Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 1300 insertions, 0 deletions

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
new file mode 100644
index 0000000..d9a721e
--- /dev/null
+++ b/fs/jffs2/wbuf.c
@@ -0,0 +1,1300 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004 Thomas Gleixner <tglx@linutronix.de>
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ * Modified debugged and enhanced by Thomas Gleixner <tglx@linutronix.de>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/crc32.h>
+#include <linux/mtd/nand.h>
+#include <linux/jiffies.h>
+#include <linux/sched.h>
+
+#include "nodelist.h"
+
+/* For testing write failures */
+#undef BREAKME
+#undef BREAKMEHEADER
+
+#ifdef BREAKME
+static unsigned char *brokenbuf;
+#endif
+
+#define PAGE_DIV(x) ( ((unsigned long)(x) / (unsigned long)(c->wbuf_pagesize)) * (unsigned long)(c->wbuf_pagesize) )
+#define PAGE_MOD(x) ( (unsigned long)(x) % (unsigned long)(c->wbuf_pagesize) )
+
+/* max. erase failures before we mark a block bad */
+#define MAX_ERASE_FAILURES 	2
+
+struct jffs2_inodirty {
+	uint32_t ino;
+	struct jffs2_inodirty *next;
+};
+
+static struct jffs2_inodirty inodirty_nomem;
+
+static int jffs2_wbuf_pending_for_ino(struct jffs2_sb_info *c, uint32_t ino)
+{
+	struct jffs2_inodirty *this = c->wbuf_inodes;
+
+	/* If a malloc failed, consider _everything_ dirty */
+	if (this == &inodirty_nomem)
+		return 1;
+
+	/* If ino == 0, _any_ non-GC writes mean 'yes' */
+	if (this && !ino)
+		return 1;
+
+	/* Look to see if the inode in question is pending in the wbuf */
+	while (this) {
+		if (this->ino == ino)
+			return 1;
+		this = this->next;
+	}
+	return 0;
+}
+
+static void jffs2_clear_wbuf_ino_list(struct jffs2_sb_info *c)
+{
+	struct jffs2_inodirty *this;
+
+	this = c->wbuf_inodes;
+
+	if (this != &inodirty_nomem) {
+		while (this) {
+			struct jffs2_inodirty *next = this->next;
+			kfree(this);
+			this = next;
+		}
+	}
+	c->wbuf_inodes = NULL;
+}
+
+static void jffs2_wbuf_dirties_inode(struct jffs2_sb_info *c, uint32_t ino)
+{
+	struct jffs2_inodirty *new;
+
+	/* Mark the superblock dirty so that kupdated will flush... */
+	jffs2_erase_pending_trigger(c);
+
+	if (jffs2_wbuf_pending_for_ino(c, ino))
+		return;
+
+	new = kmalloc(sizeof(*new), GFP_KERNEL);
+	if (!new) {
+		D1(printk(KERN_DEBUG "No memory to allocate inodirty. Fallback to all considered dirty\n"));
+		jffs2_clear_wbuf_ino_list(c);
+		c->wbuf_inodes = &inodirty_nomem;
+		return;
+	}
+	new->ino = ino;
+	new->next = c->wbuf_inodes;
+	c->wbuf_inodes = new;
+	return;
+}
+
+static inline void jffs2_refile_wbuf_blocks(struct jffs2_sb_info *c)
+{
+	struct list_head *this, *next;
+	static int n;
+
+	if (list_empty(&c->erasable_pending_wbuf_list))
+		return;
+
+	list_for_each_safe(this, next, &c->erasable_pending_wbuf_list) {
+		struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+
+		D1(printk(KERN_DEBUG "Removing eraseblock at 0x%08x from erasable_pending_wbuf_list...\n", jeb->offset));
+		list_del(this);
+		if ((jiffies + (n++)) & 127) {
+			/* Most of the time, we just erase it immediately. Otherwise we
+			   spend ages scanning it on mount, etc. */
+			D1(printk(KERN_DEBUG "...and adding to erase_pending_list\n"));
+			list_add_tail(&jeb->list, &c->erase_pending_list);
+			c->nr_erasing_blocks++;
+			jffs2_erase_pending_trigger(c);
+		} else {
+			/* Sometimes, however, we leave it elsewhere so it doesn't get
+			   immediately reused, and we spread the load a bit. */
+			D1(printk(KERN_DEBUG "...and adding to erasable_list\n"));
+			list_add_tail(&jeb->list, &c->erasable_list);
+		}
+	}
+}
+
+#define REFILE_NOTEMPTY 0
+#define REFILE_ANYWAY   1
+
+static void jffs2_block_refile(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, int allow_empty)
+{
+	D1(printk("About to refile bad block at %08x\n", jeb->offset));
+
+	/* File the existing block on the bad_used_list.... */
+	if (c->nextblock == jeb)
+		c->nextblock = NULL;
+	else /* Not sure this should ever happen... need more coffee */
+		list_del(&jeb->list);
+	if (jeb->first_node) {
+		D1(printk("Refiling block at %08x to bad_used_list\n", jeb->offset));
+		list_add(&jeb->list, &c->bad_used_list);
+	} else {
+		BUG_ON(allow_empty == REFILE_NOTEMPTY);
+		/* It has to have had some nodes or we couldn't be here */
+		D1(printk("Refiling block at %08x to erase_pending_list\n", jeb->offset));
+		list_add(&jeb->list, &c->erase_pending_list);
+		c->nr_erasing_blocks++;
+		jffs2_erase_pending_trigger(c);
+	}
+
+	if (!jffs2_prealloc_raw_node_refs(c, jeb, 1)) {
+		uint32_t oldfree = jeb->free_size;
+
+		jffs2_link_node_ref(c, jeb, 
+				    (jeb->offset+c->sector_size-oldfree) | REF_OBSOLETE,
+				    oldfree, NULL);
+		/* convert to wasted */
+		c->wasted_size += oldfree;
+		jeb->wasted_size += oldfree;
+		c->dirty_size -= oldfree;
+		jeb->dirty_size -= oldfree;
+	}
+
+	jffs2_dbg_dump_block_lists_nolock(c);
+	jffs2_dbg_acct_sanity_check_nolock(c,jeb);
+	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
+}
+
+static struct jffs2_raw_node_ref **jffs2_incore_replace_raw(struct jffs2_sb_info *c,
+							    struct jffs2_inode_info *f,
+							    struct jffs2_raw_node_ref *raw,
+							    union jffs2_node_union *node)
+{
+	struct jffs2_node_frag *frag;
+	struct jffs2_full_dirent *fd;
+
+	dbg_noderef("incore_replace_raw: node at %p is {%04x,%04x}\n",
+		    node, je16_to_cpu(node->u.magic), je16_to_cpu(node->u.nodetype));
+
+	BUG_ON(je16_to_cpu(node->u.magic) != 0x1985 &&
+	       je16_to_cpu(node->u.magic) != 0);
+
+	switch (je16_to_cpu(node->u.nodetype)) {
+	case JFFS2_NODETYPE_INODE:
+		if (f->metadata && f->metadata->raw == raw) {
+			dbg_noderef("Will replace ->raw in f->metadata at %p\n", f->metadata);
+			return &f->metadata->raw;
+		}
+		frag = jffs2_lookup_node_frag(&f->fragtree, je32_to_cpu(node->i.offset));
+		BUG_ON(!frag);
+		/* Find a frag which refers to the full_dnode we want to modify */
+		while (!frag->node || frag->node->raw != raw) {
+			frag = frag_next(frag);
+			BUG_ON(!frag);
+		}
+		dbg_noderef("Will replace ->raw in full_dnode at %p\n", frag->node);
+		return &frag->node->raw;
+
+	case JFFS2_NODETYPE_DIRENT:
+		for (fd = f->dents; fd; fd = fd->next) {
+			if (fd->raw == raw) {
+				dbg_noderef("Will replace ->raw in full_dirent at %p\n", fd);
+				return &fd->raw;
+			}
+		}
+		BUG();
+
+	default:
+		dbg_noderef("Don't care about replacing raw for nodetype %x\n",
+			    je16_to_cpu(node->u.nodetype));
+		break;
+	}
+	return NULL;
+}
+
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf,
+			      uint32_t ofs)
+{
+	int ret;
+	size_t retlen;
+	char *eccstr;
+
+	ret = c->mtd->read(c->mtd, ofs, c->wbuf_pagesize, &retlen, c->wbuf_verify);
+	if (ret && ret != -EUCLEAN && ret != -EBADMSG) {
+		printk(KERN_WARNING "jffs2_verify_write(): Read back of page at %08x failed: %d\n", c->wbuf_ofs, ret);
+		return ret;
+	} else if (retlen != c->wbuf_pagesize) {
+		printk(KERN_WARNING "jffs2_verify_write(): Read back of page at %08x gave short read: %zd not %d.\n", ofs, retlen, c->wbuf_pagesize);
+		return -EIO;
+	}
+	if (!memcmp(buf, c->wbuf_verify, c->wbuf_pagesize))
+		return 0;
+
+	if (ret == -EUCLEAN)
+		eccstr = "corrected";
+	else if (ret == -EBADMSG)
+		eccstr = "correction failed";
+	else
+		eccstr = "OK or unused";
+
+	printk(KERN_WARNING "Write verify error (ECC %s) at %08x. Wrote:\n",
+	       eccstr, c->wbuf_ofs);
+	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
+		       c->wbuf, c->wbuf_pagesize, 0);
+
+	printk(KERN_WARNING "Read back:\n");
+	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1,
+		       c->wbuf_verify, c->wbuf_pagesize, 0);
+
+	return -EIO;
+}
+#else
+#define jffs2_verify_write(c,b,o) (0)
+#endif
+
+/* Recover from failure to write wbuf. Recover the nodes up to the
+ * wbuf, not the one which we were starting to try to write. */
+
+static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
+{
+	struct jffs2_eraseblock *jeb, *new_jeb;
+	struct jffs2_raw_node_ref *raw, *next, *first_raw = NULL;
+	size_t retlen;
+	int ret;
+	int nr_refile = 0;
+	unsigned char *buf;
+	uint32_t start, end, ofs, len;
+
+	jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
+
+	spin_lock(&c->erase_completion_lock);
+	if (c->wbuf_ofs % c->mtd->erasesize)
+		jffs2_block_refile(c, jeb, REFILE_NOTEMPTY);
+	else
+		jffs2_block_refile(c, jeb, REFILE_ANYWAY);
+	spin_unlock(&c->erase_completion_lock);
+
+	BUG_ON(!ref_obsolete(jeb->last_node));
+
+	/* Find the first node to be recovered, by skipping over every
+	   node which ends before the wbuf starts, or which is obsolete. */
+	for (next = raw = jeb->first_node; next; raw = next) {
+		next = ref_next(raw);
+
+		if (ref_obsolete(raw) || 
+		    (next && ref_offset(next) <= c->wbuf_ofs)) {
+			dbg_noderef("Skipping node at 0x%08x(%d)-0x%08x which is either before 0x%08x or obsolete\n",
+				    ref_offset(raw), ref_flags(raw),
+				    (ref_offset(raw) + ref_totlen(c, jeb, raw)),
+				    c->wbuf_ofs);
+			continue;
+		}
+		dbg_noderef("First node to be recovered is at 0x%08x(%d)-0x%08x\n",
+			    ref_offset(raw), ref_flags(raw),
+			    (ref_offset(raw) + ref_totlen(c, jeb, raw)));
+
+		first_raw = raw;
+		break;
+	}
+
+	if (!first_raw) {
+		/* All nodes were obsolete. Nothing to recover. */
+		D1(printk(KERN_DEBUG "No non-obsolete nodes to be recovered. Just filing block bad\n"));
+		c->wbuf_len = 0;
+		return;
+	}
+
+	start = ref_offset(first_raw);
+	end = ref_offset(jeb->last_node);
+	nr_refile = 1;
+
+	/* Count the number of refs which need to be copied */
+	while ((raw = ref_next(raw)) != jeb->last_node)
+		nr_refile++;
+
+	dbg_noderef("wbuf recover %08x-%08x (%d bytes in %d nodes)\n",
+		    start, end, end - start, nr_refile);
+
+	buf = NULL;
+	if (start < c->wbuf_ofs) {
+		/* First affected node was already partially written.
+		 * Attempt to reread the old data into our buffer. */
+
+		buf = kmalloc(end - start, GFP_KERNEL);
+		if (!buf) {
+			printk(KERN_CRIT "Malloc failure in wbuf recovery. Data loss ensues.\n");
+
+			goto read_failed;
+		}
+
+		/* Do the read... */
+		ret = c->mtd->read(c->mtd, start, c->wbuf_ofs - start, &retlen, buf);
+
+		/* ECC recovered ? */
+		if ((ret == -EUCLEAN || ret == -EBADMSG) &&
+		    (retlen == c->wbuf_ofs - start))
+			ret = 0;
+
+		if (ret || retlen != c->wbuf_ofs - start) {
+			printk(KERN_CRIT "Old data are already lost in wbuf recovery. Data loss ensues.\n");
+
+			kfree(buf);
+			buf = NULL;
+		read_failed:
+			first_raw = ref_next(first_raw);
+			nr_refile--;
+			while (first_raw && ref_obsolete(first_raw)) {
+				first_raw = ref_next(first_raw);
+				nr_refile--;
+			}
+
+			/* If this was the only node to be recovered, give up */
+			if (!first_raw) {
+				c->wbuf_len = 0;
+				return;
+			}
+
+			/* It wasn't. Go on and try to recover nodes complete in the wbuf */
+			start = ref_offset(first_raw);
+			dbg_noderef("wbuf now recover %08x-%08x (%d bytes in %d nodes)\n",
+				    start, end, end - start, nr_refile);
+
+		} else {
+			/* Read succeeded. Copy the remaining data from the wbuf */
+			memcpy(buf + (c->wbuf_ofs - start), c->wbuf, end - c->wbuf_ofs);
+		}
+	}
+	/* OK... we're to rewrite (end-start) bytes of data from first_raw onwards.
+	   Either 'buf' contains the data, or we find it in the wbuf */
+
+	/* ... and get an allocation of space from a shiny new block instead */
+	ret = jffs2_reserve_space_gc(c, end-start, &len, JFFS2_SUMMARY_NOSUM_SIZE);
+	if (ret) {
+		printk(KERN_WARNING "Failed to allocate space for wbuf recovery. Data loss ensues.\n");
+		kfree(buf);
+		return;
+	}
+
+	/* The summary is not recovered, so it must be disabled for this erase block */
+	jffs2_sum_disable_collecting(c->summary);
+
+	ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, nr_refile);
+	if (ret) {
+		printk(KERN_WARNING "Failed to allocate node refs for wbuf recovery. Data loss ensues.\n");
+		kfree(buf);
+		return;
+	}
+
+	ofs = write_ofs(c);
+
+	if (end-start >= c->wbuf_pagesize) {
+		/* Need to do another write immediately, but it's possible
+		   that this is just because the wbuf itself is completely
+		   full, and there's nothing earlier read back from the
+		   flash. Hence 'buf' isn't necessarily what we're writing
+		   from. */
+		unsigned char *rewrite_buf = buf?:c->wbuf;
+		uint32_t towrite = (end-start) - ((end-start)%c->wbuf_pagesize);
+
+		D1(printk(KERN_DEBUG "Write 0x%x bytes at 0x%08x in wbuf recover\n",
+			  towrite, ofs));
+
+#ifdef BREAKMEHEADER
+		static int breakme;
+		if (breakme++ == 20) {
+			printk(KERN_NOTICE "Faking write error at 0x%08x\n", ofs);
+			breakme = 0;
+			c->mtd->write(c->mtd, ofs, towrite, &retlen,
+				      brokenbuf);
+			ret = -EIO;
+		} else
+#endif
+			ret = c->mtd->write(c->mtd, ofs, towrite, &retlen,
+					    rewrite_buf);
+
+		if (ret || retlen != towrite || jffs2_verify_write(c, rewrite_buf, ofs)) {
+			/* Argh. We tried. Really we did. */
+			printk(KERN_CRIT "Recovery of wbuf failed due to a second write error\n");
+			kfree(buf);
+
+			if (retlen)
+				jffs2_add_physical_node_ref(c, ofs | REF_OBSOLETE, ref_totlen(c, jeb, first_raw), NULL);
+
+			return;
+		}
+		printk(KERN_NOTICE "Recovery of wbuf succeeded to %08x\n", ofs);
+
+		c->wbuf_len = (end - start) - towrite;
+		c->wbuf_ofs = ofs + towrite;
+		memmove(c->wbuf, rewrite_buf + towrite, c->wbuf_len);
+		/* Don't muck about with c->wbuf_inodes. False positives are harmless. */
+	} else {
+		/* OK, now we're left with the dregs in whichever buffer we're using */
+		if (buf) {
+			memcpy(c->wbuf, buf, end-start);
+		} else {
+			memmove(c->wbuf, c->wbuf + (start - c->wbuf_ofs), end - start);
+		}
+		c->wbuf_ofs = ofs;
+		c->wbuf_len = end - start;
+	}
+
+	/* Now sort out the jffs2_raw_node_refs, moving them from the old to the next block */
+	new_jeb = &c->blocks[ofs / c->sector_size];
+
+	spin_lock(&c->erase_completion_lock);
+	for (raw = first_raw; raw != jeb->last_node; raw = ref_next(raw)) {
+		uint32_t rawlen = ref_totlen(c, jeb, raw);
+		struct jffs2_inode_cache *ic;
+		struct jffs2_raw_node_ref *new_ref;
+		struct jffs2_raw_node_ref **adjust_ref = NULL;
+		struct jffs2_inode_info *f = NULL;
+
+		D1(printk(KERN_DEBUG "Refiling block of %08x at %08x(%d) to %08x\n",
+			  rawlen, ref_offset(raw), ref_flags(raw), ofs));
+
+		ic = jffs2_raw_ref_to_ic(raw);
+
+		/* Ick. This XATTR mess should be fixed shortly... */
+		if (ic && ic->class == RAWNODE_CLASS_XATTR_DATUM) {
+			struct jffs2_xattr_datum *xd = (void *)ic;
+			BUG_ON(xd->node != raw);
+			adjust_ref = &xd->node;
+			raw->next_in_ino = NULL;
+			ic = NULL;
+		} else if (ic && ic->class == RAWNODE_CLASS_XATTR_REF) {
+			struct jffs2_xattr_datum *xr = (void *)ic;
+			BUG_ON(xr->node != raw);
+			adjust_ref = &xr->node;
+			raw->next_in_ino = NULL;
+			ic = NULL;
+		} else if (ic && ic->class == RAWNODE_CLASS_INODE_CACHE) {
+			struct jffs2_raw_node_ref **p = &ic->nodes;
+
+			/* Remove the old node from the per-inode list */
+			while (*p && *p != (void *)ic) {
+				if (*p == raw) {
+					(*p) = (raw->next_in_ino);
+					raw->next_in_ino = NULL;
+					break;
+				}
+				p = &((*p)->next_in_ino);
+			}
+
+			if (ic->state == INO_STATE_PRESENT && !ref_obsolete(raw)) {
+				/* If it's an in-core inode, then we have to adjust any
+				   full_dirent or full_dnode structure to point to the
+				   new version instead of the old */
+				f = jffs2_gc_fetch_inode(c, ic->ino, !ic->pino_nlink);
+				if (IS_ERR(f)) {
+					/* Should never happen; it _must_ be present */
+					JFFS2_ERROR("Failed to iget() ino #%u, err %ld\n",
+						    ic->ino, PTR_ERR(f));
+					BUG();
+				}
+				/* We don't lock f->sem. There's a number of ways we could
+				   end up in here with it already being locked, and nobody's
+				   going to modify it on us anyway because we hold the
+				   alloc_sem. We're only changing one ->raw pointer too,
+				   which we can get away with without upsetting readers. */
+				adjust_ref = jffs2_incore_replace_raw(c, f, raw,
+								      (void *)(buf?:c->wbuf) + (ref_offset(raw) - start));
+			} else if (unlikely(ic->state != INO_STATE_PRESENT &&
+					    ic->state != INO_STATE_CHECKEDABSENT &&
+					    ic->state != INO_STATE_GC)) {
+				JFFS2_ERROR("Inode #%u is in strange state %d!\n", ic->ino, ic->state);
+				BUG();
+			}
+		}
+
+		new_ref = jffs2_link_node_ref(c, new_jeb, ofs | ref_flags(raw), rawlen, ic);
+
+		if (adjust_ref) {
+			BUG_ON(*adjust_ref != raw);
+			*adjust_ref = new_ref;
+		}
+		if (f)
+			jffs2_gc_release_inode(c, f);
+
+		if (!ref_obsolete(raw)) {
+			jeb->dirty_size += rawlen;
+			jeb->used_size  -= rawlen;
+			c->dirty_size += rawlen;
+			c->used_size -= rawlen;
+			raw->flash_offset = ref_offset(raw) | REF_OBSOLETE;
+			BUG_ON(raw->next_in_ino);
+		}
+		ofs += rawlen;
+	}
+
+	kfree(buf);
+
+	/* Fix up the original jeb now it's on the bad_list */
+	if (first_raw == jeb->first_node) {
+		D1(printk(KERN_DEBUG "Failing block at %08x is now empty. Moving to erase_pending_list\n", jeb->offset));
+		list_move(&jeb->list, &c->erase_pending_list);
+		c->nr_erasing_blocks++;
+		jffs2_erase_pending_trigger(c);
+	}
+
+	jffs2_dbg_acct_sanity_check_nolock(c, jeb);
+	jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
+
+	jffs2_dbg_acct_sanity_check_nolock(c, new_jeb);
+	jffs2_dbg_acct_paranoia_check_nolock(c, new_jeb);
+
+	spin_unlock(&c->erase_completion_lock);
+
+	D1(printk(KERN_DEBUG "wbuf recovery completed OK. wbuf_ofs 0x%08x, len 0x%x\n", c->wbuf_ofs, c->wbuf_len));
+
+}
+
+/* Meaning of pad argument:
+   0: Do not pad. Probably pointless - we only ever use this when we can't pad anyway.
+   1: Pad, do not adjust nextblock free_size
+   2: Pad, adjust nextblock free_size
+*/
+#define NOPAD		0
+#define PAD_NOACCOUNT	1
+#define PAD_ACCOUNTING	2
+
+static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
+{
+	struct jffs2_eraseblock *wbuf_jeb;
+	int ret;
+	size_t retlen;
+
+	/* Nothing to do if not write-buffering the flash. In particular, we shouldn't
+	   del_timer() the timer we never initialised. */
+	if (!jffs2_is_writebuffered(c))
+		return 0;
+
+	if (mutex_trylock(&c->alloc_sem)) {
+		mutex_unlock(&c->alloc_sem);
+		printk(KERN_CRIT "jffs2_flush_wbuf() called with alloc_sem not locked!\n");
+		BUG();
+	}
+
+	if (!c->wbuf_len)	/* already checked c->wbuf above */
+		return 0;
+
+	wbuf_jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
+	if (jffs2_prealloc_raw_node_refs(c, wbuf_jeb, c->nextblock->allocated_refs + 1))
+		return -ENOMEM;
+
+	/* claim remaining space on the page
+	   this happens, if we have a change to a new block,
+	   or if fsync forces us to flush the writebuffer.
+	   if we have a switch to next page, we will not have
+	   enough remaining space for this.
+	*/
+	if (pad ) {
+		c->wbuf_len = PAD(c->wbuf_len);
+
+		/* Pad with JFFS2_DIRTY_BITMASK initially.  this helps out ECC'd NOR
+		   with 8 byte page size */
+		memset(c->wbuf + c->wbuf_len, 0, c->wbuf_pagesize - c->wbuf_len);
+
+		if ( c->wbuf_len + sizeof(struct jffs2_unknown_node) < c->wbuf_pagesize) {
+			struct jffs2_unknown_node *padnode = (void *)(c->wbuf + c->wbuf_len);
+			padnode->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
+			padnode->nodetype = cpu_to_je16(JFFS2_NODETYPE_PADDING);
+			padnode->totlen = cpu_to_je32(c->wbuf_pagesize - c->wbuf_len);
+			padnode->hdr_crc = cpu_to_je32(crc32(0, padnode, sizeof(*padnode)-4));
+		}
+	}
+	/* else jffs2_flash_writev has actually filled in the rest of the
+	   buffer for us, and will deal with the node refs etc. later. */
+
+#ifdef BREAKME
+	static int breakme;
+	if (breakme++ == 20) {
+		printk(KERN_NOTICE "Faking write error at 0x%08x\n", c->wbuf_ofs);
+		breakme = 0;
+		c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen,
+			      brokenbuf);
+		ret = -EIO;
+	} else
+#endif
+
+		ret = c->mtd->write(c->mtd, c->wbuf_ofs, c->wbuf_pagesize, &retlen, c->wbuf);
+
+	if (ret) {
+		printk(KERN_WARNING "jffs2_flush_wbuf(): Write failed with %d\n", ret);
+		goto wfail;
+	} else if (retlen != c->wbuf_pagesize) {
+		printk(KERN_WARNING "jffs2_flush_wbuf(): Write was short: %zd instead of %d\n",
+		       retlen, c->wbuf_pagesize);
+		ret = -EIO;
+		goto wfail;
+	} else if ((ret = jffs2_verify_write(c, c->wbuf, c->wbuf_ofs))) {
+	wfail:
+		jffs2_wbuf_recover(c);
+
+		return ret;
+	}
+
+	/* Adjust free size of the block if we padded. */
+	if (pad) {
+		uint32_t waste = c->wbuf_pagesize - c->wbuf_len;
+
+		D1(printk(KERN_DEBUG "jffs2_flush_wbuf() adjusting free_size of %sblock at %08x\n",
+			  (wbuf_jeb==c->nextblock)?"next":"", wbuf_jeb->offset));
+
+		/* wbuf_pagesize - wbuf_len is the amount of space that's to be
+		   padded. If there is less free space in the block than that,
+		   something screwed up */
+		if (wbuf_jeb->free_size < waste) {
+			printk(KERN_CRIT "jffs2_flush_wbuf(): Accounting error. wbuf at 0x%08x has 0x%03x bytes, 0x%03x left.\n",
+			       c->wbuf_ofs, c->wbuf_len, waste);
+			printk(KERN_CRIT "jffs2_flush_wbuf(): But free_size for block at 0x%08x is only 0x%08x\n",
+			       wbuf_jeb->offset, wbuf_jeb->free_size);
+			BUG();
+		}
+
+		spin_lock(&c->erase_completion_lock);
+
+		jffs2_link_node_ref(c, wbuf_jeb, (c->wbuf_ofs + c->wbuf_len) | REF_OBSOLETE, waste, NULL);
+		/* FIXME: that made it count as dirty. Convert to wasted */
+		wbuf_jeb->dirty_size -= waste;
+		c->dirty_size -= waste;
+		wbuf_jeb->wasted_size += waste;
+		c->wasted_size += waste;
+	} else
+		spin_lock(&c->erase_completion_lock);
+
+	/* Stick any now-obsoleted blocks on the erase_pending_list */
+	jffs2_refile_wbuf_blocks(c);
+	jffs2_clear_wbuf_ino_list(c);
+	spin_unlock(&c->erase_completion_lock);
+
+	memset(c->wbuf,0xff,c->wbuf_pagesize);
+	/* adjust write buffer offset, else we get a non contiguous write bug */
+	c->wbuf_ofs += c->wbuf_pagesize;
+	c->wbuf_len = 0;
+	return 0;
+}
+
+/* Trigger garbage collection to flush the write-buffer.
+   If ino arg is zero, do it if _any_ real (i.e. not GC) writes are
+   outstanding. If ino arg non-zero, do it only if a write for the
+   given inode is outstanding. */
+int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino)
+{
+	uint32_t old_wbuf_ofs;
+	uint32_t old_wbuf_len;
+	int ret = 0;
+
+	D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() called for ino #%u...\n", ino));
+
+	if (!c->wbuf)
+		return 0;
+
+	mutex_lock(&c->alloc_sem);
+	if (!jffs2_wbuf_pending_for_ino(c, ino)) {
+		D1(printk(KERN_DEBUG "Ino #%d not pending in wbuf. Returning\n", ino));
+		mutex_unlock(&c->alloc_sem);
+		return 0;
+	}
+
+	old_wbuf_ofs = c->wbuf_ofs;
+	old_wbuf_len = c->wbuf_len;
+
+	if (c->unchecked_size) {
+		/* GC won't make any progress for a while */
+		D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() padding. Not finished checking\n"));
+		down_write(&c->wbuf_sem);
+		ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
+		/* retry flushing wbuf in case jffs2_wbuf_recover
+		   left some data in the wbuf */
+		if (ret)
+			ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
+		up_write(&c->wbuf_sem);
+	} else while (old_wbuf_len &&
+		      old_wbuf_ofs == c->wbuf_ofs) {
+
+		mutex_unlock(&c->alloc_sem);
+
+		D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() calls gc pass\n"));
+
+		ret = jffs2_garbage_collect_pass(c);
+		if (ret) {
+			/* GC failed. Flush it with padding instead */
+			mutex_lock(&c->alloc_sem);
+			down_write(&c->wbuf_sem);
+			ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
+			/* retry flushing wbuf in case jffs2_wbuf_recover
+			   left some data in the wbuf */
+			if (ret)
+				ret = __jffs2_flush_wbuf(c, PAD_ACCOUNTING);
+			up_write(&c->wbuf_sem);
+			break;
+		}
+		mutex_lock(&c->alloc_sem);
+	}
+
+	D1(printk(KERN_DEBUG "jffs2_flush_wbuf_gc() ends...\n"));
+
+	mutex_unlock(&c->alloc_sem);
+	return ret;
+}
+
+/* Pad write-buffer to end and write it, wasting space. */
+int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c)
+{
+	int ret;
+
+	if (!c->wbuf)
+		return 0;
+
+	down_write(&c->wbuf_sem);
+	ret = __jffs2_flush_wbuf(c, PAD_NOACCOUNT);
+	/* retry - maybe wbuf recover left some data in wbuf. */
+	if (ret)
+		ret = __jffs2_flush_wbuf(c, PAD_NOACCOUNT);
+	up_write(&c->wbuf_sem);
+
+	return ret;
+}
+
+static size_t jffs2_fill_wbuf(struct jffs2_sb_info *c, const uint8_t *buf,
+			      size_t len)
+{
+	if (len && !c->wbuf_len && (len >= c->wbuf_pagesize))
+		return 0;
+
+	if (len > (c->wbuf_pagesize - c->wbuf_len))
+		len = c->wbuf_pagesize - c->wbuf_len;
+	memcpy(c->wbuf + c->wbuf_len, buf, len);
+	c->wbuf_len += (uint32_t) len;
+	return len;
+}
+
+int jffs2_flash_writev(struct jffs2_sb_info *c, const struct kvec *invecs,
+		       unsigned long count, loff_t to, size_t *retlen,
+		       uint32_t ino)
+{
+	struct jffs2_eraseblock *jeb;
+	size_t wbuf_retlen, donelen = 0;
+	uint32_t outvec_to = to;
+	int ret, invec;
+
+	/* If not writebuffered flash, don't bother */
+	if (!jffs2_is_writebuffered(c))
+		return jffs2_flash_direct_writev(c, invecs, count, to, retlen);
+
+	down_write(&c->wbuf_sem);
+
+	/* If wbuf_ofs is not initialized, set it to target address */
+	if (c->wbuf_ofs == 0xFFFFFFFF) {
+		c->wbuf_ofs = PAGE_DIV(to);
+		c->wbuf_len = PAGE_MOD(to);
+		memset(c->wbuf,0xff,c->wbuf_pagesize);
+	}
+
+	/*
+	 * Sanity checks on target address.  It's permitted to write
+	 * at PAD(c->wbuf_len+c->wbuf_ofs), and it's permitted to
+	 * write at the beginning of a new erase block. Anything else,
+	 * and you die.  New block starts at xxx000c (0-b = block
+	 * header)
+	 */
+	if (SECTOR_ADDR(to) != SECTOR_ADDR(c->wbuf_ofs)) {
+		/* It's a write to a new block */
+		if (c->wbuf_len) {
+			D1(printk(KERN_DEBUG "jffs2_flash_writev() to 0x%lx "
+				  "causes flush of wbuf at 0x%08x\n",
+				  (unsigned long)to, c->wbuf_ofs));
+			ret = __jffs2_flush_wbuf(c, PAD_NOACCOUNT);
+			if (ret)
+				goto outerr;
+		}
+		/* set pointer to new block */
+		c->wbuf_ofs = PAGE_DIV(to);
+		c->wbuf_len = PAGE_MOD(to);
+	}
+
+	if (to != PAD(c->wbuf_ofs + c->wbuf_len)) {
+		/* We're not writing immediately after the writebuffer. Bad. */
+		printk(KERN_CRIT "jffs2_flash_writev(): Non-contiguous write "
+		       "to %08lx\n", (unsigned long)to);
+		if (c->wbuf_len)
+			printk(KERN_CRIT "wbuf was previously %08x-%08x\n",
+			       c->wbuf_ofs, c->wbuf_ofs+c->wbuf_len);
+		BUG();
+	}
+
+	/* adjust alignment offset */
+	if (c->wbuf_len != PAGE_MOD(to)) {
+		c->wbuf_len = PAGE_MOD(to);
+		/* take care of alignment to next page */
+		if (!c->wbuf_len) {
+			c->wbuf_len = c->wbuf_pagesize;
+			ret = __jffs2_flush_wbuf(c, NOPAD);
+			if (ret)
+				goto outerr;
+		}
+	}
+
+	for (invec = 0; invec < count; invec++) {
+		int vlen = invecs[invec].iov_len;
+		uint8_t *v = invecs[invec].iov_base;
+
+		wbuf_retlen = jffs2_fill_wbuf(c, v, vlen);
+
+		if (c->wbuf_len == c->wbuf_pagesize) {
+			ret = __jffs2_flush_wbuf(c, NOPAD);
+			if (ret)
+				goto outerr;
+		}
+		vlen -= wbuf_retlen;
+		outvec_to += wbuf_retlen;
+		donelen += wbuf_retlen;
+		v += wbuf_retlen;
+
+		if (vlen >= c->wbuf_pagesize) {
+			ret = c->mtd->write(c->mtd, outvec_to, PAGE_DIV(vlen),
+					    &wbuf_retlen, v);
+			if (ret < 0 || wbuf_retlen != PAGE_DIV(vlen))
+				goto outfile;
+
+			vlen -= wbuf_retlen;
+			outvec_to += wbuf_retlen;
+			c->wbuf_ofs = outvec_to;
+			donelen += wbuf_retlen;
+			v += wbuf_retlen;
+		}
+
+		wbuf_retlen = jffs2_fill_wbuf(c, v, vlen);
+		if (c->wbuf_len == c->wbuf_pagesize) {
+			ret = __jffs2_flush_wbuf(c, NOPAD);
+			if (ret)
+				goto outerr;
+		}
+
+		outvec_to += wbuf_retlen;
+		donelen += wbuf_retlen;
+	}
+
+	/*
+	 * If there's a remainder in the wbuf and it's a non-GC write,
+	 * remember that the wbuf affects this ino
+	 */
+	*retlen = donelen;
+
+	if (jffs2_sum_active()) {
+		int res = jffs2_sum_add_kvec(c, invecs, count, (uint32_t) to);
+		if (res)
+			return res;
+	}
+
+	if (c->wbuf_len && ino)
+		jffs2_wbuf_dirties_inode(c, ino);
+
+	ret = 0;
+	up_write(&c->wbuf_sem);
+	return ret;
+
+outfile:
+	/*
+	 * At this point we have no problem, c->wbuf is empty. However
+	 * refile nextblock to avoid writing again to same address.
+	 */
+
+	spin_lock(&c->erase_completion_lock);
+
+	jeb = &c->blocks[outvec_to / c->sector_size];
+	jffs2_block_refile(c, jeb, REFILE_ANYWAY);
+
+	spin_unlock(&c->erase_completion_lock);
+
+outerr:
+	*retlen = 0;
+	up_write(&c->wbuf_sem);
+	return ret;
+}
+
+/*
+ *	This is the entry for flash write.
+ *	Check, if we work on NAND FLASH, if so build an kvec and write it via vritev
+*/
+int jffs2_flash_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
+		      size_t *retlen, const u_char *buf)
+{
+	struct kvec vecs[1];
+
+	if (!jffs2_is_writebuffered(c))
+		return jffs2_flash_direct_write(c, ofs, len, retlen, buf);
+
+	vecs[0].iov_base = (unsigned char *) buf;
+	vecs[0].iov_len = len;
+	return jffs2_flash_writev(c, vecs, 1, ofs, retlen, 0);
+}
+
+/*
+	Handle readback from writebuffer and ECC failure return
+*/
+int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *retlen, u_char *buf)
+{
+	loff_t	orbf = 0, owbf = 0, lwbf = 0;
+	int	ret;
+
+	if (!jffs2_is_writebuffered(c))
+		return c->mtd->read(c->mtd, ofs, len, retlen, buf);
+
+	/* Read flash */
+	down_read(&c->wbuf_sem);
+	ret = c->mtd->read(c->mtd, ofs, len, retlen, buf);
+
+	if ( (ret == -EBADMSG || ret == -EUCLEAN) && (*retlen == len) ) {
+		if (ret == -EBADMSG)
+			printk(KERN_WARNING "mtd->read(0x%zx bytes from 0x%llx)"
+			       " returned ECC error\n", len, ofs);
+		/*
+		 * We have the raw data without ECC correction in the buffer,
+		 * maybe we are lucky and all data or parts are correct. We
+		 * check the node.  If data are corrupted node check will sort
+		 * it out.  We keep this block, it will fail on write or erase
+		 * and the we mark it bad. Or should we do that now? But we
+		 * should give him a chance.  Maybe we had a system crash or
+		 * power loss before the ecc write or a erase was completed.
+		 * So we return success. :)
+		 */
+		ret = 0;
+	}
+
+	/* if no writebuffer available or write buffer empty, return */
+	if (!c->wbuf_pagesize || !c->wbuf_len)
+		goto exit;
+
+	/* if we read in a different block, return */
+	if (SECTOR_ADDR(ofs) != SECTOR_ADDR(c->wbuf_ofs))
+		goto exit;
+
+	if (ofs >= c->wbuf_ofs) {
+		owbf = (ofs - c->wbuf_ofs);	/* offset in write buffer */
+		if (owbf > c->wbuf_len)		/* is read beyond write buffer ? */
+			goto exit;
+		lwbf = c->wbuf_len - owbf;	/* number of bytes to copy */
+		if (lwbf > len)
+			lwbf = len;
+	} else {
+		orbf = (c->wbuf_ofs - ofs);	/* offset in read buffer */
+		if (orbf > len)			/* is write beyond write buffer ? */
+			goto exit;
+		lwbf = len - orbf;		/* number of bytes to copy */
+		if (lwbf > c->wbuf_len)
+			lwbf = c->wbuf_len;
+	}
+	if (lwbf > 0)
+		memcpy(buf+orbf,c->wbuf+owbf,lwbf);
+
+exit:
+	up_read(&c->wbuf_sem);
+	return ret;
+}
+
+#define NR_OOB_SCAN_PAGES 4
+
+/* For historical reasons we use only 8 bytes for OOB clean marker */
+#define OOB_CM_SIZE 8
+
+static const struct jffs2_unknown_node oob_cleanmarker =
+{
+	.magic = constant_cpu_to_je16(JFFS2_MAGIC_BITMASK),
+	.nodetype = constant_cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER),
+	.totlen = constant_cpu_to_je32(8)
+};
+
+/*
+ * Check, if the out of band area is empty. This function knows about the clean
+ * marker and if it is present in OOB, treats the OOB as empty anyway.
+ */
+int jffs2_check_oob_empty(struct jffs2_sb_info *c,
+			  struct jffs2_eraseblock *jeb, int mode)
+{
+	int i, ret;
+	int cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
+	struct mtd_oob_ops ops;
+
+	ops.mode = MTD_OOB_AUTO;
+	ops.ooblen = NR_OOB_SCAN_PAGES * c->oobavail;
+	ops.oobbuf = c->oobbuf;
+	ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0;
+	ops.datbuf = NULL;
+
+	ret = c->mtd->read_oob(c->mtd, jeb->offset, &ops);
+	if (ret || ops.oobretlen != ops.ooblen) {
+		printk(KERN_ERR "cannot read OOB for EB at %08x, requested %zd"
+				" bytes, read %zd bytes, error %d\n",
+				jeb->offset, ops.ooblen, ops.oobretlen, ret);
+		if (!ret)
+			ret = -EIO;
+		return ret;
+	}
+
+	for(i = 0; i < ops.ooblen; i++) {
+		if (mode && i < cmlen)
+			/* Yeah, we know about the cleanmarker */
+			continue;
+
+		if (ops.oobbuf[i] != 0xFF) {
+			D2(printk(KERN_DEBUG "Found %02x at %x in OOB for "
+				  "%08x\n", ops.oobbuf[i], i, jeb->offset));
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Check for a valid cleanmarker.
+ * Returns: 0 if a valid cleanmarker was found
+ *	    1 if no cleanmarker was found
+ *	    negative error code if an error occurred
+ */
+int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c,
+				 struct jffs2_eraseblock *jeb)
+{
+	struct mtd_oob_ops ops;
+	int ret, cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
+
+	ops.mode = MTD_OOB_AUTO;
+	ops.ooblen = cmlen;
+	ops.oobbuf = c->oobbuf;
+	ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0;
+	ops.datbuf = NULL;
+
+	ret = c->mtd->read_oob(c->mtd, jeb->offset, &ops);
+	if (ret || ops.oobretlen != ops.ooblen) {
+		printk(KERN_ERR "cannot read OOB for EB at %08x, requested %zd"
+				" bytes, read %zd bytes, error %d\n",
+				jeb->offset, ops.ooblen, ops.oobretlen, ret);
+		if (!ret)
+			ret = -EIO;
+		return ret;
+	}
+
+	return !!memcmp(&oob_cleanmarker, c->oobbuf, cmlen);
+}
+
+int jffs2_write_nand_cleanmarker(struct jffs2_sb_info *c,
+				 struct jffs2_eraseblock *jeb)
+{
+	int ret;
+	struct mtd_oob_ops ops;
+	int cmlen = min_t(int, c->oobavail, OOB_CM_SIZE);
+
+	ops.mode = MTD_OOB_AUTO;
+	ops.ooblen = cmlen;
+	ops.oobbuf = (uint8_t *)&oob_cleanmarker;
+	ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0;
+	ops.datbuf = NULL;
+
+	ret = c->mtd->write_oob(c->mtd, jeb->offset, &ops);
+	if (ret || ops.oobretlen != ops.ooblen) {
+		printk(KERN_ERR "cannot write OOB for EB at %08x, requested %zd"
+				" bytes, read %zd bytes, error %d\n",
+				jeb->offset, ops.ooblen, ops.oobretlen, ret);
+		if (!ret)
+			ret = -EIO;
+		return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * On NAND we try to mark this block bad. If the block was erased more
+ * than MAX_ERASE_FAILURES we mark it finaly bad.
+ * Don't care about failures. This block remains on the erase-pending
+ * or badblock list as long as nobody manipulates the flash with
+ * a bootloader or something like that.
+ */
+
+int jffs2_write_nand_badblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t bad_offset)
+{
+	int 	ret;
+
+	/* if the count is < max, we try to write the counter to the 2nd page oob area */
+	if( ++jeb->bad_count < MAX_ERASE_FAILURES)
+		return 0;
+
+	if (!c->mtd->block_markbad)
+		return 1; // What else can we do?
+
+	printk(KERN_WARNING "JFFS2: marking eraseblock at %08x\n as bad", bad_offset);
+	ret = c->mtd->block_markbad(c->mtd, bad_offset);
+
+	if (ret) {
+		D1(printk(KERN_WARNING "jffs2_write_nand_badblock(): Write failed for block at %08x: error %d\n", jeb->offset, ret));
+		return ret;
+	}
+	return 1;
+}
+
+int jffs2_nand_flash_setup(struct jffs2_sb_info *c)
+{
+	struct nand_ecclayout *oinfo = c->mtd->ecclayout;
+
+	if (!c->mtd->oobsize)
+		return 0;
+
+	/* Cleanmarker is out-of-band, so inline size zero */
+	c->cleanmarker_size = 0;
+
+	if (!oinfo || oinfo->oobavail == 0) {
+		printk(KERN_ERR "inconsistent device description\n");
+		return -EINVAL;
+	}
+
+	D1(printk(KERN_DEBUG "JFFS2 using OOB on NAND\n"));
+
+	c->oobavail = oinfo->oobavail;
+
+	/* Initialise write buffer */
+	init_rwsem(&c->wbuf_sem);
+	c->wbuf_pagesize = c->mtd->writesize;
+	c->wbuf_ofs = 0xFFFFFFFF;
+
+	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf)
+		return -ENOMEM;
+
+	c->oobbuf = kmalloc(NR_OOB_SCAN_PAGES * c->oobavail, GFP_KERNEL);
+	if (!c->oobbuf) {
+		kfree(c->wbuf);
+		return -ENOMEM;
+	}
+
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+	c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf_verify) {
+		kfree(c->oobbuf);
+		kfree(c->wbuf);
+		return -ENOMEM;
+	}
+#endif
+	return 0;
+}
+
+void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c)
+{
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+	kfree(c->wbuf_verify);
+#endif
+	kfree(c->wbuf);
+	kfree(c->oobbuf);
+}
+
+int jffs2_dataflash_setup(struct jffs2_sb_info *c) {
+	c->cleanmarker_size = 0;		/* No cleanmarkers needed */
+
+	/* Initialize write buffer */
+	init_rwsem(&c->wbuf_sem);
+
+
+	c->wbuf_pagesize =  c->mtd->erasesize;
+
+	/* Find a suitable c->sector_size
+	 * - Not too much sectors
+	 * - Sectors have to be at least 4 K + some bytes
+	 * - All known dataflashes have erase sizes of 528 or 1056
+	 * - we take at least 8 eraseblocks and want to have at least 8K size
+	 * - The concatenation should be a power of 2
+	*/
+
+	c->sector_size = 8 * c->mtd->erasesize;
+
+	while (c->sector_size < 8192) {
+		c->sector_size *= 2;
+	}
+
+	/* It may be necessary to adjust the flash size */
+	c->flash_size = c->mtd->size;
+
+	if ((c->flash_size % c->sector_size) != 0) {
+		c->flash_size = (c->flash_size / c->sector_size) * c->sector_size;
+		printk(KERN_WARNING "JFFS2 flash size adjusted to %dKiB\n", c->flash_size);
+	};
+
+	c->wbuf_ofs = 0xFFFFFFFF;
+	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf)
+		return -ENOMEM;
+
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+	c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf_verify) {
+		kfree(c->oobbuf);
+		kfree(c->wbuf);
+		return -ENOMEM;
+	}
+#endif
+
+	printk(KERN_INFO "JFFS2 write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size);
+
+	return 0;
+}
+
+void jffs2_dataflash_cleanup(struct jffs2_sb_info *c) {
+#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY
+	kfree(c->wbuf_verify);
+#endif
+	kfree(c->wbuf);
+}
+
+int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c) {
+	/* Cleanmarker currently occupies whole programming regions,
+	 * either one or 2 for 8Byte STMicro flashes. */
+	c->cleanmarker_size = max(16u, c->mtd->writesize);
+
+	/* Initialize write buffer */
+	init_rwsem(&c->wbuf_sem);
+	c->wbuf_pagesize = c->mtd->writesize;
+	c->wbuf_ofs = 0xFFFFFFFF;
+
+	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c) {
+	kfree(c->wbuf);
+}
+
+int jffs2_ubivol_setup(struct jffs2_sb_info *c) {
+	c->cleanmarker_size = 0;
+
+	if (c->mtd->writesize == 1)
+		/* We do not need write-buffer */
+		return 0;
+
+	init_rwsem(&c->wbuf_sem);
+
+	c->wbuf_pagesize =  c->mtd->writesize;
+	c->wbuf_ofs = 0xFFFFFFFF;
+	c->wbuf = kmalloc(c->wbuf_pagesize, GFP_KERNEL);
+	if (!c->wbuf)
+		return -ENOMEM;
+
+	printk(KERN_INFO "JFFS2 write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size);
+
+	return 0;
+}
+
+void jffs2_ubivol_cleanup(struct jffs2_sb_info *c) {
+	kfree(c->wbuf);
+}