c->next_ino = JFFS_MIN_INO + 1;
+	c->delete_list = (struct jffs_delete_list *) 0;
+	return c;
+
+fail_fminit:
+	D(t = "c->fmc");
+fail_hash:
+	kfree(c);
+	DJM(no_jffs_control--);
+	D(t = t ? t : "c->hash");
+fail_control:
+	D(t = t ? t : "control");
+	D(printk("jffs_create_control(): Allocation failed: (%s)\n", t));
+	return (struct jffs_control *)0;
+}
+
+
+/* Clean up all data structures associated with the file system.  */
+void
+jffs_cleanup_control(struct jffs_control *c)
+{
+	D2(printk("jffs_cleanup_control()\n"));
+
+	if (!c) {
+		D(printk("jffs_cleanup_control(): c == NULL !!!\n"));
+		return;
+	}
+
+	while (c->delete_list) {
+		struct jffs_delete_list *delete_list_element;
+		delete_list_element = c->delete_list;
+		c->delete_list = c->delete_list->next;
+		kfree(delete_list_element);
+	}
+
+	/* Free all files and nodes.  */
+	if (c->hash) {
+		jffs_foreach_file(c, jffs_free_node_list);
+		jffs_foreach_file(c, jffs_free_file);
+		kfree(c->hash);
+		DJM(no_hash--);
+	}
+	jffs_cleanup_fmcontrol(c->fmc);
+	kfree(c);
+	DJM(no_jffs_control--);
+	D3(printk("jffs_cleanup_control(): Leaving...\n"));
+}
+
+
+/* This function adds a virtual root node to the in-RAM representation.
+   Called by jffs_build_fs().  */
+static int
+jffs_add_virtual_root(struct jffs_control *c)
+{
+	struct jffs_file *root;
+	struct jffs_node *node;
+
+	D2(printk("jffs_add_virtual_root(): "
+		  "Creating a virtual root directory.\n"));
+
+	if (!(root = (struct jffs_file *)kmalloc(sizeof(struct jffs_file),
+						 GFP_KERNEL))) {
+		return -ENOMEM;
+	}
+	no_jffs_file++;
+	if (!(node = jffs_alloc_node())) {
+		kfree(root);
+		no_jffs_file--;
+		return -ENOMEM;
+	}
+	DJM(no_jffs_node++);
+	memset(node, 0, sizeof(struct jffs_node));
+	node->ino = JFFS_MIN_INO;
+	memset(root, 0, sizeof(struct jffs_file));
+	root->ino = JFFS_MIN_INO;
+	root->mode = S_IFDIR | S_IRWXU | S_IRGRP
+		     | S_IXGRP | S_IROTH | S_IXOTH;
+	root->atime = root->mtime = root->ctime = get_seconds();
+	root->nlink = 1;
+	root->c = c;
+	root->version_head = root->version_tail = node;
+	jffs_insert_file_into_hash(root);
+	return 0;
+}
+
+
+/* This is where the file system is built and initialized.  */
+int
+jffs_build_fs(struct super_block *sb)
+{
+	struct jffs_control *c;
+	int err = 0;
+
+	D2(printk("jffs_build_fs()\n"));
+
+	if (!(c = jffs_create_control(sb))) {
+		return -ENOMEM;
+	}
+	c->building_fs = 1;
+	c->sb = sb;
+	if ((err = jffs_scan_flash(c)) < 0) {
+		if(err == -EAGAIN){
+			/* scan_flash() wants us to try once more. A flipping 
+			   bits sector was detect in the middle of the scan flash.
+			   Clean up old allocated memory before going in.
+			*/
+			D1(printk("jffs_build_fs: Cleaning up all control structures,"
+				  " reallocating them and trying mount again.\n"));
+			jffs_cleanup_control(c);
+			if (!(c = jffs_create_control(sb))) {
+				return -ENOMEM;
+			}
+			c->building_fs = 1;
+			c->sb = sb;
+
+			if ((err = jffs_scan_flash(c)) < 0) {
+				goto jffs_build_fs_fail;
+			}			
+		}else{
+			goto jffs_build_fs_fail;
+		}
+	}
+
+	/* Add a virtual root node if no one exists.  */
+	if (!jffs_find_file(c, JFFS_MIN_INO)) {
+		if ((err = jffs_add_virtual_root(c)) < 0) {
+			goto jffs_build_fs_fail;
+		}
+	}
+
+	while (c->delete_list) {
+		struct jffs_file *f;
+		struct jffs_delete_list *delete_list_element;
+
+		if ((f = jffs_find_file(c, c->delete_list->ino))) {
+			f->deleted = 1;
+		}
+		delete_list_element = c->delete_list;
+		c->delete_list = c->delete_list->next;
+		kfree(delete_list_element);
+	}
+
+	/* Remove deleted nodes.  */
+	if ((err = jffs_foreach_file(c, jffs_possibly_delete_file)) < 0) {
+		printk(KERN_ERR "JFFS: Failed to remove deleted nodes.\n");
+		goto jffs_build_fs_fail;
+	}
+	/* Remove redundant nodes.  (We are not interested in the
+	   return value in this case.)  */
+	jffs_foreach_file(c, jffs_remove_redundant_nodes);
+	/* Try to build a tree from all the nodes.  */
+	if ((err = jffs_foreach_file(c, jffs_insert_file_into_tree)) < 0) {
+		printk("JFFS: Failed to build tree.\n");
+		goto jffs_build_fs_fail;
+	}
+	/* Compute the sizes of all files in the filesystem.  Adjust if
+	   necessary.  */
+	if ((err = jffs_foreach_file(c, jffs_build_file)) < 0) {
+		printk("JFFS: Failed to build file system.\n");
+		goto jffs_build_fs_fail;
+	}
+	sb->s_fs_info = (void *)c;
+	c->building_fs = 0;
+
+	D1(jffs_print_hash_table(c));
+	D1(jffs_print_tree(c->root, 0));
+
+	return 0;
+
+jffs_build_fs_fail:
+	jffs_cleanup_control(c);
+	return err;
+} /* jffs_build_fs()  */
+
+
+/*
+  This checks for sectors that were being erased in their previous 
+  lifetimes and for some reason or the other (power fail etc.), 
+  the erase cycles never completed.
+  As the flash array would have reverted back to read status, 
+  these sectors are detected by the symptom of the "flipping bits",
+  i.e. bits being read back differently from the same location in
+  flash if read multiple times.
+  The only solution to this is to re-erase the entire
+  sector.
+  Unfortunately detecting "flipping bits" is not a simple exercise
+  as a bit may be read back at 1 or 0 depending on the alignment 
+  of the stars in the universe.
+  The level of confidence is in direct proportion to the number of 
+  scans done. By power fail testing I (Vipin) have been able to 
+  proove that reading twice is not enough.
+  Maybe 4 times? Change NUM_REREADS to a higher number if you want
+  a (even) higher degree of confidence in your mount process. 
+  A higher number would of course slow down your mount.
+*/
+static int check_partly_erased_sectors(struct jffs_fmcontrol *fmc){
+
+#define NUM_REREADS             4 /* see note above */
+#define READ_AHEAD_BYTES        4096 /* must be a multiple of 4, 
+					usually set to kernel page size */
+
+	__u8 *read_buf1;
+	__u8 *read_buf2;
+
+	int err = 0;
+	int retlen;
+	int i;
+	int cnt;
+	__u32 offset;
+	loff_t pos = 0;
+	loff_t end = fmc->flash_size;
+
+
+	/* Allocate read buffers */
+	read_buf1 = (__u8 *) kmalloc (sizeof(__u8) * READ_AHEAD_BYTES, GFP_KERNEL);
+	if (!read_buf1)
+		return -ENOMEM;
+
+	read_buf2 = (__u8 *) kmalloc (sizeof(__u8) * READ_AHEAD_BYTES, GFP_KERNEL);
+	if (!read_buf2) {
+		kfree(read_buf1);
+		return -ENOMEM;
+	}
+
+ CHECK_NEXT:
+	while(pos < end){
+		
+		D1(printk("check_partly_erased_sector():checking sector which contains"
+			  " offset 0x%x for flipping bits..\n", (__u32)pos));
+		
+		retlen = flash_safe_read(fmc->mtd, pos,
+					 &read_buf1[0], READ_AHEAD_BYTES);
+		retlen &= ~3;
+		
+		for(cnt = 0; cnt < NUM_REREADS; cnt++){
+			(void)flash_safe_read(fmc->mtd, pos,
+					      &read_buf2[0], READ_AHEAD_BYTES);
+			
+			for (i=0 ; i < retlen ; i+=4) {
+				/* buffers MUST match, double word for word! */
+				if(*((__u32 *) &read_buf1[i]) !=
+				   *((__u32 *) &read_buf2[i])
+				   ){
+				        /* flipping bits detected, time to erase sector */
+					/* This will help us log some statistics etc. */
+					D1(printk("Flipping bits detected in re-read round:%i of %i\n",
+					       cnt, NUM_REREADS));
+					D1(printk("check_partly_erased_sectors:flipping bits detected"
+						  " @offset:0x%x(0x%x!=0x%x)\n",
+						  (__u32)pos+i, *((__u32 *) &read_buf1[i]), 
+						  *((__u32 *) &read_buf2[i])));
+					
+				        /* calculate start of present sector */
+					offset = (((__u32)pos+i)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size;
+					
+					D1(printk("check_partly_erased_sector():erasing sector starting 0x%x.\n",
+						  offset));
+					
+					if (flash_erase_region(fmc->mtd,
+							       offset, fmc->sector_size) < 0) {
+						printk(KERN_ERR "JFFS: Erase of flash failed. "
+						       "offset = %u, erase_size = %d\n",
+						       offset , fmc->sector_size);
+						
+						err = -EIO;
+						goto returnBack;
+
+					}else{
+						D1(printk("JFFS: Erase of flash sector @0x%x successful.\n",
+						       offset));
+						/* skip ahead to the next sector */
+						pos = (((__u32)pos+i)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size;
+						pos += fmc->sector_size;
+						goto CHECK_NEXT;
+					}
+				}
+			}
+		}
+		pos += READ_AHEAD_BYTES;
+	}
+
+ returnBack:
+	kfree(read_buf1);
+	kfree(read_buf2);
+
+	D2(printk("check_partly_erased_sector():Done checking all sectors till offset 0x%x for flipping bits.\n",
+		  (__u32)pos));
+
+	return err;
+
+}/* end check_partly_erased_sectors() */
+
+
+
+/* Scan the whole flash memory in order to find all nodes in the
+   file systems.  */
+static int
+jffs_scan_flash(struct jffs_control *c)
+{
+	char name[JFFS_MAX_NAME_LEN + 2];
+	struct jffs_raw_inode raw_inode;
+	struct jffs_node *node = NULL;
+	struct jffs_fmcontrol *fmc = c->fmc;
+	__u32 checksum;
+	__u8 tmp_accurate;
+	__u16 tmp_chksum;
+	__u32 deleted_file;
+	loff_t pos = 0;
+	loff_t start;
+	loff_t test_start;
+	loff_t end = fmc->flash_size;
+	__u8 *read_buf;
+	int i, len, retlen;
+	__u32 offset;
+
+	__u32 free_chunk_size1;
+	__u32 free_chunk_size2;
+
+	
+#define NUMFREEALLOWED     2        /* 2 chunks of at least erase size space allowed */
+	int num_free_space = 0;       /* Flag err if more than TWO
+				       free blocks found. This is NOT allowed
+				       by the current jffs design.
+				    */
+	int num_free_spc_not_accp = 0; /* For debugging purposed keep count 
+					of how much free space was rejected and
+					marked dirty
+				     */
+
+	D1(printk("jffs_scan_flash(): start pos = 0x%lx, end = 0x%lx\n",
+		  (long)pos, (long)end));
+
+	flash_safe_acquire(fmc->mtd);
+
+	/*
+	  check and make sure that any sector does not suffer
+	  from the "partly erased, bit flipping syndrome" (TM Vipin :)
+	  If so, offending sectors will be erased.
+	*/
+	if(check_partly_erased_sectors(fmc) < 0){
+
+		flash_safe_release(fmc->mtd);
+		return -EIO; /* bad, bad, bad error. Cannot continue.*/
+	}
+
+	/* Allocate read buffer */
+	read_buf = (__u8 *) kmalloc (sizeof(__u8) * 4096, GFP_KERNEL);
+	if (!read_buf) {
+		flash_safe_release(fmc->mtd);
+		return -ENOMEM;
+	}
+			      
+	/* Start the scan.  */
+	while (pos < end) {
+		deleted_file = 0;
+
+		/* Remember the position from where we started this scan.  */
+		start = pos;
+
+		switch (flash_read_u32(fmc->mtd, pos)) {
+		case JFFS_EMPTY_BITMASK:
+			/* We have found 0xffffffff at this position.  We have to
+			   scan the rest of the flash till the end or till
+			   something else than 0xffffffff is found.
+		           Keep going till we do not find JFFS_EMPTY_BITMASK 
+			   anymore */
+
+			D1(printk("jffs_scan_flash(): 0xffffffff at pos 0x%lx.\n",
+				  (long)pos));
+
+		        while(pos < end){
+
+			      len = end - pos < 4096 ? end - pos : 4096;
+			      
+			      retlen = flash_safe_read(fmc->mtd, pos,
+						 &read_buf[0], len);
+
+			      retlen &= ~3;
+			      
+			      for (i=0 ; i < retlen ; i+=4, pos += 4) {
+				      if(*((__u32 *) &read_buf[i]) !=
+					 JFFS_EMPTY_BITMASK)
+					break;
+			      }
+			      if (i == retlen)
+				    continue;
+			      else
+				    break;
+			}
+
+			D1(printk("jffs_scan_flash():0xffffffff ended at pos 0x%lx.\n",
+				  (long)pos));
+			
+			/* If some free space ends in the middle of a sector,
+			   treat it as dirty rather than clean.
+			   This is to handle the case where one thread 
+			   allocated space for a node, but didn't get to
+			   actually _write_ it before power was lost, leaving
+			   a gap in the log. Shifting all node writes into
+			   a single kernel thread will fix the original problem.
+			*/
+			if ((__u32) pos % fmc->sector_size) {
+				/* If there was free space in previous 
+				   sectors, don't mark that dirty too - 
+				   only from the beginning of this sector
+				   (or from start) 
+				*/
+
+			        test_start = pos & ~(fmc->sector_size-1); /* end of last sector */
+
+				if (start < test_start) {
+
+				        /* free space started in the previous sector! */
+
+					if((num_free_space < NUMFREEALLOWED) && 
+					   ((unsigned int)(test_start - start) >= fmc->sector_size)){
+
+				                /*
+						  Count it in if we are still under NUMFREEALLOWED *and* it is 
+						  at least 1 erase sector in length. This will keep us from 
+						  picking any little ole' space as "free".
+						*/
+					  
+					        D1(printk("Reducing end of free space to 0x%x from 0x%x\n",
+							  (unsigned int)test_start, (unsigned int)pos));
+
+						D1(printk("Free space accepted: Starting 0x%x for 0x%x bytes\n",
+							  (unsigned int) start,
+							  (unsigned int)(test_start - start)));
+
+						/* below, space from "start" to "pos" will be marked dirty. */
+						start = test_start; 
+						
+						/* Being in here means that we have found at least an entire 
+						   erase sector size of free space ending on a sector boundary.
+						   Keep track of free spaces accepted.
+						*/
+						num_free_space++;
+					}else{
+					        num_free_spc_not_accp++;
+					        D1(printk("Free space (#%i) found but *Not* accepted: Starting"
+							  " 0x%x for 0x%x bytes\n",
+							  num_free_spc_not_accp, (unsigned int)start, 
+							  (unsigned int)((unsigned int)(pos & ~(fmc->sector_size-1)) - (unsigned int)start)));
+					        
+					}
+					
+				}
+				if((((__u32)(pos - start)) != 0)){
+
+				        D1(printk("Dirty space: Starting 0x%x for 0x%x bytes\n",
+						  (unsigned int) start, (unsigned int) (pos - start)));
+					jffs_fmalloced(fmc, (__u32) start,
+						       (__u32) (pos - start), NULL);
+				}else{
+					/* "Flipping bits" detected. This means that our scan for them
+					   did not catch this offset. See check_partly_erased_sectors() for
+					   more info.
+					*/
+				        
+					D1(printk("jffs_scan_flash():wants to allocate dirty flash "
+						  "space for 0 bytes.\n"));
+					D1(printk("jffs_scan_flash(): Flipping bits! We will free "
+						  "all allocated memory, erase this sector and remount\n"));
+
+					/* calculate start of present sector */
+					offset = (((__u32)pos)/(__u32)fmc->sector_size) * (__u32)fmc->sector_size;
+					
+					D1(printk("jffs_scan_flash():erasing sector starting 0x%x.\n",
+						  offset));
+					
+					if (flash_erase_region(fmc->mtd,
+							       offset, fmc->sector_size) < 0) {
+						printk(KERN_ERR "JFFS: Erase of flash failed. "
+						       "offset = %u, erase_size = %d\n",
+						       offset , fmc->sector_size);
+
+						flash_safe_release(fmc->mtd);
+						kfree (read_buf);
+						return -1; /* bad, bad, bad! */
+
+					}
+					flash_safe_release(fmc->mtd);
+					kfree (read_buf);
+
+					return -EAGAIN; /* erased offending sector. Try mount one more time please. */
+				}
+			}else{
+			        /* Being in here means that we have found free space that ends on an erase sector
+				   boundary.
+				   Count it in if we are still under NUMFREEALLOWED *and* it is at least 1 erase 
+				   sector in length. This will keep us from picking any little ole' space as "free".
+				 */
+			         if((num_free_space < NUMFREEALLOWED) && 
+				    ((unsigned int)(pos - start) >= fmc->sector_size)){
+				           /* We really don't do anything to mark space as free, except *not* 
+					      mark it dirty and just advance the "pos" location pointer. 
+					      It will automatically be picked up as free space.
+					    */ 
+				           num_free_space++;
+				           D1(printk("Free space accepted: Starting 0x%x for 0x%x bytes\n",
+						     (unsigned int) start, (unsigned int) (pos - start)));
+				 }else{
+				         num_free_spc_not_accp++;
+					 D1(printk("Free space (#%i) found but *Not* accepted: Starting "
+						   "0x%x for 0x%x bytes\n", num_free_spc_not_accp, 
+						   (unsigned int) start, 
+						   (unsigned int) (pos - start)));
+					 
+					 /* Mark this space as dirty. We already have our free space. */
+					 D1(printk("Dirty space: Starting 0x%x for 0x%x bytes\n",
+						   (unsigned int) start, (unsigned int) (pos - start)));
+					 jffs_fmalloced(fmc, (__u32) start,
+							(__u32) (pos - start), NULL);				           
+				 }
+				 
+			}
+			if(num_free_space > NUMFREEALLOWED){
+			         printk(KERN_WARNING "jffs_scan_flash(): Found free space "
+					"number %i. Only %i free space is allowed.\n",
+					num_free_space, NUMFREEALLOWED);			      
+			}
+			continue;
+
+		case JFFS_DIRTY_BITMASK:
+			/* We have found 0x00000000 at this position.  Scan as far
+			   as possible to find out how much is dirty.  */
+			D1(printk("jffs_scan_flash(): 0x00000000 at pos 0x%lx.\n",
+				  (long)pos));
+			for (; pos < end
+			       && JFFS_DIRTY_BITMASK == flash_read_u32(fmc->mtd, pos);
+			     pos += 4);
+			D1(printk("jffs_scan_flash(): 0x00 ended at "
+				  "pos 0x%lx.\n", (long)pos));
+			jffs_fmalloced(fmc, (__u32) start,
+				       (__u32) (pos - start), NULL);
+			continue;
+
+		case JFFS_MAGIC_BITMASK:
+			/* We have probably found a new raw inode.  */
+			break;
+
+		default:
+		bad_inode:
+			/* We're f*cked.  This is not solved yet.  We have
+			   to scan for the magic pattern.  */
+			D1(printk("*************** Dirty flash memory or "
+				  "bad inode: "
+				  "hexdump(pos = 0x%lx, len = 128):\n",
+				  (long)pos));
+			D1(jffs_hexdump(fmc->mtd, pos, 128));
+
+			for (pos += 4; pos < end; pos += 4) {
+				switch (flash_read_u32(fmc->mtd, pos)) {
+				case JFFS_MAGIC_BITMASK:
+				case JFFS_EMPTY_BITMASK:
+					/* handle these in the main switch() loop */
+					goto cont_scan;
+
+				default:
+					break;
+				}
+			}
+
+			cont_scan:
+			/* First, mark as dirty the region
+			   which really does contain crap. */
+			jffs_fmalloced(fmc, (__u32) start,
+				       (__u32) (pos - start),
+				       NULL);
+			
+			continue;
+		}/* switch */
+
+		/* We have found the beginning of an inode.  Create a
+		   node for it unless there already is one available.  */
+		if (!node) {
+			if (!(node = jffs_alloc_node())) {
+				/* Free read buffer */
+				kfree (read_buf);
+
+				/* Release the flash device */
+				flash_safe_release(fmc->mtd);
+	
+				return -ENOMEM;
+			}
+			DJM(no_jffs_node++);
+		}
+
+		/* Read the next raw inode.  */
+
+		flash_safe_read(fmc->mtd, pos, (u_char *) &raw_inode,
+				sizeof(struct jffs_raw_inode));
+
+		/* When we compute the checksum for the inode, we never
+		   count the 'accurate' or the 'checksum' fields.  */
+		tmp_accurate = raw_inode.accurate;
+		tmp_chksum = raw_inode.chksum;
+		raw_inode.accurate = 0;
+		raw_inode.chksum = 0;
+		checksum = jffs_checksum(&raw_inode,
+					 sizeof(struct jffs_raw_inode));
+		raw_inode.accurate = tmp_accurate;
+		raw_inode.chksum = tmp_chksum;
+
+		D3(printk("*** We have found this raw inode at pos 0x%lx "
+			  "on the flash:\n", (long)pos));
+		D3(jffs_print_raw_inode(&raw_inode));
+
+		if (checksum != raw_inode.chksum) {
+			D1(printk("jffs_scan_flash(): Bad checksum: "
+				  "checksum = %u, "
+				  "raw_inode.chksum = %u\n",
+				  checksum, raw_inode.chksum));
+			pos += sizeof(struct jffs_raw_inode);
+			jffs_fmalloced(fmc, (__u32) start,
+				       (__u32) (pos - start), NULL);
+			/* Reuse this unused struct jffs_node.  */
+			continue;
+		}
+
+		/* Check the raw inode read so far.  Start with the
+		   maximum length of the filename.  */
+		if (raw_inode.nsize > JFFS_MAX_NAME_LEN) {
+			printk(KERN_WARNING "jffs_scan_flash: Found a "
+			       "JFFS node with name too large\n");
+			goto bad_inode;
+		}
+
+		if (raw_inode.rename && raw_inode.dsize != sizeof(__u32)) {
+			printk(KERN_WARNING "jffs_scan_flash: Found a "
+			       "rename node with dsize %u.\n",
+			       raw_inode.dsize);
+			jffs_print_raw_inode(&raw_inode);
+			goto bad_inode;
+		}
+
+		/* The node's data segment should not exceed a
+		   certain length.  */
+		if (raw_inode.dsize > fmc->max_chunk_size) {
+			printk(KERN_WARNING "jffs_scan_flash: Found a "
+			       "JFFS node with dsize (0x%x) > max_chunk_size (0x%x)\n",
+			       raw_inode.dsize, fmc->max_chunk_size);
+			goto bad_inode;
+		}
+
+		pos += sizeof(struct jffs_raw_inode);
+
+		/* This shouldn't be necessary because a node that
+		   violates the flash boundaries shouldn't be written
+		   in the first place. */
+		if (pos >= end) {
+			goto check_node;
+		}
+
+		/* Read the name.  */
+		*name = 0;
+		if (raw_inode.nsize) {
+		        flash_safe_read(fmc->mtd, pos, name, raw_inode.nsize);
+			name[raw_inode.nsize] = '\0';
+			pos += raw_inode.nsize
+			       + JFFS_GET_PAD_BYTES(raw_inode.nsize);
+			D3(printk("name == \"%s\"\n", name));
+			checksum = jffs_checksum(name, raw_inode.nsize);
+			if (checksum != raw_inode.nchksum) {
+				D1(printk("jffs_scan_flash(): Bad checksum: "
+					  "checksum = %u, "
+					  "raw_inode.nchksum = %u\n",
+					  checksum, raw_inode.nchksum));
+				jffs_fmalloced(fmc, (__u32) start,
+					       (__u32) (pos - start), NULL);
+				/* Reuse this unused struct jffs_node.  */
+				continue;
+			}
+			if (pos >= end) {
+				goto check_node;
+			}
+		}
+
+		/* Read the data, if it exists, in order to be sure it
+		   matches the checksum.  */
+		if (raw_inode.dsize) {
+			if (raw_inode.rename) {
+				deleted_file = flash_read_u32(fmc->mtd, pos);
+			}
+			if (jffs_checksum_flash(fmc->mtd, pos, raw_inode.dsize, &checksum)) {
+				printk("jffs_checksum_flash() failed to calculate a checksum\n");
+				jffs_fmalloced(fmc, (__u32) start,
+					       (__u32) (pos - start), NULL);
+				/* Reuse this unused struct jffs_node.  */
+				continue;
+			}				
+			pos += raw_inode.dsize
+			       + JFFS_GET_PAD_BYTES(raw_inode.dsize);
+
+			if (checksum != raw_inode.dchksum) {
+				D1(printk("jffs_scan_flash(): Bad checksum: "
+					  "checksum = %u, "
+					  "raw_inode.dchksum = %u\n",
+					  checksum, raw_inode.dchksum));
+				jffs_fmalloced(fmc, (__u32) start,
+					       (__u32) (pos - start), NULL);
+				/* Reuse this unused struct jffs_node.  */
+				continue;
+			}
+		}
+
+		check_node:
+
+		/* Remember the highest inode number in the whole file
+		   system.  This information will be used when assigning
+		   new files new inode numbers.  */
+		if (c->next_ino <= raw_inode.ino) {
+			c->next_ino = raw_inode.ino + 1;
+		}
+
+		if (raw_inode.accurate) {
+			int err;
+			node->data_offset = raw_inode.offset;
+			node->data_size = raw_inode.dsize;
+			node->removed_size = raw_inode.rsize;
+			/* Compute the offset to the actual data in the
+			   on-flash node.  */
+			node->fm_offset
+			= sizeof(struct jffs_raw_inode)
+			  + raw_inode.nsize
+			  + JFFS_GET_PAD_BYTES(raw_inode.nsize);
+			node->fm = jffs_fmalloced(fmc, (__u32) start,
+						  (__u32) (pos - start),
+						  node);
+			if (!node->fm) {
+				D(printk("jffs_scan_flash(): !node->fm\n"));
+				jffs_free_node(node);
+				DJM(no_jffs_node--);
+
+				/* Free read buffer */
+				kfree (read_buf);
+
+				/* Release the flash device */
+				flash_safe_release(fmc->mtd);
+
+				return -ENOMEM;
+			}
+			if ((err = jffs_insert_node(c, NULL, &raw_inode,
+						    name, node)) < 0) {
+				printk("JFFS: Failed to handle raw inode. "
+				       "(err = %d)\n", err);
+				break;
+			}
+			if (raw_inode.rename) {
+				struct jffs_delete_list *dl
+				= (struct jffs_delete_list *)
+				  kmalloc(sizeof(struct jffs_delete_list),
+					  GFP_KERNEL);
+				if (!dl) {
+					D(printk("jffs_scan_flash: !dl\n"));
+					jffs_free_node(node);
+					DJM(no_jffs_node--);
+
+					/* Release the flash device */
+					flash_safe_release(fmc->flash_part);
+
+					/* Free read buffer */
+					kfree (read_buf);
+
+					return -ENOMEM;
+				}
+				dl->ino = deleted_file;
+				dl->next = c->delete_list;
+				c->delete_list = dl;
+				node->data_size = 0;
+			}
+			D3(jffs_print_node(node));
+			node = NULL; /* Don't free the node!  */
+		}
+		else {
+			jffs_fmalloced(fmc, (__u32) start,
+				       (__u32) (pos - start), NULL);
+			D3(printk("jffs_scan_flash(): Just found an obsolete "
+				  "raw_inode. Continuing the scan...\n"));
+			/* Reuse this unused struct jffs_node.  */
+		}
+	}
+
+	if (node) {
+		jffs_free_node(node);
+		DJM(no_jffs_node--);
+	}
+	jffs_build_end(fmc);
+
+	/* Free read buffer */
+	kfree (read_buf);
+
+	if(!num_free_space){
+	        printk(KERN_WARNING "jffs_scan_flash(): Did not find even a single "
+		       "chunk of free space. This is BAD!\n");
+	}
+
+	/* Return happy */
+	D3(printk("jffs_scan_flash(): Leaving...\n"));
+	flash_safe_release(fmc->mtd);
+
+	/* This is to trap the "free size accounting screwed error. */
+	free_chunk_size1 = jffs_free_size1(fmc);
+	free_chunk_size2 = jffs_free_size2(fmc);
+
+	if (free_chunk_size1 + free_chunk_size2 != fmc->free_size) {
+
+		printk(KERN_WARNING "jffs_scan_falsh():Free size accounting screwed\n");
+		printk(KERN_WARNING "jfffs_scan_flash():free_chunk_size1 == 0x%x, "
+		       "free_chunk_size2 == 0x%x, fmc->free_size == 0x%x\n", 
+		       free_chunk_size1, free_chunk_size2, fmc->free_size);
+
+		return -1; /* Do NOT mount f/s so that we can inspect what happened.
+			      Mounting this  screwed up f/s will screw us up anyway.
+			    */
+	}	
+
+	return 0; /* as far as we are concerned, we are happy! */
+} /* jffs_scan_flash()  */
+
+
+/* Insert any kind of node into the file system.  Take care of data
+   insertions and deletions.  Also remove redundant information. The
+   memory allocated for the `name' is regarded as "given away" in the
+   caller's perspective.  */
+int
+jffs_insert_node(struct jffs_control *c, struct jffs_file *f,
+		 const struct jffs_raw_inode *raw_inode,
+		 const char *name, struct jffs_node *node)
+{
+	int update_name = 0;
+	int insert_into_tree = 0;
+
+	D2(printk("jffs_insert_node(): ino = %u, version = %u, "
+		  "name = \"%s\", deleted = %d\n",
+		  raw_inode->ino, raw_inode->version,
+		  ((name && *name) ? name : ""), raw_inode->deleted));
+
+	/* If there doesn't exist an associated jffs_file, then
+	   create, initialize and insert one into the file system.  */
+	if (!f && !(f = jffs_find_file(c, raw_inode->ino))) {
+		if (!(f = jffs_create_file(c, raw_inode))) {
+			return -ENOMEM;
+		}
+		jffs_insert_file_into_hash(f);
+		insert_into_tree = 1;
+	}
+	node->ino = raw_inode->ino;
+	node->version = raw_inode->version;
+	node->data_size = raw_inode->dsize;
+	node->fm_offset = sizeof(struct jffs_raw_inode) + raw_inode->nsize
+			  + JFFS_GET_PAD_BYTES(raw_inode->nsize);
+	node->name_size = raw_inode->nsize;
+
+	/* Now insert the node at the correct position into the file's
+	   version list.  */
+	if (!f->version_head) {
+		/* This is the first node.  */
+		f->version_head = node;
+		f->version_tail = node;
+		node->version_prev = NULL;
+		node->version_next = NULL;
+		f->highest_version = node->version;
+		update_name = 1;
+		f->mode = raw_inode->mode;
+		f->uid = raw_inode->uid;
+		f->gid = raw_inode->gid;
+		f->atime = raw_inode->atime;
+		f->mtime = raw_inode->mtime;
+		f->ctime = raw_inode->ctime;
+	}
+	else if ((f->highest_version < node->version)
+		 || (node->version == 0)) {
+		/* Insert at the end of the list.  I.e. this node is the
+		   newest one so far.  */
+		node->version_prev = f->version_tail;
+		node->version_next = NULL;
+		f->version_tail->version_next = node;
+		f->version_tail = node;
+		f->highest_version = node->version;
+		update_name = 1;
+		f->pino = raw_inode->pino;
+		f->mode = raw_inode->mode;
+		f->uid = raw_inode->uid;
+		f->gid = raw_inode->gid;
+		f->atime = raw_inode->atime;
+		f->mtime = raw_inode->mtime;
+		f->ctime = raw_inode->ctime;
+	}
+	else if (f->version_head->version > node->version) {
+		/* Insert at the bottom of the list.  */
+		node->version_prev = NULL;
+		node->version_next = f->version_head;
+		f->version_head->version_prev = node;
+		f->version_head = node;
+		if (!f->name) {
+			update_name = 1;
+		}
+	}
+	else {
+		struct jffs_node *n;
+		int newer_name = 0;
+		/* Search for the insertion position starting from
+		   the tail (newest node).  */
+		for (n = f->version_tail; n; n = n->version_prev) {
+			if (n->version < node->version) {
+				node->version_prev = n;
+				node->version_next = n->version_next;
+				node->version_next->version_prev = node;
+				n->version_next = node;
+				if (!newer_name) {
+					update_name = 1;
+				}
+				break;
+			}
+			if (n->name_size) {
+				newer_name = 1;
+			}
+		}
+	}
+
+	/* Deletion is irreversible. If any 'deleted' node is ever
+	   written, the file is deleted */
+	if (raw_inode->deleted)
+		f->deleted = raw_inode->deleted;
+
+	/* Perhaps update the name.  */
+	if (raw_inode->nsize && update_name && name && *name && (name != f->name)) {
+		if (f->name) {
+			kfree(f->name);
+			DJM(no_name--);
+		}
+		if (!(f->name = (char *) kmalloc(raw_inode->nsize + 1,
+						 GFP_KERNEL))) {
+			return -ENOMEM;
+		}
+		DJM(no_name++);
+		memcpy(f->name, name, raw_inode->nsize);
+		f->name[raw_inode->nsize] = '\0';
+		f->nsize = raw_inode->nsize;
+		D3(printk("jffs_insert_node(): Updated the name of "
+			  "the file to \"%s\".\n", name));
+	}
+
+	if (!c->building_fs) {
+		D3(printk("jffs_insert_node(): ---------------------------"
+			  "------------------------------------------- 1\n"));
+		if (insert_into_tree) {
+			jffs_insert_file_into_tree(f);
+		}
+		/* Once upon a time, we would call jffs_possibly_delete_file()
+		   here. That causes an oops if someone's still got the file
+		   open, so now we only do it in jffs_delete_inode()
+		   -- dwmw2
+		*/
+		if (node->data_size || node->removed_size) {
+			jffs_update_file(f, node);
+		}
+		jffs_remove_redundant_nodes(f);
+
+		jffs_garbage_collect_trigger(c);
+
+		D3(printk("jffs_insert_node(): ---------------------------"
+			  "------------------------------------------- 2\n"));
+	}
+
+	return 0;
+} /* jffs_insert_node()  */
+
+
+/* Unlink a jffs_node from the version list it is in.  */
+static inline void
+jffs_unlink_node_from_version_list(struct jffs_file *f,
+				   struct jffs_node *node)
+{
+	if (node->version_prev) {
+		node->version_prev->version_next = node->version_next;
+	} else {
+		f->version_head = node->version_next;
+	}
+	if (node->version_next) {
+		node->version_next->version_prev = node->version_prev;
+	} else {
+		f->version_tail = node->version_prev;
+	}
+}
+
+
+/* Unlink a jffs_node from the range list it is in.  */
+static inline void
+jffs_unlink_node_from_range_list(struct jffs_file *f, struct jffs_node *node)
+{
+	if (node->range_prev) {
+		node->range_prev->range_next = node->range_next;
+	}
+	else {
+		f->range_head = node->range_next;
+	}
+	if (node->range_next) {
+		node->range_next->range_prev = node->range_prev;
+	}
+	else {
+		f->range_tail = node->range_prev;
+	}
+}
+
+
+/* Function used by jffs_remove_redundant_nodes() below.  This function
+   classifies what kind of information a node adds to a file.  */
+static inline __u8
+jffs_classify_node(struct jffs_node *node)
+{
+	__u8 mod_type = JFFS_MODIFY_INODE;
+
+	if (node->name_size) {
+		mod_type |= JFFS_MODIFY_NAME;
+	}
+	if (node->data_size || node->removed_size) {
+		mod_type |= JFFS_MODIFY_DATA;
+	}
+	return mod_type;
+}
+
+
+/* Remove redundant nodes from a file.  Mark the on-flash memory
+   as dirty.  */
+static int
+jffs_remove_redundant_nodes(struct jffs_file *f)
+{
+	struct jffs_node *newest_node;
+	struct jffs_node *cur;
+	struct jffs_node *prev;
+	__u8 newest_type;
+	__u8 mod_type;
+	__u8 node_with_name_later = 0;
+
+	if (!(newest_node = f->version_tail)) {
+		return 0;
+	}
+
+	/* What does the `newest_node' modify?  */
+	newest_type = jffs_classify_node(newest_node);
+	node_with_name_later = newest_type & JFFS_MODIFY_NAME;
+
+	D3(printk("jffs_remove_redundant_nodes(): ino: %u, name: \"%s\", "
+		  "newest_type: %u\n", f->ino, (f->name ? f->name : ""),
+		  newest_type));
+
+	/* Traverse the file's nodes and determine which of them that are
+	   superfluous.  Yeah, this might look very complex at first
+	   glance but it is actually very simple.  */
+	for (cur = newest_node->version_prev; cur; cur = prev) {
+		prev = cur->version_prev;
+		mod_type = jffs_classify_node(cur);
+		if ((mod_type <= JFFS_MODIFY_INODE)
+		    || ((newest_type & JFFS_MODIFY_NAME)
+			&& (mod_type
+			    <= (JFFS_MODIFY_INODE + JFFS_MODIFY_NAME)))
+		    || (cur->data_size == 0 && cur->removed_size
+			&& !cur->version_prev && node_with_name_later)) {
+			/* Yes, this node is redundant. Remove it.  */
+			D2(printk("jffs_remove_redundant_nodes(): "
+				  "Removing node: ino: %u, version: %u, "
+				  "mod_type: %u\n", cur->ino, cur->version,
+				  mod_type));
+			jffs_unlink_node_from_version_list(f, cur);
+			jffs_fmfree(f->c->fmc, cur->fm, cur);
+			jffs_free_node(cur);
+			DJM(no_jffs_node--);
+		}
+		else {
+			node_with_name_later |= (mod_type & JFFS_MODIFY_NAME);
+		}
+	}
+
+	return 0;
+}
+
+
+/* Insert a file into the hash table.  */
+static int
+jffs_insert_file_into_hash(struct jffs_file *f)
+{
+	int i = f->ino % f->c->hash_len;
+
+	D3(printk("jffs_insert_file_into_hash(): f->ino: %u\n", f->ino));
+
+	list_add(&f->hash, &f->c->hash[i]);
+	return 0;
+}
+
+
+/* Insert a file into the file system tree.  */
+int
+jffs_insert_file_into_tree(struct jffs_file *f)
+{
+	struct jffs_file *parent;
+
+	D3(printk("jffs_insert_file_into_tree(): name: \"%s\"\n",
+		  (f->name ? f->name : "")));
+
+	if (!(parent = jffs_find_file(f->c, f->pino))) {
+		if (f->pino == 0) {
+			f->c->root = f;
+			f->parent = NULL;
+			f->sibling_prev = NULL;
+			f->sibling_next = NULL;
+			return 0;
+		}
+		else {
+			D1(printk("jffs_insert_file_into_tree(): Found "
+				  "inode with no parent and pino == %u\n",
+				  f->pino));
+			return -1;
+		}
+	}
+	f->parent = parent;
+	f->sibling_next = parent->children;
+	if (f->sibling_next) {
+		f->sibling_next->sibling_prev = f;
+	}
+	f->sibling_prev = NULL;
+	parent->children = f;
+	return 0;
+}
+
+
+/* Remove a file from the hash table.  */
+static int
+jffs_unlink_file_from_hash(struct jffs_file *f)
+{
+	D3(printk("jffs_unlink_file_from_hash(): f: 0x%p, "
+		  "ino %u\n", f, f->ino));
+
+	list_del(&f->hash);
+	return 0;
+}
+
+
+/* Just remove the file from the parent's children.  Don't free
+   any memory.  */
+int
+jffs_unlink_file_from_tree(struct jffs_file *f)
+{
+	D3(printk("jffs_unlink_file_from_tree(): ino: %d, pino: %d, name: "
+		  "\"%s\"\n", f->ino, f->pino, (f->name ? f->name : "")));
+
+	if (f->sibling_prev) {
+		f->sibling_prev->sibling_next = f->sibling_next;
+	}
+	else if (f->parent) {
+	        D3(printk("f->parent=%p\n", f->parent));
+		f->parent->children = f->sibling_next;
+	}
+	if (f->sibling_next) {
+		f->sibling_next->sibling_prev = f->sibling_prev;
+	}
+	return 0;
+}
+
+
+/* Find a file with its inode number.  */
+struct jffs_file *
+jffs_find_file(struct jffs_control *c, __u32 ino)
+{
+	struct jffs_file *f;
+	int i = ino % c->hash_len;
+	struct list_head *tmp;
+
+	D3(printk("jffs_find_file(): ino: %u\n", ino));
+
+	for (tmp = c->hash[i].next; tmp != &c->hash[i]; tmp = tmp->next) {
+		f = list_entry(tmp, struct jffs_file, hash);
+		if (ino != f->ino)
+			continue;
+		D3(printk("jffs_find_file(): Found file with ino "
+			       "%u. (name: \"%s\")\n",
+			       ino, (f->name ? f->name : ""));
+		);
+		return f;
+	}
+	D3(printk("jffs_find_file(): Didn't find file "
+			 "with ino %u.\n", ino);
+	);
+	return NULL;
+}
+
+
+/* Find a file in a directory.  We are comparing the names.  */
+struct jffs_file *
+jffs_find_child(struct jffs_file *dir, const char *name, int len)
+{
+	struct jffs_file *f;
+
+	D3(printk("jffs_find_child()\n"));
+
+	for (f = dir->children; f; f = f->sibling_next) {
+		if (!f->deleted && f->name
+		    && !strncmp(f->name, name, len)
+		    && f->name[len] == '\0') {
+			break;
+		}
+	}
+
+	D3(if (f) {
+		printk("jffs_find_child(): Found \"%s\".\n", f->name);
+	}
+	else {
+		char *copy = (char *) kmalloc(len + 1, GFP_KERNEL);
+		if (copy) {
+			memcpy(copy, name, len);
+			copy[len] = '\0';
+		}
+		printk("jffs_find_child(): Didn't find the file \"%s\".\n",
+		       (copy ? copy : ""));
+		if (copy) {
+			kfree(copy);
+		}
+	});
+
+	return f;
+}
+
+
+/* Write a raw inode that takes up a certain amount of space in the flash
+   memory.  At the end of the flash device, there is often space that is
+   impossible to use.  At these times we want to mark this space as not
+   used.  In the cases when the amount of space is greater or equal than
+   a struct jffs_raw_inode, we write a "dummy node" that takes up this
+   space.  The space after the raw inode, if it exists, is left as it is.
+   Since this space after the raw inode contains JFFS_EMPTY_BITMASK bytes,
+   we can compute the checksum of it; we don't have to manipulate it any
+   further.
+
+   If the space left on the device is less than the size of a struct
+   jffs_raw_inode, this space is filled with JFFS_DIRTY_BITMASK bytes.
+   No raw inode is written this time.  */
+static int
+jffs_write_dummy_node(struct jffs_control *c, struct jffs_fm *dirty_fm)
+{
+	struct jffs_fmcontrol *fmc = c->fmc;
+	int err;
+
+	D1(printk("jffs_write_dummy_node(): dirty_fm->offset = 0x%08x, "
+		  "dirty_fm->size = %u\n",
+		  dirty_fm->offset, dirty_fm->size));
+
+	if (dirty_fm->size >= sizeof(struct jffs_raw_inode)) {
+		struct jffs_raw_inode raw_inode;
+		memset(&raw_inode, 0, sizeof(struct jffs_raw_inode));
+		raw_inode.magic = JFFS_MAGIC_BITMASK;
+		raw_inode.dsize = dirty_fm->size
+				  - sizeof(struct jffs_raw_inode);
+		raw_inode.dchksum = raw_inode.dsize * 0xff;
+		raw_inode.chksum
+		= jffs_checksum(&raw_inode, sizeof(struct jffs_raw_inode));
+
+		if ((err = flash_safe_write(fmc->mtd,
+					    dirty_fm->offset,
+					    (u_char *)&raw_inode,
+					    sizeof(struct jffs_raw_inode)))
+		    < 0) {
+			printk(KERN_ERR "JFFS: jffs_write_dummy_node: "
+			       "flash_safe_write failed!\n");
+			return err;
+		}
+	}
+	else {
+		flash_safe_acquire(fmc->mtd);
+		flash_memset(fmc->mtd, dirty_fm->offset, 0, dirty_fm->size);
+		flash_safe_release(fmc->mtd);
+	}
+
+	D3(printk("jffs_write_dummy_node(): Leaving...\n"));
+	return 0;
+}
+
+
+/* Write a raw inode, possibly its name and possibly some data.  */
+int
+jffs_write_node(struct jffs_control *c, struct jffs_node *node,
+		struct jffs_raw_inode *raw_inode,
+		const char *name, const unsigned char *data,
+		int recoverable,
+		struct jffs_file *f)
+{
+	struct jffs_fmcontrol *fmc = c->fmc;
+	struct jffs_fm *fm;
+	struct kvec node_iovec[4];
+	unsigned long iovec_cnt;
+
+	__u32 pos;
+	int err;
+	__u32 slack = 0;
+
+	__u32 total_name_size = raw_inode->nsize
+				+ JFFS_GET_PAD_BYTES(raw_inode->nsize);
+	__u32 total_data_size = raw_inode->dsize
+				+ JFFS_GET_PAD_BYTES(raw_inode->dsize);
+	__u32 total_size = sizeof(struct jffs_raw_inode)
+			   + total_name_size + total_data_size;
+	
+	/* If this node isn't something that will eventually let
+	   GC free even more space, then don't allow it unless
+	   there's at least max_chunk_size space still available
+	*/
+	if (!recoverable)
+		slack = fmc->max_chunk_size;
+		
+
+	/* Fire the retrorockets and shoot the fruiton torpedoes, sir!  */
+
+	ASSERT(if (!node) {
+		printk("jffs_write_node(): node == NULL\n");
+		return -EINVAL;
+	});
+	ASSERT(if (raw_inode && raw_inode->nsize && !name) {
+		printk("*** jffs_write_node(): nsize = %u but name == NULL\n",
+		       raw_inode->nsize);
+		return -EINVAL;
+	});
+
+	D1(printk("jffs_write_node(): filename = \"%s\", ino = %u, "
+		  "total_size = %u\n",
+		  (name ? name : ""), raw_inode->ino,
+		  total_size));
+
+	jffs_fm_write_lock(fmc);
+
+retry:
+	fm = NULL;
+	err = 0;
+	while (!fm) {
+
+		/* Deadlocks suck. */
+		while(fmc->free_size < fmc->min_free_size + total_size + slack) {
+			jffs_fm_write_unlock(fmc);
+			if (!JFFS_ENOUGH_SPACE(c, total_size + slack))
+				return -ENOSPC;
+			jffs_fm_write_lock(fmc);
+		}
+
+		/* First try to allocate some flash memory.  */
+		err = jffs_fmalloc(fmc, total_size, node, &fm);
+		
+		if (err == -ENOSPC) {
+			/* Just out of space. GC and try again */
+			if (fmc->dirty_size < fmc->sector_size) {
+				D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) "
+					 "failed, no dirty space to GC\n", fmc,
+					 total_size));
+				return err;
+			}
+			
+			D1(printk(KERN_INFO "jffs_write_node(): Calling jffs_garbage_collect_now()\n"));
+			jffs_fm_write_unlock(fmc);
+			if ((err = jffs_garbage_collect_now(c))) {
+				D(printk("jffs_write_node(): jffs_garbage_collect_now() failed\n"));
+				return err;
+			}
+			jffs_fm_write_lock(fmc);
+			continue;
+		} 
+
+		if (err < 0) {
+			jffs_fm_write_unlock(fmc);
+
+			D(printk("jffs_write_node(): jffs_fmalloc(0x%p, %u) "
+				 "failed!\n", fmc, total_size));
+			return err;
+		}
+
+		if (!fm->nodes) {
+			/* The jffs_fm struct that we got is not good enough.
+			   Make that space dirty and try again  */
+			if ((err = jffs_write_dummy_node(c, fm)) < 0) {
+				kfree(fm);
+				DJM(no_jffs_fm--);
+				jffs_fm_write_unlock(fmc);
+				D(printk("jffs_write_node(): "
+					 "jffs_write_dummy_node(): Failed!\n"));
+				return err;
+			}
+			fm = NULL;
+		}
+	} /* while(!fm) */
+	node->fm = fm;
+
+	ASSERT(if (fm->nodes == 0) {
+		printk(KERN_ERR "jffs_write_node(): fm->nodes == 0\n");
+	});
+
+	pos = node->fm->offset;
+
+	/* Increment the version number here. We can't let the caller
+	   set it beforehand, because we might have had to do GC on a node
+	   of this file - and we'd end up reusing version numbers.
+	*/
+	if (f) {
+		raw_inode->version = f->highest_version + 1;
+		D1(printk (KERN_NOTICE "jffs_write_node(): setting version of %s to %d\n", f->name, raw_inode->version));
+
+		/* if the file was deleted, set the deleted bit in the raw inode */
+		if (f->deleted)
+			raw_inode->deleted = 1;
+	}
+
+	/* Compute the checksum for the data and name chunks.  */
+	raw_inode->dchksum = jffs_checksum(data, raw_inode->dsize);
+	raw_inode->nchksum = jffs_checksum(name, raw_inode->nsize);
+
+	/* The checksum is calculated without the chksum and accurate
+	   fields so set them to zero first.  */
+	raw_inode->accurate = 0;
+	raw_inode->chksum = 0;
+	raw_inode->chksum = jffs_checksum(raw_inode,
+					  sizeof(struct jffs_raw_inode));
+	raw_inode->accurate = 0xff;
+
+	D3(printk("jffs_write_node(): About to write this raw inode to the "
+		  "flash at pos 0x%lx:\n", (long)pos));
+	D3(jffs_print_raw_inode(raw_inode));
+
+	/* The actual raw JFFS node */
+	node_iovec[0].iov_base = (void *) raw_inode;
+	node_iovec[0].iov_len = (size_t) sizeof(struct jffs_raw_inode);
+	iovec_cnt = 1;
+
+	/* Get name and size if there is one */
+	if (raw_inode->nsize) {
+		node_iovec[iovec_cnt].iov_base = (void *) name;
+		node_iovec[iovec_cnt].iov_len = (size_t) raw_inode->nsize;
+		iovec_cnt++;
+
+		if (JFFS_GET_PAD_BYTES(raw_inode->nsize)) {
+			static char allff[3]={255,255,255};
+			/* Add some extra padding if necessary */
+			node_iovec[iovec_cnt].iov_base = allff;
+			node_iovec[iovec_cnt].iov_len =
+				JFFS_GET_PAD_BYTES(raw_inode->nsize);
+			iovec_cnt++;
+		}
+	}
+
+	/* Get data and size if there is any */
+	if (raw_inode->dsize) {
+		node_iovec[iovec_cnt].iov_base = (void *) data;
+		node_iovec[iovec_cnt].iov_len = (size_t) raw_inode->dsize;
+		iovec_cnt++;
+		/* No need to pad this because we're not actually putting
+		   anything after it.
+		*/
+	}
+
+	if ((err = flash_safe_writev(fmc->mtd, node_iovec, iovec_cnt,
+				    pos)) < 0) {
+		jffs_fmfree_partly(fmc, fm, 0);
+		jffs_fm_write_unlock(fmc);
+		printk(KERN_ERR "JFFS: jffs_write_node: Failed to write, "
+		       "requested %i, wrote %i\n", total_size, err);
+		goto retry;
+	}
+	if (raw_inode->deleted)
+		f->deleted = 1;
+
+	jffs_fm_write_unlock(fmc);
+	D3(printk("jffs_write_node(): Leaving...\n"));
+	return raw_inode->dsize;
+} /* jffs_write_node()  */
+
+
+/* Read data from the node and write it to the buffer.  'node_offset'
+   is how much we have read from this particular node before and which
+   shouldn't be read again.  'max_size' is how much space there is in
+   the buffer.  */
+static int
+jffs_get_node_data(struct jffs_file *f, struct jffs_node *node, 
+		   unsigned char *buf,__u32 node_offset, __u32 max_size)
+{
+	struct jffs_fmcontrol *fmc = f->c->fmc;
+	__u32 pos = node->fm->offset + node->fm_offset + node_offset;
+	__u32 avail = node->data_size - node_offset;
+	__u32 r;
+
+	D2(printk("  jffs_get_node_data(): file: \"%s\", ino: %u, "
+		  "version: %u, node_offset: %u\n",
+		  f->name, node->ino, node->version, node_offset));
+
+	r = min(avail, max_size);
+	D3(printk(KERN_NOTICE "jffs_get_node_data\n"));
+	flash_safe_read(fmc->mtd, pos, buf, r);
+
+	D3(printk("  jffs_get_node_data(): Read %u byte%s.\n",
+		  r, (r == 1 ? "" : "s")));
+
+	return r;
+}
+
+
+/* Read data from the file's nodes.  Write the data to the buffer
+   'buf'.  'read_offset' tells how much data we should skip.  */
+int
+jffs_read_data(struct jffs_file *f, unsigned char *buf, __u32 read_offset,
+	       __u32 size)
+{
+	struct jffs_node *node;
+	__u32 read_data = 0; /* Total amount of read data.  */
+	__u32 node_offset = 0;
+	__u32 pos = 0; /* Number of bytes traversed.  */
+
+	D2(printk("jffs_read_data(): file = \"%s\", read_offset = %d, "
+		  "size = %u\n",
+		  (f->name ? f->name : ""), read_offset, size));
+
+	if (read_offset >= f->size) {
+		D(printk("  f->size: %d\n", f->size));
+		return 0;
+	}
+
+	/* First find the node to read data from.  */
+	node = f->range_head;
+	while (pos <= read_offset) {
+		node_offset = read_offset - pos;
+		if (node_offset >= node->data_size) {
+			pos += node->data_size;
+			node = node->range_next;
+		}
+		else {
+			break;
+		}
+	}
+
+	/* "Cats are living proof that not everything in nature
+	   has to be useful."
+	   - Garrison Keilor ('97)  */
+
+	/* Fill the buffer.  */
+	while (node && (read_data < size)) {
+		int r;
+		if (!node->fm) {
+			/* This node does not refer to real data.  */
+			r = min(size - read_data,
+				     node->data_size - node_offset);
+			memset(&buf[read_data], 0, r);
+		}
+		else if ((r = jffs_get_node_data(f, node, &buf[read_data],
+						 node_offset,
+						 size - read_data)) < 0) {
+			return r;
+		}
+		read_data += r;
+		node_offset = 0;
+		node = node->range_next;
+	}
+	D3(printk("  jffs_read_data(): Read %u bytes.\n", read_data));
+	return read_data;
+}
+
+
+/* Used for traversing all nodes in the hash table.  */
+int
+jffs_foreach_file(struct jffs_control *c, int (*func)(struct jffs_file *))
+{
+	int pos;
+	int r;
+	int result = 0;
+
+	for (pos = 0; pos < c->hash_len; pos++) {
+		struct list_head *p, *next;
+		for (p = c->hash[pos].next; p != &c->hash[pos]; p = next) {
+			/* We need a reference to the next file in the
+			   list because `func' might remove the current
+			   file `f'.  */
+			next = p->next;
+			r = func(list_entry(p, struct jffs_file, hash));
+			if (r < 0)
+				return r;
+			result += r;
+		}
+	}
+
+	return result;
+}
+
+
+/* Free all nodes associated with a file.  */
+static int
+jffs_free_node_list(struct jffs_file *f)
+{
+	struct jffs_node *node;
+	struct jffs_node *p;
+
+	D3(printk("jffs_free_node_list(): f #%u, \"%s\"\n",
+		  f->ino, (f->name ? f->name : "")));
+	node = f->version_head;
+	while (node) {
+		p = node;
+		node = node->version_next;
+		jffs_free_node(p);
+		DJM(no_jffs_node--);
+	}
+	return 0;
+}
+
+
+/* Free a file and its name.  */
+static int
+jffs_free_file(struct jffs_file *f)
+{
+	D3(printk("jffs_free_file: f #%u, \"%s\"\n",
+		  f->ino, (f->name ? f->name : "")));
+
+	if (f->name) {
+		kfree(f->name);
+		DJM(no_name--);
+	}
+	kfree(f);
+	no_jffs_file--;
+	return 0;
+}
+
+static long
+jffs_get_file_count(void)
+{
+	return no_jffs_file;
+}
+
+/* See if a file is deleted. If so, mark that file's nodes as obsolete.  */
+int
+jffs_possibly_delete_file(struct jffs_file *f)
+{
+	struct jffs_node *n;
+
+	D3(printk("jffs_possibly_delete_file(): ino: %u\n",
+		  f->ino));
+
+	ASSERT(if (!f) {
+		printk(KERN_ERR "jffs_possibly_delete_file(): f == NULL\n");
+		return -1;
+	});
+
+	if (f->deleted) {
+		/* First try to remove all older versions.  Commence with
+		   the oldest node.  */
+		for (n = f->version_head; n; n = n->version_next) {
+			if (!n->fm) {
+				continue;
+			}
+			if (jffs_fmfree(f->c->fmc, n->fm, n) < 0) {
+				break;
+			}
+		}
+		/* Unlink the file from the filesystem.  */
+		if (!f->c->building_fs) {
+			jffs_unlink_file_from_tree(f);
+		}
+		jffs_unlink_file_from_hash(f);
+		jffs_free_node_list(f);
+		jffs_free_file(f);
+	}
+	return 0;
+}
+
+
+/* Used in conjunction with jffs_foreach_file() to count the number
+   of files in the file system.  */
+int
+jffs_file_count(struct jffs_file *f)
+{
+	return 1;
+}
+
+
+/* Build up a file's range list from scratch by going through the
+   version list.  */
+static int
+jffs_build_file(struct jffs_file *f)
+{
+	struct jffs_node *n;
+
+	D3(printk("jffs_build_file(): ino: %u, name: \"%s\"\n",
+		  f->ino, (f->name ? f->name : "")));
+
+	for (n = f->version_head; n; n = n->version_next) {
+		jffs_update_file(f, n);
+	}
+	return 0;
+}
+
+
+/* Remove an amount of data from a file. If this amount of data is
+   zero, that could mean that a node should be split in two parts.
+   We remove or change the appropriate nodes in the lists.
+
+   Starting offset of area to be removed is node->data_offset,
+   and the length of the area is in node->removed_size.   */
+static int
+jffs_delete_data(struct jffs_file *f, struct jffs_node *node)
+{
+	struct jffs_node *n;
+	__u32 offset = node->data_offset;
+	__u32 remove_size = node->removed_size;
+
+	D3(printk("jffs_delete_data(): offset = %u, remove_size = %u\n",
+		  offset, remove_size));
+
+	if (remove_size == 0
+	    && f->range_tail
+	    && f->range_tail->data_offset + f->range_tail->data_size
+	       == offset) {
+		/* A simple append; nothing to remove or no node to split.  */
+		return 0;
+	}
+
+	/* Find the node where we should begin the removal.  */
+	for (n = f->range_head; n; n = n->range_next) {
+		if (n->data_offset + n->data_size > offset) {
+			break;
+		}
+	}
+	if (!n) {
+		/* If there's no data in the file there's no data to
+		   remove either.  */
+		return 0;
+	}
+
+	if (n->data_offset > offset) {
+		/* XXX: Not implemented yet.  */
+		printk(KERN_WARNING "JFFS: An unexpected situation "
+		       "occurred in jffs_delete_data.\n");
+	}
+	else if (n->data_offset < offset) {
+		/* See if the node has to be split into two parts.  */
+		if (n->data_offset + n->data_size > offset + remove_size) {
+			/* Do the split.  */
+			struct jffs_node *new_node;
+			D3(printk("jffs_delete_data(): Split node with "
+				  "version number %u.\n", n->version));
+
+			if (!(new_node = jffs_alloc_node())) {
+				D(printk("jffs_delete_data(): -ENOMEM\n"));
+				return -ENOMEM;
+			}
+			DJM(no_jffs_node++);
+
+			new_node->ino = n->ino;
+			new_node->version = n->version;
+			new_node->data_offset = offset;
+			new_node->data_size = n->data_size - (remove_size + (offset - n->data_offset));
+			new_node->fm_offset = n->fm_offset + (remove_size + (offset - n->data_offset));
+			new_node->name_size = n->name_size;
+			new_node->fm = n->fm;
+			new_node->version_prev = n;
+			new_node->version_next = n->version_next;
+			if (new_node->version_next) {
+				new_node->version_next->version_prev
+				= new_node;
+			}
+			else {
+				f->version_tail = new_node;
+			}
+			n->version_next = new_node;
+			new_node->range_prev = n;
+			new_node->range_next = n->range_next;
+			if (new_node->range_next) {
+				new_node->range_next->range_prev = new_node;
+			}
+			else {
+				f->range_tail = new_node;
+			}
+			/* A very interesting can of worms.  */
+			n->range_next = new_node;
+			n->data_size = offset - n->data_offset;
+			if (new_node->fm)
+				jffs_add_node(new_node);
+			else {
+				D1(printk(KERN_WARNING "jffs_delete_data(): Splitting an empty node (file hold).\n!"));
+				D1(printk(KERN_WARNING "FIXME: Did dwmw2 do the right thing here?\n"));
+			}
+			n = new_node->range_next;
+			remove_size = 0;
+		}
+		else {
+			/* No.  No need to split the node.  Just remove
+			   the end of the node.  */
+			int r = min(n->data_offset + n->data_size
+					 - offset, remove_size);
+			n->data_size -= r;
+			remove_size -= r;
+			n = n->range_next;
+		}
+	}
+
+	/* Remove as many nodes as necessary.  */
+	while (n && remove_size) {
+		if (n->data_size <= remove_size) {
+			struct jffs_node *p = n;
+			remove_size -= n->data_size;
+			n = n->range_next;
+			D3(printk("jffs_delete_data(): Removing node: "
+				  "ino: %u, version: %u%s\n",
+				  p->ino, p->version,
+				  (p->fm ? "" : " (virtual)")));
+			if (p->fm) {
+				jffs_fmfree(f->c->fmc, p->fm, p);
+			}
+			jffs_unlink_node_from_range_list(f, p);
+			jffs_unlink_node_from_version_list(f, p);
+			jffs_free_node(p);
+			DJM(no_jffs_node--);
+		}
+		else {
+			n->data_size -= remove_size;
+			n->fm_offset += remove_size;
+			n->data_offset -= (node->removed_size - remove_size);
+			n = n->range_next;
+			break;
+		}
+	}
+
+	/* Adjust the following nodes' information about offsets etc.  */
+	while (n && node->removed_size) {
+		n->data_offset -= node->removed_size;
+		n = n->range_next;
+	}
+
+	if (node->removed_size > (f->size - node->data_offset)) {
+		/* It's possible that the removed_size is in fact
+		 * greater than the amount of data we actually thought
+		 * were present in the first place - some of the nodes 
+		 * which this node originally obsoleted may already have
+		 * been deleted from the flash by subsequent garbage 
+		 * collection.
+		 *
+		 * If this is the case, don't let f->size go negative.
+		 * Bad things would happen :)
+		 */
+		f->size = node->data_offset;
+	} else {
+		f->size -= node->removed_size;
+	}
+	D3(printk("jffs_delete_data(): f->size = %d\n", f->size));
+	return 0;
+} /* jffs_delete_data()  */
+
+
+/* Insert some data into a file.  Prior to the call to this function,
+   jffs_delete_data should be called.  */
+static int
+jffs_insert_data(struct jffs_file *f, struct jffs_node *node)
+{
+	D3(printk("jffs_insert_data(): node->data_offset = %u, "
+		  "node->data_size = %u, f->size = %u\n",
+		  node->data_offset, node->data_size, f->size));
+
+	/* Find the position where we should insert data.  */
+	retry:
+	if (node->data_offset == f->size) {
+		/* A simple append.  This is the most common operation.  */
+		node->range_next = NULL;
+		node->range_prev = f->range_tail;
+		if (node->range_prev) {
+			node->range_prev->range_next = node;
+		}
+		f->range_tail = node;
+		f->size += node->data_size;
+		if (!f->range_head) {
+			f->range_head = node;
+		}
+	}
+	else if (node->data_offset < f->size) {
+		/* Trying to insert data into the middle of the file.  This
+		   means no problem because jffs_delete_data() has already
+		   prepared the range list for us.  */
+		struct jffs_node *n;
+
+		/* Find the correct place for the insertion and then insert
+		   the node.  */
+		for (n = f->range_head; n; n = n->range_next) {
+			D2(printk("Cool stuff's happening!\n"));
+
+			if (n->data_offset == node->data_offset) {
+				node->range_prev = n->range_prev;
+				if (node->range_prev) {
+					node->range_prev->range_next = node;
+				}
+				else {
+					f->range_head = node;
+				}
+				node->range_next = n;
+				n->range_prev = node;
+				break;
+			}
+			ASSERT(else if (n->data_offset + n->data_size >
+					node->data_offset) {
+				printk(KERN_ERR "jffs_insert_data(): "
+				       "Couldn't find a place to insert "
+				       "the data!\n");
+				return -1;
+			});
+		}
+
+		/* Adjust later nodes' offsets etc.  */
+		n = node->range_next;
+		while (n) {
+			n->data_offset += node->data_size;
+			n = n->range_next;
+		}
+		f->size += node->data_size;
+	}
+	else if (node->data_offset > f->size) {
+		/* Okay.  This is tricky.  This means that we want to insert
+		   data at a place that is beyond the limits of the file as
+		   it is constructed right now.  This is actually a common
+		   event that for instance could occur during the mounting
+		   of the file system if a large file have been truncated,
+		   rewritten and then only partially garbage collected.  */
+
+		struct jffs_node *n;
+
+		/* We need a place holder for the data that is missing in
+		   front of this insertion.  This "virtual node" will not
+		   be associated with any space on the flash device.  */
+		struct jffs_node *virtual_node;
+		if (!(virtual_node = jffs_alloc_node())) {
+			return -ENOMEM;
+		}
+
+		D(printk("jffs_insert_data: Inserting a virtual node.\n"));
+		D(printk("  node->data_offset = %u\n", node->data_offset));
+		D(printk("  f->size = %u\n", f->size));
+
+		virtual_node->ino = node->ino;
+		virtual_node->version = node->version;
+		virtual_node->removed_size = 0;
+		virtual_node->fm_offset = 0;
+		virtual_node->name_size = 0;
+		virtual_node->fm = NULL; /* This is a virtual data holder.  */
+		virtual_node->version_prev = NULL;
+		virtual_node->version_next = NULL;
+		virtual_node->range_next = NULL;
+
+		/* Are there any data at all in the file yet?  */
+		if (f->range_head) {
+			virtual_node->data_offset
+			= f->range_tail->data_offset
+			  + f->range_tail->data_size;
+			virtual_node->data_size
+			= node->data_offset - virtual_node->data_offset;
+			virtual_node->range_prev = f->range_tail;
+			f->range_tail->range_next = virtual_node;
+		}
+		else {
+			virtual_node->data_offset = 0;
+			virtual_node->data_size = node->data_offset;
+			virtual_node->range_prev = NULL;
+			f->range_head = virtual_node;
+		}
+
+		f->range_tail = virtual_node;
+		f->size += virtual_node->data_size;
+
+		/* Insert this virtual node in the version list as well.  */
+		for (n = f->version_head; n ; n = n->version_next) {
+			if (n->version == virtual_node->version) {
+				virtual_node->version_prev = n->version_prev;
+				n->version_prev = virtual_node;
+				if (virtual_node->version_prev) {
+					virtual_node->version_prev
+					->version_next = virtual_node;
+				}
+				else {
+					f->version_head = virtual_node;
+				}
+				virtual_node->version_next = n;
+				break;
+			}
+		}
+
+		D(jffs_print_node(virtual_node));
+
+		/* Make a new try to insert the node.  */
+		goto retry;
+	}
+
+	D3(printk("jffs_insert_data(): f->size = %d\n", f->size));
+	return 0;
+}
+
+
+/* A new node (with data) has been added to the file and now the range
+   list has to be modified.  */
+static int
+jffs_update_file(struct jffs_file *f, struct jffs_node *node)
+{
+	int err;
+
+	D3(printk("jffs_update_file(): ino: %u, version: %u\n",
+		  f->ino, node->version));
+
+	if (node->data_size == 0) {
+		if (node->removed_size == 0) {
+			/* data_offset == X  */
+			/* data_size == 0  */
+			/* remove_size == 0  */
+		}
+		else {
+			/* data_offset == X  */
+			/* data_size == 0  */
+			/* remove_size != 0  */
+			if ((err = jffs_delete_data(f, node)) < 0) {
+				return err;
+			}
+		}
+	}
+	else {
+		/* data_offset == X  */
+		/* data_size != 0  */
+		/* remove_size == Y  */
+		if ((err = jffs_delete_data(f, node)) < 0) {
+			return err;
+		}
+		if ((err = jffs_insert_data(f, node)) < 0) {
+			return err;
+		}
+	}
+	return 0;
+}
+
+/* Print the contents of a node.  */
+void
+jffs_print_node(struct jffs_node *n)
+{
+	D(printk("jffs_node: 0x%p\n", n));
+	D(printk("{\n"));
+	D(printk("        0x%08x, /* version  */\n", n->version));
+	D(printk("        0x%08x, /* data_offset  */\n", n->data_offset));
+	D(printk("        0x%08x, /* data_size  */\n", n->data_size));
+	D(printk("        0x%08x, /* removed_size  */\n", n->removed_size));
+	D(printk("        0x%08x, /* fm_offset  */\n", n->fm_offset));
+	D(printk("        0x%02x,       /* name_size  */\n", n->name_size));
+	D(printk("        0x%p, /* fm,  fm->offset: %u  */\n",
+		 n->fm, (n->fm ? n->fm->offset : 0)));
+	D(printk("        0x%p, /* version_prev  */\n", n->version_prev));
+	D(printk("        0x%p, /* version_next  */\n", n->version_next));
+	D(printk("        0x%p, /* range_prev  */\n", n->range_prev));
+	D(printk("        0x%p, /* range_next  */\n", n->range_next));
+	D(printk("}\n"));
+}
+
+
+/* Print the contents of a raw inode.  */
+void
+jffs_print_raw_inode(struct jffs_raw_inode *raw_inode)
+{
+	D(printk("jffs_raw_inode: inode number: %u\n", raw_inode->ino));
+	D(printk("{\n"));
+	D(printk("        0x%08x, /* magic  */\n", raw_inode->magic));
+	D(printk("        0x%08x, /* ino  */\n", raw_inode->ino));
+	D(printk("        0x%08x, /* pino  */\n", raw_inode->pino));
+	D(printk("        0x%08x, /* version  */\n", raw_inode->version));
+	D(printk("        0x%08x, /* mode  */\n", raw_inode->mode));
+	D(printk("        0x%04x,     /* uid  */\n", raw_inode->uid));
+	D(printk("        0x%04x,     /* gid  */\n", raw_inode->gid));
+	D(printk("        0x%08x, /* atime  */\n", raw_inode->atime));
+	D(printk("        0x%08x, /* mtime  */\n", raw_inode->mtime));
+	D(printk("        0x%08x, /* ctime  */\n", raw_inode->ctime));
+	D(printk("        0x%08x, /* offset  */\n", raw_inode->offset));
+	D(printk("        0x%08x, /* dsize  */\n", raw_inode->dsize));
+	D(printk("        0x%08x, /* rsize  */\n", raw_inode->rsize));
+	D(printk("        0x%02x,       /* nsize  */\n", raw_inode->nsize));
+	D(printk("        0x%02x,       /* nlink  */\n", raw_inode->nlink));
+	D(printk("        0x%02x,       /* spare  */\n",
+		 raw_inode->spare));
+	D(printk("        %u,          /* rename  */\n",
+		 raw_inode->rename));
+	D(printk("        %u,          /* deleted  */\n",
+		 raw_inode->deleted));
+	D(printk("        0x%02x,       /* accurate  */\n",
+		 raw_inode->accurate));
+	D(printk("        0x%08x, /* dchksum  */\n", raw_inode->dchksum));
+	D(printk("        0x%04x,     /* nchksum  */\n", raw_inode->nchksum));
+	D(printk("        0x%04x,     /* chksum  */\n", raw_inode->chksum));
+	D(printk("}\n"));
+}
+
+
+/* Print the contents of a file.  */
+#if 0
+int
+jffs_print_file(struct jffs_file *f)
+{
+	D(int i);
+	D(printk("jffs_file: 0x%p\n", f));
+	D(printk("{\n"));
+	D(printk("        0x%08x, /* ino  */\n", f->ino));
+	D(printk("        0x%08x, /* pino  */\n", f->pino));
+	D(printk("        0x%08x, /* mode  */\n", f->mode));
+	D(printk("        0x%04x,     /* uid  */\n", f->uid));
+	D(printk("        0x%04x,     /* gid  */\n", f->gid));
+	D(printk("        0x%08x, /* atime  */\n", f->atime));
+	D(printk("        0x%08x, /* mtime  */\n", f->mtime));
+	D(printk("        0x%08x, /* ctime  */\n", f->ctime));
+	D(printk("        0x%02x,       /* nsize  */\n", f->nsize));
+	D(printk("        0x%02x,       /* nlink  */\n", f->nlink));
+	D(printk("        0x%02x,       /* deleted  */\n", f->deleted));
+	D(printk("        \"%s\", ", (f->name ? f->name : "")));
+	D(for (i = strlen(f->name ? f->name : ""); i < 8; ++i) {
+		printk(" ");
+	});
+	D(printk("/* name  */\n"));
+	D(printk("        0x%08x, /* size  */\n", f->size));
+	D(printk("        0x%08x, /* highest_version  */\n",
+		 f->highest_version));
+	D(printk("        0x%p, /* c  */\n", f->c));
+	D(printk("        0x%p, /* parent  */\n", f->parent));
+	D(printk("        0x%p, /* children  */\n", f->children));
+	D(printk("        0x%p, /* sibling_prev  */\n", f->sibling_prev));
+	D(printk("        0x%p, /* sibling_next  */\n", f->sibling_next));
+	D(printk("        0x%p, /* hash_prev  */\n", f->hash.prev));
+	D(printk("        0x%p, /* hash_next  */\n", f->hash.next));
+	D(printk("        0x%p, /* range_head  */\n", f->range_head));
+	D(printk("        0x%p, /* range_tail  */\n", f->range_tail));
+	D(printk("        0x%p, /* version_head  */\n", f->version_head));
+	D(printk("        0x%p, /* version_tail  */\n", f->version_tail));
+	D(printk("}\n"));
+	return 0;
+}
+#endif  /*  0  */
+
+void
+jffs_print_hash_table(struct jffs_control *c)
+{
+	int i;
+
+	printk("JFFS: Dumping the file system's hash table...\n");
+	for (i = 0; i < c->hash_len; i++) {
+		struct list_head *p;
+		for (p = c->hash[i].next; p != &c->hash[i]; p = p->next) {
+			struct jffs_file *f=list_entry(p,struct jffs_file,hash);
+			printk("*** c->hash[%u]: \"%s\" "
+			       "(ino: %u, pino: %u)\n",
+			       i, (f->name ? f->name : ""),
+			       f->ino, f->pino);
+		}
+	}
+}
+
+
+void
+jffs_print_tree(struct jffs_file *first_file, int indent)
+{
+	struct jffs_file *f;
+	char *space;
+	int dir;
+
+	if (!first_file) {
+		return;
+	}
+
+	if (!(space = (char *) kmalloc(indent + 1, GFP_KERNEL))) {
+		printk("jffs_print_tree(): Out of memory!\n");
+		return;
+	}
+
+	memset(space, ' ', indent);
+	space[indent] = '\0';
+
+	for (f = first_file; f; f = f->sibling_next) {
+		dir = S_ISDIR(f->mode);
+		printk("%s%s%s (ino: %u, highest_version: %u, size: %u)\n",
+		       space, (f->name ? f->name : ""), (dir ? "/" : ""),
+		       f->ino, f->highest_version, f->size);
+		if (dir) {
+			jffs_print_tree(f->children, indent + 2);
+		}
+	}
+
+	kfree(space);
+}
+
+
+#if defined(JFFS_MEMORY_DEBUG) && JFFS_MEMORY_DEBUG
+void
+jffs_print_memory_allocation_statistics(void)
+{
+	static long printout;
+	printk("________ Memory printout #%ld ________\n", ++printout);
+	printk("no_jffs_file = %ld\n", no_jffs_file);
+	printk("no_jffs_node = %ld\n", no_jffs_node);
+	printk("no_jffs_control = %ld\n", no_jffs_control);
+	printk("no_jffs_raw_inode = %ld\n", no_jffs_raw_inode);
+	printk("no_jffs_node_ref = %ld\n", no_jffs_node_ref);
+	printk("no_jffs_fm = %ld\n", no_jffs_fm);
+	printk("no_jffs_fmcontrol = %ld\n", no_jffs_fmcontrol);
+	printk("no_hash = %ld\n", no_hash);
+	printk("no_name = %ld\n", no_name);
+	printk("\n");
+}
+#endif
+
+
+/* Rewrite `size' bytes, and begin at `node'.  */
+static int
+jffs_rewrite_data(struct jffs_file *f, struct jffs_node *node, __u32 size)
+{
+	struct jffs_control *c = f->c;
+	struct jffs_fmcontrol *fmc = c->fmc;
+	struct jffs_raw_inode raw_inode;
+	struct jffs_node *new_node;
+	struct jffs_fm *fm;
+	__u32 pos;
+	__u32 pos_dchksum;
+	__u32 total_name_size;
+	__u32 total_data_size;
+	__u32 total_size;
+	int err;
+
+	D1(printk("***jffs_rewrite_data(): node: %u, name: \"%s\", size: %u\n",
+		  f->ino, (f->name ? f->name : "(null)"), size));
+
+	/* Create and initialize the new node.  */
+	if (!(new_node = jffs_alloc_node())) {
+		D(printk("jffs_rewrite_data(): "
+			 "Failed to allocate node.\n"));
+		return -ENOMEM;
+	}
+	DJM(no_jffs_node++);
+	new_node->data_offset = node->data_offset;
+	new_node->removed_size = size;
+	total_name_size = JFFS_PAD(f->nsize);
+	total_data_size = JFFS_PAD(size);
+	total_size = sizeof(struct jffs_raw_inode)
+		     + total_name_size + total_data_size;
+	new_node->fm_offset = sizeof(struct jffs_raw_inode)
+			      + total_name_size;
+
+retry:
+	jffs_fm_write_lock(fmc);
+	err = 0;
+
+	if ((err = jffs_fmalloc(fmc, total_size, new_node, &fm)) < 0) {
+		DJM(no_jffs_node--);
+		jffs_fm_write_unlock(fmc);
+		D(printk("jffs_rewrite_data(): Failed to allocate fm.\n"));
+		jffs_free_node(new_node);
+		return err;
+	}
+	else if (!fm->nodes) {
+		/* The jffs_fm struct that we got is not big enough.  */
+		/* This should never happen, because we deal with this case
+		   in jffs_garbage_collect_next().*/
+		printk(KERN_WARNING "jffs_rewrite_data(): Allocated node is too small (%d bytes of %d)\n", fm->size, total_size);
+		if ((err = jffs_write_dummy_node(c, fm)) < 0) {
+			D(printk("jffs_rewrite_data(): "
+				 "jffs_write_dummy_node() Failed!\n"));
+		} else {
+			err = -ENOSPC;
+		}
+		DJM(no_jffs_fm--);
+		jffs_fm_write_unlock(fmc);
+		kfree(fm);
+		
+		return err;
+	}
+	new_node->fm = fm;
+
+	/* Initialize the raw inode.  */
+	raw_inode.magic = JFFS_MAGIC_BITMASK;
+	raw_inode.ino = f->ino;
+	raw_inode.pino = f->pino;
+	raw_inode.version = f->highest_version + 1;
+	raw_inode.mode = f->mode;
+	raw_inode.uid = f->uid;
+	raw_inode.gid = f->gid;
+	raw_inode.atime = f->atime;
+	raw_inode.mtime = f->mtime;
+	raw_inode.ctime = f->ctime;
+	raw_inode.offset = node->data_offset;
+	raw_inode.dsize = size;
+	raw_inode.rsize = size;
+	raw_inode.nsize = f->nsize;
+	raw_inode.nlink = f->nlink;
+	raw_inode.spare = 0;
+	raw_inode.rename = 0;
+	raw_inode.deleted = f->deleted;
+	raw_inode.accurate = 0xff;
+	raw_inode.dchksum = 0;
+	raw_inode.nchksum = 0;
+
+	pos = new_node->fm->offset;
+	pos_dchksum = pos +JFFS_RAW_INODE_DCHKSUM_OFFSET;
+
+	D3(printk("jffs_rewrite_data(): Writing this raw inode "
+		  "to pos 0x%ul.\n", pos));
+	D3(jffs_print_raw_inode(&raw_inode));
+
+	if ((err = flash_safe_write(fmc->mtd, pos,
+				    (u_char *) &raw_inode,
+				    sizeof(struct jffs_raw_inode)
+				    - sizeof(__u32)
+				    - sizeof(__u16) - sizeof(__u16))) < 0) {
+		jffs_fmfree_partly(fmc, fm,
+				   total_name_size + total_data_size);
+		jffs_fm_write_unlock(fmc);
+		printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during "
+			"rewrite. (raw inode)\n");
+		printk(KERN_ERR "JFFS: jffs_rewrite_data: Now retrying "
+			"rewrite. (raw inode)\n");
+		goto retry;
+	}
+	pos += sizeof(struct jffs_raw_inode);
+
+	/* Write the name to the flash memory.  */
+	if (f->nsize) {
+		D3(printk("jffs_rewrite_data(): Writing name \"%s\" to "
+			  "pos 0x%ul.\n", f->name, (unsigned int) pos));
+		if ((err = flash_safe_write(fmc->mtd, pos,
+					    (u_char *)f->name,
+					    f->nsize)) < 0) {
+			jffs_fmfree_partly(fmc, fm, total_data_size);
+			jffs_fm_write_unlock(fmc);
+			printk(KERN_ERR "JFFS: jffs_rewrite_data: Write "
+				"error during rewrite. (name)\n");
+			printk(KERN_ERR "JFFS: jffs_rewrite_data: Now retrying "
+				"rewrite. (name)\n");
+			goto retry;
+		}
+		pos += total_name_size;
+		raw_inode.nchksum = jffs_checksum(f->name, f->nsize);
+	}
+
+	/* Write the data.  */
+	if (size) {
+		int r;
+		unsigned char *page;
+		__u32 offset = node->data_offset;
+
+		if (!(page = (unsigned char *)__get_free_page(GFP_KERNEL))) {
+			jffs_fmfree_partly(fmc, fm, 0);
+			return -1;
+		}
+
+		while (size) {
+			__u32 s = min(size, (__u32)PAGE_SIZE);
+			if ((r = jffs_read_data(f, (char *)page,
+						offset, s)) < s) {
+				free_page((unsigned long)page);
+				jffs_fmfree_partly(fmc, fm, 0);
+				jffs_fm_write_unlock(fmc);
+				printk(KERN_ERR "JFFS: jffs_rewrite_data: "
+					 "jffs_read_data() "
+					 "failed! (r = %d)\n", r);
+				return -1;
+			}
+			if ((err = flash_safe_write(fmc->mtd,
+						    pos, page, r)) < 0) {
+				free_page((unsigned long)page);
+				jffs_fmfree_partly(fmc, fm, 0);
+				jffs_fm_write_unlock(fmc);
+				printk(KERN_ERR "JFFS: jffs_rewrite_data: "
+				       "Write error during rewrite. "
+				       "(data)\n");
+				goto retry;
+			}
+			pos += r;
+			size -= r;
+			offset += r;
+			raw_inode.dchksum += jffs_checksum(page, r);
+		}
+
+	        free_page((unsigned long)page);
+	}
+
+	raw_inode.accurate = 0;
+	raw_inode.chksum = jffs_checksum(&raw_inode,
+					 sizeof(struct jffs_raw_inode)
+					 - sizeof(__u16));
+
+	/* Add the checksum.  */
+	if ((err
+	     = flash_safe_write(fmc->mtd, pos_dchksum,
+				&((u_char *)
+				&raw_inode)[JFFS_RAW_INODE_DCHKSUM_OFFSET],
+				sizeof(__u32) + sizeof(__u16)
+				+ sizeof(__u16))) < 0) {
+		jffs_fmfree_partly(fmc, fm, 0);
+		jffs_fm_write_unlock(fmc);
+		printk(KERN_ERR "JFFS: jffs_rewrite_data: Write error during "
+		       "rewrite. (checksum)\n");
+		goto retry;
+	}
+
+	/* Now make the file system aware of the newly written node.  */
+	jffs_insert_node(c, f, &raw_inode, f->name, new_node);
+	jffs_fm_write_unlock(fmc);
+
+	D3(printk("jffs_rewrite_data(): Leaving...\n"));
+	return 0;
+} /* jffs_rewrite_data()  */
+
+
+/* jffs_garbage_collect_next implements one step in the garbage collect
+   process and is often called multiple times at each occasion of a
+   garbage collect.  */
+
+static int
+jffs_garbage_collect_next(struct jffs_control *c)
+{
+	struct jffs_fmcontrol *fmc = c->fmc;
+	struct jffs_node *node;
+	struct jffs_file *f;
+	int err = 0;
+	__u32 size;
+	__u32 data_size;
+	__u32 total_name_size;
+	__u32 extra_available;
+	__u32 space_needed;
+	__u32 free_chunk_size1 = jffs_free_size1(fmc);
+	D2(__u32 free_chunk_size2 = jffs_free_size2(fmc));
+
+	/* Get the oldest node in the flash.  */
+	node = jffs_get_oldest_node(fmc);
+	ASSERT(if (!node) {
+		printk(KERN_ERR "JFFS: jffs_garbage_collect_next: "
+		       "No oldest node found!\n");
+                err = -1;
+                goto jffs_garbage_collect_next_end;
+		
+
+	});
+
+	/* Find its corresponding file too.  */
+	f = jffs_find_file(c, node->ino);
+
+	if (!f) {
+	  printk (KERN_ERR "JFFS: jffs_garbage_collect_next: "
+                  "No file to garbage collect! "
+		  "(ino = 0x%08x)\n", node->ino);
+          /* FIXME: Free the offending node and recover. */
+          err = -1;
+          goto jffs_garbage_collect_next_end;
+	}
+
+	/* We always write out the name. Theoretically, we don't need
+	   to, but for now it's easier - because otherwise we'd have
+	   to keep track of how many times the current name exists on
+	   the flash and make sure it never reaches zero.
+
+	   The current approach means that would be possible to cause
+	   the GC to end up eating its tail by writing lots of nodes
+	   with no name for it to garbage-collect. Hence the change in
+	   inode.c to write names with _every_ node.
+
+	   It sucks, but it _should_ work.
+	*/
+	total_name_size = JFFS_PAD(f->nsize);
+
+	D1(printk("jffs_garbage_collect_next(): \"%s\", "
+		  "ino: %u, version: %u, location 0x%x, dsize %u\n",
+		  (f->name ? f->name : ""), node->ino, node->version, 
+		  node->fm->offset, node->data_size));
+
+	/* Compute how many data it's possible to rewrite at the moment.  */
+	data_size = f->size - node->data_offset;
+
+	/* And from that, the total size of the chunk we want to write */
+	size = sizeof(struct jffs_raw_inode) + total_name_size
+	       + data_size + JFFS_GET_PAD_BYTES(data_size);
+
+	/* If that's more than max_chunk_size, reduce it accordingly */
+	if (size > fmc->max_chunk_size) {
+		size = fmc->max_chunk_size;
+		data_size = size - sizeof(struct jffs_raw_inode)
+			    - total_name_size;
+	}
+
+	/* If we're asking to take up more space than free_chunk_size1
+	   but we _could_ fit in it, shrink accordingly.
+	*/
+	if (size > free_chunk_size1) {
+
+		if (free_chunk_size1 <
+		    (sizeof(struct jffs_raw_inode) + total_name_size + BLOCK_SIZE)){
+			/* The space left is too small to be of any
+			   use really.  */
+			struct jffs_fm *dirty_fm
+			= jffs_fmalloced(fmc,
+					 fmc->tail->offset + fmc->tail->size,
+					 free_chunk_size1, NULL);
+			if (!dirty_fm) {
+				printk(KERN_ERR "JFFS: "
+				       "jffs_garbage_collect_next: "
+				       "Failed to allocate `dirty' "
+				       "flash memory!\n");
+				err = -1;
+                                goto jffs_garbage_collect_next_end;
+			}
+			D1(printk("Dirtying end of flash - too small\n"));
+			jffs_write_dummy_node(c, dirty_fm);
+                        err = 0;
+			goto jffs_garbage_collect_next_end;
+		}
+		D1(printk("Reducing size of new node from %d to %d to avoid "
+			  " exceeding free_chunk_size1\n",
+			  size, free_chunk_size1));
+
+		size = free_chunk_size1;
+		data_size = size - sizeof(struct jffs_raw_inode)
+			    - total_name_size;
+	}
+
+
+	/* Calculate the amount of space needed to hold the nodes
+	   which are remaining in the tail */
+	space_needed = fmc->min_free_size - (node->fm->offset % fmc->sector_size);
+
+	/* From that, calculate how much 'extra' space we can use to
+	   increase the size of the node we're writing from the size
+	   of the node we're obsoleting
+	*/
+	if (space_needed > fmc->free_size) {
+		/* If we've gone below min_free_size for some reason,
+		   don't fuck up. This is why we have 
+		   min_free_size > sector_size. Whinge about it though,
+		   just so I can convince myself my maths is right.
+		*/
+		D1(printk(KERN_WARNING "jffs_garbage_collect_next(): "
+			  "space_needed %d exceeded free_size %d\n",
+			  space_needed, fmc->free_size));
+		extra_available = 0;
+	} else {
+		extra_available = fmc->free_size - space_needed;
+	}
+
+	/* Check that we don't use up any more 'extra' space than
+	   what's available */
+	if (size > JFFS_PAD(node->data_size) + total_name_size + 
+	    sizeof(struct jffs_raw_inode) + extra_available) {
+		D1(printk("Reducing size of new node from %d to %ld to avoid "
+		       "catching our tail\n", size, 
+			  (long) (JFFS_PAD(node->data_size) + JFFS_PAD(node->name_size) + 
+			  sizeof(struct jffs_raw_inode) + extra_available)));
+		D1(printk("space_needed = %d, extra_available = %d\n", 
+			  space_needed, extra_available));
+
+		size = JFFS_PAD(node->data_size) + total_name_size + 
+		  sizeof(struct jffs_raw_inode) + extra_available;
+		data_size = size - sizeof(struct jffs_raw_inode)
+			- total_name_size;
+	};
+
+	D2(printk("  total_name_size: %u\n", total_name_size));
+	D2(printk("  data_size: %u\n", data_size));
+	D2(printk("  size: %u\n", size));
+	D2(printk("  f->nsize: %u\n", f->nsize));
+	D2(printk("  f->size: %u\n", f->size));
+	D2(printk("  node->data_offset: %u\n", node->data_offset));
+	D2(printk("  free_chunk_size1: %u\n", free_chunk_size1));
+	D2(printk("  free_chunk_size2: %u\n", free_chunk_size2));
+	D2(printk("  node->fm->offset: 0x%08x\n", node->fm->offset));
+
+	if ((err = jffs_rewrite_data(f, node, data_size))) {
+		printk(KERN_WARNING "jffs_rewrite_data() failed: %d\n", err);
+		return err;
+	}
+	  
+jffs_garbage_collect_next_end:
+	D3(printk("jffs_garbage_collect_next: Leaving...\n"));
+	return err;
+} /* jffs_garbage_collect_next */
+
+
+/* If an obsolete node is partly going to be erased due to garbage
+   collection, the part that isn't going to be erased must be filled
+   with zeroes so that the scan of the flash will work smoothly next
+   time.  (The data in the file could for instance be a JFFS image
+   which could cause enormous confusion during a scan of the flash
+   device if we didn't do this.)
+     There are two phases in this procedure: First, the clearing of
+   the name and data parts of the node. Second, possibly also clearing
+   a part of the raw inode as well.  If the box is power cycled during
+   the first phase, only the checksum of this node-to-be-cleared-at-
+   the-end will be wrong.  If the box is power cycled during, or after,
+   the clearing of the raw inode, the information like the length of
+   the name and data parts are zeroed.  The next time the box is
+   powered up, the scanning algorithm manages this faulty data too
+   because:
+
+   - The checksum is invalid and thus the raw inode must be discarded
+     in any case.
+   - If the lengths of the data part or the name part are zeroed, the
+     scanning just continues after the raw inode.  But after the inode
+     the scanning procedure just finds zeroes which is the same as
+     dirt.
+
+   So, in the end, this could never fail. :-)  Even if it does fail,
+   the scanning algorithm should manage that too.  */
+
+static int
+jffs_clear_end_of_node(struct jffs_control *c, __u32 erase_size)
+{
+	struct jffs_fm *fm;
+	struct jffs_fmcontrol *fmc = c->fmc;
+	__u32 zero_offset;
+	__u32 zero_size;
+	__u32 zero_offset_data;
+	__u32 zero_size_data;
+	__u32 cutting_raw_inode = 0;
+
+	if (!(fm = jffs_cut_node(fmc, erase_size))) {
+		D3(printk("jffs_clear_end_of_node(): fm == NULL\n"));
+		return 0;
+	}
+
+	/* Where and how much shall we clear?  */
+	zero_offset = fmc->head->offset + erase_size;
+	zero_size = fm->offset + fm->size - zero_offset;
+
+	/* Do we have to clear the raw_inode explicitly?  */
+	if (fm->size - zero_size < sizeof(struct jffs_raw_inode)) {
+		cutting_raw_inode = sizeof(struct jffs_raw_inode)
+				    - (fm->size - zero_size);
+	}
+
+	/* First, clear the name and data fields.  */
+	zero_offset_data = zero_offset + cutting_raw_inode;
+	zero_size_data = zero_size - cutting_raw_inode;
+	flash_safe_acquire(fmc->mtd);
+	flash_memset(fmc->mtd, zero_offset_data, 0, zero_size_data);
+	flash_safe_release(fmc->mtd);
+
+	/* Should we clear a part of the raw inode?  */
+	if (cutting_raw_inode) {
+		/* I guess it is ok to clear the raw inode in this order.  */
+		flash_safe_acquire(fmc->mtd);
+		flash_memset(fmc->mtd, zero_offset, 0,
+			     cutting_raw_inode);
+		flash_safe_release(fmc->mtd);
+	}
+
+	return 0;
+} /* jffs_clear_end_of_node()  */
+
+/* Try to erase as much as possible of the dirt in the flash memory.  */
+static long
+jffs_try_to_erase(struct jffs_control *c)
+{
+	struct jffs_fmcontrol *fmc = c->fmc;
+	long erase_size;
+	int err;
+	__u32 offset;
+
+	D3(printk("jffs_try_to_erase()\n"));
+
+	erase_size = jffs_erasable_size(fmc);
+
+	D2(printk("jffs_try_to_erase(): erase_size = %ld\n", erase_size));
+
+	if (erase_size == 0) {
+		return 0;
+	}
+	else if (erase_size < 0) {
+		printk(KERN_ERR "JFFS: jffs_try_to_erase: "
+		       "jffs_erasable_size returned %ld.\n", erase_size);
+		return erase_size;
+	}
+
+	if ((err = jffs_clear_end_of_node(c, erase_size)) < 0) {
+		printk(KERN_ERR "JFFS: jffs_try_to_erase: "
+		       "Clearing of node failed.\n");
+		return err;
+	}
+
+	offset = fmc->head->offset;
+
+	/* Now, let's try to do the erase.  */
+	if ((err = flash_erase_region(fmc->mtd,
+				      offset, erase_size)) < 0) {
+		printk(KERN_ERR "JFFS: Erase of flash failed. "
+		       "offset = %u, erase_size = %ld\n",
+		       offset, erase_size);
+		/* XXX: Here we should allocate this area as dirty
+		   with jffs_fmalloced or something similar.  Now
+		   we just report the error.  */
+		return err;
+	}
+
+#if 0
+	/* Check if the erased sectors really got erased.  */
+	{
+		__u32 pos;
+		__u32 end;
+
+		pos = (__u32)flash_get_direct_pointer(to_kdev_t(c->sb->s_dev), offset);
+		end = pos + erase_size;
+
+		D2(printk("JFFS: Checking erased sector(s)...\n"));
+
+		flash_safe_acquire(fmc->mtd);
+
+		for (; pos < end; pos += 4) {
+			if (*(__u32 *)pos != JFFS_EMPTY_BITMASK) {
+				printk("JFFS: Erase failed! pos = 0x%lx\n",
+				       (long)pos);
+				jffs_hexdump(fmc->mtd, pos,
+					     jffs_min(256, end - pos));
+				err = -1;
+				break;
+			}
+		}
+
+		flash_safe_release(fmc->mtd);
+
+		if (!err) {
+			D2(printk("JFFS: Erase succeeded.\n"));
+		}
+		else {
+			/* XXX: Here we should allocate the memory
+			   with jffs_fmalloced() in order to prevent
+			   JFFS from using this area accidentally.  */
+			return err;
+		}
+	}
+#endif
+
+	/* Update the flash memory data structures.  */
+	jffs_sync_erase(fmc, erase_size);
+
+	return erase_size;
+}
+
+
+/* There are different criteria that should trigger a garbage collect:
+
+   1. There is too much dirt in the memory.
+   2. The free space is becoming small.
+   3. There are many versions of a node.
+
+   The garbage collect should always be done in a manner that guarantees
+   that future garbage collects cannot be locked.  E.g. Rewritten chunks
+   should not be too large (span more than one sector in the flash memory
+   for exemple).  Of course there is a limit on how intelligent this garbage
+   collection can be.  */
+
+
+static int
+jffs_garbage_collect_now(struct jffs_control *c)
+{
+	struct jffs_fmcontrol *fmc = c->fmc;
+	long erased = 0;
+	int result = 0;
+	D1(int i = 1);
+	D2(printk("***jffs_garbage_collect_now(): fmc->dirty_size = %u, fmc->free_size = 0x%x\n, fcs1=0x%x, fcs2=0x%x",
+		  fmc->dirty_size, fmc->free_size, jffs_free_size1(fmc), jffs_free_size2(fmc)));
+	D2(jffs_print_fmcontrol(fmc));
+
+	//	down(&fmc->gclock);
+
+	/* If it is possible to garbage collect, do so.  */
+	
+	while (erased == 0) {
+		D1(printk("***jffs_garbage_collect_now(): round #%u, "
+			  "fmc->dirty_size = %u\n", i++, fmc->dirty_size));
+		D2(jffs_print_fmcontrol(fmc));
+
+		if ((erased = jffs_try_to_erase(c)) < 0) {
+			printk(KERN_WARNING "JFFS: Error in "
+			       "garbage collector.\n");
+			result = erased;
+			goto gc_end;
+		}
+		if (erased)
+			break;
+		
+		if (fmc->free_size == 0) {
+			/* Argh */
+			printk(KERN_ERR "jffs_garbage_collect_now(): free_size == 0. This is BAD.\n");
+			result = -ENOSPC;
+			break;
+		}
+
+		if (fmc->dirty_size < fmc->sector_size) {
+			/* Actually, we _may_ have been able to free some, 
+			 * if there are many overlapping nodes which aren't
+			 * actually marked dirty because they still have
+			 * some valid data in each.
+			 */
+			result = -ENOSPC;
+			break;
+		}
+
+		/* Let's dare to make a garbage collect.  */
+		if ((result = jffs_garbage_collect_next(c)) < 0) {
+			printk(KERN_ERR "JFFS: Something "
+			       "has gone seriously wrong "
+			       "with a garbage collect.\n");
+			goto gc_end;
+		}
+
+		D1(printk("   jffs_garbage_collect_now(): erased: %ld\n", erased));
+		DJM(jffs_print_memory_allocation_statistics());
+	}
+	
+gc_end:
+	//	up(&fmc->gclock);
+
+	D3(printk("   jffs_garbage_collect_now(): Leaving...\n"));
+	D1(if (erased) {
+		printk("jffs_g_c_now(): erased = %ld\n", erased);
+		jffs_print_fmcontrol(fmc);
+	});
+
+	if (!erased && !result)
+		return -ENOSPC;
+
+	return result;
+} /* jffs_garbage_collect_now() */
+
+
+/* Determine if it is reasonable to start garbage collection.
+   We start a gc pass if either:
+   - The number of free bytes < MIN_FREE_BYTES && at least one
+     block is dirty, OR
+   - The number of dirty bytes > MAX_DIRTY_BYTES
+*/
+static inline int thread_should_wake (struct jffs_control *c)
+{
+	D1(printk (KERN_NOTICE "thread_should_wake(): free=%d, dirty=%d, blocksize=%d.\n",
+		   c->fmc->free_size, c->fmc->dirty_size, c->fmc->sector_size));
+
+	/* If there's not enough dirty space to free a block, there's no point. */
+	if (c->fmc->dirty_size < c->fmc->sector_size) {
+		D2(printk(KERN_NOTICE "thread_should_wake(): Not waking. Insufficient dirty space\n"));
+		return 0;
+	}
+#if 1
+	/* If there is too much RAM used by the various structures, GC */
+	if (jffs_get_node_inuse() > (c->fmc->used_size/c->fmc->max_chunk_size * 5 + jffs_get_file_count() * 2 + 50)) {
+		/* FIXME: Provide proof that this test can be satisfied. We
+		   don't want a filesystem doing endless GC just because this
+		   condition cannot ever be false.
+		*/
+		D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to number of nodes\n"));
+		return 1;
+	}
+#endif
+	/* If there are fewer free bytes than the threshold, GC */
+	if (c->fmc->free_size < c->gc_minfree_threshold) {
+		D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to insufficent free space\n"));
+		return 1;
+	}
+	/* If there are more dirty bytes than the threshold, GC */
+	if (c->fmc->dirty_size > c->gc_maxdirty_threshold) {
+		D2(printk(KERN_NOTICE "thread_should_wake(): Waking due to excessive dirty space\n"));
+		return 1;
+	}	
+	/* FIXME: What about the "There are many versions of a node" condition? */
+
+	return 0;
+}
+
+
+void jffs_garbage_collect_trigger(struct jffs_control *c)
+{
+	/* NOTE: We rely on the fact that we have the BKL here.
+	 * Otherwise, the gc_task could go away between the check
+	 * and the wake_up_process()
+	 */
+	if (c->gc_task && thread_should_wake(c))
+		send_sig(SIGHUP, c->gc_task, 1);
+}
+  
+
+/* Kernel threads  take (void *) as arguments.   Thus we pass
+   the jffs_control data as a (void *) and then cast it. */
+int
+jffs_garbage_collect_thread(void *ptr)
+{
+        struct jffs_control *c = (struct jffs_control *) ptr;
+	struct jffs_fmcontrol *fmc = c->fmc;
+	long erased;
+	int result = 0;
+	D1(int i = 1);
+
+	daemonize("jffs_gcd");
+
+	c->gc_task = current;
+
+	lock_kernel();
+	init_completion(&c->gc_thread_comp); /* barrier */ 
+	spin_lock_irq(&current->sighand->siglock);
+	siginitsetinv (&current->blocked, sigmask(SIGHUP) | sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGCONT));
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): Starting infinite loop.\n"));
+
+	for (;;) {
+
+		/* See if we need to start gc.  If we don't, go to sleep.
+		   
+		   Current implementation is a BAD THING(tm).  If we try 
+		   to unmount the FS, the unmount operation will sleep waiting
+		   for this thread to exit.  We need to arrange to send it a
+		   sig before the umount process sleeps.
+		*/
+
+		if (!thread_should_wake(c))
+			set_current_state (TASK_INTERRUPTIBLE);
+		
+		schedule(); /* Yes, we do this even if we want to go
+				       on immediately - we're a low priority 
+				       background task. */
+
+		/* Put_super will send a SIGKILL and then wait on the sem. 
+		 */
+		while (signal_pending(current)) {
+			siginfo_t info;
+			unsigned long signr = 0;
+
+			spin_lock_irq(&current->sighand->siglock);
+			signr = dequeue_signal(current, &current->blocked, &info);
+			spin_unlock_irq(&current->sighand->siglock);
+
+			switch(signr) {
+			case SIGSTOP:
+				D1(printk("jffs_garbage_collect_thread(): SIGSTOP received.\n"));
+				set_current_state(TASK_STOPPED);
+				schedule();
+				break;
+
+			case SIGKILL:
+				D1(printk("jffs_garbage_collect_thread(): SIGKILL received.\n"));
+				c->gc_task = NULL;
+				complete_and_exit(&c->gc_thread_comp, 0);
+			}
+		}
+
+
+		D1(printk (KERN_NOTICE "jffs_garbage_collect_thread(): collecting.\n"));
+
+		D3(printk (KERN_NOTICE "g_c_thread(): down biglock\n"));
+		down(&fmc->biglock);
+		
+		D1(printk("***jffs_garbage_collect_thread(): round #%u, "
+			  "fmc->dirty_size = %u\n", i++, fmc->dirty_size));
+		D2(jffs_print_fmcontrol(fmc));
+
+		if ((erased = jffs_try_to_erase(c)) < 0) {
+			printk(KERN_WARNING "JFFS: Error in "
+			       "garbage collector: %ld.\n", erased);
+		}
+
+		if (erased)
+			goto gc_end;
+
+		if (fmc->free_size == 0) {
+			/* Argh. Might as well commit suicide. */
+			printk(KERN_ERR "jffs_garbage_collect_thread(): free_size == 0. This is BAD.\n");
+			send_sig(SIGQUIT, c->gc_task, 1);
+			// panic()
+			goto gc_end;
+		}
+		
+		/* Let's dare to make a garbage collect.  */
+		if ((result = jffs_garbage_collect_next(c)) < 0) {
+			printk(KERN_ERR "JFFS: Something "
+			       "has gone seriously wrong "
+			       "with a garbage collect: %d\n", result);
+		}
+		
+	gc_end:
+		D3(printk (KERN_NOTICE "g_c_thread(): up biglock\n"));
+		up(&fmc->biglock);
+	} /* for (;;) */
+} /* jffs_garbage_collect_thread() */