[U-Boot] [PATCH] [UBI] Basic Unsorted Block Image (UBI) support (part 1)

21 Oct 2008

Now it can use UBI support on U-Boot
Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
---
 Makefile                       |    1 +
 drivers/mtd/Makefile           |    1 +
 drivers/mtd/mtdcore.c          |  142 ++++
 drivers/mtd/mtdpart.c          |  531 +++++++++++++
 drivers/mtd/ubi/Makefile       |   48 ++
 drivers/mtd/ubi/build.c        | 1182 ++++++++++++++++++++++++++++
 drivers/mtd/ubi/crc32.c        |  514 ++++++++++++
 drivers/mtd/ubi/crc32defs.h    |   32 +
 drivers/mtd/ubi/crc32table.h   |  136 ++++
 drivers/mtd/ubi/debug.c        |  192 +++++
 drivers/mtd/ubi/debug.h        |  152 ++++
 drivers/mtd/ubi/eba.c          | 1256 ++++++++++++++++++++++++++++++
 drivers/mtd/ubi/io.c           | 1274 ++++++++++++++++++++++++++++++
 drivers/mtd/ubi/kapi.c         |  638 +++++++++++++++
 drivers/mtd/ubi/misc.c         |  106 +++
 drivers/mtd/ubi/scan.c         | 1361 ++++++++++++++++++++++++++++++++
 drivers/mtd/ubi/scan.h         |  165 ++++
 drivers/mtd/ubi/ubi-media.h    |  372 +++++++++
 drivers/mtd/ubi/ubi.h          |  641 +++++++++++++++
 drivers/mtd/ubi/upd.c          |  441 +++++++++++
 drivers/mtd/ubi/vmt.c          |  862 +++++++++++++++++++++
 drivers/mtd/ubi/vtbl.c         |  837 ++++++++++++++++++++
 drivers/mtd/ubi/wl.c           | 1670 ++++++++++++++++++++++++++++++++++++++++
 include/linux/crc32.h          |   27 +
 include/linux/mtd/mtd.h        |    1 +
 include/linux/mtd/partitions.h |   84 ++
 include/linux/mtd/ubi.h        |  186 +++++
 include/linux/types.h          |   24 +
 include/mtd/ubi-header.h       |  372 +++++++++
 include/mtd/ubi-user.h         |  268 +++++++
 include/ubi_uboot.h            |  209 +++++
 31 files changed, 13725 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/mtdcore.c
 create mode 100644 drivers/mtd/mtdpart.c
 create mode 100644 drivers/mtd/ubi/Makefile
 create mode 100644 drivers/mtd/ubi/build.c
 create mode 100644 drivers/mtd/ubi/crc32.c
 create mode 100644 drivers/mtd/ubi/crc32defs.h
 create mode 100644 drivers/mtd/ubi/crc32table.h
 create mode 100644 drivers/mtd/ubi/debug.c
 create mode 100644 drivers/mtd/ubi/debug.h
 create mode 100644 drivers/mtd/ubi/eba.c
 create mode 100644 drivers/mtd/ubi/io.c
 create mode 100644 drivers/mtd/ubi/kapi.c
 create mode 100644 drivers/mtd/ubi/misc.c
 create mode 100644 drivers/mtd/ubi/scan.c
 create mode 100644 drivers/mtd/ubi/scan.h
 create mode 100644 drivers/mtd/ubi/ubi-media.h
 create mode 100644 drivers/mtd/ubi/ubi.h
 create mode 100644 drivers/mtd/ubi/upd.c
 create mode 100644 drivers/mtd/ubi/vmt.c
 create mode 100644 drivers/mtd/ubi/vtbl.c
 create mode 100644 drivers/mtd/ubi/wl.c
 create mode 100644 include/linux/crc32.h
 create mode 100644 include/linux/mtd/partitions.h
 create mode 100644 include/linux/mtd/ubi.h
 create mode 100644 include/mtd/ubi-header.h
 create mode 100644 include/mtd/ubi-user.h
 create mode 100644 include/ubi_uboot.h

diff --git a/Makefile b/Makefile
index 9a132f7..93759e4 100644
--- a/Makefile
+++ b/Makefile
@@ -230,6 +230,7 @@ LIBS += drivers/mtd/libmtd.a
 LIBS += drivers/mtd/nand/libnand.a
 LIBS += drivers/mtd/nand_legacy/libnand_legacy.a
 LIBS += drivers/mtd/onenand/libonenand.a
+LIBS += drivers/mtd/ubi/libubi.a
 LIBS += drivers/mtd/spi/libspi_flash.a
 LIBS += drivers/net/libnet.a
 LIBS += drivers/net/phy/libphy.a
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 6538f7a..d225a68 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -25,6 +25,7 @@ include $(TOPDIR)/config.mk
LIB	:= $(obj)libmtd.a
+COBJS-$(CONFIG_CMD_UBI) += mtdcore.o mtdpart.o
 COBJS-$(CONFIG_HAS_DATAFLASH) += at45.o
 COBJS-$(CONFIG_FLASH_CFI_DRIVER) += cfi_flash.o
 COBJS-$(CONFIG_HAS_DATAFLASH) += dataflash.o
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
new file mode 100644
index 0000000..a9f494a
--- /dev/null
+++ b/drivers/mtd/mtdcore.c
@@ -0,0 +1,142 @@
+/*
+ * $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $
+ *
+ * Core registration and callback routines for MTD
+ * drivers and users.
+ */
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/compat.h>
+#include <ubi_uboot.h>
+
+struct mtd_info *mtd_table[MAX_MTD_DEVICES];
+
+int add_mtd_device(struct mtd_info *mtd)
+{
+	int i;
+
+	BUG_ON(mtd->writesize == 0);
+
+	for (i=0; i < MAX_MTD_DEVICES; i++)
+		if (!mtd_table[i]) {
+			mtd_table[i] = mtd;
+			mtd->index = i;
+			mtd->usecount = 0;
+
+			printf("mtd: Giving out device %d to %s\n",i, mtd->name);
+			/* No need to get a refcount on the module containing
+			   the notifier, since we hold the mtd_table_mutex */
+
+			/* We _know_ we aren't being removed, because
+			   our caller is still holding us here. So none
+			   of this try_ nonsense, and no bitching about it
+			   either. :) */
+			return 0;
+		}
+
+	return 1;
+}
+
+/**
+ *      del_mtd_device - unregister an MTD device
+ *      @mtd: pointer to MTD device info structure
+ *
+ *      Remove a device from the list of MTD devices present in the system,
+ *      and notify each currently active MTD 'user' of its departure.
+ *      Returns zero on success or 1 on failure, which currently will happen
+ *      if the requested device does not appear to be present in the list.
+ */
+int del_mtd_device (struct mtd_info *mtd)
+{
+	int ret;
+
+	if (mtd_table[mtd->index] != mtd) {
+		ret = -ENODEV;
+	} else if (mtd->usecount) {
+		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
+				mtd->index, mtd->name, mtd->usecount);
+		ret = -EBUSY;
+	} else {
+		/* No need to get a refcount on the module containing
+		 *                    the notifier, since we hold the mtd_table_mutex */
+		mtd_table[mtd->index] = NULL;
+
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/**
+ *	get_mtd_device - obtain a validated handle for an MTD device
+ *	@mtd: last known address of the required MTD device
+ *	@num: internal device number of the required MTD device
+ *
+ *	Given a number and NULL address, return the num'th entry in the device
+ *      table, if any.  Given an address and num == -1, search the device table
+ *      for a device with that address and return if it's still present. Given
+ *      both, return the num'th driver only if its address matches. Return
+ *      error code if not.
+ */
+struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
+{
+	struct mtd_info *ret = NULL;
+	int i, err = -ENODEV;
+
+	if (num == -1) {
+		for (i=0; i< MAX_MTD_DEVICES; i++)
+			if (mtd_table[i] == mtd)
+				ret = mtd_table[i];
+	} else if (num < MAX_MTD_DEVICES) {
+		ret = mtd_table[num];
+		if (mtd && mtd != ret)
+			ret = NULL;
+	}
+
+	if (!ret)
+		goto out_unlock;
+
+	ret->usecount++;
+	return ret;
+
+out_unlock:
+	return ERR_PTR(err);
+}
+
+/**
+ *      get_mtd_device_nm - obtain a validated handle for an MTD device by
+ *      device name
+ *      @name: MTD device name to open
+ *
+ *      This function returns MTD device description structure in case of
+ *      success and an error code in case of failure.
+ */
+struct mtd_info *get_mtd_device_nm(const char *name)
+{
+	int i, err = -ENODEV;
+	struct mtd_info *mtd = NULL;
+
+	for (i = 0; i < MAX_MTD_DEVICES; i++) {
+		if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
+			mtd = mtd_table[i];
+			break;
+		}
+	}
+
+	if (!mtd)
+		goto out_unlock;
+
+	mtd->usecount++;
+	return mtd;
+
+out_unlock:
+	return ERR_PTR(err);
+}
+
+void put_mtd_device(struct mtd_info *mtd)
+{
+	int c;
+
+	c = --mtd->usecount;
+	BUG_ON(c < 0);
+}
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
new file mode 100644
index 0000000..113516a
--- /dev/null
+++ b/drivers/mtd/mtdpart.c
@@ -0,0 +1,531 @@
+/*
+ * Simple MTD partitioning layer
+ *
+ * (C) 2000 Nicolas Pitre nico@cam.org
+ *
+ * This code is GPL
+ *
+ * $Id: mtdpart.c,v 1.55 2005/11/07 11:14:20 gleixner Exp $
+ *
+ * 	02-21-2002	Thomas Gleixner gleixner@autronix.de
+ *			added support for read_oob, write_oob
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <asm/errno.h>
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/compat.h>
+
+/* Our partition linked list */
+static LIST_HEAD(mtd_partitions);
+
+/* Our partition node structure */
+struct mtd_part {
+	struct mtd_info mtd;
+	struct mtd_info *master;
+	u_int32_t offset;
+	int index;
+	struct list_head list;
+	int registered;
+};
+
+/*
+ * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
+ * the pointer to that structure with this macro.
+ */
+#define PART(x)  ((struct mtd_part *)(x))
+
+
+/*
+ * MTD methods which simply translate the effective address and pass through
+ * to the _real_ device.
+ */
+
+static int part_read (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (from >= mtd->size)
+		len = 0;
+	else if (from + len > mtd->size)
+		len = mtd->size - from;
+	res = part->master->read (part->master, from + part->offset,
+				   len, retlen, buf);
+#if 0
+	if (unlikely(res)) {
+		if (res == -EUCLEAN)
+			mtd->ecc_stats.corrected++;
+		if (res == -EBADMSG)
+			mtd->ecc_stats.failed++;
+	}
+#endif
+	return res;
+}
+
+#if 0
+static int part_point (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys)
+{
+	struct mtd_part *part = PART(mtd);
+	if (from >= mtd->size)
+		len = 0;
+	else if (from + len > mtd->size)
+		len = mtd->size - from;
+	return part->master->point (part->master, from + part->offset,
+				    len, retlen, virt, phys);
+}
+
+static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+
+	part->master->unpoint(part->master, from + part->offset, len);
+}
+
+static int part_read_oob(struct mtd_info *mtd, loff_t from,
+			 struct mtd_oob_ops *ops)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (from >= mtd->size)
+		return -EINVAL;
+	if (ops->datbuf && from + ops->len > mtd->size)
+		return -EINVAL;
+	res = part->master->read_oob(part->master, from + part->offset, ops);
+
+	if (unlikely(res)) {
+		if (res == -EUCLEAN)
+			mtd->ecc_stats.corrected++;
+		if (res == -EBADMSG)
+			mtd->ecc_stats.failed++;
+	}
+	return res;
+}
+
+static int part_read_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->read_user_prot_reg (part->master, from,
+					len, retlen, buf);
+}
+
+static int part_get_user_prot_info (struct mtd_info *mtd,
+				    struct otp_info *buf, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->get_user_prot_info (part->master, buf, len);
+}
+
+static int part_read_fact_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->read_fact_prot_reg (part->master, from,
+					len, retlen, buf);
+}
+
+static int part_get_fact_prot_info (struct mtd_info *mtd,
+				    struct otp_info *buf, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->get_fact_prot_info (part->master, buf, len);
+}
+#endif
+
+static int part_write (struct mtd_info *mtd, loff_t to, size_t len,
+			size_t *retlen, const u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (to >= mtd->size)
+		len = 0;
+	else if (to + len > mtd->size)
+		len = mtd->size - to;
+	return part->master->write (part->master, to + part->offset,
+				    len, retlen, buf);
+}
+
+#if 0
+static int part_panic_write (struct mtd_info *mtd, loff_t to, size_t len,
+			size_t *retlen, const u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (to >= mtd->size)
+		len = 0;
+	else if (to + len > mtd->size)
+		len = mtd->size - to;
+	return part->master->panic_write (part->master, to + part->offset,
+				    len, retlen, buf);
+}
+
+static int part_write_oob(struct mtd_info *mtd, loff_t to,
+			 struct mtd_oob_ops *ops)
+{
+	struct mtd_part *part = PART(mtd);
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+
+	if (to >= mtd->size)
+		return -EINVAL;
+	if (ops->datbuf && to + ops->len > mtd->size)
+		return -EINVAL;
+	return part->master->write_oob(part->master, to + part->offset, ops);
+}
+
+static int part_write_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->write_user_prot_reg (part->master, from,
+					len, retlen, buf);
+}
+
+static int part_lock_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->lock_user_prot_reg (part->master, from, len);
+}
+
+static int part_writev (struct mtd_info *mtd,  const struct kvec *vecs,
+			 unsigned long count, loff_t to, size_t *retlen)
+{
+	struct mtd_part *part = PART(mtd);
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	return part->master->writev (part->master, vecs, count,
+					to + part->offset, retlen);
+}
+#endif
+
+static int part_erase (struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mtd_part *part = PART(mtd);
+	int ret;
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (instr->addr >= mtd->size)
+		return -EINVAL;
+	instr->addr += part->offset;
+	ret = part->master->erase(part->master, instr);
+	if (ret) {
+		if (instr->fail_addr != 0xffffffff)
+			instr->fail_addr -= part->offset;
+		instr->addr -= part->offset;
+	}
+	return ret;
+}
+
+void mtd_erase_callback(struct erase_info *instr)
+{
+	if (instr->mtd->erase == part_erase) {
+		struct mtd_part *part = PART(instr->mtd);
+
+		if (instr->fail_addr != 0xffffffff)
+			instr->fail_addr -= part->offset;
+		instr->addr -= part->offset;
+	}
+	if (instr->callback)
+		instr->callback(instr);
+}
+#if 0
+EXPORT_SYMBOL_GPL(mtd_erase_callback);
+#endif
+
+#if 0
+static int part_lock (struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	if ((len + ofs) > mtd->size)
+		return -EINVAL;
+	return part->master->lock(part->master, ofs + part->offset, len);
+}
+
+static int part_unlock (struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	if ((len + ofs) > mtd->size)
+		return -EINVAL;
+	return part->master->unlock(part->master, ofs + part->offset, len);
+}
+#endif
+
+static void part_sync(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+	part->master->sync(part->master);
+}
+
+#if 0
+static int part_suspend(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->suspend(part->master);
+}
+
+static void part_resume(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+	part->master->resume(part->master);
+}
+#endif
+
+static int part_block_isbad (struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	if (ofs >= mtd->size)
+		return -EINVAL;
+	ofs += part->offset;
+	return part->master->block_isbad(part->master, ofs);
+}
+
+static int part_block_markbad (struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (ofs >= mtd->size)
+		return -EINVAL;
+	ofs += part->offset;
+	res = part->master->block_markbad(part->master, ofs);
+#if 0
+	if (!res)
+		mtd->ecc_stats.badblocks++;
+#endif
+	return res;
+}
+
+/*
+ * This function unregisters and destroy all slave MTD objects which are
+ * attached to the given master MTD object.
+ */
+
+int del_mtd_partitions(struct mtd_info *master)
+{
+	struct list_head *node;
+	struct mtd_part *slave;
+
+	for (node = mtd_partitions.next;
+	     node != &mtd_partitions;
+	     node = node->next) {
+		slave = list_entry(node, struct mtd_part, list);
+		if (slave->master == master) {
+			struct list_head *prev = node->prev;
+			__list_del(prev, node->next);
+			if(slave->registered)
+				del_mtd_device(&slave->mtd);
+			kfree(slave);
+			node = prev;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * This function, given a master MTD object and a partition table, creates
+ * and registers slave MTD objects which are bound to the master according to
+ * the partition definitions.
+ * (Q: should we register the master MTD object as well?)
+ */
+
+int add_mtd_partitions(struct mtd_info *master,
+		       const struct mtd_partition *parts,
+		       int nbparts)
+{
+	struct mtd_part *slave;
+	u_int32_t cur_offset = 0;
+	int i;
+
+	printk (KERN_NOTICE "Creating %d MTD partitions on "%s":\n", nbparts, master->name);
+
+	for (i = 0; i < nbparts; i++) {
+
+		/* allocate the partition structure */
+		slave = kzalloc (sizeof(*slave), GFP_KERNEL);
+		if (!slave) {
+			printk ("memory allocation error while creating partitions for "%s"\n",
+				master->name);
+			del_mtd_partitions(master);
+			return -ENOMEM;
+		}
+		list_add(&slave->list, &mtd_partitions);
+
+		/* set up the MTD object for this partition */
+		slave->mtd.type = master->type;
+		slave->mtd.flags = master->flags & ~parts[i].mask_flags;
+		slave->mtd.size = parts[i].size;
+		slave->mtd.writesize = master->writesize;
+		slave->mtd.oobsize = master->oobsize;
+		slave->mtd.oobavail = master->oobavail;
+		slave->mtd.subpage_sft = master->subpage_sft;
+
+		slave->mtd.name = parts[i].name;
+		slave->mtd.owner = master->owner;
+
+		slave->mtd.read = part_read;
+		slave->mtd.write = part_write;
+
+#if 0
+		if (master->panic_write)
+			slave->mtd.panic_write = part_panic_write;
+
+		if(master->point && master->unpoint){
+			slave->mtd.point = part_point;
+			slave->mtd.unpoint = part_unpoint;
+		}
+
+		if (master->read_oob)
+			slave->mtd.read_oob = part_read_oob;
+		if (master->write_oob)
+			slave->mtd.write_oob = part_write_oob;
+		if(master->read_user_prot_reg)
+			slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
+		if(master->read_fact_prot_reg)
+			slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
+		if(master->write_user_prot_reg)
+			slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
+		if(master->lock_user_prot_reg)
+			slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
+		if(master->get_user_prot_info)
+			slave->mtd.get_user_prot_info = part_get_user_prot_info;
+		if(master->get_fact_prot_info)
+			slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
+#endif
+		if (master->sync)
+			slave->mtd.sync = part_sync;
+#if 0
+		if (!i && master->suspend && master->resume) {
+				slave->mtd.suspend = part_suspend;
+				slave->mtd.resume = part_resume;
+		}
+		if (master->writev)
+			slave->mtd.writev = part_writev;
+		if (master->lock)
+			slave->mtd.lock = part_lock;
+		if (master->unlock)
+			slave->mtd.unlock = part_unlock;
+#endif
+		if (master->block_isbad)
+			slave->mtd.block_isbad = part_block_isbad;
+		if (master->block_markbad)
+			slave->mtd.block_markbad = part_block_markbad;
+		slave->mtd.erase = part_erase;
+		slave->master = master;
+		slave->offset = parts[i].offset;
+		slave->index = i;
+
+		if (slave->offset == MTDPART_OFS_APPEND)
+			slave->offset = cur_offset;
+		if (slave->offset == MTDPART_OFS_NXTBLK) {
+			slave->offset = cur_offset;
+			if ((cur_offset % master->erasesize) != 0) {
+				/* Round up to next erasesize */
+				slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
+				printk(KERN_NOTICE "Moving partition %d: "
+				       "0x%08x -> 0x%08x\n", i,
+				       cur_offset, slave->offset);
+			}
+		}
+		if (slave->mtd.size == MTDPART_SIZ_FULL)
+			slave->mtd.size = master->size - slave->offset;
+		cur_offset = slave->offset + slave->mtd.size;
+
+		printk (KERN_NOTICE "0x%08x-0x%08x : "%s"\n", slave->offset,
+			slave->offset + slave->mtd.size, slave->mtd.name);
+
+		/* let's do some sanity checks */
+		if (slave->offset >= master->size) {
+				/* let's register it anyway to preserve ordering */
+			slave->offset = 0;
+			slave->mtd.size = 0;
+			printk ("mtd: partition "%s" is out of reach -- disabled\n",
+				parts[i].name);
+		}
+		if (slave->offset + slave->mtd.size > master->size) {
+			slave->mtd.size = master->size - slave->offset;
+			printk ("mtd: partition "%s" extends beyond the end of device "%s" -- size truncated to %#x\n",
+				parts[i].name, master->name, slave->mtd.size);
+		}
+		if (master->numeraseregions>1) {
+			/* Deal with variable erase size stuff */
+			int i;
+			struct mtd_erase_region_info *regions = master->eraseregions;
+
+			/* Find the first erase regions which is part of this partition. */
+			for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
+				;
+
+			for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
+				if (slave->mtd.erasesize < regions[i].erasesize) {
+					slave->mtd.erasesize = regions[i].erasesize;
+				}
+			}
+		} else {
+			/* Single erase size */
+			slave->mtd.erasesize = master->erasesize;
+		}
+
+		if ((slave->mtd.flags & MTD_WRITEABLE) &&
+		    (slave->offset % slave->mtd.erasesize)) {
+			/* Doesn't start on a boundary of major erase size */
+			/* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
+			slave->mtd.flags &= ~MTD_WRITEABLE;
+			printk ("mtd: partition "%s" doesn't start on an erase block boundary -- force read-only\n",
+				parts[i].name);
+		}
+		if ((slave->mtd.flags & MTD_WRITEABLE) &&
+		    (slave->mtd.size % slave->mtd.erasesize)) {
+			slave->mtd.flags &= ~MTD_WRITEABLE;
+			printk ("mtd: partition "%s" doesn't end on an erase block -- force read-only\n",
+				parts[i].name);
+		}
+
+#if 0
+		slave->mtd.ecclayout = master->ecclayout;
+		if (master->block_isbad) {
+			uint32_t offs = 0;
+
+			while(offs < slave->mtd.size) {
+				if (master->block_isbad(master,
+							offs + slave->offset))
+					slave->mtd.ecc_stats.badblocks++;
+				offs += slave->mtd.erasesize;
+			}
+		}
+
+		if(parts[i].mtdp)
+		{	/* store the object pointer (caller may or may not register it */
+			*parts[i].mtdp = &slave->mtd;
+			slave->registered = 0;
+		}
+		else
+#endif
+		{
+			/* register our partition */
+			add_mtd_device(&slave->mtd);
+			slave->registered = 1;
+		}
+	}
+
+	return 0;
+}
+
+#if 0
+EXPORT_SYMBOL(add_mtd_partitions);
+EXPORT_SYMBOL(del_mtd_partitions);
+#endif
diff --git a/drivers/mtd/ubi/Makefile b/drivers/mtd/ubi/Makefile
new file mode 100644
index 0000000..30eed96
--- /dev/null
+++ b/drivers/mtd/ubi/Makefile
@@ -0,0 +1,48 @@
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program 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.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB 	:= $(obj)libubi.a
+COBJS-y += build.o vtbl.o vmt.o upd.o kapi.o eba.o io.o wl.o scan.o crc32.o
+
+COBJS-y += misc.o
+COBJS-y += debug.o
+
+COBJS	:= $(COBJS-y)
+SRCS 	:= $(COBJS:.o=.c)
+OBJS 	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(AR) $(ARFLAGS) $@ $(OBJS)
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
new file mode 100644
index 0000000..bf8a19f
--- /dev/null
+++ b/drivers/mtd/ubi/build.c
@@ -0,0 +1,1182 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ * Copyright (c) Nokia Corporation, 2007
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём),
+ *         Frank Haverkamp
+ */
+
+/*
+ * This file includes UBI initialization and building of UBI devices.
+ *
+ * When UBI is initialized, it attaches all the MTD devices specified as the
+ * module load parameters or the kernel boot parameters. If MTD devices were
+ * specified, UBI does not attach any MTD device, but it is possible to do
+ * later using the "UBI control device".
+ *
+ * At the moment we only attach UBI devices by scanning, which will become a
+ * bottleneck when flashes reach certain large size. Then one may improve UBI
+ * and add other methods, although it does not seem to be easy to do.
+ */
+
+#if 0
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/stringify.h>
+#include <linux/stat.h>
+#include <linux/miscdevice.h>
+#include <linux/log2.h>
+#include <linux/kthread.h>
+#endif
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+/* Maximum length of the 'mtd=' parameter */
+#define MTD_PARAM_LEN_MAX 64
+
+/**
+ * struct mtd_dev_param - MTD device parameter description data structure.
+ * @name: MTD device name or number string
+ * @vid_hdr_offs: VID header offset
+ */
+struct mtd_dev_param
+{
+	char name[MTD_PARAM_LEN_MAX];
+	int vid_hdr_offs;
+};
+
+/* Numbers of elements set in the @mtd_dev_param array */
+static int mtd_devs = 0;
+
+/* MTD devices specification parameters */
+static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
+
+/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
+struct class *ubi_class;
+
+#if 0
+/* Slab cache for wear-leveling entries */
+struct kmem_cache *ubi_wl_entry_slab;
+
+/* UBI control character device */
+static struct miscdevice ubi_ctrl_cdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "ubi_ctrl",
+	.fops = &ubi_ctrl_cdev_operations,
+};
+#endif
+
+/* All UBI devices in system */
+struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+
+#if 0
+/* Serializes UBI devices creations and removals */
+DEFINE_MUTEX(ubi_devices_mutex);
+
+/* Protects @ubi_devices and @ubi->ref_count */
+static DEFINE_SPINLOCK(ubi_devices_lock);
+
+/* "Show" method for files in '/<sysfs>/class/ubi/' */
+static ssize_t ubi_version_show(struct class *class, char *buf)
+{
+	return sprintf(buf, "%d\n", UBI_VERSION);
+}
+
+/* UBI version attribute ('/<sysfs>/class/ubi/version') */
+static struct class_attribute ubi_version =
+	__ATTR(version, S_IRUGO, ubi_version_show, NULL);
+
+static ssize_t dev_attribute_show(struct device *dev,
+				  struct device_attribute *attr, char *buf);
+
+/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
+static struct device_attribute dev_eraseblock_size =
+	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_avail_eraseblocks =
+	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_total_eraseblocks =
+	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_volumes_count =
+	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_max_ec =
+	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_reserved_for_bad =
+	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_bad_peb_count =
+	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_max_vol_count =
+	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_min_io_size =
+	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_bgt_enabled =
+	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_mtd_num =
+	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
+#endif
+
+/**
+ * ubi_get_device - get UBI device.
+ * @ubi_num: UBI device number
+ *
+ * This function returns UBI device description object for UBI device number
+ * @ubi_num, or %NULL if the device does not exist. This function increases the
+ * device reference count to prevent removal of the device. In other words, the
+ * device cannot be removed if its reference count is not zero.
+ */
+struct ubi_device *ubi_get_device(int ubi_num)
+{
+	struct ubi_device *ubi;
+
+	spin_lock(&ubi_devices_lock);
+	ubi = ubi_devices[ubi_num];
+	if (ubi) {
+		ubi_assert(ubi->ref_count >= 0);
+		ubi->ref_count += 1;
+		get_device(&ubi->dev);
+	}
+	spin_unlock(&ubi_devices_lock);
+
+	return ubi;
+}
+
+/**
+ * ubi_put_device - drop an UBI device reference.
+ * @ubi: UBI device description object
+ */
+void ubi_put_device(struct ubi_device *ubi)
+{
+	spin_lock(&ubi_devices_lock);
+	ubi->ref_count -= 1;
+	put_device(&ubi->dev);
+	spin_unlock(&ubi_devices_lock);
+}
+
+/**
+ * ubi_get_by_major - get UBI device description object by character device
+ *                    major number.
+ * @major: major number
+ *
+ * This function is similar to 'ubi_get_device()', but it searches the device
+ * by its major number.
+ */
+struct ubi_device *ubi_get_by_major(int major)
+{
+	int i;
+	struct ubi_device *ubi;
+
+	spin_lock(&ubi_devices_lock);
+	for (i = 0; i < UBI_MAX_DEVICES; i++) {
+		ubi = ubi_devices[i];
+		if (ubi && MAJOR(ubi->cdev.dev) == major) {
+			ubi_assert(ubi->ref_count >= 0);
+			ubi->ref_count += 1;
+			get_device(&ubi->dev);
+			spin_unlock(&ubi_devices_lock);
+			return ubi;
+		}
+	}
+	spin_unlock(&ubi_devices_lock);
+
+	return NULL;
+}
+
+/**
+ * ubi_major2num - get UBI device number by character device major number.
+ * @major: major number
+ *
+ * This function searches UBI device number object by its major number. If UBI
+ * device was not found, this function returns -ENODEV, otherwise the UBI device
+ * number is returned.
+ */
+int ubi_major2num(int major)
+{
+	int i, ubi_num = -ENODEV;
+
+	spin_lock(&ubi_devices_lock);
+	for (i = 0; i < UBI_MAX_DEVICES; i++) {
+		struct ubi_device *ubi = ubi_devices[i];
+
+		if (ubi && MAJOR(ubi->cdev.dev) == major) {
+			ubi_num = ubi->ubi_num;
+			break;
+		}
+	}
+	spin_unlock(&ubi_devices_lock);
+
+	return ubi_num;
+}
+
+#if 0
+/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
+static ssize_t dev_attribute_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	ssize_t ret;
+	struct ubi_device *ubi;
+
+	/*
+	 * The below code looks weird, but it actually makes sense. We get the
+	 * UBI device reference from the contained 'struct ubi_device'. But it
+	 * is unclear if the device was removed or not yet. Indeed, if the
+	 * device was removed before we increased its reference count,
+	 * 'ubi_get_device()' will return -ENODEV and we fail.
+	 *
+	 * Remember, 'struct ubi_device' is freed in the release function, so
+	 * we still can use 'ubi->ubi_num'.
+	 */
+	ubi = container_of(dev, struct ubi_device, dev);
+	ubi = ubi_get_device(ubi->ubi_num);
+	if (!ubi)
+		return -ENODEV;
+
+	if (attr == &dev_eraseblock_size)
+		ret = sprintf(buf, "%d\n", ubi->leb_size);
+	else if (attr == &dev_avail_eraseblocks)
+		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
+	else if (attr == &dev_total_eraseblocks)
+		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
+	else if (attr == &dev_volumes_count)
+		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
+	else if (attr == &dev_max_ec)
+		ret = sprintf(buf, "%d\n", ubi->max_ec);
+	else if (attr == &dev_reserved_for_bad)
+		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
+	else if (attr == &dev_bad_peb_count)
+		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
+	else if (attr == &dev_max_vol_count)
+		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
+	else if (attr == &dev_min_io_size)
+		ret = sprintf(buf, "%d\n", ubi->min_io_size);
+	else if (attr == &dev_bgt_enabled)
+		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
+	else if (attr == &dev_mtd_num)
+		ret = sprintf(buf, "%d\n", ubi->mtd->index);
+	else
+		ret = -EINVAL;
+
+	ubi_put_device(ubi);
+	return ret;
+}
+
+/* Fake "release" method for UBI devices */
+static void dev_release(struct device *dev) { }
+
+/**
+ * ubi_sysfs_init - initialize sysfs for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int ubi_sysfs_init(struct ubi_device *ubi)
+{
+	int err;
+
+	ubi->dev.release = dev_release;
+	ubi->dev.devt = ubi->cdev.dev;
+	ubi->dev.class = ubi_class;
+	sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
+	err = device_register(&ubi->dev);
+	if (err)
+		return err;
+
+	err = device_create_file(&ubi->dev, &dev_eraseblock_size);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_volumes_count);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_max_ec);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_bad_peb_count);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_max_vol_count);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_min_io_size);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_bgt_enabled);
+	if (err)
+		return err;
+	err = device_create_file(&ubi->dev, &dev_mtd_num);
+	return err;
+}
+
+/**
+ * ubi_sysfs_close - close sysfs for an UBI device.
+ * @ubi: UBI device description object
+ */
+static void ubi_sysfs_close(struct ubi_device *ubi)
+{
+	device_remove_file(&ubi->dev, &dev_mtd_num);
+	device_remove_file(&ubi->dev, &dev_bgt_enabled);
+	device_remove_file(&ubi->dev, &dev_min_io_size);
+	device_remove_file(&ubi->dev, &dev_max_vol_count);
+	device_remove_file(&ubi->dev, &dev_bad_peb_count);
+	device_remove_file(&ubi->dev, &dev_reserved_for_bad);
+	device_remove_file(&ubi->dev, &dev_max_ec);
+	device_remove_file(&ubi->dev, &dev_volumes_count);
+	device_remove_file(&ubi->dev, &dev_total_eraseblocks);
+	device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
+	device_remove_file(&ubi->dev, &dev_eraseblock_size);
+	device_unregister(&ubi->dev);
+}
+#endif
+
+/**
+ * kill_volumes - destroy all volumes.
+ * @ubi: UBI device description object
+ */
+static void kill_volumes(struct ubi_device *ubi)
+{
+	int i;
+
+	for (i = 0; i < ubi->vtbl_slots; i++)
+		if (ubi->volumes[i])
+			ubi_free_volume(ubi, ubi->volumes[i]);
+}
+
+/**
+ * uif_init - initialize user interfaces for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int uif_init(struct ubi_device *ubi)
+{
+	int i, err;
+	dev_t dev;
+
+	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
+
+	/*
+	 * Major numbers for the UBI character devices are allocated
+	 * dynamically. Major numbers of volume character devices are
+	 * equivalent to ones of the corresponding UBI character device. Minor
+	 * numbers of UBI character devices are 0, while minor numbers of
+	 * volume character devices start from 1. Thus, we allocate one major
+	 * number and ubi->vtbl_slots + 1 minor numbers.
+	 */
+	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
+	if (err) {
+		ubi_err("cannot register UBI character devices");
+		return err;
+	}
+
+	ubi_assert(MINOR(dev) == 0);
+	cdev_init(&ubi->cdev, &ubi_cdev_operations);
+	dbg_msg("%s major is %u", ubi->ubi_name, MAJOR(dev));
+	ubi->cdev.owner = THIS_MODULE;
+
+	err = cdev_add(&ubi->cdev, dev, 1);
+	if (err) {
+		ubi_err("cannot add character device");
+		goto out_unreg;
+	}
+
+	err = ubi_sysfs_init(ubi);
+	if (err)
+		goto out_sysfs;
+
+	for (i = 0; i < ubi->vtbl_slots; i++)
+		if (ubi->volumes[i]) {
+			err = ubi_add_volume(ubi, ubi->volumes[i]);
+			if (err) {
+				ubi_err("cannot add volume %d", i);
+				goto out_volumes;
+			}
+		}
+
+	return 0;
+
+out_volumes:
+	kill_volumes(ubi);
+out_sysfs:
+	ubi_sysfs_close(ubi);
+	cdev_del(&ubi->cdev);
+out_unreg:
+	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
+	ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
+	return err;
+}
+
+/**
+ * uif_close - close user interfaces for an UBI device.
+ * @ubi: UBI device description object
+ */
+static void uif_close(struct ubi_device *ubi)
+{
+	kill_volumes(ubi);
+	ubi_sysfs_close(ubi);
+	cdev_del(&ubi->cdev);
+	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
+}
+
+/**
+ * attach_by_scanning - attach an MTD device using scanning method.
+ * @ubi: UBI device descriptor
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ *
+ * Note, currently this is the only method to attach UBI devices. Hopefully in
+ * the future we'll have more scalable attaching methods and avoid full media
+ * scanning. But even in this case scanning will be needed as a fall-back
+ * attaching method if there are some on-flash table corruptions.
+ */
+static int attach_by_scanning(struct ubi_device *ubi)
+{
+	int err;
+	struct ubi_scan_info *si;
+
+	si = ubi_scan(ubi);
+	if (IS_ERR(si))
+		return PTR_ERR(si);
+
+	ubi->bad_peb_count = si->bad_peb_count;
+	ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+	ubi->max_ec = si->max_ec;
+	ubi->mean_ec = si->mean_ec;
+
+	err = ubi_read_volume_table(ubi, si);
+	if (err)
+		goto out_si;
+
+	err = ubi_wl_init_scan(ubi, si);
+	if (err)
+		goto out_vtbl;
+
+	err = ubi_eba_init_scan(ubi, si);
+	if (err)
+		goto out_wl;
+
+	ubi_scan_destroy_si(si);
+	return 0;
+
+out_wl:
+	ubi_wl_close(ubi);
+out_vtbl:
+	vfree(ubi->vtbl);
+out_si:
+	ubi_scan_destroy_si(si);
+	return err;
+}
+
+/**
+ * io_init - initialize I/O unit for a given UBI device.
+ * @ubi: UBI device description object
+ *
+ * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
+ * assumed:
+ *   o EC header is always at offset zero - this cannot be changed;
+ *   o VID header starts just after the EC header at the closest address
+ *     aligned to @io->hdrs_min_io_size;
+ *   o data starts just after the VID header at the closest address aligned to
+ *     @io->min_io_size
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int io_init(struct ubi_device *ubi)
+{
+	if (ubi->mtd->numeraseregions != 0) {
+		/*
+		 * Some flashes have several erase regions. Different regions
+		 * may have different eraseblock size and other
+		 * characteristics. It looks like mostly multi-region flashes
+		 * have one "main" region and one or more small regions to
+		 * store boot loader code or boot parameters or whatever. I
+		 * guess we should just pick the largest region. But this is
+		 * not implemented.
+		 */
+		ubi_err("multiple regions, not implemented");
+		return -EINVAL;
+	}
+
+	if (ubi->vid_hdr_offset < 0)
+		return -EINVAL;
+
+	/*
+	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
+	 * physical eraseblocks maximum.
+	 */
+
+	ubi->peb_size   = ubi->mtd->erasesize;
+	ubi->peb_count  = ubi->mtd->size / ubi->mtd->erasesize;
+	ubi->flash_size = ubi->mtd->size;
+
+	if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
+		ubi->bad_allowed = 1;
+
+	ubi->min_io_size = ubi->mtd->writesize;
+	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
+
+	/*
+	 * Make sure minimal I/O unit is power of 2. Note, there is no
+	 * fundamental reason for this assumption. It is just an optimization
+	 * which allows us to avoid costly division operations.
+	 */
+	if (!is_power_of_2(ubi->min_io_size)) {
+		ubi_err("min. I/O unit (%d) is not power of 2",
+			ubi->min_io_size);
+		return -EINVAL;
+	}
+
+	ubi_assert(ubi->hdrs_min_io_size > 0);
+	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
+	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
+
+	/* Calculate default aligned sizes of EC and VID headers */
+	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
+	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
+
+	dbg_msg("min_io_size      %d", ubi->min_io_size);
+	dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
+	dbg_msg("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
+	dbg_msg("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
+
+	if (ubi->vid_hdr_offset == 0)
+		/* Default offset */
+		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
+				      ubi->ec_hdr_alsize;
+	else {
+		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
+						~(ubi->hdrs_min_io_size - 1);
+		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
+						ubi->vid_hdr_aloffset;
+	}
+
+	/* Similar for the data offset */
+	ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
+	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
+
+	dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
+	dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
+	dbg_msg("vid_hdr_shift    %d", ubi->vid_hdr_shift);
+	dbg_msg("leb_start        %d", ubi->leb_start);
+
+	/* The shift must be aligned to 32-bit boundary */
+	if (ubi->vid_hdr_shift % 4) {
+		ubi_err("unaligned VID header shift %d",
+			ubi->vid_hdr_shift);
+		return -EINVAL;
+	}
+
+	/* Check sanity */
+	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
+	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
+	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
+	    ubi->leb_start & (ubi->min_io_size - 1)) {
+		ubi_err("bad VID header (%d) or data offsets (%d)",
+			ubi->vid_hdr_offset, ubi->leb_start);
+		return -EINVAL;
+	}
+
+	/*
+	 * It may happen that EC and VID headers are situated in one minimal
+	 * I/O unit. In this case we can only accept this UBI image in
+	 * read-only mode.
+	 */
+	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
+		ubi_warn("EC and VID headers are in the same minimal I/O unit, "
+			 "switch to read-only mode");
+		ubi->ro_mode = 1;
+	}
+
+	ubi->leb_size = ubi->peb_size - ubi->leb_start;
+
+	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
+		ubi_msg("MTD device %d is write-protected, attach in "
+			"read-only mode", ubi->mtd->index);
+		ubi->ro_mode = 1;
+	}
+
+	ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
+		ubi->peb_size, ubi->peb_size >> 10);
+	ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
+	ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
+	if (ubi->hdrs_min_io_size != ubi->min_io_size)
+		ubi_msg("sub-page size:              %d",
+			ubi->hdrs_min_io_size);
+	ubi_msg("VID header offset:          %d (aligned %d)",
+		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
+	ubi_msg("data offset:                %d", ubi->leb_start);
+
+	/*
+	 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
+	 * unfortunately, MTD does not provide this information. We should loop
+	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
+	 * each physical eraseblock. So, we skip ubi->bad_peb_count
+	 * uninitialized and initialize it after scanning.
+	 */
+
+	return 0;
+}
+
+/**
+ * autoresize - re-size the volume which has the "auto-resize" flag set.
+ * @ubi: UBI device description object
+ * @vol_id: ID of the volume to re-size
+ *
+ * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
+ * the volume table to the largest possible size. See comments in ubi-header.h
+ * for more description of the flag. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+static int autoresize(struct ubi_device *ubi, int vol_id)
+{
+	struct ubi_volume_desc desc;
+	struct ubi_volume *vol = ubi->volumes[vol_id];
+	int err, old_reserved_pebs = vol->reserved_pebs;
+
+	/*
+	 * Clear the auto-resize flag in the volume in-memory copy of the
+	 * volume table, and 'ubi_resize_volume()' will propogate this change
+	 * to the flash.
+	 */
+	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
+
+	if (ubi->avail_pebs == 0) {
+		struct ubi_vtbl_record vtbl_rec;
+
+		/*
+		 * No avalilable PEBs to re-size the volume, clear the flag on
+		 * flash and exit.
+		 */
+		memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
+		       sizeof(struct ubi_vtbl_record));
+		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+		if (err)
+			ubi_err("cannot clean auto-resize flag for volume %d",
+				vol_id);
+	} else {
+		desc.vol = vol;
+		err = ubi_resize_volume(&desc,
+					old_reserved_pebs + ubi->avail_pebs);
+		if (err)
+			ubi_err("cannot auto-resize volume %d", vol_id);
+	}
+
+	if (err)
+		return err;
+
+	ubi_msg("volume %d ("%s") re-sized from %d to %d LEBs", vol_id,
+		vol->name, old_reserved_pebs, vol->reserved_pebs);
+	return 0;
+}
+
+/**
+ * ubi_attach_mtd_dev - attach an MTD device.
+ * @mtd_dev: MTD device description object
+ * @ubi_num: number to assign to the new UBI device
+ * @vid_hdr_offset: VID header offset
+ *
+ * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
+ * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
+ * which case this function finds a vacant device nubert and assings it
+ * automatically. Returns the new UBI device number in case of success and a
+ * negative error code in case of failure.
+ *
+ * Note, the invocations of this function has to be serialized by the
+ * @ubi_devices_mutex.
+ */
+int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
+{
+	struct ubi_device *ubi;
+	int i, err;
+
+	/*
+	 * Check if we already have the same MTD device attached.
+	 *
+	 * Note, this function assumes that UBI devices creations and deletions
+	 * are serialized, so it does not take the &ubi_devices_lock.
+	 */
+	for (i = 0; i < UBI_MAX_DEVICES; i++) {
+		ubi = ubi_devices[i];
+		if (ubi && mtd->index == ubi->mtd->index) {
+			dbg_err("mtd%d is already attached to ubi%d",
+				mtd->index, i);
+			return -EEXIST;
+		}
+	}
+
+	/*
+	 * Make sure this MTD device is not emulated on top of an UBI volume
+	 * already. Well, generally this recursion works fine, but there are
+	 * different problems like the UBI module takes a reference to itself
+	 * by attaching (and thus, opening) the emulated MTD device. This
+	 * results in inability to unload the module. And in general it makes
+	 * no sense to attach emulated MTD devices, so we prohibit this.
+	 */
+	if (mtd->type == MTD_UBIVOLUME) {
+		ubi_err("refuse attaching mtd%d - it is already emulated on "
+			"top of UBI", mtd->index);
+		return -EINVAL;
+	}
+
+	if (ubi_num == UBI_DEV_NUM_AUTO) {
+		/* Search for an empty slot in the @ubi_devices array */
+		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
+			if (!ubi_devices[ubi_num])
+				break;
+		if (ubi_num == UBI_MAX_DEVICES) {
+			dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES);
+			return -ENFILE;
+		}
+	} else {
+		if (ubi_num >= UBI_MAX_DEVICES)
+			return -EINVAL;
+
+		/* Make sure ubi_num is not busy */
+		if (ubi_devices[ubi_num]) {
+			dbg_err("ubi%d already exists", ubi_num);
+			return -EEXIST;
+		}
+	}
+
+	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
+	if (!ubi)
+		return -ENOMEM;
+
+	ubi->mtd = mtd;
+	ubi->ubi_num = ubi_num;
+	ubi->vid_hdr_offset = vid_hdr_offset;
+	ubi->autoresize_vol_id = -1;
+
+	mutex_init(&ubi->buf_mutex);
+	mutex_init(&ubi->ckvol_mutex);
+	mutex_init(&ubi->volumes_mutex);
+	spin_lock_init(&ubi->volumes_lock);
+
+	ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
+
+	err = io_init(ubi);
+	if (err)
+		goto out_free;
+
+	ubi->peb_buf1 = vmalloc(ubi->peb_size);
+	if (!ubi->peb_buf1)
+		goto out_free;
+
+	ubi->peb_buf2 = vmalloc(ubi->peb_size);
+	if (!ubi->peb_buf2)
+		 goto out_free;
+
+#ifdef CONFIG_MTD_UBI_DEBUG
+	mutex_init(&ubi->dbg_buf_mutex);
+	ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
+	if (!ubi->dbg_peb_buf)
+		 goto out_free;
+#endif
+
+	err = attach_by_scanning(ubi);
+	if (err) {
+		dbg_err("failed to attach by scanning, error %d", err);
+		goto out_free;
+	}
+
+	if (ubi->autoresize_vol_id != -1) {
+		err = autoresize(ubi, ubi->autoresize_vol_id);
+		if (err)
+			goto out_detach;
+	}
+
+	err = uif_init(ubi);
+	if (err)
+		goto out_detach;
+
+	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
+	if (IS_ERR(ubi->bgt_thread)) {
+		err = PTR_ERR(ubi->bgt_thread);
+		ubi_err("cannot spawn "%s", error %d", ubi->bgt_name,
+			err);
+		goto out_uif;
+	}
+
+	ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
+	ubi_msg("MTD device name:            "%s"", mtd->name);
+	ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
+	ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
+	ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
+	ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
+	ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
+	ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
+	ubi_msg("number of user volumes:     %d",
+		ubi->vol_count - UBI_INT_VOL_COUNT);
+	ubi_msg("available PEBs:             %d", ubi->avail_pebs);
+	ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
+	ubi_msg("number of PEBs reserved for bad PEB handling: %d",
+		ubi->beb_rsvd_pebs);
+	ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
+
+	/* Enable the background thread */
+	if (!DBG_DISABLE_BGT) {
+		ubi->thread_enabled = 1;
+		wake_up_process(ubi->bgt_thread);
+	}
+
+	ubi_devices[ubi_num] = ubi;
+	return ubi_num;
+
+out_uif:
+	uif_close(ubi);
+out_detach:
+	ubi_eba_close(ubi);
+	ubi_wl_close(ubi);
+	vfree(ubi->vtbl);
+out_free:
+	vfree(ubi->peb_buf1);
+	vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG
+	vfree(ubi->dbg_peb_buf);
+#endif
+	kfree(ubi);
+	return err;
+}
+
+/**
+ * ubi_detach_mtd_dev - detach an MTD device.
+ * @ubi_num: UBI device number to detach from
+ * @anyway: detach MTD even if device reference count is not zero
+ *
+ * This function destroys an UBI device number @ubi_num and detaches the
+ * underlying MTD device. Returns zero in case of success and %-EBUSY if the
+ * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
+ * exist.
+ *
+ * Note, the invocations of this function has to be serialized by the
+ * @ubi_devices_mutex.
+ */
+int ubi_detach_mtd_dev(int ubi_num, int anyway)
+{
+	struct ubi_device *ubi;
+
+	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+		return -EINVAL;
+
+	spin_lock(&ubi_devices_lock);
+	ubi = ubi_devices[ubi_num];
+	if (!ubi) {
+		spin_unlock(&ubi_devices_lock);
+		return -EINVAL;
+	}
+
+	if (ubi->ref_count) {
+		if (!anyway) {
+			spin_unlock(&ubi_devices_lock);
+			return -EBUSY;
+		}
+		/* This may only happen if there is a bug */
+		ubi_err("%s reference count %d, destroy anyway",
+			ubi->ubi_name, ubi->ref_count);
+	}
+	ubi_devices[ubi_num] = NULL;
+	spin_unlock(&ubi_devices_lock);
+
+	ubi_assert(ubi_num == ubi->ubi_num);
+	dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
+
+	/*
+	 * Before freeing anything, we have to stop the background thread to
+	 * prevent it from doing anything on this device while we are freeing.
+	 */
+	if (ubi->bgt_thread)
+		kthread_stop(ubi->bgt_thread);
+
+	uif_close(ubi);
+	ubi_eba_close(ubi);
+	ubi_wl_close(ubi);
+	vfree(ubi->vtbl);
+	put_mtd_device(ubi->mtd);
+	vfree(ubi->peb_buf1);
+	vfree(ubi->peb_buf2);
+#ifdef CONFIG_MTD_UBI_DEBUG
+	vfree(ubi->dbg_peb_buf);
+#endif
+	ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
+	kfree(ubi);
+	return 0;
+}
+
+/**
+ * find_mtd_device - open an MTD device by its name or number.
+ * @mtd_dev: name or number of the device
+ *
+ * This function tries to open and MTD device described by @mtd_dev string,
+ * which is first treated as an ASCII number, and if it is not true, it is
+ * treated as MTD device name. Returns MTD device description object in case of
+ * success and a negative error code in case of failure.
+ */
+static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
+{
+	struct mtd_info *mtd;
+	int mtd_num;
+	char *endp;
+
+	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
+	if (*endp != '\0' || mtd_dev == endp) {
+		/*
+		 * This does not look like an ASCII integer, probably this is
+		 * MTD device name.
+		 */
+		mtd = get_mtd_device_nm(mtd_dev);
+	} else
+		mtd = get_mtd_device(NULL, mtd_num);
+
+	return mtd;
+}
+
+int __init ubi_init(void)
+{
+	int err, i, k;
+
+	/* Ensure that EC and VID headers have correct size */
+	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
+	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
+
+	if (mtd_devs > UBI_MAX_DEVICES) {
+		ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
+		return -EINVAL;
+	}
+
+	/* Create base sysfs directory and sysfs files */
+	ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
+	if (IS_ERR(ubi_class)) {
+		err = PTR_ERR(ubi_class);
+		ubi_err("cannot create UBI class");
+		goto out;
+	}
+
+	err = class_create_file(ubi_class, &ubi_version);
+	if (err) {
+		ubi_err("cannot create sysfs file");
+		goto out_class;
+	}
+
+	err = misc_register(&ubi_ctrl_cdev);
+	if (err) {
+		ubi_err("cannot register device");
+		goto out_version;
+	}
+
+#if 0
+	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
+					      sizeof(struct ubi_wl_entry),
+					      0, 0, NULL);
+	if (!ubi_wl_entry_slab)
+		goto out_dev_unreg;
+#endif
+
+	/* Attach MTD devices */
+	for (i = 0; i < mtd_devs; i++) {
+		struct mtd_dev_param *p = &mtd_dev_param[i];
+		struct mtd_info *mtd;
+
+		cond_resched();
+
+		mtd = open_mtd_device(p->name);
+		if (IS_ERR(mtd)) {
+			err = PTR_ERR(mtd);
+			goto out_detach;
+		}
+
+		mutex_lock(&ubi_devices_mutex);
+		err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
+					 p->vid_hdr_offs);
+		mutex_unlock(&ubi_devices_mutex);
+		if (err < 0) {
+			put_mtd_device(mtd);
+			ubi_err("cannot attach mtd%d", mtd->index);
+			goto out_detach;
+		}
+	}
+
+	return 0;
+
+out_detach:
+	for (k = 0; k < i; k++)
+		if (ubi_devices[k]) {
+			mutex_lock(&ubi_devices_mutex);
+			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
+			mutex_unlock(&ubi_devices_mutex);
+		}
+	kmem_cache_destroy(ubi_wl_entry_slab);
+out_dev_unreg:
+	misc_deregister(&ubi_ctrl_cdev);
+out_version:
+	class_remove_file(ubi_class, &ubi_version);
+out_class:
+	class_destroy(ubi_class);
+out:
+	ubi_err("UBI error: cannot initialize UBI, error %d", err);
+	return err;
+}
+module_init(ubi_init);
+
+void __exit ubi_exit(void)
+{
+	int i;
+
+	for (i = 0; i < UBI_MAX_DEVICES; i++)
+		if (ubi_devices[i]) {
+			mutex_lock(&ubi_devices_mutex);
+			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
+			mutex_unlock(&ubi_devices_mutex);
+		}
+	kmem_cache_destroy(ubi_wl_entry_slab);
+	misc_deregister(&ubi_ctrl_cdev);
+	class_remove_file(ubi_class, &ubi_version);
+	class_destroy(ubi_class);
+}
+module_exit(ubi_exit);
+
+/**
+ * bytes_str_to_int - convert a string representing number of bytes to an
+ * integer.
+ * @str: the string to convert
+ *
+ * This function returns positive resulting integer in case of success and a
+ * negative error code in case of failure.
+ */
+static int __init bytes_str_to_int(const char *str)
+{
+	char *endp;
+	unsigned long result;
+
+	result = simple_strtoul(str, &endp, 0);
+	if (str == endp || result < 0) {
+		printk(KERN_ERR "UBI error: incorrect bytes count: "%s"\n",
+		       str);
+		return -EINVAL;
+	}
+
+	switch (*endp) {
+	case 'G':
+		result *= 1024;
+	case 'M':
+		result *= 1024;
+	case 'K':
+		result *= 1024;
+		if (endp[1] == 'i' && endp[2] == 'B')
+			endp += 2;
+	case '\0':
+		break;
+	default:
+		printk(KERN_ERR "UBI error: incorrect bytes count: "%s"\n",
+		       str);
+		return -EINVAL;
+	}
+
+	return result;
+}
+
+/**
+ * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
+ * @val: the parameter value to parse
+ * @kp: not used
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of error.
+ */
+int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
+{
+	int i, len;
+	struct mtd_dev_param *p;
+	char buf[MTD_PARAM_LEN_MAX];
+	char *pbuf = &buf[0];
+	char *tokens[2] = {NULL, NULL};
+
+	if (!val)
+		return -EINVAL;
+
+	if (mtd_devs == UBI_MAX_DEVICES) {
+		printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
+		       UBI_MAX_DEVICES);
+		return -EINVAL;
+	}
+
+	len = strnlen(val, MTD_PARAM_LEN_MAX);
+	if (len == MTD_PARAM_LEN_MAX) {
+		printk(KERN_ERR "UBI error: parameter "%s" is too long, "
+		       "max. is %d\n", val, MTD_PARAM_LEN_MAX);
+		return -EINVAL;
+	}
+
+	if (len == 0) {
+		printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
+		       "ignored\n");
+		return 0;
+	}
+
+	strcpy(buf, val);
+
+	/* Get rid of the final newline */
+	if (buf[len - 1] == '\n')
+		buf[len - 1] = '\0';
+
+	for (i = 0; i < 2; i++)
+		tokens[i] = strsep(&pbuf, ",");
+
+	if (pbuf) {
+		printk(KERN_ERR "UBI error: too many arguments at "%s"\n",
+		       val);
+		return -EINVAL;
+	}
+
+	p = &mtd_dev_param[mtd_devs];
+	strcpy(&p->name[0], tokens[0]);
+
+	if (tokens[1])
+		p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
+
+	if (p->vid_hdr_offs < 0)
+		return p->vid_hdr_offs;
+
+	mtd_devs += 1;
+	return 0;
+}
+
+module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
+MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
+		      "mtd=<name|num>[,<vid_hdr_offs>].\n"
+		      "Multiple "mtd" parameters may be specified.\n"
+		      "MTD devices may be specified by their number or name.\n"
+		      "Optional "vid_hdr_offs" parameter specifies UBI VID "
+		      "header position and data starting position to be used "
+		      "by UBI.\n"
+		      "Example: mtd=content,1984 mtd=4 - attach MTD device"
+		      "with name "content" using VID header offset 1984, and "
+		      "MTD device number 4 with default VID header offset.");
+
+MODULE_VERSION(__stringify(UBI_VERSION));
+MODULE_DESCRIPTION("UBI - Unsorted Block Images");
+MODULE_AUTHOR("Artem Bityutskiy");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mtd/ubi/crc32.c b/drivers/mtd/ubi/crc32.c
new file mode 100644
index 0000000..1204543
--- /dev/null
+++ b/drivers/mtd/ubi/crc32.c
@@ -0,0 +1,514 @@
+/*
+ * Oct 15, 2000 Matt Domsch Matt_Domsch@dell.com
+ * Nicer crc32 functions/docs submitted by linux@horizon.com.  Thanks!
+ * Code was from the public domain, copyright abandoned.  Code was
+ * subsequently included in the kernel, thus was re-licensed under the
+ * GNU GPL v2.
+ *
+ * Oct 12, 2000 Matt Domsch Matt_Domsch@dell.com
+ * Same crc32 function was used in 5 other places in the kernel.
+ * I made one version, and deleted the others.
+ * There are various incantations of crc32().  Some use a seed of 0 or ~0.
+ * Some xor at the end with ~0.  The generic crc32() function takes
+ * seed as an argument, and doesn't xor at the end.  Then individual
+ * users can do whatever they need.
+ *   drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
+ *   fs/jffs2 uses seed 0, doesn't xor with ~0.
+ *   fs/partitions/efi.c uses seed ~0, xor's with ~0.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+//#include <linux/crc32.h>
+//#include <linux/kernel.h>
+//#include <linux/module.h>
+//#include <linux/compiler.h>
+#include <linux/types.h>
+
+#include <asm/byteorder.h>
+
+//#include <linux/slab.h>
+//#include <linux/init.h>
+//#include <asm/atomic.h>
+#include "crc32defs.h"
+#define CRC_LE_BITS 8
+
+# define __force
+#ifndef __constant_cpu_to_le32
+#define __constant_cpu_to_le32(x) ((__force __le32)(__u32)(x))
+#endif
+#ifndef __constant_le32_to_cpu
+#define __constant_le32_to_cpu(x) ((__force __u32)(__le32)(x))
+#endif
+
+#if CRC_LE_BITS == 8
+#define tole(x) __constant_cpu_to_le32(x)
+#define tobe(x) __constant_cpu_to_be32(x)
+#else
+#define tole(x) (x)
+#define tobe(x) (x)
+#endif
+#include "crc32table.h"
+#if 0
+MODULE_AUTHOR("Matt Domsch Matt_Domsch@dell.com");
+MODULE_DESCRIPTION("Ethernet CRC32 calculations");
+MODULE_LICENSE("GPL");
+#endif
+/**
+ * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
+ * @crc: seed value for computation.  ~0 for Ethernet, sometimes 0 for
+ *	other uses, or the previous crc32 value if computing incrementally.
+ * @p: pointer to buffer over which CRC is run
+ * @len: length of buffer @p
+ */
+u32  crc32_le(u32 crc, unsigned char const *p, size_t len);
+
+#if CRC_LE_BITS == 1
+/*
+ * In fact, the table-based code will work in this case, but it can be
+ * simplified by inlining the table in ?: form.
+ */
+
+u32 crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++;
+		for (i = 0; i < 8; i++)
+			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
+	}
+	return crc;
+}
+#else				/* Table-based approach */
+
+u32 crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+# if CRC_LE_BITS == 8
+	const u32      *b =(u32 *)p;
+	const u32      *tab = crc32table_le;
+
+# ifdef __LITTLE_ENDIAN
+#  define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
+# else
+#  define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
+# endif
+    //printf("Crc32_le crc=%x\n",crc);
+	crc = __cpu_to_le32(crc);
+	/* Align it */
+	if((((long)b)&3 && len)){
+		do {
+			u8 *p = (u8 *)b;
+			DO_CRC(*p++);
+			b = (void *)p;
+		} while ((--len) && ((long)b)&3 );
+	}
+	if((len >= 4)){
+		/* load data 32 bits wide, xor data 32 bits wide. */
+		size_t save_len = len & 3;
+	        len = len >> 2;
+		--b; /* use pre increment below(*++b) for speed */
+		do {
+			crc ^= *++b;
+			DO_CRC(0);
+			DO_CRC(0);
+			DO_CRC(0);
+			DO_CRC(0);
+		} while (--len);
+		b++; /* point to next byte(s) */
+		len = save_len;
+	}
+	/* And the last few bytes */
+	if(len){
+		do {
+			u8 *p = (u8 *)b;
+			DO_CRC(*p++);
+			b = (void *)p;
+		} while (--len);
+	}
+
+	return __le32_to_cpu(crc);
+#undef ENDIAN_SHIFT
+#undef DO_CRC
+
+# elif CRC_LE_BITS == 4
+	while (len--) {
+		crc ^= *p++;
+		crc = (crc >> 4) ^ crc32table_le[crc & 15];
+		crc = (crc >> 4) ^ crc32table_le[crc & 15];
+	}
+	return crc;
+# elif CRC_LE_BITS == 2
+	while (len--) {
+		crc ^= *p++;
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+	}
+	return crc;
+# endif
+}
+#endif
+#if 0
+/**
+ * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
+ * @crc: seed value for computation.  ~0 for Ethernet, sometimes 0 for
+ *	other uses, or the previous crc32 value if computing incrementally.
+ * @p: pointer to buffer over which CRC is run
+ * @len: length of buffer @p
+ */
+u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len);
+
+#if CRC_BE_BITS == 1
+/*
+ * In fact, the table-based code will work in this case, but it can be
+ * simplified by inlining the table in ?: form.
+ */
+
+u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++ << 24;
+		for (i = 0; i < 8; i++)
+			crc =
+			    (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
+					  0);
+	}
+	return crc;
+}
+
+#else				/* Table-based approach */
+u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+# if CRC_BE_BITS == 8
+	const u32      *b =(u32 *)p;
+	const u32      *tab = crc32table_be;
+
+# ifdef __LITTLE_ENDIAN
+#  define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
+# else
+#  define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
+# endif
+
+	crc = __cpu_to_be32(crc);
+	/* Align it */
+	if(unlikely(((long)b)&3 && len)){
+		do {
+			u8 *p = (u8 *)b;
+			DO_CRC(*p++);
+			b = (u32 *)p;
+		} while ((--len) && ((long)b)&3 );
+	}
+	if(likely(len >= 4)){
+		/* load data 32 bits wide, xor data 32 bits wide. */
+		size_t save_len = len & 3;
+	        len = len >> 2;
+		--b; /* use pre increment below(*++b) for speed */
+		do {
+			crc ^= *++b;
+			DO_CRC(0);
+			DO_CRC(0);
+			DO_CRC(0);
+			DO_CRC(0);
+		} while (--len);
+		b++; /* point to next byte(s) */
+		len = save_len;
+	}
+	/* And the last few bytes */
+	if(len){
+		do {
+			u8 *p = (u8 *)b;
+			DO_CRC(*p++);
+			b = (void *)p;
+		} while (--len);
+	}
+	return __be32_to_cpu(crc);
+#undef ENDIAN_SHIFT
+#undef DO_CRC
+
+# elif CRC_BE_BITS == 4
+	while (len--) {
+		crc ^= *p++ << 24;
+		crc = (crc << 4) ^ crc32table_be[crc >> 28];
+		crc = (crc << 4) ^ crc32table_be[crc >> 28];
+	}
+	return crc;
+# elif CRC_BE_BITS == 2
+	while (len--) {
+		crc ^= *p++ << 24;
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+	}
+	return crc;
+# endif
+}
+#endif
+
+EXPORT_SYMBOL(crc32_le);
+EXPORT_SYMBOL(crc32_be);
+#endif
+/*
+ * A brief CRC tutorial.
+ *
+ * A CRC is a long-division remainder.  You add the CRC to the message,
+ * and the whole thing (message+CRC) is a multiple of the given
+ * CRC polynomial.  To check the CRC, you can either check that the
+ * CRC matches the recomputed value, *or* you can check that the
+ * remainder computed on the message+CRC is 0.  This latter approach
+ * is used by a lot of hardware implementations, and is why so many
+ * protocols put the end-of-frame flag after the CRC.
+ *
+ * It's actually the same long division you learned in school, except that
+ * - We're working in binary, so the digits are only 0 and 1, and
+ * - When dividing polynomials, there are no carries.  Rather than add and
+ *   subtract, we just xor.  Thus, we tend to get a bit sloppy about
+ *   the difference between adding and subtracting.
+ *
+ * A 32-bit CRC polynomial is actually 33 bits long.  But since it's
+ * 33 bits long, bit 32 is always going to be set, so usually the CRC
+ * is written in hex with the most significant bit omitted.  (If you're
+ * familiar with the IEEE 754 floating-point format, it's the same idea.)
+ *
+ * Note that a CRC is computed over a string of *bits*, so you have
+ * to decide on the endianness of the bits within each byte.  To get
+ * the best error-detecting properties, this should correspond to the
+ * order they're actually sent.  For example, standard RS-232 serial is
+ * little-endian; the most significant bit (sometimes used for parity)
+ * is sent last.  And when appending a CRC word to a message, you should
+ * do it in the right order, matching the endianness.
+ *
+ * Just like with ordinary division, the remainder is always smaller than
+ * the divisor (the CRC polynomial) you're dividing by.  Each step of the
+ * division, you take one more digit (bit) of the dividend and append it
+ * to the current remainder.  Then you figure out the appropriate multiple
+ * of the divisor to subtract to being the remainder back into range.
+ * In binary, it's easy - it has to be either 0 or 1, and to make the
+ * XOR cancel, it's just a copy of bit 32 of the remainder.
+ *
+ * When computing a CRC, we don't care about the quotient, so we can
+ * throw the quotient bit away, but subtract the appropriate multiple of
+ * the polynomial from the remainder and we're back to where we started,
+ * ready to process the next bit.
+ *
+ * A big-endian CRC written this way would be coded like:
+ * for (i = 0; i < input_bits; i++) {
+ * 	multiple = remainder & 0x80000000 ? CRCPOLY : 0;
+ * 	remainder = (remainder << 1 | next_input_bit()) ^ multiple;
+ * }
+ * Notice how, to get at bit 32 of the shifted remainder, we look
+ * at bit 31 of the remainder *before* shifting it.
+ *
+ * But also notice how the next_input_bit() bits we're shifting into
+ * the remainder don't actually affect any decision-making until
+ * 32 bits later.  Thus, the first 32 cycles of this are pretty boring.
+ * Also, to add the CRC to a message, we need a 32-bit-long hole for it at
+ * the end, so we have to add 32 extra cycles shifting in zeros at the
+ * end of every message,
+ *
+ * So the standard trick is to rearrage merging in the next_input_bit()
+ * until the moment it's needed.  Then the first 32 cycles can be precomputed,
+ * and merging in the final 32 zero bits to make room for the CRC can be
+ * skipped entirely.
+ * This changes the code to:
+ * for (i = 0; i < input_bits; i++) {
+ *      remainder ^= next_input_bit() << 31;
+ * 	multiple = (remainder & 0x80000000) ? CRCPOLY : 0;
+ * 	remainder = (remainder << 1) ^ multiple;
+ * }
+ * With this optimization, the little-endian code is simpler:
+ * for (i = 0; i < input_bits; i++) {
+ *      remainder ^= next_input_bit();
+ * 	multiple = (remainder & 1) ? CRCPOLY : 0;
+ * 	remainder = (remainder >> 1) ^ multiple;
+ * }
+ *
+ * Note that the other details of endianness have been hidden in CRCPOLY
+ * (which must be bit-reversed) and next_input_bit().
+ *
+ * However, as long as next_input_bit is returning the bits in a sensible
+ * order, we can actually do the merging 8 or more bits at a time rather
+ * than one bit at a time:
+ * for (i = 0; i < input_bytes; i++) {
+ * 	remainder ^= next_input_byte() << 24;
+ * 	for (j = 0; j < 8; j++) {
+ * 		multiple = (remainder & 0x80000000) ? CRCPOLY : 0;
+ * 		remainder = (remainder << 1) ^ multiple;
+ * 	}
+ * }
+ * Or in little-endian:
+ * for (i = 0; i < input_bytes; i++) {
+ * 	remainder ^= next_input_byte();
+ * 	for (j = 0; j < 8; j++) {
+ * 		multiple = (remainder & 1) ? CRCPOLY : 0;
+ * 		remainder = (remainder << 1) ^ multiple;
+ * 	}
+ * }
+ * If the input is a multiple of 32 bits, you can even XOR in a 32-bit
+ * word at a time and increase the inner loop count to 32.
+ *
+ * You can also mix and match the two loop styles, for example doing the
+ * bulk of a message byte-at-a-time and adding bit-at-a-time processing
+ * for any fractional bytes at the end.
+ *
+ * The only remaining optimization is to the byte-at-a-time table method.
+ * Here, rather than just shifting one bit of the remainder to decide
+ * in the correct multiple to subtract, we can shift a byte at a time.
+ * This produces a 40-bit (rather than a 33-bit) intermediate remainder,
+ * but again the multiple of the polynomial to subtract depends only on
+ * the high bits, the high 8 bits in this case.  
+ *
+ * The multile we need in that case is the low 32 bits of a 40-bit
+ * value whose high 8 bits are given, and which is a multiple of the
+ * generator polynomial.  This is simply the CRC-32 of the given
+ * one-byte message.
+ *
+ * Two more details: normally, appending zero bits to a message which
+ * is already a multiple of a polynomial produces a larger multiple of that
+ * polynomial.  To enable a CRC to detect this condition, it's common to
+ * invert the CRC before appending it.  This makes the remainder of the
+ * message+crc come out not as zero, but some fixed non-zero value.
+ *
+ * The same problem applies to zero bits prepended to the message, and
+ * a similar solution is used.  Instead of starting with a remainder of
+ * 0, an initial remainder of all ones is used.  As long as you start
+ * the same way on decoding, it doesn't make a difference.
+ */
+
+#ifdef UNITTEST
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#if 0				/*Not used at present */
+static void
+buf_dump(char const *prefix, unsigned char const *buf, size_t len)
+{
+	fputs(prefix, stdout);
+	while (len--)
+		printf(" %02x", *buf++);
+	putchar('\n');
+
+}
+#endif
+
+static void bytereverse(unsigned char *buf, size_t len)
+{
+	while (len--) {
+		unsigned char x = bitrev8(*buf);
+		*buf++ = x;
+	}
+}
+
+static void random_garbage(unsigned char *buf, size_t len)
+{
+	while (len--)
+		*buf++ = (unsigned char) random();
+}
+
+#if 0				/* Not used at present */
+static void store_le(u32 x, unsigned char *buf)
+{
+	buf[0] = (unsigned char) x;
+	buf[1] = (unsigned char) (x >> 8);
+	buf[2] = (unsigned char) (x >> 16);
+	buf[3] = (unsigned char) (x >> 24);
+}
+#endif
+
+static void store_be(u32 x, unsigned char *buf)
+{
+	buf[0] = (unsigned char) (x >> 24);
+	buf[1] = (unsigned char) (x >> 16);
+	buf[2] = (unsigned char) (x >> 8);
+	buf[3] = (unsigned char) x;
+}
+
+/*
+ * This checks that CRC(buf + CRC(buf)) = 0, and that
+ * CRC commutes with bit-reversal.  This has the side effect
+ * of bytewise bit-reversing the input buffer, and returns
+ * the CRC of the reversed buffer.
+ */
+static u32 test_step(u32 init, unsigned char *buf, size_t len)
+{
+	u32 crc1, crc2;
+	size_t i;
+
+	crc1 = crc32_be(init, buf, len);
+	store_be(crc1, buf + len);
+	crc2 = crc32_be(init, buf, len + 4);
+	if (crc2)
+		printf("\nCRC cancellation fail: 0x%08x should be 0\n",
+		       crc2);
+
+	for (i = 0; i <= len + 4; i++) {
+		crc2 = crc32_be(init, buf, i);
+		crc2 = crc32_be(crc2, buf + i, len + 4 - i);
+		if (crc2)
+			printf("\nCRC split fail: 0x%08x\n", crc2);
+	}
+
+	/* Now swap it around for the other test */
+
+	bytereverse(buf, len + 4);
+	init = bitrev32(init);
+	crc2 = bitrev32(crc1);
+	if (crc1 != bitrev32(crc2))
+		printf("\nBit reversal fail: 0x%08x -> 0x%08x -> 0x%08x\n",
+		       crc1, crc2, bitrev32(crc2));
+	crc1 = crc32_le(init, buf, len);
+	if (crc1 != crc2)
+		printf("\nCRC endianness fail: 0x%08x != 0x%08x\n", crc1,
+		       crc2);
+	crc2 = crc32_le(init, buf, len + 4);
+	if (crc2)
+		printf("\nCRC cancellation fail: 0x%08x should be 0\n",
+		       crc2);
+
+	for (i = 0; i <= len + 4; i++) {
+		crc2 = crc32_le(init, buf, i);
+		crc2 = crc32_le(crc2, buf + i, len + 4 - i);
+		if (crc2)
+			printf("\nCRC split fail: 0x%08x\n", crc2);
+	}
+
+	return crc1;
+}
+
+#define SIZE 64
+#define INIT1 0
+#define INIT2 0
+
+int main(void)
+{
+	unsigned char buf1[SIZE + 4];
+	unsigned char buf2[SIZE + 4];
+	unsigned char buf3[SIZE + 4];
+	int i, j;
+	u32 crc1, crc2, crc3;
+
+	for (i = 0; i <= SIZE; i++) {
+		printf("\rTesting length %d...", i);
+		fflush(stdout);
+		random_garbage(buf1, i);
+		random_garbage(buf2, i);
+		for (j = 0; j < i; j++)
+			buf3[j] = buf1[j] ^ buf2[j];
+
+		crc1 = test_step(INIT1, buf1, i);
+		crc2 = test_step(INIT2, buf2, i);
+		/* Now check that CRC(buf1 ^ buf2) = CRC(buf1) ^ CRC(buf2) */
+		crc3 = test_step(INIT1 ^ INIT2, buf3, i);
+		if (crc3 != (crc1 ^ crc2))
+			printf("CRC XOR fail: 0x%08x != 0x%08x ^ 0x%08x\n",
+			       crc3, crc1, crc2);
+	}
+	printf("\nAll test complete.  No failures expected.\n");
+	return 0;
+}
+
+#endif				/* UNITTEST */
diff --git a/drivers/mtd/ubi/crc32defs.h b/drivers/mtd/ubi/crc32defs.h
new file mode 100644
index 0000000..9b6773d
--- /dev/null
+++ b/drivers/mtd/ubi/crc32defs.h
@@ -0,0 +1,32 @@
+/*
+ * There are multiple 16-bit CRC polynomials in common use, but this is
+ * *the* standard CRC-32 polynomial, first popularized by Ethernet.
+ * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0
+ */
+#define CRCPOLY_LE 0xedb88320
+#define CRCPOLY_BE 0x04c11db7
+
+/* How many bits at a time to use.  Requires a table of 4<<CRC_xx_BITS bytes. */
+/* For less performance-sensitive, use 4 */
+#ifndef CRC_LE_BITS 
+# define CRC_LE_BITS 8
+#endif
+#ifndef CRC_BE_BITS
+# define CRC_BE_BITS 8
+#endif
+
+/*
+ * Little-endian CRC computation.  Used with serial bit streams sent
+ * lsbit-first.  Be sure to use cpu_to_le32() to append the computed CRC.
+ */
+#if CRC_LE_BITS > 8 || CRC_LE_BITS < 1 || CRC_LE_BITS & CRC_LE_BITS-1
+# error CRC_LE_BITS must be a power of 2 between 1 and 8
+#endif
+
+/*
+ * Big-endian CRC computation.  Used with serial bit streams sent
+ * msbit-first.  Be sure to use cpu_to_be32() to append the computed CRC.
+ */
+#if CRC_BE_BITS > 8 || CRC_BE_BITS < 1 || CRC_BE_BITS & CRC_BE_BITS-1
+# error CRC_BE_BITS must be a power of 2 between 1 and 8
+#endif
diff --git a/drivers/mtd/ubi/crc32table.h b/drivers/mtd/ubi/crc32table.h
new file mode 100644
index 0000000..1b1e9c7
--- /dev/null
+++ b/drivers/mtd/ubi/crc32table.h
@@ -0,0 +1,136 @@
+/* this file is generated - do not edit */
+
+static const u32 crc32table_le[] = {
+tole(0x00000000L), tole(0x77073096L), tole(0xee0e612cL), tole(0x990951baL),
+tole(0x076dc419L), tole(0x706af48fL), tole(0xe963a535L), tole(0x9e6495a3L), 
+tole(0x0edb8832L), tole(0x79dcb8a4L), tole(0xe0d5e91eL), tole(0x97d2d988L), 
+tole(0x09b64c2bL), tole(0x7eb17cbdL), tole(0xe7b82d07L), tole(0x90bf1d91L), 
+tole(0x1db71064L), tole(0x6ab020f2L), tole(0xf3b97148L), tole(0x84be41deL), 
+tole(0x1adad47dL), tole(0x6ddde4ebL), tole(0xf4d4b551L), tole(0x83d385c7L), 
+tole(0x136c9856L), tole(0x646ba8c0L), tole(0xfd62f97aL), tole(0x8a65c9ecL), 
+tole(0x14015c4fL), tole(0x63066cd9L), tole(0xfa0f3d63L), tole(0x8d080df5L), 
+tole(0x3b6e20c8L), tole(0x4c69105eL), tole(0xd56041e4L), tole(0xa2677172L), 
+tole(0x3c03e4d1L), tole(0x4b04d447L), tole(0xd20d85fdL), tole(0xa50ab56bL), 
+tole(0x35b5a8faL), tole(0x42b2986cL), tole(0xdbbbc9d6L), tole(0xacbcf940L), 
+tole(0x32d86ce3L), tole(0x45df5c75L), tole(0xdcd60dcfL), tole(0xabd13d59L), 
+tole(0x26d930acL), tole(0x51de003aL), tole(0xc8d75180L), tole(0xbfd06116L), 
+tole(0x21b4f4b5L), tole(0x56b3c423L), tole(0xcfba9599L), tole(0xb8bda50fL), 
+tole(0x2802b89eL), tole(0x5f058808L), tole(0xc60cd9b2L), tole(0xb10be924L), 
+tole(0x2f6f7c87L), tole(0x58684c11L), tole(0xc1611dabL), tole(0xb6662d3dL), 
+tole(0x76dc4190L), tole(0x01db7106L), tole(0x98d220bcL), tole(0xefd5102aL), 
+tole(0x71b18589L), tole(0x06b6b51fL), tole(0x9fbfe4a5L), tole(0xe8b8d433L), 
+tole(0x7807c9a2L), tole(0x0f00f934L), tole(0x9609a88eL), tole(0xe10e9818L), 
+tole(0x7f6a0dbbL), tole(0x086d3d2dL), tole(0x91646c97L), tole(0xe6635c01L), 
+tole(0x6b6b51f4L), tole(0x1c6c6162L), tole(0x856530d8L), tole(0xf262004eL), 
+tole(0x6c0695edL), tole(0x1b01a57bL), tole(0x8208f4c1L), tole(0xf50fc457L), 
+tole(0x65b0d9c6L), tole(0x12b7e950L), tole(0x8bbeb8eaL), tole(0xfcb9887cL), 
+tole(0x62dd1ddfL), tole(0x15da2d49L), tole(0x8cd37cf3L), tole(0xfbd44c65L), 
+tole(0x4db26158L), tole(0x3ab551ceL), tole(0xa3bc0074L), tole(0xd4bb30e2L), 
+tole(0x4adfa541L), tole(0x3dd895d7L), tole(0xa4d1c46dL), tole(0xd3d6f4fbL), 
+tole(0x4369e96aL), tole(0x346ed9fcL), tole(0xad678846L), tole(0xda60b8d0L), 
+tole(0x44042d73L), tole(0x33031de5L), tole(0xaa0a4c5fL), tole(0xdd0d7cc9L), 
+tole(0x5005713cL), tole(0x270241aaL), tole(0xbe0b1010L), tole(0xc90c2086L), 
+tole(0x5768b525L), tole(0x206f85b3L), tole(0xb966d409L), tole(0xce61e49fL), 
+tole(0x5edef90eL), tole(0x29d9c998L), tole(0xb0d09822L), tole(0xc7d7a8b4L), 
+tole(0x59b33d17L), tole(0x2eb40d81L), tole(0xb7bd5c3bL), tole(0xc0ba6cadL), 
+tole(0xedb88320L), tole(0x9abfb3b6L), tole(0x03b6e20cL), tole(0x74b1d29aL), 
+tole(0xead54739L), tole(0x9dd277afL), tole(0x04db2615L), tole(0x73dc1683L), 
+tole(0xe3630b12L), tole(0x94643b84L), tole(0x0d6d6a3eL), tole(0x7a6a5aa8L), 
+tole(0xe40ecf0bL), tole(0x9309ff9dL), tole(0x0a00ae27L), tole(0x7d079eb1L), 
+tole(0xf00f9344L), tole(0x8708a3d2L), tole(0x1e01f268L), tole(0x6906c2feL), 
+tole(0xf762575dL), tole(0x806567cbL), tole(0x196c3671L), tole(0x6e6b06e7L), 
+tole(0xfed41b76L), tole(0x89d32be0L), tole(0x10da7a5aL), tole(0x67dd4accL), 
+tole(0xf9b9df6fL), tole(0x8ebeeff9L), tole(0x17b7be43L), tole(0x60b08ed5L), 
+tole(0xd6d6a3e8L), tole(0xa1d1937eL), tole(0x38d8c2c4L), tole(0x4fdff252L), 
+tole(0xd1bb67f1L), tole(0xa6bc5767L), tole(0x3fb506ddL), tole(0x48b2364bL), 
+tole(0xd80d2bdaL), tole(0xaf0a1b4cL), tole(0x36034af6L), tole(0x41047a60L), 
+tole(0xdf60efc3L), tole(0xa867df55L), tole(0x316e8eefL), tole(0x4669be79L), 
+tole(0xcb61b38cL), tole(0xbc66831aL), tole(0x256fd2a0L), tole(0x5268e236L), 
+tole(0xcc0c7795L), tole(0xbb0b4703L), tole(0x220216b9L), tole(0x5505262fL), 
+tole(0xc5ba3bbeL), tole(0xb2bd0b28L), tole(0x2bb45a92L), tole(0x5cb36a04L), 
+tole(0xc2d7ffa7L), tole(0xb5d0cf31L), tole(0x2cd99e8bL), tole(0x5bdeae1dL), 
+tole(0x9b64c2b0L), tole(0xec63f226L), tole(0x756aa39cL), tole(0x026d930aL), 
+tole(0x9c0906a9L), tole(0xeb0e363fL), tole(0x72076785L), tole(0x05005713L), 
+tole(0x95bf4a82L), tole(0xe2b87a14L), tole(0x7bb12baeL), tole(0x0cb61b38L), 
+tole(0x92d28e9bL), tole(0xe5d5be0dL), tole(0x7cdcefb7L), tole(0x0bdbdf21L), 
+tole(0x86d3d2d4L), tole(0xf1d4e242L), tole(0x68ddb3f8L), tole(0x1fda836eL), 
+tole(0x81be16cdL), tole(0xf6b9265bL), tole(0x6fb077e1L), tole(0x18b74777L), 
+tole(0x88085ae6L), tole(0xff0f6a70L), tole(0x66063bcaL), tole(0x11010b5cL), 
+tole(0x8f659effL), tole(0xf862ae69L), tole(0x616bffd3L), tole(0x166ccf45L), 
+tole(0xa00ae278L), tole(0xd70dd2eeL), tole(0x4e048354L), tole(0x3903b3c2L), 
+tole(0xa7672661L), tole(0xd06016f7L), tole(0x4969474dL), tole(0x3e6e77dbL), 
+tole(0xaed16a4aL), tole(0xd9d65adcL), tole(0x40df0b66L), tole(0x37d83bf0L), 
+tole(0xa9bcae53L), tole(0xdebb9ec5L), tole(0x47b2cf7fL), tole(0x30b5ffe9L), 
+tole(0xbdbdf21cL), tole(0xcabac28aL), tole(0x53b39330L), tole(0x24b4a3a6L), 
+tole(0xbad03605L), tole(0xcdd70693L), tole(0x54de5729L), tole(0x23d967bfL), 
+tole(0xb3667a2eL), tole(0xc4614ab8L), tole(0x5d681b02L), tole(0x2a6f2b94L), 
+tole(0xb40bbe37L), tole(0xc30c8ea1L), tole(0x5a05df1bL), tole(0x2d02ef8dL)
+};
+#if 0
+static const u32 crc32table_be[] = {
+tobe(0x00000000L), tobe(0x04c11db7L), tobe(0x09823b6eL), tobe(0x0d4326d9L), 
+tobe(0x130476dcL), tobe(0x17c56b6bL), tobe(0x1a864db2L), tobe(0x1e475005L), 
+tobe(0x2608edb8L), tobe(0x22c9f00fL), tobe(0x2f8ad6d6L), tobe(0x2b4bcb61L), 
+tobe(0x350c9b64L), tobe(0x31cd86d3L), tobe(0x3c8ea00aL), tobe(0x384fbdbdL), 
+tobe(0x4c11db70L), tobe(0x48d0c6c7L), tobe(0x4593e01eL), tobe(0x4152fda9L), 
+tobe(0x5f15adacL), tobe(0x5bd4b01bL), tobe(0x569796c2L), tobe(0x52568b75L), 
+tobe(0x6a1936c8L), tobe(0x6ed82b7fL), tobe(0x639b0da6L), tobe(0x675a1011L), 
+tobe(0x791d4014L), tobe(0x7ddc5da3L), tobe(0x709f7b7aL), tobe(0x745e66cdL), 
+tobe(0x9823b6e0L), tobe(0x9ce2ab57L), tobe(0x91a18d8eL), tobe(0x95609039L), 
+tobe(0x8b27c03cL), tobe(0x8fe6dd8bL), tobe(0x82a5fb52L), tobe(0x8664e6e5L), 
+tobe(0xbe2b5b58L), tobe(0xbaea46efL), tobe(0xb7a96036L), tobe(0xb3687d81L), 
+tobe(0xad2f2d84L), tobe(0xa9ee3033L), tobe(0xa4ad16eaL), tobe(0xa06c0b5dL), 
+tobe(0xd4326d90L), tobe(0xd0f37027L), tobe(0xddb056feL), tobe(0xd9714b49L), 
+tobe(0xc7361b4cL), tobe(0xc3f706fbL), tobe(0xceb42022L), tobe(0xca753d95L), 
+tobe(0xf23a8028L), tobe(0xf6fb9d9fL), tobe(0xfbb8bb46L), tobe(0xff79a6f1L), 
+tobe(0xe13ef6f4L), tobe(0xe5ffeb43L), tobe(0xe8bccd9aL), tobe(0xec7dd02dL), 
+tobe(0x34867077L), tobe(0x30476dc0L), tobe(0x3d044b19L), tobe(0x39c556aeL), 
+tobe(0x278206abL), tobe(0x23431b1cL), tobe(0x2e003dc5L), tobe(0x2ac12072L), 
+tobe(0x128e9dcfL), tobe(0x164f8078L), tobe(0x1b0ca6a1L), tobe(0x1fcdbb16L), 
+tobe(0x018aeb13L), tobe(0x054bf6a4L), tobe(0x0808d07dL), tobe(0x0cc9cdcaL), 
+tobe(0x7897ab07L), tobe(0x7c56b6b0L), tobe(0x71159069L), tobe(0x75d48ddeL), 
+tobe(0x6b93dddbL), tobe(0x6f52c06cL), tobe(0x6211e6b5L), tobe(0x66d0fb02L), 
+tobe(0x5e9f46bfL), tobe(0x5a5e5b08L), tobe(0x571d7dd1L), tobe(0x53dc6066L), 
+tobe(0x4d9b3063L), tobe(0x495a2dd4L), tobe(0x44190b0dL), tobe(0x40d816baL), 
+tobe(0xaca5c697L), tobe(0xa864db20L), tobe(0xa527fdf9L), tobe(0xa1e6e04eL), 
+tobe(0xbfa1b04bL), tobe(0xbb60adfcL), tobe(0xb6238b25L), tobe(0xb2e29692L), 
+tobe(0x8aad2b2fL), tobe(0x8e6c3698L), tobe(0x832f1041L), tobe(0x87ee0df6L), 
+tobe(0x99a95df3L), tobe(0x9d684044L), tobe(0x902b669dL), tobe(0x94ea7b2aL), 
+tobe(0xe0b41de7L), tobe(0xe4750050L), tobe(0xe9362689L), tobe(0xedf73b3eL), 
+tobe(0xf3b06b3bL), tobe(0xf771768cL), tobe(0xfa325055L), tobe(0xfef34de2L), 
+tobe(0xc6bcf05fL), tobe(0xc27dede8L), tobe(0xcf3ecb31L), tobe(0xcbffd686L), 
+tobe(0xd5b88683L), tobe(0xd1799b34L), tobe(0xdc3abdedL), tobe(0xd8fba05aL), 
+tobe(0x690ce0eeL), tobe(0x6dcdfd59L), tobe(0x608edb80L), tobe(0x644fc637L), 
+tobe(0x7a089632L), tobe(0x7ec98b85L), tobe(0x738aad5cL), tobe(0x774bb0ebL), 
+tobe(0x4f040d56L), tobe(0x4bc510e1L), tobe(0x46863638L), tobe(0x42472b8fL), 
+tobe(0x5c007b8aL), tobe(0x58c1663dL), tobe(0x558240e4L), tobe(0x51435d53L), 
+tobe(0x251d3b9eL), tobe(0x21dc2629L), tobe(0x2c9f00f0L), tobe(0x285e1d47L), 
+tobe(0x36194d42L), tobe(0x32d850f5L), tobe(0x3f9b762cL), tobe(0x3b5a6b9bL), 
+tobe(0x0315d626L), tobe(0x07d4cb91L), tobe(0x0a97ed48L), tobe(0x0e56f0ffL), 
+tobe(0x1011a0faL), tobe(0x14d0bd4dL), tobe(0x19939b94L), tobe(0x1d528623L), 
+tobe(0xf12f560eL), tobe(0xf5ee4bb9L), tobe(0xf8ad6d60L), tobe(0xfc6c70d7L), 
+tobe(0xe22b20d2L), tobe(0xe6ea3d65L), tobe(0xeba91bbcL), tobe(0xef68060bL), 
+tobe(0xd727bbb6L), tobe(0xd3e6a601L), tobe(0xdea580d8L), tobe(0xda649d6fL), 
+tobe(0xc423cd6aL), tobe(0xc0e2d0ddL), tobe(0xcda1f604L), tobe(0xc960ebb3L), 
+tobe(0xbd3e8d7eL), tobe(0xb9ff90c9L), tobe(0xb4bcb610L), tobe(0xb07daba7L), 
+tobe(0xae3afba2L), tobe(0xaafbe615L), tobe(0xa7b8c0ccL), tobe(0xa379dd7bL), 
+tobe(0x9b3660c6L), tobe(0x9ff77d71L), tobe(0x92b45ba8L), tobe(0x9675461fL), 
+tobe(0x8832161aL), tobe(0x8cf30badL), tobe(0x81b02d74L), tobe(0x857130c3L), 
+tobe(0x5d8a9099L), tobe(0x594b8d2eL), tobe(0x5408abf7L), tobe(0x50c9b640L), 
+tobe(0x4e8ee645L), tobe(0x4a4ffbf2L), tobe(0x470cdd2bL), tobe(0x43cdc09cL), 
+tobe(0x7b827d21L), tobe(0x7f436096L), tobe(0x7200464fL), tobe(0x76c15bf8L), 
+tobe(0x68860bfdL), tobe(0x6c47164aL), tobe(0x61043093L), tobe(0x65c52d24L), 
+tobe(0x119b4be9L), tobe(0x155a565eL), tobe(0x18197087L), tobe(0x1cd86d30L), 
+tobe(0x029f3d35L), tobe(0x065e2082L), tobe(0x0b1d065bL), tobe(0x0fdc1becL), 
+tobe(0x3793a651L), tobe(0x3352bbe6L), tobe(0x3e119d3fL), tobe(0x3ad08088L), 
+tobe(0x2497d08dL), tobe(0x2056cd3aL), tobe(0x2d15ebe3L), tobe(0x29d4f654L), 
+tobe(0xc5a92679L), tobe(0xc1683bceL), tobe(0xcc2b1d17L), tobe(0xc8ea00a0L), 
+tobe(0xd6ad50a5L), tobe(0xd26c4d12L), tobe(0xdf2f6bcbL), tobe(0xdbee767cL), 
+tobe(0xe3a1cbc1L), tobe(0xe760d676L), tobe(0xea23f0afL), tobe(0xeee2ed18L), 
+tobe(0xf0a5bd1dL), tobe(0xf464a0aaL), tobe(0xf9278673L), tobe(0xfde69bc4L), 
+tobe(0x89b8fd09L), tobe(0x8d79e0beL), tobe(0x803ac667L), tobe(0x84fbdbd0L), 
+tobe(0x9abc8bd5L), tobe(0x9e7d9662L), tobe(0x933eb0bbL), tobe(0x97ffad0cL), 
+tobe(0xafb010b1L), tobe(0xab710d06L), tobe(0xa6322bdfL), tobe(0xa2f33668L), 
+tobe(0xbcb4666dL), tobe(0xb8757bdaL), tobe(0xb5365d03L), tobe(0xb1f740b4L)
+};
+#endif
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
new file mode 100644
index 0000000..492ab5c
--- /dev/null
+++ b/drivers/mtd/ubi/debug.c
@@ -0,0 +1,192 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * Here we keep all the UBI debugging stuff which should normally be disabled
+ * and compiled-out, but it is extremely helpful when hunting bugs or doing big
+ * changes.
+ */
+#include <ubi_uboot.h>
+
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG
+
+#include "ubi.h"
+
+/**
+ * ubi_dbg_dump_ec_hdr - dump an erase counter header.
+ * @ec_hdr: the erase counter header to dump
+ */
+void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
+{
+	dbg_msg("erase counter header dump:");
+	dbg_msg("magic          %#08x", be32_to_cpu(ec_hdr->magic));
+	dbg_msg("version        %d",    (int)ec_hdr->version);
+	dbg_msg("ec             %llu",  (long long)be64_to_cpu(ec_hdr->ec));
+	dbg_msg("vid_hdr_offset %d",    be32_to_cpu(ec_hdr->vid_hdr_offset));
+	dbg_msg("data_offset    %d",    be32_to_cpu(ec_hdr->data_offset));
+	dbg_msg("hdr_crc        %#08x", be32_to_cpu(ec_hdr->hdr_crc));
+	dbg_msg("erase counter header hexdump:");
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		       ec_hdr, UBI_EC_HDR_SIZE, 1);
+}
+
+/**
+ * ubi_dbg_dump_vid_hdr - dump a volume identifier header.
+ * @vid_hdr: the volume identifier header to dump
+ */
+void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
+{
+	dbg_msg("volume identifier header dump:");
+	dbg_msg("magic     %08x", be32_to_cpu(vid_hdr->magic));
+	dbg_msg("version   %d",   (int)vid_hdr->version);
+	dbg_msg("vol_type  %d",   (int)vid_hdr->vol_type);
+	dbg_msg("copy_flag %d",   (int)vid_hdr->copy_flag);
+	dbg_msg("compat    %d",   (int)vid_hdr->compat);
+	dbg_msg("vol_id    %d",   be32_to_cpu(vid_hdr->vol_id));
+	dbg_msg("lnum      %d",   be32_to_cpu(vid_hdr->lnum));
+	dbg_msg("leb_ver   %u",   be32_to_cpu(vid_hdr->leb_ver));
+	dbg_msg("data_size %d",   be32_to_cpu(vid_hdr->data_size));
+	dbg_msg("used_ebs  %d",   be32_to_cpu(vid_hdr->used_ebs));
+	dbg_msg("data_pad  %d",   be32_to_cpu(vid_hdr->data_pad));
+	dbg_msg("sqnum     %llu",
+		(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
+	dbg_msg("hdr_crc   %08x", be32_to_cpu(vid_hdr->hdr_crc));
+	dbg_msg("volume identifier header hexdump:");
+}
+
+/**
+ * ubi_dbg_dump_vol_info- dump volume information.
+ * @vol: UBI volume description object
+ */
+void ubi_dbg_dump_vol_info(const struct ubi_volume *vol)
+{
+	dbg_msg("volume information dump:");
+	dbg_msg("vol_id          %d", vol->vol_id);
+	dbg_msg("reserved_pebs   %d", vol->reserved_pebs);
+	dbg_msg("alignment       %d", vol->alignment);
+	dbg_msg("data_pad        %d", vol->data_pad);
+	dbg_msg("vol_type        %d", vol->vol_type);
+	dbg_msg("name_len        %d", vol->name_len);
+	dbg_msg("usable_leb_size %d", vol->usable_leb_size);
+	dbg_msg("used_ebs        %d", vol->used_ebs);
+	dbg_msg("used_bytes      %lld", vol->used_bytes);
+	dbg_msg("last_eb_bytes   %d", vol->last_eb_bytes);
+	dbg_msg("corrupted       %d", vol->corrupted);
+	dbg_msg("upd_marker      %d", vol->upd_marker);
+
+	if (vol->name_len <= UBI_VOL_NAME_MAX &&
+	    strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
+		dbg_msg("name            %s", vol->name);
+	} else {
+		dbg_msg("the 1st 5 characters of the name: %c%c%c%c%c",
+			vol->name[0], vol->name[1], vol->name[2],
+			vol->name[3], vol->name[4]);
+	}
+}
+
+/**
+ * ubi_dbg_dump_vtbl_record - dump a &struct ubi_vtbl_record object.
+ * @r: the object to dump
+ * @idx: volume table index
+ */
+void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx)
+{
+	int name_len = be16_to_cpu(r->name_len);
+
+	dbg_msg("volume table record %d dump:", idx);
+	dbg_msg("reserved_pebs   %d", be32_to_cpu(r->reserved_pebs));
+	dbg_msg("alignment       %d", be32_to_cpu(r->alignment));
+	dbg_msg("data_pad        %d", be32_to_cpu(r->data_pad));
+	dbg_msg("vol_type        %d", (int)r->vol_type);
+	dbg_msg("upd_marker      %d", (int)r->upd_marker);
+	dbg_msg("name_len        %d", name_len);
+
+	if (r->name[0] == '\0') {
+		dbg_msg("name            NULL");
+		return;
+	}
+
+	if (name_len <= UBI_VOL_NAME_MAX &&
+	    strnlen(&r->name[0], name_len + 1) == name_len) {
+		dbg_msg("name            %s", &r->name[0]);
+	} else {
+		dbg_msg("1st 5 characters of the name: %c%c%c%c%c",
+			r->name[0], r->name[1], r->name[2], r->name[3],
+			r->name[4]);
+	}
+	dbg_msg("crc             %#08x", be32_to_cpu(r->crc));
+}
+
+/**
+ * ubi_dbg_dump_sv - dump a &struct ubi_scan_volume object.
+ * @sv: the object to dump
+ */
+void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv)
+{
+	dbg_msg("volume scanning information dump:");
+	dbg_msg("vol_id         %d", sv->vol_id);
+	dbg_msg("highest_lnum   %d", sv->highest_lnum);
+	dbg_msg("leb_count      %d", sv->leb_count);
+	dbg_msg("compat         %d", sv->compat);
+	dbg_msg("vol_type       %d", sv->vol_type);
+	dbg_msg("used_ebs       %d", sv->used_ebs);
+	dbg_msg("last_data_size %d", sv->last_data_size);
+	dbg_msg("data_pad       %d", sv->data_pad);
+}
+
+/**
+ * ubi_dbg_dump_seb - dump a &struct ubi_scan_leb object.
+ * @seb: the object to dump
+ * @type: object type: 0 - not corrupted, 1 - corrupted
+ */
+void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type)
+{
+	dbg_msg("eraseblock scanning information dump:");
+	dbg_msg("ec       %d", seb->ec);
+	dbg_msg("pnum     %d", seb->pnum);
+	if (type == 0) {
+		dbg_msg("lnum     %d", seb->lnum);
+		dbg_msg("scrub    %d", seb->scrub);
+		dbg_msg("sqnum    %llu", seb->sqnum);
+		dbg_msg("leb_ver  %u", seb->leb_ver);
+	}
+}
+
+/**
+ * ubi_dbg_dump_mkvol_req - dump a &struct ubi_mkvol_req object.
+ * @req: the object to dump
+ */
+void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req)
+{
+	char nm[17];
+
+	dbg_msg("volume creation request dump:");
+	dbg_msg("vol_id    %d",   req->vol_id);
+	dbg_msg("alignment %d",   req->alignment);
+	dbg_msg("bytes     %lld", (long long)req->bytes);
+	dbg_msg("vol_type  %d",   req->vol_type);
+	dbg_msg("name_len  %d",   req->name_len);
+
+	memcpy(nm, req->name, 16);
+	nm[16] = 0;
+	dbg_msg("the 1st 16 characters of the name: %s", nm);
+}
+
+#endif /* CONFIG_MTD_UBI_DEBUG_MSG */
diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
new file mode 100644
index 0000000..3ea43a4
--- /dev/null
+++ b/drivers/mtd/ubi/debug.h
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+#ifndef __UBI_DEBUG_H__
+#define __UBI_DEBUG_H__
+
+#ifdef CONFIG_MTD_UBI_DEBUG
+#if 0
+#include <linux/random.h>
+#endif
+
+#define ubi_assert(expr)  BUG_ON(!(expr))
+#define dbg_err(fmt, ...) ubi_err(fmt, ##__VA_ARGS__)
+#else
+#define ubi_assert(expr)  ({})
+#define dbg_err(fmt, ...) ({})
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT
+#define DBG_DISABLE_BGT 1
+#else
+#define DBG_DISABLE_BGT 0
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG
+/* Generic debugging message */
+#define dbg_msg(fmt, ...)                                    \
+	printk(KERN_DEBUG "UBI DBG: %s: " fmt "\n", \
+	       __FUNCTION__, ##__VA_ARGS__)
+
+#define ubi_dbg_dump_stack() dump_stack()
+
+struct ubi_ec_hdr;
+struct ubi_vid_hdr;
+struct ubi_volume;
+struct ubi_vtbl_record;
+struct ubi_scan_volume;
+struct ubi_scan_leb;
+struct ubi_mkvol_req;
+
+void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr);
+void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr);
+void ubi_dbg_dump_vol_info(const struct ubi_volume *vol);
+void ubi_dbg_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx);
+void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv);
+void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type);
+void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req);
+
+#else
+
+#define dbg_msg(fmt, ...)    ({})
+#define ubi_dbg_dump_stack() ({})
+#define ubi_dbg_dump_ec_hdr(ec_hdr)      ({})
+#define ubi_dbg_dump_vid_hdr(vid_hdr)    ({})
+#define ubi_dbg_dump_vol_info(vol)       ({})
+#define ubi_dbg_dump_vtbl_record(r, idx) ({})
+#define ubi_dbg_dump_sv(sv)              ({})
+#define ubi_dbg_dump_seb(seb, type)      ({})
+#define ubi_dbg_dump_mkvol_req(req)      ({})
+
+#endif /* CONFIG_MTD_UBI_DEBUG_MSG */
+
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG_EBA
+/* Messages from the eraseblock association unit */
+#define dbg_eba(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+#else
+#define dbg_eba(fmt, ...) ({})
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG_WL
+/* Messages from the wear-leveling unit */
+#define dbg_wl(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+#else
+#define dbg_wl(fmt, ...) ({})
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG_IO
+/* Messages from the input/output unit */
+#define dbg_io(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+#else
+#define dbg_io(fmt, ...) ({})
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_MSG_BLD
+/* Initialization and build messages */
+#define dbg_bld(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+#else
+#define dbg_bld(fmt, ...) ({})
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_BITFLIPS
+/**
+ * ubi_dbg_is_bitflip - if it is time to emulate a bit-flip.
+ *
+ * Returns non-zero if a bit-flip should be emulated, otherwise returns zero.
+ */
+static inline int ubi_dbg_is_bitflip(void)
+{
+	return !(random32() % 200);
+}
+#else
+#define ubi_dbg_is_bitflip() 0
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_WRITE_FAILURES
+/**
+ * ubi_dbg_is_write_failure - if it is time to emulate a write failure.
+ *
+ * Returns non-zero if a write failure should be emulated, otherwise returns
+ * zero.
+ */
+static inline int ubi_dbg_is_write_failure(void)
+{
+	return !(random32() % 500);
+}
+#else
+#define ubi_dbg_is_write_failure() 0
+#endif
+
+#ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_ERASE_FAILURES
+/**
+ * ubi_dbg_is_erase_failure - if its time to emulate an erase failure.
+ *
+ * Returns non-zero if an erase failure should be emulated, otherwise returns
+ * zero.
+ */
+static inline int ubi_dbg_is_erase_failure(void)
+{
+		return !(random32() % 400);
+}
+#else
+#define ubi_dbg_is_erase_failure() 0
+#endif
+
+#endif /* !__UBI_DEBUG_H__ */
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
new file mode 100644
index 0000000..3f9b780
--- /dev/null
+++ b/drivers/mtd/ubi/eba.c
@@ -0,0 +1,1256 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * The UBI Eraseblock Association (EBA) unit.
+ *
+ * This unit is responsible for I/O to/from logical eraseblock.
+ *
+ * Although in this implementation the EBA table is fully kept and managed in
+ * RAM, which assumes poor scalability, it might be (partially) maintained on
+ * flash in future implementations.
+ *
+ * The EBA unit implements per-logical eraseblock locking. Before accessing a
+ * logical eraseblock it is locked for reading or writing. The per-logical
+ * eraseblock locking is implemented by means of the lock tree. The lock tree
+ * is an RB-tree which refers all the currently locked logical eraseblocks. The
+ * lock tree elements are &struct ubi_ltree_entry objects. They are indexed by
+ * (@vol_id, @lnum) pairs.
+ *
+ * EBA also maintains the global sequence counter which is incremented each
+ * time a logical eraseblock is mapped to a physical eraseblock and it is
+ * stored in the volume identifier header. This means that each VID header has
+ * a unique sequence number. The sequence number is only increased an we assume
+ * 64 bits is enough to never overflow.
+ */
+
+#if 0
+#include <linux/slab.h>
+#include <linux/crc32.h>
+#include <linux/err.h>
+#endif
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+/* Number of physical eraseblocks reserved for atomic LEB change operation */
+#define EBA_RESERVED_PEBS 1
+
+/**
+ * next_sqnum - get next sequence number.
+ * @ubi: UBI device description object
+ *
+ * This function returns next sequence number to use, which is just the current
+ * global sequence counter value. It also increases the global sequence
+ * counter.
+ */
+static unsigned long long next_sqnum(struct ubi_device *ubi)
+{
+	unsigned long long sqnum;
+
+	spin_lock(&ubi->ltree_lock);
+	sqnum = ubi->global_sqnum++;
+	spin_unlock(&ubi->ltree_lock);
+
+	return sqnum;
+}
+
+/**
+ * ubi_get_compat - get compatibility flags of a volume.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ *
+ * This function returns compatibility flags for an internal volume. User
+ * volumes have no compatibility flags, so %0 is returned.
+ */
+static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
+{
+	if (vol_id == UBI_LAYOUT_VOLUME_ID)
+		return UBI_LAYOUT_VOLUME_COMPAT;
+	return 0;
+}
+
+/**
+ * ltree_lookup - look up the lock tree.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function returns a pointer to the corresponding &struct ubi_ltree_entry
+ * object if the logical eraseblock is locked and %NULL if it is not.
+ * @ubi->ltree_lock has to be locked.
+ */
+static struct ubi_ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
+					    int lnum)
+{
+	struct rb_node *p;
+
+	p = ubi->ltree.rb_node;
+	while (p) {
+		struct ubi_ltree_entry *le;
+
+		le = rb_entry(p, struct ubi_ltree_entry, rb);
+
+		if (vol_id < le->vol_id)
+			p = p->rb_left;
+		else if (vol_id > le->vol_id)
+			p = p->rb_right;
+		else {
+			if (lnum < le->lnum)
+				p = p->rb_left;
+			else if (lnum > le->lnum)
+				p = p->rb_right;
+			else
+				return le;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * ltree_add_entry - add new entry to the lock tree.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function adds new entry for logical eraseblock (@vol_id, @lnum) to the
+ * lock tree. If such entry is already there, its usage counter is increased.
+ * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
+ * failed.
+ */
+static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
+					       int vol_id, int lnum)
+{
+	struct ubi_ltree_entry *le, *le1, *le_free;
+
+	le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS);
+	if (!le)
+		return ERR_PTR(-ENOMEM);
+
+	le->users = 0;
+	init_rwsem(&le->mutex);
+	le->vol_id = vol_id;
+	le->lnum = lnum;
+
+	spin_lock(&ubi->ltree_lock);
+	le1 = ltree_lookup(ubi, vol_id, lnum);
+
+	if (le1) {
+		/*
+		 * This logical eraseblock is already locked. The newly
+		 * allocated lock entry is not needed.
+		 */
+		le_free = le;
+		le = le1;
+	} else {
+		struct rb_node **p, *parent = NULL;
+
+		/*
+		 * No lock entry, add the newly allocated one to the
+		 * @ubi->ltree RB-tree.
+		 */
+		le_free = NULL;
+
+		p = &ubi->ltree.rb_node;
+		while (*p) {
+			parent = *p;
+			le1 = rb_entry(parent, struct ubi_ltree_entry, rb);
+
+			if (vol_id < le1->vol_id)
+				p = &(*p)->rb_left;
+			else if (vol_id > le1->vol_id)
+				p = &(*p)->rb_right;
+			else {
+				ubi_assert(lnum != le1->lnum);
+				if (lnum < le1->lnum)
+					p = &(*p)->rb_left;
+				else
+					p = &(*p)->rb_right;
+			}
+		}
+
+		rb_link_node(&le->rb, parent, p);
+		rb_insert_color(&le->rb, &ubi->ltree);
+	}
+	le->users += 1;
+	spin_unlock(&ubi->ltree_lock);
+
+	if (le_free)
+		kfree(le_free);
+
+	return le;
+}
+
+/**
+ * leb_read_lock - lock logical eraseblock for reading.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function locks a logical eraseblock for reading. Returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+	struct ubi_ltree_entry *le;
+
+	le = ltree_add_entry(ubi, vol_id, lnum);
+	if (IS_ERR(le))
+		return PTR_ERR(le);
+	down_read(&le->mutex);
+	return 0;
+}
+
+/**
+ * leb_read_unlock - unlock logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ */
+static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+	int _free = 0;
+	struct ubi_ltree_entry *le;
+
+	spin_lock(&ubi->ltree_lock);
+	le = ltree_lookup(ubi, vol_id, lnum);
+	le->users -= 1;
+	ubi_assert(le->users >= 0);
+	if (le->users == 0) {
+		rb_erase(&le->rb, &ubi->ltree);
+		_free = 1;
+	}
+	spin_unlock(&ubi->ltree_lock);
+
+	up_read(&le->mutex);
+	if (_free)
+		kfree(le);
+}
+
+/**
+ * leb_write_lock - lock logical eraseblock for writing.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function locks a logical eraseblock for writing. Returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+	struct ubi_ltree_entry *le;
+
+	le = ltree_add_entry(ubi, vol_id, lnum);
+	if (IS_ERR(le))
+		return PTR_ERR(le);
+	down_write(&le->mutex);
+	return 0;
+}
+
+/**
+ * leb_write_lock - lock logical eraseblock for writing.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ *
+ * This function locks a logical eraseblock for writing if there is no
+ * contention and does nothing if there is contention. Returns %0 in case of
+ * success, %1 in case of contention, and and a negative error code in case of
+ * failure.
+ */
+static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+	int _free;
+	struct ubi_ltree_entry *le;
+
+	le = ltree_add_entry(ubi, vol_id, lnum);
+	if (IS_ERR(le))
+		return PTR_ERR(le);
+	if (down_write_trylock(&le->mutex))
+		return 0;
+
+	/* Contention, cancel */
+	spin_lock(&ubi->ltree_lock);
+	le->users -= 1;
+	ubi_assert(le->users >= 0);
+	if (le->users == 0) {
+		rb_erase(&le->rb, &ubi->ltree);
+		_free = 1;
+	} else
+		_free = 0;
+	spin_unlock(&ubi->ltree_lock);
+	if (_free)
+		kfree(le);
+
+	return 1;
+}
+
+/**
+ * leb_write_unlock - unlock logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ */
+static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
+{
+	int _free;
+	struct ubi_ltree_entry *le;
+
+	spin_lock(&ubi->ltree_lock);
+	le = ltree_lookup(ubi, vol_id, lnum);
+	le->users -= 1;
+	ubi_assert(le->users >= 0);
+	if (le->users == 0) {
+		rb_erase(&le->rb, &ubi->ltree);
+		_free = 1;
+	} else
+		_free = 0;
+	spin_unlock(&ubi->ltree_lock);
+
+	up_write(&le->mutex);
+	if (_free)
+		kfree(le);
+}
+
+/**
+ * ubi_eba_unmap_leb - un-map logical eraseblock.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ *
+ * This function un-maps logical eraseblock @lnum and schedules corresponding
+ * physical eraseblock for erasure. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
+		      int lnum)
+{
+	int err, pnum, vol_id = vol->vol_id;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	err = leb_write_lock(ubi, vol_id, lnum);
+	if (err)
+		return err;
+
+	pnum = vol->eba_tbl[lnum];
+	if (pnum < 0)
+		/* This logical eraseblock is already unmapped */
+		goto out_unlock;
+
+	dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
+
+	vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
+	err = ubi_wl_put_peb(ubi, pnum, 0);
+
+out_unlock:
+	leb_write_unlock(ubi, vol_id, lnum);
+	return err;
+}
+
+/**
+ * ubi_eba_read_leb - read data.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: buffer to store the read data
+ * @offset: offset from where to read
+ * @len: how many bytes to read
+ * @check: data CRC check flag
+ *
+ * If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
+ * bytes. The @check flag only makes sense for static volumes and forces
+ * eraseblock data CRC checking.
+ *
+ * In case of success this function returns zero. In case of a static volume,
+ * if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
+ * returned for any volume type if an ECC error was detected by the MTD device
+ * driver. Other negative error cored may be returned in case of other errors.
+ */
+int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+		     void *buf, int offset, int len, int check)
+{
+	int err, pnum, scrub = 0, vol_id = vol->vol_id;
+	struct ubi_vid_hdr *vid_hdr;
+	uint32_t uninitialized_var(crc);
+
+	err = leb_read_lock(ubi, vol_id, lnum);
+	if (err)
+		return err;
+
+	pnum = vol->eba_tbl[lnum];
+	if (pnum < 0) {
+		/*
+		 * The logical eraseblock is not mapped, fill the whole buffer
+		 * with 0xFF bytes. The exception is static volumes for which
+		 * it is an error to read unmapped logical eraseblocks.
+		 */
+		dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
+			len, offset, vol_id, lnum);
+		leb_read_unlock(ubi, vol_id, lnum);
+		ubi_assert(vol->vol_type != UBI_STATIC_VOLUME);
+		memset(buf, 0xFF, len);
+		return 0;
+	}
+
+	dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
+		len, offset, vol_id, lnum, pnum);
+
+	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+		check = 0;
+
+retry:
+	if (check) {
+		vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+		if (!vid_hdr) {
+			err = -ENOMEM;
+			goto out_unlock;
+		}
+
+		err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
+		if (err && err != UBI_IO_BITFLIPS) {
+			if (err > 0) {
+				/*
+				 * The header is either absent or corrupted.
+				 * The former case means there is a bug -
+				 * switch to read-only mode just in case.
+				 * The latter case means a real corruption - we
+				 * may try to recover data. FIXME: but this is
+				 * not implemented.
+				 */
+				if (err == UBI_IO_BAD_VID_HDR) {
+					ubi_warn("bad VID header at PEB %d, LEB"
+						 "%d:%d", pnum, vol_id, lnum);
+					err = -EBADMSG;
+				} else
+					ubi_ro_mode(ubi);
+			}
+			goto out_free;
+		} else if (err == UBI_IO_BITFLIPS)
+			scrub = 1;
+
+		ubi_assert(lnum < be32_to_cpu(vid_hdr->used_ebs));
+		ubi_assert(len == be32_to_cpu(vid_hdr->data_size));
+
+		crc = be32_to_cpu(vid_hdr->data_crc);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+	}
+
+	err = ubi_io_read_data(ubi, buf, pnum, offset, len);
+	if (err) {
+		if (err == UBI_IO_BITFLIPS) {
+			scrub = 1;
+			err = 0;
+		} else if (err == -EBADMSG) {
+			if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+				goto out_unlock;
+			scrub = 1;
+			if (!check) {
+				ubi_msg("force data checking");
+				check = 1;
+				goto retry;
+			}
+		} else
+			goto out_unlock;
+	}
+
+	if (check) {
+		uint32_t crc1 = crc32(UBI_CRC32_INIT, buf, len);
+		if (crc1 != crc) {
+			ubi_warn("CRC error: calculated %#08x, must be %#08x",
+				 crc1, crc);
+			err = -EBADMSG;
+			goto out_unlock;
+		}
+	}
+
+	if (scrub)
+		err = ubi_wl_scrub_peb(ubi, pnum);
+
+	leb_read_unlock(ubi, vol_id, lnum);
+	return err;
+
+out_free:
+	ubi_free_vid_hdr(ubi, vid_hdr);
+out_unlock:
+	leb_read_unlock(ubi, vol_id, lnum);
+	return err;
+}
+
+/**
+ * recover_peb - recover from write failure.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock to recover
+ * @vol_id: volume ID
+ * @lnum: logical eraseblock number
+ * @buf: data which was not written because of the write failure
+ * @offset: offset of the failed write
+ * @len: how many bytes should have been written
+ *
+ * This function is called in case of a write failure and moves all good data
+ * from the potentially bad physical eraseblock to a good physical eraseblock.
+ * This function also writes the data which was not written due to the failure.
+ * Returns new physical eraseblock number in case of success, and a negative
+ * error code in case of failure.
+ */
+static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
+		       const void *buf, int offset, int len)
+{
+	int err, idx = vol_id2idx(ubi, vol_id), new_pnum, data_size, tries = 0;
+	struct ubi_volume *vol = ubi->volumes[idx];
+	struct ubi_vid_hdr *vid_hdr;
+
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+	if (!vid_hdr) {
+		return -ENOMEM;
+	}
+
+	mutex_lock(&ubi->buf_mutex);
+
+retry:
+	new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
+	if (new_pnum < 0) {
+		mutex_unlock(&ubi->buf_mutex);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return new_pnum;
+	}
+
+	ubi_msg("recover PEB %d, move data to PEB %d", pnum, new_pnum);
+
+	err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
+	if (err && err != UBI_IO_BITFLIPS) {
+		if (err > 0)
+			err = -EIO;
+		goto out_put;
+	}
+
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr);
+	if (err)
+		goto write_error;
+
+	data_size = offset + len;
+	memset(ubi->peb_buf1 + offset, 0xFF, len);
+
+	/* Read everything before the area where the write failure happened */
+	if (offset > 0) {
+		err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
+		if (err && err != UBI_IO_BITFLIPS)
+			goto out_put;
+	}
+
+	memcpy(ubi->peb_buf1 + offset, buf, len);
+
+	err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
+	if (err)
+		goto write_error;
+
+	mutex_unlock(&ubi->buf_mutex);
+	ubi_free_vid_hdr(ubi, vid_hdr);
+
+	vol->eba_tbl[lnum] = new_pnum;
+	ubi_wl_put_peb(ubi, pnum, 1);
+
+	ubi_msg("data was successfully recovered");
+	return 0;
+
+out_put:
+	mutex_unlock(&ubi->buf_mutex);
+	ubi_wl_put_peb(ubi, new_pnum, 1);
+	ubi_free_vid_hdr(ubi, vid_hdr);
+	return err;
+
+write_error:
+	/*
+	 * Bad luck? This physical eraseblock is bad too? Crud. Let's try to
+	 * get another one.
+	 */
+	ubi_warn("failed to write to PEB %d", new_pnum);
+	ubi_wl_put_peb(ubi, new_pnum, 1);
+	if (++tries > UBI_IO_RETRIES) {
+		mutex_unlock(&ubi->buf_mutex);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return err;
+	}
+	ubi_msg("try again");
+	goto retry;
+}
+
+/**
+ * ubi_eba_write_leb - write data to dynamic volume.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: the data to write
+ * @offset: offset within the logical eraseblock where to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ *
+ * This function writes data to logical eraseblock @lnum of a dynamic volume
+ * @vol. Returns zero in case of success and a negative error code in case
+ * of failure. In case of error, it is possible that something was still
+ * written to the flash media, but may be some garbage.
+ */
+int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+		      const void *buf, int offset, int len, int dtype)
+{
+	int err, pnum, tries = 0, vol_id = vol->vol_id;
+	struct ubi_vid_hdr *vid_hdr;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	err = leb_write_lock(ubi, vol_id, lnum);
+	if (err)
+		return err;
+
+	pnum = vol->eba_tbl[lnum];
+	if (pnum >= 0) {
+		dbg_eba("write %d bytes at offset %d of LEB %d:%d, PEB %d",
+			len, offset, vol_id, lnum, pnum);
+
+		err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+		if (err) {
+			ubi_warn("failed to write data to PEB %d", pnum);
+			if (err == -EIO && ubi->bad_allowed)
+				err = recover_peb(ubi, pnum, vol_id, lnum, buf,
+						  offset, len);
+			if (err)
+				ubi_ro_mode(ubi);
+		}
+		leb_write_unlock(ubi, vol_id, lnum);
+		return err;
+	}
+
+	/*
+	 * The logical eraseblock is not mapped. We have to get a free physical
+	 * eraseblock and write the volume identifier header there first.
+	 */
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+	if (!vid_hdr) {
+		leb_write_unlock(ubi, vol_id, lnum);
+		return -ENOMEM;
+	}
+
+	vid_hdr->vol_type = UBI_VID_DYNAMIC;
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->vol_id = cpu_to_be32(vol_id);
+	vid_hdr->lnum = cpu_to_be32(lnum);
+	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
+
+retry:
+	pnum = ubi_wl_get_peb(ubi, dtype);
+	if (pnum < 0) {
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		leb_write_unlock(ubi, vol_id, lnum);
+		return pnum;
+	}
+
+	dbg_eba("write VID hdr and %d bytes at offset %d of LEB %d:%d, PEB %d",
+		len, offset, vol_id, lnum, pnum);
+
+	err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+	if (err) {
+		ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
+			 vol_id, lnum, pnum);
+		goto write_error;
+	}
+
+	if (len) {
+		err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+		if (err) {
+			ubi_warn("failed to write %d bytes at offset %d of "
+				 "LEB %d:%d, PEB %d", len, offset, vol_id,
+				 lnum, pnum);
+			goto write_error;
+		}
+	}
+
+	vol->eba_tbl[lnum] = pnum;
+
+	leb_write_unlock(ubi, vol_id, lnum);
+	ubi_free_vid_hdr(ubi, vid_hdr);
+	return 0;
+
+write_error:
+	if (err != -EIO || !ubi->bad_allowed) {
+		ubi_ro_mode(ubi);
+		leb_write_unlock(ubi, vol_id, lnum);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return err;
+	}
+
+	/*
+	 * Fortunately, this is the first write operation to this physical
+	 * eraseblock, so just put it and request a new one. We assume that if
+	 * this physical eraseblock went bad, the erase code will handle that.
+	 */
+	err = ubi_wl_put_peb(ubi, pnum, 1);
+	if (err || ++tries > UBI_IO_RETRIES) {
+		ubi_ro_mode(ubi);
+		leb_write_unlock(ubi, vol_id, lnum);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return err;
+	}
+
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	ubi_msg("try another PEB");
+	goto retry;
+}
+
+/**
+ * ubi_eba_write_leb_st - write data to static volume.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: data to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ * @used_ebs: how many logical eraseblocks will this volume contain
+ *
+ * This function writes data to logical eraseblock @lnum of static volume
+ * @vol. The @used_ebs argument should contain total number of logical
+ * eraseblock in this static volume.
+ *
+ * When writing to the last logical eraseblock, the @len argument doesn't have
+ * to be aligned to the minimal I/O unit size. Instead, it has to be equivalent
+ * to the real data size, although the @buf buffer has to contain the
+ * alignment. In all other cases, @len has to be aligned.
+ *
+ * It is prohibited to write more then once to logical eraseblocks of static
+ * volumes. This function returns zero in case of success and a negative error
+ * code in case of failure.
+ */
+int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
+			 int lnum, const void *buf, int len, int dtype,
+			 int used_ebs)
+{
+	int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id;
+	struct ubi_vid_hdr *vid_hdr;
+	uint32_t crc;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	if (lnum == used_ebs - 1)
+		/* If this is the last LEB @len may be unaligned */
+		len = ALIGN(data_size, ubi->min_io_size);
+	else
+		ubi_assert(!(len & (ubi->min_io_size - 1)));
+
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+	if (!vid_hdr)
+		return -ENOMEM;
+
+	err = leb_write_lock(ubi, vol_id, lnum);
+	if (err) {
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return err;
+	}
+
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->vol_id = cpu_to_be32(vol_id);
+	vid_hdr->lnum = cpu_to_be32(lnum);
+	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
+
+	crc = crc32(UBI_CRC32_INIT, buf, data_size);
+	vid_hdr->vol_type = UBI_VID_STATIC;
+	vid_hdr->data_size = cpu_to_be32(data_size);
+	vid_hdr->used_ebs = cpu_to_be32(used_ebs);
+	vid_hdr->data_crc = cpu_to_be32(crc);
+
+retry:
+	pnum = ubi_wl_get_peb(ubi, dtype);
+	if (pnum < 0) {
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		leb_write_unlock(ubi, vol_id, lnum);
+		return pnum;
+	}
+
+	dbg_eba("write VID hdr and %d bytes at LEB %d:%d, PEB %d, used_ebs %d",
+		len, vol_id, lnum, pnum, used_ebs);
+
+	err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+	if (err) {
+		ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
+			 vol_id, lnum, pnum);
+		goto write_error;
+	}
+
+	err = ubi_io_write_data(ubi, buf, pnum, 0, len);
+	if (err) {
+		ubi_warn("failed to write %d bytes of data to PEB %d",
+			 len, pnum);
+		goto write_error;
+	}
+
+	ubi_assert(vol->eba_tbl[lnum] < 0);
+	vol->eba_tbl[lnum] = pnum;
+
+	leb_write_unlock(ubi, vol_id, lnum);
+	ubi_free_vid_hdr(ubi, vid_hdr);
+	return 0;
+
+write_error:
+	if (err != -EIO || !ubi->bad_allowed) {
+		/*
+		 * This flash device does not admit of bad eraseblocks or
+		 * something nasty and unexpected happened. Switch to read-only
+		 * mode just in case.
+		 */
+		ubi_ro_mode(ubi);
+		leb_write_unlock(ubi, vol_id, lnum);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return err;
+	}
+
+	err = ubi_wl_put_peb(ubi, pnum, 1);
+	if (err || ++tries > UBI_IO_RETRIES) {
+		ubi_ro_mode(ubi);
+		leb_write_unlock(ubi, vol_id, lnum);
+		ubi_free_vid_hdr(ubi, vid_hdr);
+		return err;
+	}
+
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	ubi_msg("try another PEB");
+	goto retry;
+}
+
+/*
+ * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
+ * @ubi: UBI device description object
+ * @vol: volume description object
+ * @lnum: logical eraseblock number
+ * @buf: data to write
+ * @len: how many bytes to write
+ * @dtype: data type
+ *
+ * This function changes the contents of a logical eraseblock atomically. @buf
+ * has to contain new logical eraseblock data, and @len - the length of the
+ * data, which has to be aligned. This function guarantees that in case of an
+ * unclean reboot the old contents is preserved. Returns zero in case of
+ * success and a negative error code in case of failure.
+ *
+ * UBI reserves one LEB for the "atomic LEB change" operation, so only one
+ * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
+ */
+int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
+			      int lnum, const void *buf, int len, int dtype)
+{
+	int err, pnum, tries = 0, vol_id = vol->vol_id;
+	struct ubi_vid_hdr *vid_hdr;
+	uint32_t crc;
+
+	if (ubi->ro_mode)
+		return -EROFS;
+
+	if (len == 0) {
+		/*
+		 * Special case when data length is zero. In this case the LEB
+		 * has to be unmapped and mapped somewhere else.
+		 */
+		err = ubi_eba_unmap_leb(ubi, vol, lnum);
+		if (err)
+			return err;
+		return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
+	}
+
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+	if (!vid_hdr)
+		return -ENOMEM;
+
+	mutex_lock(&ubi->alc_mutex);
+	err = leb_write_lock(ubi, vol_id, lnum);
+	if (err)
+		goto out_mutex;
+
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	vid_hdr->vol_id = cpu_to_be32(vol_id);
+	vid_hdr->lnum = cpu_to_be32(lnum);
+	vid_hdr->compat = ubi_get_compat(ubi, vol_id);
+	vid_hdr->data_pad = cpu_to_be32(vol->data_pad);
+
+	crc = crc32(UBI_CRC32_INIT, buf, len);
+	vid_hdr->vol_type = UBI_VID_DYNAMIC;
+	vid_hdr->data_size = cpu_to_be32(len);
+	vid_hdr->copy_flag = 1;
+	vid_hdr->data_crc = cpu_to_be32(crc);
+
+retry:
+	pnum = ubi_wl_get_peb(ubi, dtype);
+	if (pnum < 0) {
+		err = pnum;
+		goto out_leb_unlock;
+	}
+
+	dbg_eba("change LEB %d:%d, PEB %d, write VID hdr to PEB %d",
+		vol_id, lnum, vol->eba_tbl[lnum], pnum);
+
+	err = ubi_io_write_vid_hdr(ubi, pnum, vid_hdr);
+	if (err) {
+		ubi_warn("failed to write VID header to LEB %d:%d, PEB %d",
+			 vol_id, lnum, pnum);
+		goto write_error;
+	}
+
+	err = ubi_io_write_data(ubi, buf, pnum, 0, len);
+	if (err) {
+		ubi_warn("failed to write %d bytes of data to PEB %d",
+			 len, pnum);
+		goto write_error;
+	}
+
+	if (vol->eba_tbl[lnum] >= 0) {
+		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
+		if (err)
+			goto out_leb_unlock;
+	}
+
+	vol->eba_tbl[lnum] = pnum;
+
+out_leb_unlock:
+	leb_write_unlock(ubi, vol_id, lnum);
+out_mutex:
+	mutex_unlock(&ubi->alc_mutex);
+	ubi_free_vid_hdr(ubi, vid_hdr);
+	return err;
+
+write_error:
+	if (err != -EIO || !ubi->bad_allowed) {
+		/*
+		 * This flash device does not admit of bad eraseblocks or
+		 * something nasty and unexpected happened. Switch to read-only
+		 * mode just in case.
+		 */
+		ubi_ro_mode(ubi);
+		goto out_leb_unlock;
+	}
+
+	err = ubi_wl_put_peb(ubi, pnum, 1);
+	if (err || ++tries > UBI_IO_RETRIES) {
+		ubi_ro_mode(ubi);
+		goto out_leb_unlock;
+	}
+
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+	ubi_msg("try another PEB");
+	goto retry;
+}
+
+/**
+ * ubi_eba_copy_leb - copy logical eraseblock.
+ * @ubi: UBI device description object
+ * @from: physical eraseblock number from where to copy
+ * @to: physical eraseblock number where to copy
+ * @vid_hdr: VID header of the @from physical eraseblock
+ *
+ * This function copies logical eraseblock from physical eraseblock @from to
+ * physical eraseblock @to. The @vid_hdr buffer may be changed by this
+ * function. Returns:
+ *   o %0  in case of success;
+ *   o %1 if the operation was canceled and should be tried later (e.g.,
+ *     because a bit-flip was detected at the target PEB);
+ *   o %2 if the volume is being deleted and this LEB should not be moved.
+ */
+int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
+		     struct ubi_vid_hdr *vid_hdr)
+{
+	int err, vol_id, lnum, data_size, aldata_size, idx;
+	struct ubi_volume *vol;
+	uint32_t crc;
+
+	vol_id = be32_to_cpu(vid_hdr->vol_id);
+	lnum = be32_to_cpu(vid_hdr->lnum);
+
+	dbg_eba("copy LEB %d:%d, PEB %d to PEB %d", vol_id, lnum, from, to);
+
+	if (vid_hdr->vol_type == UBI_VID_STATIC) {
+		data_size = be32_to_cpu(vid_hdr->data_size);
+		aldata_size = ALIGN(data_size, ubi->min_io_size);
+	} else
+		data_size = aldata_size =
+			    ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);
+
+	idx = vol_id2idx(ubi, vol_id);
+	spin_lock(&ubi->volumes_lock);
+	/*
+	 * Note, we may race with volume deletion, which means that the volume
+	 * this logical eraseblock belongs to might be being deleted. Since the
+	 * volume deletion unmaps all the volume's logical eraseblocks, it will
+	 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
+	 */
+	vol = ubi->volumes[idx];
+	if (!vol) {
+		/* No need to do further work, cancel */
+		dbg_eba("volume %d is being removed, cancel", vol_id);
+		spin_unlock(&ubi->volumes_lock);
+		return 2;
+	}
+	spin_unlock(&ubi->volumes_lock);
+
+	/*
+	 * We do not want anybody to write to this logical eraseblock while we
+	 * are moving it, so lock it.
+	 *
+	 * Note, we are using non-waiting locking here, because we cannot sleep
+	 * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
+	 * unmapping the LEB which is mapped to the PEB we are going to move
+	 * (@from). This task locks the LEB and goes sleep in the
+	 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
+	 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
+	 * LEB is already locked, we just do not move it and return %1.
+	 */
+	err = leb_write_trylock(ubi, vol_id, lnum);
+	if (err) {
+		dbg_eba("contention on LEB %d:%d, cancel", vol_id, lnum);
+		return err;
+	}
+
+	/*
+	 * The LEB might have been put meanwhile, and the task which put it is
+	 * probably waiting on @ubi->move_mutex. No need to continue the work,
+	 * cancel it.
+	 */
+	if (vol->eba_tbl[lnum] != from) {
+		dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
+			"PEB %d, cancel", vol_id, lnum, from,
+			vol->eba_tbl[lnum]);
+		err = 1;
+		goto out_unlock_leb;
+	}
+
+	/*
+	 * OK, now the LEB is locked and we can safely start moving iy. Since
+	 * this function utilizes thie @ubi->peb1_buf buffer which is shared
+	 * with some other functions, so lock the buffer by taking the
+	 * @ubi->buf_mutex.
+	 */
+	mutex_lock(&ubi->buf_mutex);
+	dbg_eba("read %d bytes of data", aldata_size);
+	err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
+	if (err && err != UBI_IO_BITFLIPS) {
+		ubi_warn("error %d while reading data from PEB %d",
+			 err, from);
+		goto out_unlock_buf;
+	}
+
+	/*
+	 * Now we have got to calculate how much data we have to to copy. In
+	 * case of a static volume it is fairly easy - the VID header contains
+	 * the data size. In case of a dynamic volume it is more difficult - we
+	 * have to read the contents, cut 0xFF bytes from the end and copy only
+	 * the first part. We must do this to avoid writing 0xFF bytes as it
+	 * may have some side-effects. And not only this. It is important not
+	 * to include those 0xFFs to CRC because later the they may be filled
+	 * by data.
+	 */
+	if (vid_hdr->vol_type == UBI_VID_DYNAMIC)
+		aldata_size = data_size =
+			ubi_calc_data_len(ubi, ubi->peb_buf1, data_size);
+
+	cond_resched();
+	crc = crc32(UBI_CRC32_INIT, ubi->peb_buf1, data_size);
+	cond_resched();
+
+	/*
+	 * It may turn out to me that the whole @from physical eraseblock
+	 * contains only 0xFF bytes. Then we have to only write the VID header
+	 * and do not write any data. This also means we should not set
+	 * @vid_hdr->copy_flag, @vid_hdr->data_size, and @vid_hdr->data_crc.
+	 */
+	if (data_size > 0) {
+		vid_hdr->copy_flag = 1;
+		vid_hdr->data_size = cpu_to_be32(data_size);
+		vid_hdr->data_crc = cpu_to_be32(crc);
+	}
+	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+
+	err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
+	if (err)
+		goto out_unlock_buf;
+
+	cond_resched();
+
+	/* Read the VID header back and check if it was written correctly */
+	err = ubi_io_read_vid_hdr(ubi, to, vid_hdr, 1);
+	if (err) {
+		if (err != UBI_IO_BITFLIPS)
+			ubi_warn("cannot read VID header back from PEB %d", to);
+		else
+			err = 1;
+		goto out_unlock_buf;
+	}
+
+	if (data_size > 0) {
+		err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
+		if (err)
+			goto out_unlock_buf;
+
+		cond_resched();
+
+		/*
+		 * We've written the data and are going to read it back to make
+		 * sure it was written correctly.
+		 */
+
+		err = ubi_io_read_data(ubi, ubi->peb_buf2, to, 0, aldata_size);
+		if (err) {
+			if (err != UBI_IO_BITFLIPS)
+				ubi_warn("cannot read data back from PEB %d",
+					 to);
+			else
+				err = 1;
+			goto out_unlock_buf;
+		}
+
+		cond_resched();
+
+		if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
+			ubi_warn("read data back from PEB %d - it is different",
+				 to);
+			goto out_unlock_buf;
+		}
+	}
+
+	ubi_assert(vol->eba_tbl[lnum] == from);
+	vol->eba_tbl[lnum] = to;
+
+out_unlock_buf:
+	mutex_unlock(&ubi->buf_mutex);
+out_unlock_leb:
+	leb_write_unlock(ubi, vol_id, lnum);
+	return err;
+}
+
+/**
+ * ubi_eba_init_scan - initialize the EBA unit using scanning information.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
+{
+	int i, j, err, num_volumes;
+	struct ubi_scan_volume *sv;
+	struct ubi_volume *vol;
+	struct ubi_scan_leb *seb;
+	struct rb_node *rb;
+
+	dbg_eba("initialize EBA unit");
+
+	spin_lock_init(&ubi->ltree_lock);
+	mutex_init(&ubi->alc_mutex);
+	ubi->ltree = RB_ROOT;
+
+	ubi->global_sqnum = si->max_sqnum + 1;
+	num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+
+	for (i = 0; i < num_volumes; i++) {
+		vol = ubi->volumes[i];
+		if (!vol)
+			continue;
+
+		cond_resched();
+
+		vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int),
+				       GFP_KERNEL);
+		if (!vol->eba_tbl) {
+			err = -ENOMEM;
+			goto out_free;
+		}
+
+		for (j = 0; j < vol->reserved_pebs; j++)
+			vol->eba_tbl[j] = UBI_LEB_UNMAPPED;
+
+		sv = ubi_scan_find_sv(si, idx2vol_id(ubi, i));
+		if (!sv)
+			continue;
+
+		ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
+			if (seb->lnum >= vol->reserved_pebs)
+				/*
+				 * This may happen in case of an unclean reboot
+				 * during re-size.
+				 */
+				ubi_scan_move_to_list(sv, seb, &si->erase);
+			vol->eba_tbl[seb->lnum] = seb->pnum;
+		}
+	}
+
+	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
+		ubi_err("no enough physical eraseblocks (%d, need %d)",
+			ubi->avail_pebs, EBA_RESERVED_PEBS);
+		err = -ENOSPC;
+		goto out_free;
+	}
+	ubi->avail_pebs -= EBA_RESERVED_PEBS;
+	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
+
+	if (ubi->bad_allowed) {
+		ubi_calculate_reserved(ubi);
+
+		if (ubi->avail_pebs < ubi->beb_rsvd_level) {
+			/* No enough free physical eraseblocks */
+			ubi->beb_rsvd_pebs = ubi->avail_pebs;
+			ubi_warn("cannot reserve enough PEBs for bad PEB "
+				 "handling, reserved %d, need %d",
+				 ubi->beb_rsvd_pebs, ubi->beb_rsvd_level);
+		} else
+			ubi->beb_rsvd_pebs = ubi->beb_rsvd_level;
+
+		ubi->avail_pebs -= ubi->beb_rsvd_pebs;
+		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
+	}
+
+	dbg_eba("EBA unit is initialized");
+	return 0;
+
+out_free:
+	for (i = 0; i < num_volumes; i++) {
+		if (!ubi->volumes[i])
+			continue;
+		kfree(ubi->volumes[i]->eba_tbl);
+	}
+	return err;
+}
+
+/**
+ * ubi_eba_close - close EBA unit.
+ * @ubi: UBI device description object
+ */
+void ubi_eba_close(const struct ubi_device *ubi)
+{
+	int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+
+	dbg_eba("close EBA unit");
+
+	for (i = 0; i < num_volumes; i++) {
+		if (!ubi->volumes[i])
+			continue;
+		kfree(ubi->volumes[i]->eba_tbl);
+	}
+}
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
new file mode 100644
index 0000000..3387d7e
--- /dev/null
+++ b/drivers/mtd/ubi/io.c
@@ -0,0 +1,1274 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ * Copyright (c) Nokia Corporation, 2006, 2007
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * UBI input/output unit.
+ *
+ * This unit provides a uniform way to work with all kinds of the underlying
+ * MTD devices. It also implements handy functions for reading and writing UBI
+ * headers.
+ *
+ * We are trying to have a paranoid mindset and not to trust to what we read
+ * from the flash media in order to be more secure and robust. So this unit
+ * validates every single header it reads from the flash media.
+ *
+ * Some words about how the eraseblock headers are stored.
+ *
+ * The erase counter header is always stored at offset zero. By default, the
+ * VID header is stored after the EC header at the closest aligned offset
+ * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
+ * header at the closest aligned offset. But this default layout may be
+ * changed. For example, for different reasons (e.g., optimization) UBI may be
+ * asked to put the VID header at further offset, and even at an unaligned
+ * offset. Of course, if the offset of the VID header is unaligned, UBI adds
+ * proper padding in front of it. Data offset may also be changed but it has to
+ * be aligned.
+ *
+ * About minimal I/O units. In general, UBI assumes flash device model where
+ * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
+ * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
+ * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
+ * (smaller) minimal I/O unit size for EC and VID headers to make it possible
+ * to do different optimizations.
+ *
+ * This is extremely useful in case of NAND flashes which admit of several
+ * write operations to one NAND page. In this case UBI can fit EC and VID
+ * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
+ * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
+ * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
+ * users.
+ *
+ * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
+ * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
+ * headers.
+ *
+ * Q: why not just to treat sub-page as a minimal I/O unit of this flash
+ * device, e.g., make @ubi->min_io_size = 512 in the example above?
+ *
+ * A: because when writing a sub-page, MTD still writes a full 2K page but the
+ * bytes which are no relevant to the sub-page are 0xFF. So, basically, writing
+ * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we
+ * prefer to use sub-pages only for EV and VID headers.
+ *
+ * As it was noted above, the VID header may start at a non-aligned offset.
+ * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
+ * the VID header may reside at offset 1984 which is the last 64 bytes of the
+ * last sub-page (EC header is always at offset zero). This causes some
+ * difficulties when reading and writing VID headers.
+ *
+ * Suppose we have a 64-byte buffer and we read a VID header at it. We change
+ * the data and want to write this VID header out. As we can only write in
+ * 512-byte chunks, we have to allocate one more buffer and copy our VID header
+ * to offset 448 of this buffer.
+ *
+ * The I/O unit does the following trick in order to avoid this extra copy.
+ * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header
+ * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the
+ * VID header is being written out, it shifts the VID header pointer back and
+ * writes the whole sub-page.
+ */
+
+#if 0
+#include <linux/crc32.h>
+#include <linux/err.h>
+#endif
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum);
+static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
+static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
+				 const struct ubi_ec_hdr *ec_hdr);
+static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
+static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
+				  const struct ubi_vid_hdr *vid_hdr);
+static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
+				 int len);
+#else
+#define paranoid_check_not_bad(ubi, pnum) 0
+#define paranoid_check_peb_ec_hdr(ubi, pnum)  0
+#define paranoid_check_ec_hdr(ubi, pnum, ec_hdr)  0
+#define paranoid_check_peb_vid_hdr(ubi, pnum) 0
+#define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0
+#define paranoid_check_all_ff(ubi, pnum, offset, len) 0
+#endif
+
+/**
+ * ubi_io_read - read data from a physical eraseblock.
+ * @ubi: UBI device description object
+ * @buf: buffer where to store the read data
+ * @pnum: physical eraseblock number to read from
+ * @offset: offset within the physical eraseblock from where to read
+ * @len: how many bytes to read
+ *
+ * This function reads data from offset @offset of physical eraseblock @pnum
+ * and stores the read data in the @buf buffer. The following return codes are
+ * possible:
+ *
+ * o %0 if all the requested data were successfully read;
+ * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
+ *   correctable bit-flips were detected; this is harmless but may indicate
+ *   that this eraseblock may become bad soon (but do not have to);
+ * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
+ *   example it can be an ECC error in case of NAND; this most probably means
+ *   that the data is corrupted;
+ * o %-EIO if some I/O error occurred;
+ * o other negative error codes in case of other errors.
+ */
+int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
+		int len)
+{
+	int err, retries = 0;
+	size_t read;
+	loff_t addr;
+
+	dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
+
+	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+	ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
+	ubi_assert(len > 0);
+
+	err = paranoid_check_not_bad(ubi, pnum);
+	if (err)
+		return err > 0 ? -EINVAL : err;
+
+	addr = (loff_t)pnum * ubi->peb_size + offset;
+retry:
+	err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
+	if (err) {
+		if (err == -EUCLEAN) {
+			/*
+			 * -EUCLEAN is reported if there was a bit-flip which
+			 * was corrected, so this is harmless.
+			 */
+			ubi_msg("fixable bit-flip detected at PEB %d", pnum);
+			ubi_assert(len == read);
+			return UBI_IO_BITFLIPS;
+		}
+
+		if (read != len && retries++ < UBI_IO_RETRIES) {
+			dbg_io("error %d while reading %d bytes from PEB %d:%d, "
+			       "read only %zd bytes, retry",
+			       err, len, pnum, offset, read);
+			yield();
+			goto retry;
+		}
+
+		ubi_err("error %d while reading %d bytes from PEB %d:%d, "
+			"read %zd bytes", err, len, pnum, offset, read);
+		ubi_dbg_dump_stack();
+
+		/*
+		 * The driver should never return -EBADMSG if it failed to read
+		 * all the requested data. But some buggy drivers might do
+		 * this, so we change it to -EIO.
+		 */
+		if (read != len && err == -EBADMSG) {
+			ubi_assert(0);
+			printk("%s[%d] not here\n", __func__, __LINE__);
+//			err = -EIO;
+		}
+	} else {
+		ubi_assert(len == read);
+
+		if (ubi_dbg_is_bitflip()) {
+			dbg_msg("bit-flip (emulated)");
+			err = UBI_IO_BITFLIPS;
+		}
+	}
+
+	return err;
+}
+
+/**
+ * ubi_io_write - write data to a physical eraseblock.
+ * @ubi: UBI device description object
+ * @buf: buffer with the data to write
+ * @pnum: physical eraseblock number to write to
+ * @offset: offset within the physical eraseblock where to write
+ * @len: how many bytes to write
+ *
+ * This function writes @len bytes of data from buffer @buf to offset @offset
+ * of physical eraseblock @pnum. If all the data were successfully written,
+ * zero is returned. If an error occurred, this function returns a negative
+ * error code. If %-EIO is returned, the physical eraseblock most probably went
+ * bad.
+ *
+ * Note, in case of an error, it is possible that something was still written
+ * to the flash media, but may be some garbage.
+ */
+int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
+		 int len)
+{
+	int err;
+	size_t written;
+	loff_t addr;
+
+	dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
+
+	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+	ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
+	ubi_assert(offset % ubi->hdrs_min_io_size == 0);
+	ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
+
+	if (ubi->ro_mode) {
+		ubi_err("read-only mode");
+		return -EROFS;
+	}
+
+	/* The below has to be compiled out if paranoid checks are disabled */
+
+	err = paranoid_check_not_bad(ubi, pnum);
+	if (err)
+		return err > 0 ? -EINVAL : err;
+
+	/* The area we are writing to has to contain all 0xFF bytes */
+	err = paranoid_check_all_ff(ubi, pnum, offset, len);
+	if (err)
+		return err > 0 ? -EINVAL : err;
+
+	if (offset >= ubi->leb_start) {
+		/*
+		 * We write to the data area of the physical eraseblock. Make
+		 * sure it has valid EC and VID headers.
+		 */
+		err = paranoid_check_peb_ec_hdr(ubi, pnum);
+		if (err)
+			return err > 0 ? -EINVAL : err;
+		err = paranoid_check_peb_vid_hdr(ubi, pnum);
+		if (err)
+			return err > 0 ? -EINVAL : err;
+	}
+
+	if (ubi_dbg_is_write_failure()) {
+		dbg_err("cannot write %d bytes to PEB %d:%d "
+			"(emulated)", len, pnum, offset);
+		ubi_dbg_dump_stack();
+		return -EIO;
+	}
+
+	addr = (loff_t)pnum * ubi->peb_size + offset;
+	err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf);
+	if (err) {
+		ubi_err("error %d while writing %d bytes to PEB %d:%d, written"
+			" %zd bytes", err, len, pnum, offset, written);
+		ubi_dbg_dump_stack();
+	} else
+		ubi_assert(written == len);
+
+	return err;
+}
+
+/**
+ * erase_callback - MTD erasure call-back.
+ * @ei: MTD erase information object.
+ *
+ * Note, even though MTD erase interface is asynchronous, all the current
+ * implementations are synchronous anyway.
+ */
+static void erase_callback(struct erase_info *ei)
+{
+	wake_up_interruptible((wait_queue_head_t *)ei->priv);
+}
+
+/**
+ * do_sync_erase - synchronously erase a physical eraseblock.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to erase
+ *
+ * This function synchronously erases physical eraseblock @pnum and returns
+ * zero in case of success and a negative error code in case of failure. If
+ * %-EIO is returned, the physical eraseblock most probably went bad.
+ */
+static int do_sync_erase(struct ubi_device *ubi, int pnum)
+{
+	int err, retries = 0;
+	struct erase_info ei;
+	wait_queue_head_t wq;
+
+	dbg_io("erase PEB %d", pnum);
+
+retry:
+	init_waitqueue_head(&wq);
+	memset(&ei, 0, sizeof(struct erase_info));
+
+	ei.mtd      = ubi->mtd;
+	ei.addr     = (loff_t)pnum * ubi->peb_size;
+	ei.len      = ubi->peb_size;
+	ei.callback = erase_callback;
+	ei.priv     = (unsigned long)&wq;
+
+	err = ubi->mtd->erase(ubi->mtd, &ei);
+	if (err) {
+		if (retries++ < UBI_IO_RETRIES) {
+			dbg_io("error %d while erasing PEB %d, retry",
+			       err, pnum);
+			yield();
+			goto retry;
+		}
+		ubi_err("cannot erase PEB %d, error %d", pnum, err);
+		ubi_dbg_dump_stack();
+		return err;
+	}
+
+	err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
+					   ei.state == MTD_ERASE_FAILED);
+	if (err) {
+		ubi_err("interrupted PEB %d erasure", pnum);
+		return -EINTR;
+	}
+
+	if (ei.state == MTD_ERASE_FAILED) {
+		if (retries++ < UBI_IO_RETRIES) {
+			dbg_io("error while erasing PEB %d, retry", pnum);
+			yield();
+			goto retry;
+		}
+		ubi_err("cannot erase PEB %d", pnum);
+		ubi_dbg_dump_stack();
+		return -EIO;
+	}
+
+	err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size);
+	if (err)
+		return err > 0 ? -EINVAL : err;
+
+	if (ubi_dbg_is_erase_failure() && !err) {
+		dbg_err("cannot erase PEB %d (emulated)", pnum);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * check_pattern - check if buffer contains only a certain byte pattern.
+ * @buf: buffer to check
+ * @patt: the pattern to check
+ * @size: buffer size in bytes
+ *
+ * This function returns %1 in there are only @patt bytes in @buf, and %0 if
+ * something else was also found.
+ */
+static int check_pattern(const void *buf, uint8_t patt, int size)
+{
+	int i;
+
+	for (i = 0; i < size; i++)
+		if (((const uint8_t *)buf)[i] != patt)
+			return 0;
+	return 1;
+}
+
+/* Patterns to write to a physical eraseblock when torturing it */
+static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
+
+/**
+ * torture_peb - test a supposedly bad physical eraseblock.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to test
+ *
+ * This function returns %-EIO if the physical eraseblock did not pass the
+ * test, a positive number of erase operations done if the test was
+ * successfully passed, and other negative error codes in case of other errors.
+ */
+static int torture_peb(struct ubi_device *ubi, int pnum)
+{
+	int err, i, patt_count;
+
+	patt_count = ARRAY_SIZE(patterns);
+	ubi_assert(patt_count > 0);
+
+	mutex_lock(&ubi->buf_mutex);
+	for (i = 0; i < patt_count; i++) {
+		err = do_sync_erase(ubi, pnum);
+		if (err)
+			goto out;
+
+		/* Make sure the PEB contains only 0xFF bytes */
+		err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
+		if (err)
+			goto out;
+
+		err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
+		if (err == 0) {
+			ubi_err("erased PEB %d, but a non-0xFF byte found",
+				pnum);
+			err = -EIO;
+			goto out;
+		}
+
+		/* Write a pattern and check it */
+		memset(ubi->peb_buf1, patterns[i], ubi->peb_size);
+		err = ubi_io_write(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
+		if (err)
+			goto out;
+
+		memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size);
+		err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
+		if (err)
+			goto out;
+
+		err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
+		if (err == 0) {
+			ubi_err("pattern %x checking failed for PEB %d",
+				patterns[i], pnum);
+			err = -EIO;
+			goto out;
+		}
+	}
+
+	err = patt_count;
+
+out:
+	mutex_unlock(&ubi->buf_mutex);
+	if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
+		/*
+		 * If a bit-flip or data integrity error was detected, the test
+		 * has not passed because it happened on a freshly erased
+		 * physical eraseblock which means something is wrong with it.
+		 */
+		ubi_err("read problems on freshly erased PEB %d, must be bad",
+			pnum);
+		err = -EIO;
+	}
+	return err;
+}
+
+/**
+ * ubi_io_sync_erase - synchronously erase a physical eraseblock.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number to erase
+ * @torture: if this physical eraseblock has to be tortured
+ *
+ * This function synchronously erases physical eraseblock @pnum. If @torture
+ * flag is not zero, the physical eraseblock is checked by means of writing
+ * different patterns to it and reading them back. If the torturing is enabled,
+ * the physical eraseblock is erased more then once.
+ *
+ * This function returns the number of erasures made in case of success, %-EIO
+ * if the erasure failed or the torturing test failed, and other negative error
+ * codes in case of other errors. Note, %-EIO means that the physical
+ * eraseblock is bad.
+ */
+int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
+{
+	int err, ret = 0;
+
+	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+	err = paranoid_check_not_bad(ubi, pnum);
+	if (err != 0)
+		return err > 0 ? -EINVAL : err;
+
+	if (ubi->ro_mode) {
+		ubi_err("read-only mode");
+		return -EROFS;
+	}
+
+	if (torture) {
+		ret = torture_peb(ubi, pnum);
+		if (ret < 0)
+			return ret;
+	}
+
+	err = do_sync_erase(ubi, pnum);
+	if (err)
+		return err;
+
+	return ret + 1;
+}
+
+/**
+ * ubi_io_is_bad - check if a physical eraseblock is bad.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ *
+ * This function returns a positive number if the physical eraseblock is bad,
+ * zero if not, and a negative error code if an error occurred.
+ */
+int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
+{
+	struct mtd_info *mtd = ubi->mtd;
+
+	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+	if (ubi->bad_allowed) {
+		int ret;
+
+		ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
+		if (ret < 0)
+			ubi_err("error %d while checking if PEB %d is bad",
+				ret, pnum);
+		else if (ret)
+			dbg_io("PEB %d is bad", pnum);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * ubi_io_mark_bad - mark a physical eraseblock as bad.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to mark
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
+{
+	int err;
+	struct mtd_info *mtd = ubi->mtd;
+
+	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+
+	if (ubi->ro_mode) {
+		ubi_err("read-only mode");
+		return -EROFS;
+	}
+
+	if (!ubi->bad_allowed)
+		return 0;
+
+	err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
+	if (err)
+		ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
+	return err;
+}
+
+/**
+ * validate_ec_hdr - validate an erase counter header.
+ * @ubi: UBI device description object
+ * @ec_hdr: the erase counter header to check
+ *
+ * This function returns zero if the erase counter header is OK, and %1 if
+ * not.
+ */
+static int validate_ec_hdr(const struct ubi_device *ubi,
+			   const struct ubi_ec_hdr *ec_hdr)
+{
+	long long ec;
+	int vid_hdr_offset, leb_start;
+
+	ec = be64_to_cpu(ec_hdr->ec);
+	vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
+	leb_start = be32_to_cpu(ec_hdr->data_offset);
+
+	if (ec_hdr->version != UBI_VERSION) {
+		ubi_err("node with incompatible UBI version found: "
+			"this UBI version is %d, image version is %d",
+			UBI_VERSION, (int)ec_hdr->version);
+		goto bad;
+	}
+
+	if (vid_hdr_offset != ubi->vid_hdr_offset) {
+		ubi_err("bad VID header offset %d, expected %d",
+			vid_hdr_offset, ubi->vid_hdr_offset);
+		goto bad;
+	}
+
+	if (leb_start != ubi->leb_start) {
+		ubi_err("bad data offset %d, expected %d",
+			leb_start, ubi->leb_start);
+		goto bad;
+	}
+
+	if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
+		ubi_err("bad erase counter %lld", ec);
+		goto bad;
+	}
+
+	return 0;
+
+bad:
+	ubi_err("bad EC header");
+	ubi_dbg_dump_ec_hdr(ec_hdr);
+	ubi_dbg_dump_stack();
+	return 1;
+}
+
+/**
+ * ubi_io_read_ec_hdr - read and check an erase counter header.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock to read from
+ * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
+ * header
+ * @verbose: be verbose if the header is corrupted or was not found
+ *
+ * This function reads erase counter header from physical eraseblock @pnum and
+ * stores it in @ec_hdr. This function also checks CRC checksum of the read
+ * erase counter header. The following codes may be returned:
+ *
+ * o %0 if the CRC checksum is correct and the header was successfully read;
+ * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
+ *   and corrected by the flash driver; this is harmless but may indicate that
+ *   this eraseblock may become bad soon (but may be not);
+ * o %UBI_IO_BAD_EC_HDR if the erase counter header is corrupted (a CRC error);
+ * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
+ * o a negative error code in case of failure.
+ */
+int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
+		       struct ubi_ec_hdr *ec_hdr, int verbose)
+{
+	int err, read_err = 0;
+	uint32_t crc, magic, hdr_crc;
+
+	dbg_io("read EC header from PEB %d", pnum);
+	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
+	if (UBI_IO_DEBUG)
+		verbose = 1;
+
+	err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
+	if (err) {
+		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
+			return err;
+
+		/*
+		 * We read all the data, but either a correctable bit-flip
+		 * occurred, or MTD reported about some data integrity error,
+		 * like an ECC error in case of NAND. The former is harmless,
+		 * the later may mean that the read data is corrupted. But we
+		 * have a CRC check-sum and we will detect this. If the EC
+		 * header is still OK, we just report this as there was a
+		 * bit-flip.
+		 */
+		read_err = err;
+	}
+
+	magic = be32_to_cpu(ec_hdr->magic);
+	if (magic != UBI_EC_HDR_MAGIC) {
+		/*
+		 * The magic field is wrong. Let's check if we have read all
+		 * 0xFF. If yes, this physical eraseblock is assumed to be
+		 * empty.
+		 *
+		 * But if there was a read error, we do not test it for all
+		 * 0xFFs. Even if it does contain all 0xFFs, this error
+		 * indicates that something is still wrong with this physical
+		 * eraseblock and we anyway cannot treat it as empty.
+		 */
+		if (read_err != -EBADMSG &&
+		    check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
+			/* The physical eraseblock is supposedly empty */
+
+			/*
+			 * The below is just a paranoid check, it has to be
+			 * compiled out if paranoid checks are disabled.
+			 */
+			err = paranoid_check_all_ff(ubi, pnum, 0,
+						    ubi->peb_size);
+			if (err)
+				return err > 0 ? UBI_IO_BAD_EC_HDR : err;
+
+			if (verbose)
+				ubi_warn("no EC header found at PEB %d, "
+					 "only 0xFF bytes", pnum);
+			return UBI_IO_PEB_EMPTY;
+		}
+
+		/*
+		 * This is not a valid erase counter header, and these are not
+		 * 0xFF bytes. Report that the header is corrupted.
+		 */
+		if (verbose) {
+			ubi_warn("bad magic number at PEB %d: %08x instead of "
+				 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
+			ubi_dbg_dump_ec_hdr(ec_hdr);
+		}
+		return UBI_IO_BAD_EC_HDR;
+	}
+
+	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
+	hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
+
+	if (hdr_crc != crc) {
+		if (verbose) {
+			ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
+				 " read %#08x", pnum, crc, hdr_crc);
+			ubi_dbg_dump_ec_hdr(ec_hdr);
+		}
+		return UBI_IO_BAD_EC_HDR;
+	}
+
+	/* And of course validate what has just been read from the media */
+	err = validate_ec_hdr(ubi, ec_hdr);
+	if (err) {
+		ubi_err("validation failed for PEB %d", pnum);
+		return -EINVAL;
+	}
+
+	return read_err ? UBI_IO_BITFLIPS : 0;
+}
+
+/**
+ * ubi_io_write_ec_hdr - write an erase counter header.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock to write to
+ * @ec_hdr: the erase counter header to write
+ *
+ * This function writes erase counter header described by @ec_hdr to physical
+ * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
+ * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
+ * field.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure. If %-EIO is returned, the physical eraseblock most probably
+ * went bad.
+ */
+int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
+			struct ubi_ec_hdr *ec_hdr)
+{
+	int err;
+	uint32_t crc;
+
+	dbg_io("write EC header to PEB %d", pnum);
+	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);
+
+	ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
+	ec_hdr->version = UBI_VERSION;
+	ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
+	ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
+	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
+	ec_hdr->hdr_crc = cpu_to_be32(crc);
+
+	err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
+	if (err)
+		return -EINVAL;
+
+	err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
+	return err;
+}
+
+/**
+ * validate_vid_hdr - validate a volume identifier header.
+ * @ubi: UBI device description object
+ * @vid_hdr: the volume identifier header to check
+ *
+ * This function checks that data stored in the volume identifier header
+ * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
+ */
+static int validate_vid_hdr(const struct ubi_device *ubi,
+			    const struct ubi_vid_hdr *vid_hdr)
+{
+	int vol_type = vid_hdr->vol_type;
+	int copy_flag = vid_hdr->copy_flag;
+	int vol_id = be32_to_cpu(vid_hdr->vol_id);
+	int lnum = be32_to_cpu(vid_hdr->lnum);
+	int compat = vid_hdr->compat;
+	int data_size = be32_to_cpu(vid_hdr->data_size);
+	int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
+	int data_pad = be32_to_cpu(vid_hdr->data_pad);
+	int data_crc = be32_to_cpu(vid_hdr->data_crc);
+	int usable_leb_size = ubi->leb_size - data_pad;
+
+	if (copy_flag != 0 && copy_flag != 1) {
+		dbg_err("bad copy_flag");
+		goto bad;
+	}
+
+	if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
+	    data_pad < 0) {
+		dbg_err("negative values");
+		goto bad;
+	}
+
+	if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
+		dbg_err("bad vol_id");
+		goto bad;
+	}
+
+	if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
+		dbg_err("bad compat");
+		goto bad;
+	}
+
+	if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
+	    compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
+	    compat != UBI_COMPAT_REJECT) {
+		dbg_err("bad compat");
+		goto bad;
+	}
+
+	if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
+		dbg_err("bad vol_type");
+		goto bad;
+	}
+
+	if (data_pad >= ubi->leb_size / 2) {
+		dbg_err("bad data_pad");
+		goto bad;
+	}
+
+	if (vol_type == UBI_VID_STATIC) {
+		/*
+		 * Although from high-level point of view static volumes may
+		 * contain zero bytes of data, but no VID headers can contain
+		 * zero at these fields, because they empty volumes do not have
+		 * mapped logical eraseblocks.
+		 */
+		if (used_ebs == 0) {
+			dbg_err("zero used_ebs");
+			goto bad;
+		}
+		if (data_size == 0) {
+			dbg_err("zero data_size");
+			goto bad;
+		}
+		if (lnum < used_ebs - 1) {
+			if (data_size != usable_leb_size) {
+				dbg_err("bad data_size");
+				goto bad;
+			}
+		} else if (lnum == used_ebs - 1) {
+			if (data_size == 0) {
+				dbg_err("bad data_size at last LEB");
+				goto bad;
+			}
+		} else {
+			dbg_err("too high lnum");
+			goto bad;
+		}
+	} else {
+		if (copy_flag == 0) {
+			if (data_crc != 0) {
+				dbg_err("non-zero data CRC");
+				goto bad;
+			}
+			if (data_size != 0) {
+				dbg_err("non-zero data_size");
+				goto bad;
+			}
+		} else {
+			if (data_size == 0) {
+				dbg_err("zero data_size of copy");
+				goto bad;
+			}
+		}
+		if (used_ebs != 0) {
+			dbg_err("bad used_ebs");
+			goto bad;
+		}
+	}
+
+	return 0;
+
+bad:
+	ubi_err("bad VID header");
+	ubi_dbg_dump_vid_hdr(vid_hdr);
+	ubi_dbg_dump_stack();
+	return 1;
+}
+
+/**
+ * ubi_io_read_vid_hdr - read and check a volume identifier header.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number to read from
+ * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
+ * identifier header
+ * @verbose: be verbose if the header is corrupted or wasn't found
+ *
+ * This function reads the volume identifier header from physical eraseblock
+ * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
+ * volume identifier header. The following codes may be returned:
+ *
+ * o %0 if the CRC checksum is correct and the header was successfully read;
+ * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
+ *   and corrected by the flash driver; this is harmless but may indicate that
+ *   this eraseblock may become bad soon;
+ * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC
+ *   error detected);
+ * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
+ *   header there);
+ * o a negative error code in case of failure.
+ */
+int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
+			struct ubi_vid_hdr *vid_hdr, int verbose)
+{
+	int err, read_err = 0;
+	uint32_t crc, magic, hdr_crc;
+	void *p;
+
+	dbg_io("read VID header from PEB %d", pnum);
+	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);
+	if (UBI_IO_DEBUG)
+		verbose = 1;
+
+	p = (char *)vid_hdr - ubi->vid_hdr_shift;
+	err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
+			  ubi->vid_hdr_alsize);
+	if (err) {
+		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
+			return err;
+
+		/*
+		 * We read all the data, but either a correctable bit-flip
+		 * occurred, or MTD reported about some data integrity error,
+		 * like an ECC error in case of NAND. The former is harmless,
+		 * the later may mean the read data is corrupted. But we have a
+		 * CRC check-sum and we will identify this. If the VID header is
+		 * still OK, we just report this as there was a bit-flip.
+		 */
+		read_err = err;
+	}
+
+	magic = be32_to_cpu(vid_hdr->magic);
+	if (magic != UBI_VID_HDR_MAGIC) {
+		/*
+		 * If we have read all 0xFF bytes, the VID header probably does
+		 * not exist and the physical eraseblock is assumed to be free.
+		 *
+		 * But if there was a read error, we do not test the data for
+		 * 0xFFs. Even if it does contain all 0xFFs, this error
+		 * indicates that something is still wrong with this physical
+		 * eraseblock and it cannot be regarded as free.
+		 */
+		if (read_err != -EBADMSG &&
+		    check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
+			/* The physical eraseblock is supposedly free */
+
+			/*
+			 * The below is just a paranoid check, it has to be
+			 * compiled out if paranoid checks are disabled.
+			 */
+			err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start,
+						    ubi->leb_size);
+			if (err)
+				return err > 0 ? UBI_IO_BAD_VID_HDR : err;
+
+			if (verbose)
+				ubi_warn("no VID header found at PEB %d, "
+					 "only 0xFF bytes", pnum);
+			return UBI_IO_PEB_FREE;
+		}
+
+		/*
+		 * This is not a valid VID header, and these are not 0xFF
+		 * bytes. Report that the header is corrupted.
+		 */
+		if (verbose) {
+			ubi_warn("bad magic number at PEB %d: %08x instead of "
+				 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
+			ubi_dbg_dump_vid_hdr(vid_hdr);
+		}
+		return UBI_IO_BAD_VID_HDR;
+	}
+
+	crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
+	hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
+
+	if (hdr_crc != crc) {
+		if (verbose) {
+			ubi_warn("bad CRC at PEB %d, calculated %#08x, "
+				 "read %#08x", pnum, crc, hdr_crc);
+			ubi_dbg_dump_vid_hdr(vid_hdr);
+		}
+		return UBI_IO_BAD_VID_HDR;
+	}
+
+	/* Validate the VID header that we have just read */
+	err = validate_vid_hdr(ubi, vid_hdr);
+	if (err) {
+		ubi_err("validation failed for PEB %d", pnum);
+		return -EINVAL;
+	}
+
+	return read_err ? UBI_IO_BITFLIPS : 0;
+}
+
+/**
+ * ubi_io_write_vid_hdr - write a volume identifier header.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to write to
+ * @vid_hdr: the volume identifier header to write
+ *
+ * This function writes the volume identifier header described by @vid_hdr to
+ * physical eraseblock @pnum. This function automatically fills the
+ * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
+ * header CRC checksum and stores it at vid_hdr->hdr_crc.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure. If %-EIO is returned, the physical eraseblock probably went
+ * bad.
+ */
+int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
+			 struct ubi_vid_hdr *vid_hdr)
+{
+	int err;
+	uint32_t crc;
+	void *p;
+
+	dbg_io("write VID header to PEB %d", pnum);
+	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);
+
+	err = paranoid_check_peb_ec_hdr(ubi, pnum);
+	if (err)
+		return err > 0 ? -EINVAL: err;
+
+	vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
+	vid_hdr->version = UBI_VERSION;
+	crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
+	vid_hdr->hdr_crc = cpu_to_be32(crc);
+
+	err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
+	if (err)
+		return -EINVAL;
+
+	p = (char *)vid_hdr - ubi->vid_hdr_shift;
+	err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
+			   ubi->vid_hdr_alsize);
+	return err;
+}
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+
+/**
+ * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number to check
+ *
+ * This function returns zero if the physical eraseblock is good, a positive
+ * number if it is bad and a negative error code if an error occurred.
+ */
+static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
+{
+	int err;
+
+	err = ubi_io_is_bad(ubi, pnum);
+	if (!err)
+		return err;
+
+	ubi_err("paranoid check failed for PEB %d", pnum);
+	ubi_dbg_dump_stack();
+	return err;
+}
+
+/**
+ * paranoid_check_ec_hdr - check if an erase counter header is all right.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number the erase counter header belongs to
+ * @ec_hdr: the erase counter header to check
+ *
+ * This function returns zero if the erase counter header contains valid
+ * values, and %1 if not.
+ */
+static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
+				 const struct ubi_ec_hdr *ec_hdr)
+{
+	int err;
+	uint32_t magic;
+
+	magic = be32_to_cpu(ec_hdr->magic);
+	if (magic != UBI_EC_HDR_MAGIC) {
+		ubi_err("bad magic %#08x, must be %#08x",
+			magic, UBI_EC_HDR_MAGIC);
+		goto fail;
+	}
+
+	err = validate_ec_hdr(ubi, ec_hdr);
+	if (err) {
+		ubi_err("paranoid check failed for PEB %d", pnum);
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	ubi_dbg_dump_ec_hdr(ec_hdr);
+	ubi_dbg_dump_stack();
+	return 1;
+}
+
+/**
+ * paranoid_check_peb_ec_hdr - check that the erase counter header of a
+ * physical eraseblock is in-place and is all right.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ *
+ * This function returns zero if the erase counter header is all right, %1 if
+ * not, and a negative error code if an error occurred.
+ */
+static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
+{
+	int err;
+	uint32_t crc, hdr_crc;
+	struct ubi_ec_hdr *ec_hdr;
+
+	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
+	if (!ec_hdr)
+		return -ENOMEM;
+
+	err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
+	if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
+		goto exit;
+
+	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
+	hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
+	if (hdr_crc != crc) {
+		ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
+		ubi_err("paranoid check failed for PEB %d", pnum);
+		ubi_dbg_dump_ec_hdr(ec_hdr);
+		ubi_dbg_dump_stack();
+		err = 1;
+		goto exit;
+	}
+
+	err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
+
+exit:
+	kfree(ec_hdr);
+	return err;
+}
+
+/**
+ * paranoid_check_vid_hdr - check that a volume identifier header is all right.
+ * @ubi: UBI device description object
+ * @pnum: physical eraseblock number the volume identifier header belongs to
+ * @vid_hdr: the volume identifier header to check
+ *
+ * This function returns zero if the volume identifier header is all right, and
+ * %1 if not.
+ */
+static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
+				  const struct ubi_vid_hdr *vid_hdr)
+{
+	int err;
+	uint32_t magic;
+
+	magic = be32_to_cpu(vid_hdr->magic);
+	if (magic != UBI_VID_HDR_MAGIC) {
+		ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
+			magic, pnum, UBI_VID_HDR_MAGIC);
+		goto fail;
+	}
+
+	err = validate_vid_hdr(ubi, vid_hdr);
+	if (err) {
+		ubi_err("paranoid check failed for PEB %d", pnum);
+		goto fail;
+	}
+
+	return err;
+
+fail:
+	ubi_err("paranoid check failed for PEB %d", pnum);
+	ubi_dbg_dump_vid_hdr(vid_hdr);
+	ubi_dbg_dump_stack();
+	return 1;
+
+}
+
+/**
+ * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
+ * physical eraseblock is in-place and is all right.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ *
+ * This function returns zero if the volume identifier header is all right,
+ * %1 if not, and a negative error code if an error occurred.
+ */
+static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
+{
+	int err;
+	uint32_t crc, hdr_crc;
+	struct ubi_vid_hdr *vid_hdr;
+	void *p;
+
+	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+	if (!vid_hdr)
+		return -ENOMEM;
+
+	p = (char *)vid_hdr - ubi->vid_hdr_shift;
+	err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
+			  ubi->vid_hdr_alsize);
+	if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
+		goto exit;
+
+	crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
+	hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
+	if (hdr_crc != crc) {
+		ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
+			"read %#08x", pnum, crc, hdr_crc);
+		ubi_err("paranoid check failed for PEB %d", pnum);
+		ubi_dbg_dump_vid_hdr(vid_hdr);
+		ubi_dbg_dump_stack();
+		err = 1;
+		goto exit;
+	}
+
+	err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
+
+exit:
+	ubi_free_vid_hdr(ubi, vid_hdr);
+	return err;
+}
+
+/**
+ * paranoid_check_all_ff - check that a region of flash is empty.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to check
+ * @offset: the starting offset within the physical eraseblock to check
+ * @len: the length of the region to check
+ *
+ * This function returns zero if only 0xFF bytes are present at offset
+ * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
+ * code if an error occurred.
+ */
+static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
+				 int len)
+{
+	size_t read;
+	int err;
+	loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
+
+	mutex_lock(&ubi->dbg_buf_mutex);
+	err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
+	if (err && err != -EUCLEAN) {
+		ubi_err("error %d while reading %d bytes from PEB %d:%d, "
+			"read %zd bytes", err, len, pnum, offset, read);
+		goto error;
+	}
+
+	err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
+	if (err == 0) {
+		ubi_err("flash region at PEB %d:%d, length %d does not "
+			"contain all 0xFF bytes", pnum, offset, len);
+		goto fail;
+	}
+	mutex_unlock(&ubi->dbg_buf_mutex);
+
+	return 0;
+
+fail:
+	ubi_err("paranoid check failed for PEB %d", pnum);
+	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		       ubi->dbg_peb_buf, len, 1);
+	err = 1;
+error:
+	ubi_dbg_dump_stack();
+	mutex_unlock(&ubi->dbg_buf_mutex);
+	return err;
+}
+
+#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
new file mode 100644
index 0000000..7aa0a3b
--- /dev/null
+++ b/drivers/mtd/ubi/kapi.c
@@ -0,0 +1,638 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/* This file mostly implements UBI kernel API functions */
+
+#if 0
+#include <linux/module.h>
+#include <linux/err.h>
+#include <asm/div64.h>
+#endif
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+/**
+ * ubi_get_device_info - get information about UBI device.
+ * @ubi_num: UBI device number
+ * @di: the information is stored here
+ *
+ * This function returns %0 in case of success, %-EINVAL if the UBI device
+ * number is invalid, and %-ENODEV if there is no such UBI device.
+ */
+int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
+{
+	struct ubi_device *ubi;
+
+	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+		return -EINVAL;
+
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
+		return -ENODEV;
+
+	di->ubi_num = ubi->ubi_num;
+	di->leb_size = ubi->leb_size;
+	di->min_io_size = ubi->min_io_size;
+	di->ro_mode = ubi->ro_mode;
+	di->cdev = ubi->cdev.dev;
+
+	ubi_put_device(ubi);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ubi_get_device_info);
+
+/**
+ * ubi_get_volume_info - get information about UBI volume.
+ * @desc: volume descriptor
+ * @vi: the information is stored here
+ */
+void ubi_get_volume_info(struct ubi_volume_desc *desc,
+			 struct ubi_volume_info *vi)
+{
+	const struct ubi_volume *vol = desc->vol;
+	const struct ubi_device *ubi = vol->ubi;
+
+	vi->vol_id = vol->vol_id;
+	vi->ubi_num = ubi->ubi_num;
+	vi->size = vol->reserved_pebs;
+	vi->used_bytes = vol->used_bytes;
+	vi->vol_type = vol->vol_type;
+	vi->corrupted = vol->corrupted;
+	vi->upd_marker = vol->upd_marker;
+	vi->alignment = vol->alignment;
+	vi->usable_leb_size = vol->usable_leb_size;
+	vi->name_len = vol->name_len;
+	vi->name = vol->name;
+	vi->cdev = vol->cdev.dev;
+}
+EXPORT_SYMBOL_GPL(ubi_get_volume_info);
+
+/**
+ * ubi_open_volume - open UBI volume.
+ * @ubi_num: UBI device number
+ * @vol_id: volume ID
+ * @mode: open mode
+ *
+ * The @mode parameter specifies if the volume should be opened in read-only
+ * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
+ * nobody else will be able to open this volume. UBI allows to have many volume
+ * readers and one writer at a time.
+ *
+ * If a static volume is being opened for the first time since boot, it will be
+ * checked by this function, which means it will be fully read and the CRC
+ * checksum of each logical eraseblock will be checked.
+ *
+ * This function returns volume descriptor in case of success and a negative
+ * error code in case of failure.
+ */
+struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
+{
+	int err;
+	struct ubi_volume_desc *desc;
+	struct ubi_device *ubi;
+	struct ubi_volume *vol;
+
+	dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
+
+	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+		return ERR_PTR(-EINVAL);
+
+	if (mode != UBI_READONLY && mode != UBI_READWRITE &&
+	    mode != UBI_EXCLUSIVE)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * First of all, we have to get the UBI device to prevent its removal.
+	 */
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
+		return ERR_PTR(-ENODEV);
+
+	if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
+		err = -EINVAL;
+		goto out_put_ubi;
+	}
+
+	desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
+	if (!desc) {
+		err = -ENOMEM;
+		goto out_put_ubi;
+	}
+
+	err = -ENODEV;
+	if (!try_module_get(THIS_MODULE))
+		goto out_free;
+
+	spin_lock(&ubi->volumes_lock);
+	vol = ubi->volumes[vol_id];
+	if (!vol)
+		goto out_unlock;
+
+	err = -EBUSY;
+	switch (mode) {
+	case UBI_READONLY:
+		if (vol->exclusive)
+			goto out_unlock;
+		vol->readers += 1;
+		break;
+
+	case UBI_READWRITE:
+		if (vol->exclusive || vol->writers > 0)
+			goto out_unlock;
+		vol->writers += 1;
+		break;
+
+	case UBI_EXCLUSIVE:
+		if (vol->exclusive || vol->writers || vol->readers)
+			goto out_unlock;
+		vol->exclusive = 1;
+		break;
+	}
+	get_device(&vol->dev);
+	vol->ref_count += 1;
+	spin_unlock(&ubi->volumes_lock);
+
+	desc->vol = vol;
+	desc->mode = mode;
+
+	mutex_lock(&ubi->ckvol_mutex);
+	if (!vol->checked) {
+		/* This is the first open - check the volume */
+		err = ubi_check_volume(ubi, vol_id);
+		if (err < 0) {
+			mutex_unlock(&ubi->ckvol_mutex);
+			ubi_close_volume(desc);
+			return ERR_PTR(err);
+		}
+		if (err == 1) {
+			ubi_warn("volume %d on UBI device %d is corrupted",
+				 vol_id, ubi->ubi_num);
+			vol->corrupted = 1;
+		}
+		vol->checked = 1;
+	}
+	mutex_unlock(&ubi->ckvol_mutex);
+
+	return desc;
+
+out_unlock:
+	spin_unlock(&ubi->volumes_lock);
+	module_put(THIS_MODULE);
+out_free:
+	kfree(desc);
+out_put_ubi:
+	ubi_put_device(ubi);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(ubi_open_volume);
+
+/**
+ * ubi_open_volume_nm - open UBI volume by name.
+ * @ubi_num: UBI device number
+ * @name: volume name
+ * @mode: open mode
+ *
+ * This function is similar to 'ubi_open_volume()', but opens a volume by name.
+ */
+struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
+					   int mode)
+{
+	int i, vol_id = -1, len;
+	struct ubi_device *ubi;
+	struct ubi_volume_desc *ret;
+
+	dbg_msg("open volume %s, mode %d", name, mode);
+
+	if (!name)
+		return ERR_PTR(-EINVAL);
+
+	len = strnlen(name, UBI_VOL_NAME_MAX + 1);
+	if (len > UBI_VOL_NAME_MAX)
+		return ERR_PTR(-EINVAL);
+
+	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
+		return ERR_PTR(-EINVAL);
+
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
+		return ERR_PTR(-ENODEV);
+
+	spin_lock(&ubi->volumes_lock);
+	/* Walk all volumes of this UBI device */
+	for (i = 0; i < ubi->vtbl_slots; i++) {
+		struct ubi_volume *vol = ubi->volumes[i];
+
+		if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
+			vol_id = i;
+			break;
+		}
+	}
+	spin_unlock(&ubi->volumes_lock);
+
+	if (vol_id >= 0)
+		ret = ubi_open_volume(ubi_num, vol_id, mode);
+	else
+		ret = ERR_PTR(-ENODEV);
+
+	/*
+	 * We should put the UBI device even in case of success, because
+	 * 'ubi_open_volume()' took a reference as well.
+	 */
+	ubi_put_device(ubi);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
+
+/**
+ * ubi_close_volume - close UBI volume.
+ * @desc: volume descriptor
+ */
+void ubi_close_volume(struct ubi_volume_desc *desc)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+
+	dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode);
+
+	spin_lock(&ubi->volumes_lock);
+	switch (desc->mode) {
+	case UBI_READONLY:
+		vol->readers -= 1;
+		break;
+	case UBI_READWRITE:
+		vol->writers -= 1;
+		break;
+	case UBI_EXCLUSIVE:
+		vol->exclusive = 0;
+	}
+	vol->ref_count -= 1;
+	spin_unlock(&ubi->volumes_lock);
+
+	kfree(desc);
+	put_device(&vol->dev);
+	ubi_put_device(ubi);
+	module_put(THIS_MODULE);
+}
+EXPORT_SYMBOL_GPL(ubi_close_volume);
+
+/**
+ * ubi_leb_read - read data.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number to read from
+ * @buf: buffer where to store the read data
+ * @offset: offset within the logical eraseblock to read from
+ * @len: how many bytes to read
+ * @check: whether UBI has to check the read data's CRC or not.
+ *
+ * This function reads data from offset @offset of logical eraseblock @lnum and
+ * stores the data at @buf. When reading from static volumes, @check specifies
+ * whether the data has to be checked or not. If yes, the whole logical
+ * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
+ * checksum is per-eraseblock). So checking may substantially slow down the
+ * read speed. The @check argument is ignored for dynamic volumes.
+ *
+ * In case of success, this function returns zero. In case of failure, this
+ * function returns a negative error code.
+ *
+ * %-EBADMSG error code is returned:
+ * o for both static and dynamic volumes if MTD driver has detected a data
+ *   integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
+ * o for static volumes in case of data CRC mismatch.
+ *
+ * If the volume is damaged because of an interrupted update this function just
+ * returns immediately with %-EBADF error code.
+ */
+int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
+		 int len, int check)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	int err, vol_id = vol->vol_id;
+
+	dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
+
+	if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
+	    lnum >= vol->used_ebs || offset < 0 || len < 0 ||
+	    offset + len > vol->usable_leb_size)
+		return -EINVAL;
+
+	if (vol->vol_type == UBI_STATIC_VOLUME) {
+		if (vol->used_ebs == 0)
+			/* Empty static UBI volume */
+			return 0;
+		if (lnum == vol->used_ebs - 1 &&
+		    offset + len > vol->last_eb_bytes)
+			return -EINVAL;
+	}
+
+	if (vol->upd_marker)
+		return -EBADF;
+	if (len == 0)
+		return 0;
+
+	err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
+	if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
+		ubi_warn("mark volume %d as corrupted", vol_id);
+		vol->corrupted = 1;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(ubi_leb_read);
+
+/**
+ * ubi_leb_write - write data.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number to write to
+ * @buf: data to write
+ * @offset: offset within the logical eraseblock where to write
+ * @len: how many bytes to write
+ * @dtype: expected data type
+ *
+ * This function writes @len bytes of data from @buf to offset @offset of
+ * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
+ * the data.
+ *
+ * This function takes care of physical eraseblock write failures. If write to
+ * the physical eraseblock write operation fails, the logical eraseblock is
+ * re-mapped to another physical eraseblock, the data is recovered, and the
+ * write finishes. UBI has a pool of reserved physical eraseblocks for this.
+ *
+ * If all the data were successfully written, zero is returned. If an error
+ * occurred and UBI has not been able to recover from it, this function returns
+ * a negative error code. Note, in case of an error, it is possible that
+ * something was still written to the flash media, but that may be some
+ * garbage.
+ *
+ * If the volume is damaged because of an interrupted update this function just
+ * returns immediately with %-EBADF code.
+ */
+int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
+		  int offset, int len, int dtype)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	int vol_id = vol->vol_id;
+
+	dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
+
+	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+		return -EINVAL;
+
+	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+		return -EROFS;
+
+	if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
+	    offset + len > vol->usable_leb_size ||
+	    offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
+		return -EINVAL;
+
+	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+	    dtype != UBI_UNKNOWN)
+		return -EINVAL;
+
+	if (vol->upd_marker)
+		return -EBADF;
+
+	if (len == 0)
+		return 0;
+
+	return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_write);
+
+/*
+ * ubi_leb_change - change logical eraseblock atomically.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number to change
+ * @buf: data to write
+ * @len: how many bytes to write
+ * @dtype: expected data type
+ *
+ * This function changes the contents of a logical eraseblock atomically. @buf
+ * has to contain new logical eraseblock data, and @len - the length of the
+ * data, which has to be aligned. The length may be shorter then the logical
+ * eraseblock size, ant the logical eraseblock may be appended to more times
+ * later on. This function guarantees that in case of an unclean reboot the old
+ * contents is preserved. Returns zero in case of success and a negative error
+ * code in case of failure.
+ */
+int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
+		   int len, int dtype)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	int vol_id = vol->vol_id;
+
+	dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
+
+	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+		return -EINVAL;
+
+	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+		return -EROFS;
+
+	if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
+	    len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
+		return -EINVAL;
+
+	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+	    dtype != UBI_UNKNOWN)
+		return -EINVAL;
+
+	if (vol->upd_marker)
+		return -EBADF;
+
+	if (len == 0)
+		return 0;
+
+	return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_change);
+
+/**
+ * ubi_leb_erase - erase logical eraseblock.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ *
+ * This function un-maps logical eraseblock @lnum and synchronously erases the
+ * correspondent physical eraseblock. Returns zero in case of success and a
+ * negative error code in case of failure.
+ *
+ * If the volume is damaged because of an interrupted update this function just
+ * returns immediately with %-EBADF code.
+ */
+int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+	int err;
+
+	dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
+
+	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+		return -EROFS;
+
+	if (lnum < 0 || lnum >= vol->reserved_pebs)
+		return -EINVAL;
+
+	if (vol->upd_marker)
+		return -EBADF;
+
+	err = ubi_eba_unmap_leb(ubi, vol, lnum);
+	if (err)
+		return err;
+
+	return ubi_wl_flush(ubi);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_erase);
+
+/**
+ * ubi_leb_unmap - un-map logical eraseblock.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ *
+ * This function un-maps logical eraseblock @lnum and schedules the
+ * corresponding physical eraseblock for erasure, so that it will eventually be
+ * physically erased in background. This operation is much faster then the
+ * erase operation.
+ *
+ * Unlike erase, the un-map operation does not guarantee that the logical
+ * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
+ * example, if several logical eraseblocks are un-mapped, and an unclean reboot
+ * happens after this, the logical eraseblocks will not necessarily be
+ * un-mapped again when this MTD device is attached. They may actually be
+ * mapped to the same physical eraseblocks again. So, this function has to be
+ * used with care.
+ *
+ * In other words, when un-mapping a logical eraseblock, UBI does not store
+ * any information about this on the flash media, it just marks the logical
+ * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
+ * eraseblock is physically erased, it will be mapped again to the same logical
+ * eraseblock when the MTD device is attached again.
+ *
+ * The main and obvious use-case of this function is when the contents of a
+ * logical eraseblock has to be re-written. Then it is much more efficient to
+ * first un-map it, then write new data, rather then first erase it, then write
+ * new data. Note, once new data has been written to the logical eraseblock,
+ * UBI guarantees that the old contents has gone forever. In other words, if an
+ * unclean reboot happens after the logical eraseblock has been un-mapped and
+ * then written to, it will contain the last written data.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure. If the volume is damaged because of an interrupted update
+ * this function just returns immediately with %-EBADF code.
+ */
+int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+
+	dbg_msg("unmap LEB %d:%d", vol->vol_id, lnum);
+
+	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+		return -EROFS;
+
+	if (lnum < 0 || lnum >= vol->reserved_pebs)
+		return -EINVAL;
+
+	if (vol->upd_marker)
+		return -EBADF;
+
+	return ubi_eba_unmap_leb(ubi, vol, lnum);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_unmap);
+
+/**
+ * ubi_leb_map - map logical erasblock to a physical eraseblock.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ * @dtype: expected data type
+ *
+ * This function maps an un-mapped logical eraseblock @lnum to a physical
+ * eraseblock. This means, that after a successfull invocation of this
+ * function the logical eraseblock @lnum will be empty (contain only %0xFF
+ * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
+ * happens.
+ *
+ * This function returns zero in case of success, %-EBADF if the volume is
+ * damaged because of an interrupted update, %-EBADMSG if the logical
+ * eraseblock is already mapped, and other negative error codes in case of
+ * other failures.
+ */
+int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
+{
+	struct ubi_volume *vol = desc->vol;
+	struct ubi_device *ubi = vol->ubi;
+
+	dbg_msg("unmap LEB %d:%d", vol->vol_id, lnum);
+
+	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+		return -EROFS;
+
+	if (lnum < 0 || lnum >= vol->reserved_pebs)
+		return -EINVAL;
+
+	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+	    dtype != UBI_UNKNOWN)
+		return -EINVAL;
+
+	if (vol->upd_marker)
+		return -EBADF;
+
+	if (vol->eba_tbl[lnum] >= 0)
+		return -EBADMSG;
+
+	return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_map);
+
+/**
+ * ubi_is_mapped - check if logical eraseblock is mapped.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ *
+ * This function checks if logical eraseblock @lnum is mapped to a physical
+ * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
+ * mean it will still be un-mapped after the UBI device is re-attached. The
+ * logical eraseblock may become mapped to the physical eraseblock it was last
+ * mapped to.
+ *
+ * This function returns %1 if the LEB is mapped, %0 if not, and a negative
+ * error code in case of failure. If the volume is damaged because of an
+ * interrupted update this function just returns immediately with %-EBADF error
+ * code.
+ */
+int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
+{
+	struct ubi_volume *vol = desc->vol;
+
+	dbg_msg("test LEB %d:%d", vol->vol_id, lnum);
+
+	if (lnum < 0 || lnum >= vol->reserved_pebs)
+		return -EINVAL;
+
+	if (vol->upd_marker)
+		return -EBADF;
+
+	return vol->eba_tbl[lnum] >= 0;
+}
+EXPORT_SYMBOL_GPL(ubi_is_mapped);
diff --git a/drivers/mtd/ubi/misc.c b/drivers/mtd/ubi/misc.c
new file mode 100644
index 0000000..a6410bf
--- /dev/null
+++ b/drivers/mtd/ubi/misc.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/* Here we keep miscellaneous functions which are used all over the UBI code */
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+/**
+ * calc_data_len - calculate how much real data is stored in a buffer.
+ * @ubi: UBI device description object
+ * @buf: a buffer with the contents of the physical eraseblock
+ * @length: the buffer length
+ *
+ * This function calculates how much "real data" is stored in @buf and returnes
+ * the length. Continuous 0xFF bytes at the end of the buffer are not
+ * considered as "real data".
+ */
+int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
+		      int length)
+{
+	int i;
+
+	ubi_assert(!(length & (ubi->min_io_size - 1)));
+
+	for (i = length - 1; i >= 0; i--)
+		if (((const uint8_t *)buf)[i] != 0xFF)
+			break;
+
+	/* The resulting length must be aligned to the minimum flash I/O size */
+	length = ALIGN(i + 1, ubi->min_io_size);
+	return length;
+}
+
+/**
+ * ubi_check_volume - check the contents of a static volume.
+ * @ubi: UBI device description object
+ * @vol_id: ID of the volume to check
+ *
+ * This function checks if static volume @vol_id is corrupted by fully reading
+ * it and checking data CRC. This function returns %0 if the volume is not
+ * corrupted, %1 if it is corrupted and a negative error code in case of
+ * failure. Dynamic volumes are not checked and zero is returned immediately.
+ */
+int ubi_check_volume(struct ubi_device *ubi, int vol_id)
+{
+	void *buf;
+	int err = 0, i;
+	struct ubi_volume *vol = ubi->volumes[vol_id];
+
+	if (vol->vol_type != UBI_STATIC_VOLUME)
+		return 0;
+
+	buf = vmalloc(vol->usable_leb_size);
+	if (!buf)
+		return -ENOMEM;
+
+	for (i = 0; i < vol->used_ebs; i++) {
+		int size;
+
+		if (i == vol->used_ebs - 1)
+			size = vol->last_eb_bytes;
+		else
+			size = vol->usable_leb_size;
+
+		err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
+		if (err) {
+			if (err == -EBADMSG)
+				err = 1;
+			break;
+		}
+	}
+
+	vfree(buf);
+	return err;
+}
+
+/**
+ * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad
+ * eraseblock handling.
+ * @ubi: UBI device description object
+ */
+void ubi_calculate_reserved(struct ubi_device *ubi)
+{
+	ubi->beb_rsvd_level = ubi->good_peb_count/100;
+	ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
+	if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
+		ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
+}
diff --git a/drivers/mtd/ubi/scan.c b/drivers/mtd/ubi/scan.c
new file mode 100644
index 0000000..fb02cd8
--- /dev/null
+++ b/drivers/mtd/ubi/scan.c
@@ -0,0 +1,1361 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * This program 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * UBI scanning unit.
+ *
+ * This unit is responsible for scanning the flash media, checking UBI
+ * headers and providing complete information about the UBI flash image.
+ *
+ * The scanning information is represented by a &struct ubi_scan_info' object.
+ * Information about found volumes is represented by &struct ubi_scan_volume
+ * objects which are kept in volume RB-tree with root at the @volumes field.
+ * The RB-tree is indexed by the volume ID.
+ *
+ * Found logical eraseblocks are represented by &struct ubi_scan_leb objects.
+ * These objects are kept in per-volume RB-trees with the root at the
+ * corresponding &struct ubi_scan_volume object. To put it differently, we keep
+ * an RB-tree of per-volume objects and each of these objects is the root of
+ * RB-tree of per-eraseblock objects.
+ *
+ * Corrupted physical eraseblocks are put to the @corr list, free physical
+ * eraseblocks are put to the @free list and the physical eraseblock to be
+ * erased are put to the @erase list.
+ */
+
+#if 0
+#include <linux/err.h>
+#include <linux/crc32.h>
+#include <asm/div64.h>
+#endif
+
+#include <ubi_uboot.h>
+#include "ubi.h"
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si);
+#else
+#define paranoid_check_si(ubi, si) 0
+#endif
+
+/* Temporary variables used during scanning */
+static struct ubi_ec_hdr *ech;
+static struct ubi_vid_hdr *vidh;
+
+/**
+ * add_to_list - add physical eraseblock to a list.
+ * @si: scanning information
+ * @pnum: physical eraseblock number to add
+ * @ec: erase counter of the physical eraseblock
+ * @list: the list to add to
+ *
+ * This function adds physical eraseblock @pnum to free, erase, corrupted or
+ * alien lists. Returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int add_to_list(struct ubi_scan_info *si, int pnum, int ec,
+		       struct list_head *list)
+{
+	struct ubi_scan_leb *seb;
+
+	if (list == &si->free)
+		dbg_bld("add to free: PEB %d, EC %d", pnum, ec);
+	else if (list == &si->erase)
+		dbg_bld("add to erase: PEB %d, EC %d", pnum, ec);
+	else if (list == &si->corr)
+		dbg_bld("add to corrupted: PEB %d, EC %d", pnum, ec);
+	else if (list == &si->alien)
+		dbg_bld("add to alien: PEB %d, EC %d", pnum, ec);
+	else
+		BUG();
+
+	seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
+	if (!seb)
+		return -ENOMEM;
+
+	seb->pnum = pnum;
+	seb->ec = ec;
+	list_add_tail(&seb->u.list, list);
+	return 0;
+}
+
+/**
+ * validate_vid_hdr - check that volume identifier header is correct and
+ * consistent.
+ * @vid_hdr: the volume identifier header to check
+ * @sv: information about the volume this logical eraseblock belongs to
+ * @pnum: physical eraseblock number the VID header came from
+ *
+ * This function checks that data stored in @vid_hdr is consistent. Returns
+ * non-zero if an inconsistency was found and zero if not.
+ *
+ * Note, UBI does sanity check of everything it reads from the flash media.
+ * Most of the checks are done in the I/O unit. Here we check that the
+ * information in the VID header is consistent to the information in other VID
+ * headers of the same volume.
+ */
+static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
+			    const struct ubi_scan_volume *sv, int pnum)
+{
+	int vol_type = vid_hdr->vol_type;
+	int vol_id = be32_to_cpu(vid_hdr->vol_id);
+	int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
+	int data_pad = be32_to_cpu(vid_hdr->data_pad);
+
+	if (sv->leb_count != 0) {
+		int sv_vol_type;
+
+		/*
+		 * This is not the first logical eraseblock belonging to this
+		 * volume. Ensure that the data in its VID header is consistent
+		 * to the data in previous logical eraseblock headers.
+		 */
+
+		if (vol_id != sv->vol_id) {
+			dbg_err("inconsistent vol_id");
+			goto bad;
+		}
+
+		if (sv->vol_type == UBI_STATIC_VOLUME)
+			sv_vol_type = UBI_VID_STATIC;
+		else
+			sv_vol_type = UBI_VID_DYNAMIC;
+
+		if (vol_type != sv_vol_type) {
+			dbg_err("inconsistent vol_type");
+			goto bad;
+		}
+
+		if (used_ebs != sv->used_ebs) {
+			dbg_err("inconsistent used_ebs");
+			goto bad;
+		}
+
+		if (data_pad != sv->data_pad) {
+			dbg_err("inconsistent data_pad");
+			goto bad;
+		}
+	}
+
+	return 0;
+
+bad:
+	ubi_err("inconsistent VID header at PEB %d", pnum);
+	ubi_dbg_dump_vid_hdr(vid_hdr);
+	ubi_dbg_dump_sv(sv);
+	return -EINVAL;
+}
+
+/**
+ * add_volume - add volume to the scanning information.
+ * @si: scanning information
+ * @vol_id: ID of the volume to add
+ * @pnum: physical eraseblock number
+ * @vid_hdr: volume identifier header
+ *
+ * If the volume corresponding to the @vid_hdr logical eraseblock is already
+ * present in the scanning information, this function does nothing. Otherwise
+ * it adds corresponding volume to the scanning information. Returns a pointer
+ * to the scanning volume object in case of success and a negative error code
+ * in case of failure.
+ */
+static struct ubi_scan_volume *add_volume(struct ubi_scan_info *si, int vol_id,
+					  int pnum,
+					  const struct ubi_vid_hdr *vid_hdr)
+{
+	struct ubi_scan_volume *sv;
+	struct rb_node **p = &si->volumes.rb_node, *parent = NULL;
+
+	ubi_assert(vol_id == be32_to_cpu(vid_hdr->vol_id));
+
+	/* Walk the volume RB-tree to look if this volume is already present */
+	while (*p) {
+		parent = *p;
+		sv = rb_entry(parent, struct ubi_scan_volume, rb);
+
+		if (vol_id == sv->vol_id)
+			return sv;
+
+		if (vol_id > sv->vol_id)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	/* The volume is absent - add it */
+	sv = kmalloc(sizeof(struct ubi_scan_volume), GFP_KERNEL);
+	if (!sv)
+		return ERR_PTR(-ENOMEM);
+
+	sv->highest_lnum = sv->leb_count = 0;
+	sv->vol_id = vol_id;
+	sv->root = RB_ROOT;
+	sv->used_ebs = be32_to_cpu(vid_hdr->used_ebs);
+	sv->data_pad = be32_to_cpu(vid_hdr->data_pad);
+	sv->compat = vid_hdr->compat;
+	sv->vol_type = vid_hdr->vol_type == UBI_VID_DYNAMIC ? UBI_DYNAMIC_VOLUME
+							    : UBI_STATIC_VOLUME;
+	if (vol_id > si->highest_vol_id)
+		si->highest_vol_id = vol_id;
+
+	rb_link_node(&sv->rb, parent, p);
+	rb_insert_color(&sv->rb, &si->volumes);
+	si->vols_found += 1;
+	dbg_bld("added volume %d", vol_id);
+	return sv;
+}
+
+/**
+ * compare_lebs - find out which logical eraseblock is newer.
+ * @ubi: UBI device description object
+ * @seb: first logical eraseblock to compare
+ * @pnum: physical eraseblock number of the second logical eraseblock to
+ * compare
+ * @vid_hdr: volume identifier header of the second logical eraseblock
+ *
+ * This function compares 2 copies of a LEB and informs which one is newer. In
+ * case of success this function returns a positive value, in case of failure, a
+ * negative error code is returned. The success return codes use the following
+ * bits:
+ *     o bit 0 is cleared: the first PEB (described by @seb) is newer then the
+ *       second PEB (described by @pnum and @vid_hdr);
+ *     o bit 0 is set: the second PEB is newer;
+ *     o bit 1 is cleared: no bit-flips were detected in the newer LEB;
+ *     o bit 1 is set: bit-flips were detected in the newer LEB;
+ *     o bit 2 is cleared: the older LEB is not corrupted;
+ *     o bit 2 is set: the older LEB is corrupted.
+ */
+static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
+			int pnum, const struct ubi_vid_hdr *vid_hdr)
+{
+	void *buf;
+	int len, err, second_is_newer, bitflips = 0, corrupted = 0;
+	uint32_t data_crc, crc;
+	struct ubi_vid_hdr *vh = NULL;
+	unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
+
+	if (seb->sqnum == 0 && sqnum2 == 0) {
+		long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
+
+		/*
+		 * UBI constantly increases the logical eraseblock version
+		 * number and it can overflow. Thus, we have to bear in mind
+		 * that versions that are close to %0xFFFFFFFF are less then
+		 * versions that are close to %0.
+		 *
+		 * The UBI WL unit guarantees that the number of pending tasks
+		 * is not greater then %0x7FFFFFFF. So, if the difference
+		 * between any two versions is greater or equivalent to
+		 * %0x7FFFFFFF, there was an overflow and the logical
+		 * eraseblock with lower version is actually newer then the one
+		 * with higher version.
+		 *
+		 * FIXME: but this is anyway obsolete and will be removed at
+		 * some point.
+		 */
+		dbg_bld("using old crappy leb_ver stuff");
+
+		if (v1 == v2) {
+			ubi_err("PEB %d and PEB %d have the same version %lld",
+				seb->pnum, pnum, v1);
+			return -EINVAL;
+		}
+
+		abs = v1 - v2;
+		if (abs < 0)
+			abs = -abs;
+
+		if (abs < 0x7FFFFFFF)
+			/* Non-overflow situation */
+			second_is_newer = (v2 > v1);
+		else
+			second_is_newer = (v2 < v1);
+	} else
+		/* Obviously the LEB with lower sequence counter is older */
+		second_is_newer = sqnum2 > seb->sqnum;
+
+	/*
+	 * Now we know which copy is newer. If the copy flag of the PEB with
+	 * newer version is not set, then we just return, otherwise we have to
+	 * check data CRC. For the second PEB we already have the VID header,
+	 * for the first one - we'll need to re-read it from flash.
+	 *
+	 * FIXME: this may be optimized so that we wouldn't read twice.
+	 */
+
+	if (second_is_newer) {
+		if (!vid_hdr->copy_flag) {
+			/* It is not a copy, so it is newer */
+			dbg_bld("second PEB %d is newer, copy_flag is unset",
+				pnum);
+			return 1;
+		}
+	} else {
+		pnum = seb->pnum;
+
+		vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+		if (!vh)
+			return -ENOMEM;
+
+		err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
+		if (err) {
+			if (err == UBI_IO_BITFLIPS)
+				bitflips = 1;
+			else {
+				dbg_err("VID of PEB %d header is bad, but it "
+					"was OK earlier", pnum);
+				if (err > 0)
+					err = -EIO;
+
+				goto out_free_vidh;
+			}
+		}
+
+		if (!vh->copy_flag) {
+			/* It is not a copy, so it is newer */
+			dbg_bld("first PEB %d is newer, copy_flag is unset",
+				pnum);
+			err = bitflips << 1;
+			goto out_free_vidh;
+		}
+
+		vid_hdr = vh;
+	}
+
+	/* Read the data of the copy and check the CRC */
+
+	len = be32_to_cpu(vid_hdr->data_size);
+	buf = vmalloc(len);
+	if (!buf) {
+		err = -ENOMEM;
+		goto out_free_vidh;
+	}
+
+	err = ubi_io_read_data(ubi, buf, pnum, 0, len);
+	if (err && err != UBI_IO_BITFLIPS)
+		goto out_free_buf;
+
+	data_crc = be32_to_cpu(vid_hdr->data_crc);
+	crc = crc32(UBI_CRC32_INIT, buf, len);
+	if (crc != data_crc) {
+		dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
+			pnum, crc, data_crc);
+		corrupted = 1;
+		bitflips = 0;
+		second_is_newer = !second_is_newer;
+	} else {
+		dbg_bld("PEB %d CRC is OK", pnum);
+		bitflips = !!err;
+	}
+
+	vfree(buf);
+	ubi_free_vid_hdr(ubi, vh);
+
+	if (second_is_newer)
+		dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
+	else
+		dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
+
+	return second_is_newer | (bitflips << 1) | (corrupted << 2);
+
+out_free_buf:
+	vfree(buf);
+out_free_vidh:
+	ubi_free_vid_hdr(ubi, vh);
+	return err;
+}
+
+/**
+ * ubi_scan_add_used - add information about a physical eraseblock to the
+ * scanning information.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ * @pnum: the physical eraseblock number
+ * @ec: erase counter
+ * @vid_hdr: the volume identifier header
+ * @bitflips: if bit-flips were detected when this physical eraseblock was read
+ *
+ * This function adds information about a used physical eraseblock to the
+ * 'used' tree of the corresponding volume. The function is rather complex
+ * because it has to handle cases when this is not the first physical
+ * eraseblock belonging to the same logical eraseblock, and the newer one has
+ * to be picked, while the older one has to be dropped. This function returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+int ubi_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
+		      int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
+		      int bitflips)
+{
+	int err, vol_id, lnum;
+	uint32_t leb_ver;
+	unsigned long long sqnum;
+	struct ubi_scan_volume *sv;
+	struct ubi_scan_leb *seb;
+	struct rb_node **p, *parent = NULL;
+
+	vol_id = be32_to_cpu(vid_hdr->vol_id);
+	lnum = be32_to_cpu(vid_hdr->lnum);
+	sqnum = be64_to_cpu(vid_hdr->sqnum);
+	leb_ver = be32_to_cpu(vid_hdr->leb_ver);
+
+	dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
+		pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
+
+	sv = add_volume(si, vol_id, pnum, vid_hdr);
+	if (IS_ERR(sv) < 0)
+		return PTR_ERR(sv);
+
+	if (si->max_sqnum < sqnum)
+		si->max_sqnum = sqnum;
+
+	/*
+	 * Walk the RB-tree of logical eraseblocks of volume @vol_id to look
+	 * if this is the first instance of this logical eraseblock or not.
+	 */
+	p = &sv->root.rb_node;
+	while (*p) {
+		int cmp_res;
+
+		parent = *p;
+		seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
+		if (lnum != seb->lnum) {
+			if (lnum < seb->lnum)
+				p = &(*p)->rb_left;
+			else
+				p = &(*p)->rb_right;
+			continue;
+		}
+
+		/*
+		 * There is already a physical eraseblock describing the same
+		 * logical eraseblock present.
+		 */
+
+		dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
+			"LEB ver %u, EC %d", seb->pnum, seb->sqnum,
+			seb->leb_ver, seb->ec);
+
+		/*
+		 * Make sure that the logical eraseblocks have different
+		 * versions. Otherwise the image is bad.
+		 */
+		if (seb->leb_ver == leb_ver && leb_ver != 0) {
+			ubi_err("two LEBs with same version %u", leb_ver);
+			ubi_dbg_dump_seb(seb, 0);
+			ubi_dbg_dump_vid_hdr(vid_hdr);
+			return -EINVAL;
+		}
+
+		/*
+		 * Make sure that the logical eraseblocks have different
+		 * sequence numbers. Otherwise the image is bad.
+		 *
+		 * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
+		 */
+		if (seb->sqnum == sqnum && sqnum != 0) {
+			ubi_err("two LEBs with same sequence number %llu",
+				sqnum);
+			ubi_dbg_dump_seb(seb, 0);
+			ubi_dbg_dump_vid_hdr(vid_hdr);
+			return -EINVAL;
+		}
+
+		/*
+		 * Now we have to drop the older one and preserve the newer
+		 * one.
+		 */
+		cmp_res = compare_lebs(ubi, seb, pnum, vid_hdr);
+		if (cmp_res < 0)
+			return cmp_res;
+
+		if (cmp_res & 1) {
+			/*
+			 * This logical eraseblock is newer then the one
+			 * found earlier.
+			 */
+			err = validate_vid_hdr(vid_hdr, sv, pnum);
+			if (err)
+				return err;
+
+			if (cmp_res & 4)
+				err = add_to_list(si, seb->pnum, seb->ec,
+						  &si->corr);
+			else
+				err = add_to_list(si, seb->pnum, seb->ec,
+						  &si->erase);
+			if (err)
+				return err;
+
+			seb->ec = ec;
+			seb->pnum = pnum;
+			seb->scrub = ((cmp_res & 2) || bitflips);
+			seb->sqnum = sqnum;
+			seb->leb_ver = leb_ver;
+
+			if (sv->highest_lnum == lnum)
+				sv->last_data_size =
+					be32_to_cpu(vid_hdr->data_size);
+
+			return 0;
+		} else {
+			/*
+			 * This logical eraseblock is older then the one found
+			 * previously.
+			 */
+			if (cmp_res & 4)
+				return add_to_list(si, pnum, ec, &si->corr);
+			else
+				return add_to_list(si, pnum, ec, &si->erase);
+		}
+	}
+
+	/*
+	 * We've met this logical eraseblock for the first time, add it to the
+	 * scanning information.
+	 */
+
+	err = validate_vid_hdr(vid_hdr, sv, pnum);
+	if (err)
+		return err;
+
+	seb = kmalloc(sizeof(struct ubi_scan_leb), GFP_KERNEL);
+	if (!seb)
+		return -ENOMEM;
+
+	seb->ec = ec;
+	seb->pnum = pnum;
+	seb->lnum = lnum;
+	seb->sqnum = sqnum;
+	seb->scrub = bitflips;
+	seb->leb_ver = leb_ver;
+
+	if (sv->highest_lnum <= lnum) {
+		sv->highest_lnum = lnum;
+		sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
+	}
+
+	sv->leb_count += 1;
+	rb_link_node(&seb->u.rb, parent, p);
+	rb_insert_color(&seb->u.rb, &sv->root);
+	return 0;
+}
+
+/**
+ * ubi_scan_find_sv - find information about a particular volume in the
+ * scanning information.
+ * @si: scanning information
+ * @vol_id: the requested volume ID
+ *
+ * This function returns a pointer to the volume description or %NULL if there
+ * are no data about this volume in the scanning information.
+ */
+struct ubi_scan_volume *ubi_scan_find_sv(const struct ubi_scan_info *si,
+					 int vol_id)
+{
+	struct ubi_scan_volume *sv;
+	struct rb_node *p = si->volumes.rb_node;
+
+	while (p) {
+		sv = rb_entry(p, struct ubi_scan_volume, rb);
+
+		if (vol_id == sv->vol_id)
+			return sv;
+
+		if (vol_id > sv->vol_id)
+			p = p->rb_left;
+		else
+			p = p->rb_right;
+	}
+
+	return NULL;
+}
+
+/**
+ * ubi_scan_find_seb - find information about a particular logical
+ * eraseblock in the volume scanning information.
+ * @sv: a pointer to the volume scanning information
+ * @lnum: the requested logical eraseblock
+ *
+ * This function returns a pointer to the scanning logical eraseblock or %NULL
+ * if there are no data about it in the scanning volume information.
+ */
+struct ubi_scan_leb *ubi_scan_find_seb(const struct ubi_scan_volume *sv,
+				       int lnum)
+{
+	struct ubi_scan_leb *seb;
+	struct rb_node *p = sv->root.rb_node;
+
+	while (p) {
+		seb = rb_entry(p, struct ubi_scan_leb, u.rb);
+
+		if (lnum == seb->lnum)
+			return seb;
+
+		if (lnum > seb->lnum)
+			p = p->rb_left;
+		else
+			p = p->rb_right;
+	}
+
+	return NULL;
+}
+
+/**
+ * ubi_scan_rm_volume - delete scanning information about a volume.
+ * @si: scanning information
+ * @sv: the volume scanning information to delete
+ */
+void ubi_scan_rm_volume(struct ubi_scan_info *si, struct ubi_scan_volume *sv)
+{
+	struct rb_node *rb;
+	struct ubi_scan_leb *seb;
+
+	dbg_bld("remove scanning information about volume %d", sv->vol_id);
+
+	while ((rb = rb_first(&sv->root))) {
+		seb = rb_entry(rb, struct ubi_scan_leb, u.rb);
+		rb_erase(&seb->u.rb, &sv->root);
+		list_add_tail(&seb->u.list, &si->erase);
+	}
+
+	rb_erase(&sv->rb, &si->volumes);
+	kfree(sv);
+	si->vols_found -= 1;
+}
+
+/**
+ * ubi_scan_erase_peb - erase a physical eraseblock.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ * @pnum: physical eraseblock number to erase;
+ * @ec: erase counter value to write (%UBI_SCAN_UNKNOWN_EC if it is unknown)
+ *
+ * This function erases physical eraseblock 'pnum', and writes the erase
+ * counter header to it. This function should only be used on UBI device
+ * initialization stages, when the EBA unit had not been yet initialized. This
+ * function returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
+		       int pnum, int ec)
+{
+	int err;
+	struct ubi_ec_hdr *ec_hdr;
+
+	if ((long long)ec >= UBI_MAX_ERASECOUNTER) {
+		/*
+		 * Erase counter overflow. Upgrade UBI and use 64-bit
+		 * erase counters internally.
+		 */
+		ubi_err("erase counter overflow at PEB %d, EC %d", pnum, ec);
+		return -EINVAL;
+	}
+
+	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	if (!ec_hdr)
+		return -ENOMEM;
+
+	ec_hdr->ec = cpu_to_be64(ec);
+
+	err = ubi_io_sync_erase(ubi, pnum, 0);
+	if (err < 0)
+		goto out_free;
+
+	err = ubi_io_write_ec_hdr(ubi, pnum, ec_hdr);
+
+out_free:
+	kfree(ec_hdr);
+	return err;
+}
+
+/**
+ * ubi_scan_get_free_peb - get a free physical eraseblock.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ *
+ * This function returns a free physical eraseblock. It is supposed to be
+ * called on the UBI initialization stages when the wear-leveling unit is not
+ * initialized yet. This function picks a physical eraseblocks from one of the
+ * lists, writes the EC header if it is needed, and removes it from the list.
+ *
+ * This function returns scanning physical eraseblock information in case of
+ * success and an error code in case of failure.
+ */
+struct ubi_scan_leb *ubi_scan_get_free_peb(struct ubi_device *ubi,
+					   struct ubi_scan_info *si)
+{
+	int err = 0, i;
+	struct ubi_scan_leb *seb;
+
+	if (!list_empty(&si->free)) {
+		seb = list_entry(si->free.next, struct ubi_scan_leb, u.list);
+		list_del(&seb->u.list);
+		dbg_bld("return free PEB %d, EC %d", seb->pnum, seb->ec);
+		return seb;
+	}
+
+	for (i = 0; i < 2; i++) {
+		struct list_head *head;
+		struct ubi_scan_leb *tmp_seb;
+
+		if (i == 0)
+			head = &si->erase;
+		else
+			head = &si->corr;
+
+		/*
+		 * We try to erase the first physical eraseblock from the @head
+		 * list and pick it if we succeed, or try to erase the
+		 * next one if not. And so forth. We don't want to take care
+		 * about bad eraseblocks here - they'll be handled later.
+		 */
+		list_for_each_entry_safe(seb, tmp_seb, head, u.list) {
+			if (seb->ec == UBI_SCAN_UNKNOWN_EC)
+				seb->ec = si->mean_ec;
+
+			err = ubi_scan_erase_peb(ubi, si, seb->pnum, seb->ec+1);
+			if (err)
+				continue;
+
+			seb->ec += 1;
+			list_del(&seb->u.list);
+			dbg_bld("return PEB %d, EC %d", seb->pnum, seb->ec);
+			return seb;
+		}
+	}
+
+	ubi_err("no eraseblocks found");
+	return ERR_PTR(-ENOSPC);
+}
+
+/**
+ * process_eb - read UBI headers, check them and add corresponding data
+ * to the scanning information.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ * @pnum: the physical eraseblock number
+ *
+ * This function returns a zero if the physical eraseblock was successfully
+ * handled and a negative error code in case of failure.
+ */
+static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
+{
+	long long uninitialized_var(ec);
+	int err, bitflips = 0, vol_id, ec_corr = 0;
+
+	dbg_bld("scan PEB %d", pnum);
+
+	/* Skip bad physical eraseblocks */
+	err = ubi_io_is_bad(ubi, pnum);
+	if (err < 0)
+		return err;
+	else if (err) {
+		/*
+		 * FIXME: this is actually duty of the I/O unit to initialize
+		 * this, but MTD does not provide enough information.
+		 */
+		si->bad_peb_count += 1;
+		return 0;
+	}
+
+	err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
+	if (err < 0)
+		return err;
+	else if (err == UBI_IO_BITFLIPS)
+		bitflips = 1;
+	else if (err == UBI_IO_PEB_EMPTY)
+		return add_to_list(si, pnum, UBI_SCAN_UNKNOWN_EC, &si->erase);
+	else if (err == UBI_IO_BAD_EC_HDR) {
+		/*
+		 * We have to also look at the VID header, possibly it is not
+		 * corrupted. Set %bitflips flag in order to make this PEB be
+		 * moved and EC be re-created.
+		 */
+		ec_corr = 1;
+		ec = UBI_SCAN_UNKNOWN_EC;
+		bitflips = 1;
+	}
+
+	si->is_empty = 0;
+
+	if (!ec_corr) {
+		/* Make sure UBI version is OK */
+		if (ech->version != UBI_VERSION) {
+			ubi_err("this UBI version is %d, image version is %d",
+				UBI_VERSION, (int)ech->version);
+			return -EINVAL;
+		}
+
+		ec = be64_to_cpu(ech->ec);
+		if (ec > UBI_MAX_ERASECOUNTER) {
+			/*
+			 * Erase counter overflow. The EC headers have 64 bits
+			 * reserved, but we anyway make use of only 31 bit
+			 * values, as this seems to be enough for any existing
+			 * flash. Upgrade UBI and use 64-bit erase counters
+			 * internally.
+			 */
+			ubi_err("erase counter overflow, max is %d",
+				UBI_MAX_ERASECOUNTER);
+			ubi_dbg_dump_ec_hdr(ech);
+			return -EINVAL;
+		}
+	}
+
+	/* OK, we've done with the EC header, let's look at the VID header */
+
+	err = ubi_io_read_vid_hdr(ubi, pnum, vidh, 0);
+	if (err < 0)
+		return err;
+	else if (err == UBI_IO_BITFLIPS)
+		bitflips = 1;
+	else if (err == UBI_IO_BAD_VID_HDR ||
+		 (err == UBI_IO_PEB_FREE && ec_corr)) {
+		/* VID header is corrupted */
+		err = add_to_list(si, pnum, ec, &si->corr);
+		if (err)
+			return err;
+		goto adjust_mean_ec;
+	} else if (err == UBI_IO_PEB_FREE) {
+		/* No VID header - the physical eraseblock is free */
+		err = add_to_list(si, pnum, ec, &si->free);
+		if (err)
+			return err;
+		goto adjust_mean_ec;
+	}
+
+	vol_id = be32_to_cpu(vidh->vol_id);
+	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
+		int lnum = be32_to_cpu(vidh->lnum);
+
+		/* Unsupported internal volume */
+		switch (vidh->compat) {
+		case UBI_COMPAT_DELETE:
+			ubi_msg(""delete" compatible internal volume %d:%d"
+				" found, remove it", vol_id, lnum);
+			err = add_to_list(si, pnum, ec, &si->corr);
+			if (err)
+				return err;
+			break;
+
+		case UBI_COMPAT_RO:
+			ubi_msg("read-only compatible internal volume %d:%d"
+				" found, switch to read-only mode",
+				vol_id, lnum);
+			ubi->ro_mode = 1;
+			break;
+
+		case UBI_COMPAT_PRESERVE:
+			ubi_msg(""preserve" compatible internal volume %d:%d"
+				" found", vol_id, lnum);
+			err = add_to_list(si, pnum, ec, &si->alien);
+			if (err)
+				return err;
+			si->alien_peb_count += 1;
+			return 0;
+
+		case UBI_COMPAT_REJECT:
+			ubi_err("incompatible internal volume %d:%d found",
+				vol_id, lnum);
+			return -EINVAL;
+		}
+	}
+
+	/* Both UBI headers seem to be fine */
+	err = ubi_scan_add_used(ubi, si, pnum, ec, vidh, bitflips);
+	if (err)
+		return err;
+
+adjust_mean_ec:
+	if (!ec_corr) {
+		si->ec_sum += ec;
+		si->ec_count += 1;
+		if (ec > si->max_ec)
+			si->max_ec = ec;
+		if (ec < si->min_ec)
+			si->min_ec = ec;
+	}
+
+	return 0;
+}
+
+/**
+ * ubi_scan - scan an MTD device.
+ * @ubi: UBI device description object
+ *
+ * This function does full scanning of an MTD device and returns complete
+ * information about it. In case of failure, an error code is returned.
+ */
+struct ubi_scan_info *ubi_scan(struct ubi_device *ubi)
+{
+	int err, pnum;
+	struct rb_node *rb1, *rb2;
+	struct ubi_scan_volume *sv;
+	struct ubi_scan_leb *seb;
+	struct ubi_scan_info *si;
+
+	si = kzalloc(sizeof(struct ubi_scan_info), GFP_KERNEL);
+	if (!si)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&si->corr);
+	INIT_LIST_HEAD(&si->free);
+	INIT_LIST_HEAD(&si->erase);
+	INIT_LIST_HEAD(&si->alien);
+	si->volumes = RB_ROOT;
+	si->is_empty = 1;
+
+	err = -ENOMEM;
+	ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+	if (!ech)
+		goto out_si;
+
+	vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+	if (!vidh)
+		goto out_ech;
+
+	DPRINTK("peb_count %d", ubi->peb_count);
+	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+		cond_resched();
+
+		dbg_msg("process PEB %d", pnum);
+		err = process_eb(ubi, si, pnum);
+		if (err < 0)
+			goto out_vidh;
+	}
+
+	dbg_msg("scanning is finished");
+
+	/* Calculate mean erase counter */
+	if (si->ec_count) {
+		do_div(si->ec_sum, si->ec_count);
+		si->mean_ec = si->ec_sum;
+	}
+
+	if (si->is_empty)
+		ubi_msg("empty MTD device detected");
+
+	/*
+	 * In case of unknown erase counter we use the mean erase counter
+	 * value.
+	 */
+	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
+		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
+			if (seb->ec == UBI_SCAN_UNKNOWN_EC)
+				seb->ec = si->mean_ec;
+	}
+
+	list_for_each_entry(seb, &si->free, u.list) {
+		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
+			seb->ec = si->mean_ec;
+	}
+
+	list_for_each_entry(seb, &si->corr, u.list)
+		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
+			seb->ec = si->mean_ec;
+
+	list_for_each_entry(seb, &si->erase, u.list)
+		if (seb->ec == UBI_SCAN_UNKNOWN_EC)
+			seb->ec = si->mean_ec;
+
+	err = paranoid_check_si(ubi, si);
+	if (err) {
+		if (err > 0)
+			err = -EINVAL;
+		goto out_vidh;
+	}
+
+	ubi_free_vid_hdr(ubi, vidh);
+	kfree(ech);
+
+	return si;
+
+out_vidh:
+	ubi_free_vid_hdr(ubi, vidh);
+out_ech:
+	kfree(ech);
+out_si:
+	ubi_scan_destroy_si(si);
+	return ERR_PTR(err);
+}
+
+/**
+ * destroy_sv - free the scanning volume information
+ * @sv: scanning volume information
+ *
+ * This function destroys the volume RB-tree (@sv->root) and the scanning
+ * volume information.
+ */
+static void destroy_sv(struct ubi_scan_volume *sv)
+{
+	struct ubi_scan_leb *seb;
+	struct rb_node *this = sv->root.rb_node;
+
+	while (this) {
+		if (this->rb_left)
+			this = this->rb_left;
+		else if (this->rb_right)
+			this = this->rb_right;
+		else {
+			seb = rb_entry(this, struct ubi_scan_leb, u.rb);
+			this = rb_parent(this);
+			if (this) {
+				if (this->rb_left == &seb->u.rb)
+					this->rb_left = NULL;
+				else
+					this->rb_right = NULL;
+			}
+
+			kfree(seb);
+		}
+	}
+	kfree(sv);
+}
+
+/**
+ * ubi_scan_destroy_si - destroy scanning information.
+ * @si: scanning information
+ */
+void ubi_scan_destroy_si(struct ubi_scan_info *si)
+{
+	struct ubi_scan_leb *seb, *seb_tmp;
+	struct ubi_scan_volume *sv;
+	struct rb_node *rb;
+
+	list_for_each_entry_safe(seb, seb_tmp, &si->alien, u.list) {
+		list_del(&seb->u.list);
+		kfree(seb);
+	}
+	list_for_each_entry_safe(seb, seb_tmp, &si->erase, u.list) {
+		list_del(&seb->u.list);
+		kfree(seb);
+	}
+	list_for_each_entry_safe(seb, seb_tmp, &si->corr, u.list) {
+		list_del(&seb->u.list);
+		kfree(seb);
+	}
+	list_for_each_entry_safe(seb, seb_tmp, &si->free, u.list) {
+		list_del(&seb->u.list);
+		kfree(seb);
+	}
+
+	/* Destroy the volume RB-tree */
+	rb = si->volumes.rb_node;
+	while (rb) {
+		if (rb->rb_left)
+			rb = rb->rb_left;
+		else if (rb->rb_right)
+			rb = rb->rb_right;
+		else {
+			sv = rb_entry(rb, struct ubi_scan_volume, rb);
+
+			rb = rb_parent(rb);
+			if (rb) {
+				if (rb->rb_left == &sv->rb)
+					rb->rb_left = NULL;
+				else
+					rb->rb_right = NULL;
+			}
+
+			destroy_sv(sv);
+		}
+	}
+
+	kfree(si);
+}
+
+#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+
+/**
+ * paranoid_check_si - check if the scanning information is correct and
+ * consistent.
+ * @ubi: UBI device description object
+ * @si: scanning information
+ *
+ * This function returns zero if the scanning information is all right, %1 if
+ * not and a negative error code if an error occurred.
+ */
+static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
+{
+	int pnum, err, vols_found = 0;
+	struct rb_node *rb1, *rb2;
+	struct ubi_scan_volume *sv;
+	struct ubi_scan_leb *seb, *last_seb;
+	uint8_t *buf;
+
+	/*
+	 * At first, check that scanning information is OK.
+	 */
+	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
+		int leb_count = 0;
+
+		cond_resched();
+
+		vols_found += 1;
+
+		if (si->is_empty) {
+			ubi_err("bad is_empty flag");
+			goto bad_sv;
+		}
+
+		if (sv->vol_id < 0 || sv->highest_lnum < 0 ||
+		    sv->leb_count < 0 || sv->vol_type < 0 || sv->used_ebs < 0 ||
+		    sv->data_pad < 0 || sv->last_data_size < 0) {
+			ubi_err("negative values");
+			goto bad_sv;
+		}
+
+		if (sv->vol_id >= UBI_MAX_VOLUMES &&
+		    sv->vol_id < UBI_INTERNAL_VOL_START) {
+			ubi_err("bad vol_id");
+			goto bad_sv;
+		}
+
+		if (sv->vol_id > si->highest_vol_id) {
+			ubi_err("highest_vol_id is %d, but vol_id %d is there",
+				si->highest_vol_id, sv->vol_id);
+			goto out;
+		}
+
+		if (sv->vol_type != UBI_DYNAMIC_VOLUME &&
+		    sv->vol_type != UBI_STATIC_VOLUME) {
+			ubi_err("bad vol_type");
+			goto bad_sv;
+		}
+
+		if (sv->data_pad > ubi->leb_size / 2) {
+			ubi_err("bad data_pad");
+			goto bad_sv;
+		}
+
+		last_seb = NULL;
+		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
+			cond_resched();
+
+			last_seb = seb;
+			leb_count += 1;
+
+			if (seb->pnum < 0 || seb->ec < 0) {
+				ubi_err("negative values");
+				goto bad_seb;
+			}
+
+			if (seb->ec < si->min_ec) {
+				ubi_err("bad si->min_ec (%d), %d found",
+					si->min_ec, seb->ec);
+				goto bad_seb;
+			}
+
+			if (seb->ec > si->max_ec) {
+				ubi_err("bad si->max_ec (%d), %d found",
+					si->max_ec, seb->ec);
+				goto bad_seb;
+			}
+
+			if (seb->pnum >= ubi->peb_count) {
+				ubi_err("too high PEB number %d, total PEBs %d",
+					seb->pnum, ubi->peb_count);
+				goto bad_seb;
+			}
+
+			if (sv->vol_type == UBI_STATIC_VOLUME) {
+				if (seb->lnum >= sv->used_ebs) {
+					ubi_err("bad lnum or used_ebs");
+					goto bad_seb;
+				}
+			} else {
+				if (sv->used_ebs != 0) {
+					ubi_err("non-zero used_ebs");
+					goto bad_seb;
+				}
+			}
+
+			if (seb->lnum > sv->highest_lnum) {
+				ubi_err("incorrect highest_lnum or lnum");
+				goto bad_seb;
+			}
+		}
+
+		if (sv->leb_count != leb_count) {
+			ubi_err("bad leb_count, %d objects in the tree",
+				leb_count);
+			goto bad_sv;
+		}
+
+		if (!last_seb)
+			continue;
+
+		seb = last_seb;
+
+		if (seb->lnum != sv->highest_lnum) {
+			ubi_err("bad highest_lnum");
+			goto bad_seb;
+		}
+	}
+
+	if (vols_found != si->vols_found) {
+		ubi_err("bad si->vols_found %d, should be %d",
+			si->vols_found, vols_found);
+		goto out;
+	}
+
+	/* Check that scanning information is correct */
+	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb) {
+		last_seb = NULL;
+		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
+			int vol_type;
+
+			cond_resched();
+
+			last_seb = seb;
+
+			err = ubi_io_read_vid_hdr(ubi, seb->pnum, vidh, 1);
+			if (err && err != UBI_IO_BITFLIPS) {
+				ubi_err("VID header is not OK (%d)", err);
+				if (err > 0)
+					err = -EIO;
+				return err;
+			}
+
+			vol_type = vidh->vol_type == UBI_VID_DYNAMIC ?
+				   UBI_DYNAMIC_VOLUME : UBI_STATIC_VOLUME;
+			if (sv->vol_type != vol_type) {
+				ubi_err("bad vol_type");
+				goto bad_vid_hdr;
+			}
+
+			if (seb->sqnum != be64_to_cpu(vidh->sqnum)) {
+				ubi_err("bad sqnum %llu", seb->sqnum);
+				goto bad_vid_hdr;
+			}
+
+			if (sv->vol_id != be32_to_cpu(vidh->vol_id)) {
+				ubi_err("bad vol_id %d", sv->vol_id);
+				goto bad_vid_hdr;
+			}
+
+			if (sv->compat != vidh->compat) {
+				ubi_err("bad compat %d", vidh->compat);
+				goto bad_vid_hdr;
+			}
+
+			if (seb->lnum != be32_to_cpu(vidh->lnum)) {
+				ubi_err("bad lnum %d", seb->lnum);
+				goto bad_vid_hdr;
+			}
+
+			if (sv->used_ebs != be32_to_cpu(vidh->used_ebs)) {
+				ubi_err("bad used_ebs %d", sv->used_ebs);
+				goto bad_vid_hdr;
+			}
+
+			if (sv->data_pad != be32_to_cpu(vidh->data_pad)) {
+				ubi_err("bad data_pad %d", sv->data_pad);
+				goto bad_vid_hdr;
+			}
+
+			if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
+				ubi_err("bad leb_ver %u", seb->leb_ver);
+				goto bad_vid_hdr;
+			}
+		}
+
+		if (!last_seb)
+			continue;
+
+		if (sv->highest_lnum != be32_to_cpu(vidh->lnum)) {
+			ubi_err("bad highest_lnum %d", sv->highest_lnum);
+			goto bad_vid_hdr;
+		}
+
+		if (sv->last_data_size != be32_to_cpu(vidh->data_size)) {
+			ubi_err("bad last_data_size %d", sv->last_data_size);
+			goto bad_vid_hdr;
+		}
+	}
+
+	/*
+	 * Make sure that all the physical eraseblocks are in one of the lists
+	 * or trees.
+	 */
+	buf = kzalloc(ubi->peb_count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+		err = ubi_io_is_bad(ubi, pnum);
+		if (err < 0) {
+			kfree(buf);
+			return err;
+		}
+		else if (err)
+			buf[pnum] = 1;
+	}
+
+	ubi_rb_for_each_entry(rb1, sv, &si->volumes, rb)
+		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb)
+			buf[seb->pnum] = 1;
+
+	list_for_each_entry(seb, &si->free, u.list)
+		buf[seb->pnum] = 1;
+
+	list_for_each_entry(seb, &si->corr, u.list)
+		buf[seb->pnum] = 1;
+
+	list_for_each_entry(seb, &si->erase, u.list)
+		buf[seb->pnum] = 1;
+
+	list_for_each_entry(seb, &si->alien, u.list)
+		buf[seb->pnum] = 1;
+
+	err = 0;
+	for (pnum = 0; pnum < ubi->peb_count; pnum++)
+		if (!buf[pnum]) {
+			ubi_err("PEB %d is not referred", pnum);
+			err = 1;
+		}
+
+	kfree(buf);
+	if (err)
+		goto out;
+	return 0;
+
+bad_seb:
+	ubi_err("bad scanning information about LEB %d", seb->lnum);
+	ubi_dbg_dump_seb(seb, 0);
+	ubi_dbg_dump_sv(sv);
+	goto out;
+
+bad_sv:
+	ubi_err("bad scanning information about volume %d", sv->vol_id);
+	ubi_dbg_dump_sv(sv);
+	goto out;
+
+bad_vid_hdr:
+	ubi_err("bad scanning information about volume %d", sv->vol_id);
+	ubi_dbg_dump_sv(sv);
+	ubi_dbg_dump_vid_hdr(vidh);
+
+out:
+	ubi_dbg_dump_stack();
+	return 1;
+}
+
+#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */

    