mtd, ubi, ubifs: resync with Linux-3.14

resync ubi subsystem with linux:

commit 455c6fdbd219161bd09b1165f11699d6d73de11c
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun Mar 30 20:40:15 2014 -0700

    Linux 3.14

A nice side effect of this, is we introduce UBI Fastmap support
to U-Boot.

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Sergey Lapin <slapin@ossfans.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Joerg Krause <jkrause@posteo.de>

1 files changed, 586 insertions, 226 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 6d86c0b6bc..7094b9c0e8 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -15,56 +15,88 @@
  * 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.
  */
 
-#ifdef UBI_LINUX
-#include <linux/err.h>
+#define __UBOOT__
+#ifndef __UBOOT__
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/stringify.h>
+#include <linux/namei.h>
 #include <linux/stat.h>
 #include <linux/miscdevice.h>
 #include <linux/log2.h>
 #include <linux/kthread.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/major.h>
+#else
+#include <linux/compat.h>
 #endif
+#include <linux/err.h>
 #include <ubi_uboot.h>
+#include <linux/mtd/partitions.h>
+
 #include "ubi.h"
 
+/* Maximum length of the 'mtd=' parameter */
+#define MTD_PARAM_LEN_MAX 64
+
+/* Maximum number of comma-separated items in the 'mtd=' parameter */
+#define MTD_PARAM_MAX_COUNT 4
+
+/* Maximum value for the number of bad PEBs per 1024 PEBs */
+#define MAX_MTD_UBI_BEB_LIMIT 768
+
+#ifdef CONFIG_MTD_UBI_MODULE
+#define ubi_is_module() 1
+#else
+#define ubi_is_module() 0
+#endif
+
 #if (CONFIG_SYS_MALLOC_LEN < (512 << 10))
 #error Malloc area too small for UBI, increase CONFIG_SYS_MALLOC_LEN to >= 512k
 #endif
 
-/* 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
+ * @name: MTD character device node path, MTD device name, or MTD device number
+ *        string
  * @vid_hdr_offs: VID header offset
+ * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
  */
-struct mtd_dev_param
-{
+struct mtd_dev_param {
 	char name[MTD_PARAM_LEN_MAX];
+	int ubi_num;
 	int vid_hdr_offs;
+	int max_beb_per1024;
 };
 
 /* Numbers of elements set in the @mtd_dev_param array */
-static int mtd_devs = 0;
+static int __initdata mtd_devs;
 
 /* MTD devices specification parameters */
-static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
-
+static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
+#ifndef __UBOOT__
+#ifdef CONFIG_MTD_UBI_FASTMAP
+/* UBI module parameter to enable fastmap automatically on non-fastmap images */
+static bool fm_autoconvert;
+#endif
+#else
+#ifdef CONFIG_MTD_UBI_FASTMAP
+#if !defined(CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT)
+#define CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 0
+#endif
+static bool fm_autoconvert = CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT;
+#endif
+#endif
 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
 struct class *ubi_class;
 
-#ifdef UBI_LINUX
 /* Slab cache for wear-leveling entries */
 struct kmem_cache *ubi_wl_entry_slab;
 
+#ifndef __UBOOT__
 /* UBI control character device */
 static struct miscdevice ubi_ctrl_cdev = {
 	.minor = MISC_DYNAMIC_MINOR,
@@ -74,9 +106,13 @@ static struct miscdevice ubi_ctrl_cdev = {
 #endif
 
 /* All UBI devices in system */
+#ifndef __UBOOT__
+static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+#else
 struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+#endif
 
-#ifdef UBI_LINUX
+#ifndef __UBOOT__
 /* Serializes UBI devices creations and removals */
 DEFINE_MUTEX(ubi_devices_mutex);
 
@@ -84,7 +120,8 @@ DEFINE_MUTEX(ubi_devices_mutex);
 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)
+static ssize_t ubi_version_show(struct class *class,
+				struct class_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%d\n", UBI_VERSION);
 }
@@ -122,6 +159,112 @@ static struct device_attribute dev_mtd_num =
 #endif
 
 /**
+ * ubi_volume_notify - send a volume change notification.
+ * @ubi: UBI device description object
+ * @vol: volume description object of the changed volume
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ *
+ * This is a helper function which notifies all subscribers about a volume
+ * change event (creation, removal, re-sizing, re-naming, updating). Returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
+{
+	struct ubi_notification nt;
+
+	ubi_do_get_device_info(ubi, &nt.di);
+	ubi_do_get_volume_info(ubi, vol, &nt.vi);
+
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	switch (ntype) {
+	case UBI_VOLUME_ADDED:
+	case UBI_VOLUME_REMOVED:
+	case UBI_VOLUME_RESIZED:
+	case UBI_VOLUME_RENAMED:
+		if (ubi_update_fastmap(ubi)) {
+			ubi_err("Unable to update fastmap!");
+			ubi_ro_mode(ubi);
+		}
+	}
+#endif
+	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
+}
+
+/**
+ * ubi_notify_all - send a notification to all volumes.
+ * @ubi: UBI device description object
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ * @nb: the notifier to call
+ *
+ * This function walks all volumes of UBI device @ubi and sends the @ntype
+ * notification for each volume. If @nb is %NULL, then all registered notifiers
+ * are called, otherwise only the @nb notifier is called. Returns the number of
+ * sent notifications.
+ */
+int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
+{
+	struct ubi_notification nt;
+	int i, count = 0;
+#ifndef __UBOOT__
+	int ret;
+#endif
+
+	ubi_do_get_device_info(ubi, &nt.di);
+
+	mutex_lock(&ubi->device_mutex);
+	for (i = 0; i < ubi->vtbl_slots; i++) {
+		/*
+		 * Since the @ubi->device is locked, and we are not going to
+		 * change @ubi->volumes, we do not have to lock
+		 * @ubi->volumes_lock.
+		 */
+		if (!ubi->volumes[i])
+			continue;
+
+		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
+#ifndef __UBOOT__
+		if (nb)
+			nb->notifier_call(nb, ntype, &nt);
+		else
+			ret = blocking_notifier_call_chain(&ubi_notifiers, ntype,
+						     &nt);
+#endif
+		count += 1;
+	}
+	mutex_unlock(&ubi->device_mutex);
+
+	return count;
+}
+
+/**
+ * ubi_enumerate_volumes - send "add" notification for all existing volumes.
+ * @nb: the notifier to call
+ *
+ * This function walks all UBI devices and volumes and sends the
+ * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
+ * registered notifiers are called, otherwise only the @nb notifier is called.
+ * Returns the number of sent notifications.
+ */
+int ubi_enumerate_volumes(struct notifier_block *nb)
+{
+	int i, count = 0;
+
+	/*
+	 * Since the @ubi_devices_mutex is locked, and we are not going to
+	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
+	 */
+	for (i = 0; i < UBI_MAX_DEVICES; i++) {
+		struct ubi_device *ubi = ubi_devices[i];
+
+		if (!ubi)
+			continue;
+		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
+	}
+
+	return count;
+}
+
+/**
  * ubi_get_device - get UBI device.
  * @ubi_num: UBI device number
  *
@@ -159,8 +302,7 @@ void ubi_put_device(struct ubi_device *ubi)
 }
 
 /**
- * ubi_get_by_major - get UBI device description object by character device
- *                    major number.
+ * ubi_get_by_major - get UBI device by character device major number.
  * @major: major number
  *
  * This function is similar to 'ubi_get_device()', but it searches the device
@@ -213,7 +355,7 @@ int ubi_major2num(int major)
 	return ubi_num;
 }
 
-#ifdef UBI_LINUX
+#ifndef __UBOOT__
 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
 static ssize_t dev_attribute_show(struct device *dev,
 				  struct device_attribute *attr, char *buf)
@@ -265,28 +407,35 @@ static ssize_t dev_attribute_show(struct device *dev,
 	return ret;
 }
 
-/* Fake "release" method for UBI devices */
-static void dev_release(struct device *dev) { }
+static void dev_release(struct device *dev)
+{
+	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
+
+	kfree(ubi);
+}
 
 /**
  * ubi_sysfs_init - initialize sysfs for an UBI device.
  * @ubi: UBI device description object
+ * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
+ *       taken
  *
  * 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)
+static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
 {
 	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);
+	dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
 	err = device_register(&ubi->dev);
 	if (err)
 		return err;
 
+	*ref = 1;
 	err = device_create_file(&ubi->dev, &dev_eraseblock_size);
 	if (err)
 		return err;
@@ -343,7 +492,7 @@ static void ubi_sysfs_close(struct ubi_device *ubi)
 #endif
 
 /**
- * kill_volumes - destroy all volumes.
+ * kill_volumes - destroy all user volumes.
  * @ubi: UBI device description object
  */
 static void kill_volumes(struct ubi_device *ubi)
@@ -358,17 +507,29 @@ static void kill_volumes(struct ubi_device *ubi)
 /**
  * uif_init - initialize user interfaces for an UBI device.
  * @ubi: UBI device description object
+ * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
+ *       taken, otherwise set to %0
+ *
+ * This function initializes various user interfaces for an UBI device. If the
+ * initialization fails at an early stage, this function frees all the
+ * resources it allocated, returns an error, and @ref is set to %0. However,
+ * if the initialization fails after the UBI device was registered in the
+ * driver core subsystem, this function takes a reference to @ubi->dev, because
+ * otherwise the release function ('dev_release()') would free whole @ubi
+ * object. The @ref argument is set to %1 in this case. The caller has to put
+ * this reference.
  *
  * 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)
+static int uif_init(struct ubi_device *ubi, int *ref)
 {
 	int i, err;
-#ifdef UBI_LINUX
+#ifndef __UBOOT__
 	dev_t dev;
 #endif
 
+	*ref = 0;
 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 
 	/*
@@ -387,7 +548,7 @@ static int uif_init(struct ubi_device *ubi)
 
 	ubi_assert(MINOR(dev) == 0);
 	cdev_init(&ubi->cdev, &ubi_cdev_operations);
-	dbg_msg("%s major is %u", ubi->ubi_name, MAJOR(dev));
+	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
 	ubi->cdev.owner = THIS_MODULE;
 
 	err = cdev_add(&ubi->cdev, dev, 1);
@@ -396,7 +557,7 @@ static int uif_init(struct ubi_device *ubi)
 		goto out_unreg;
 	}
 
-	err = ubi_sysfs_init(ubi);
+	err = ubi_sysfs_init(ubi, ref);
 	if (err)
 		goto out_sysfs;
 
@@ -414,6 +575,8 @@ static int uif_init(struct ubi_device *ubi)
 out_volumes:
 	kill_volumes(ubi);
 out_sysfs:
+	if (*ref)
+		get_device(&ubi->dev);
 	ubi_sysfs_close(ubi);
 	cdev_del(&ubi->cdev);
 out_unreg:
@@ -425,6 +588,10 @@ out_unreg:
 /**
  * uif_close - close user interfaces for an UBI device.
  * @ubi: UBI device description object
+ *
+ * Note, since this function un-registers UBI volume device objects (@vol->dev),
+ * the memory allocated voe the volumes is freed as well (in the release
+ * function).
  */
 static void uif_close(struct ubi_device *ubi)
 {
@@ -435,58 +602,52 @@ static void uif_close(struct ubi_device *ubi)
 }
 
 /**
- * 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.
+ * ubi_free_internal_volumes - free internal volumes.
+ * @ubi: UBI device description object
  */
-static int attach_by_scanning(struct ubi_device *ubi)
+void ubi_free_internal_volumes(struct ubi_device *ubi)
 {
-	int err;
-	struct ubi_scan_info *si;
+	int i;
 
-	si = ubi_scan(ubi);
-	if (IS_ERR(si))
-		return PTR_ERR(si);
+	for (i = ubi->vtbl_slots;
+	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
+		kfree(ubi->volumes[i]->eba_tbl);
+		kfree(ubi->volumes[i]);
+	}
+}
 
-	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;
+static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
+{
+	int limit, device_pebs;
+	uint64_t device_size;
 
-	err = ubi_read_volume_table(ubi, si);
-	if (err)
-		goto out_si;
+	if (!max_beb_per1024)
+		return 0;
 
-	err = ubi_eba_init_scan(ubi, si);
-	if (err)
-		goto out_vtbl;
+	/*
+	 * Here we are using size of the entire flash chip and
+	 * not just the MTD partition size because the maximum
+	 * number of bad eraseblocks is a percentage of the
+	 * whole device and bad eraseblocks are not fairly
+	 * distributed over the flash chip. So the worst case
+	 * is that all the bad eraseblocks of the chip are in
+	 * the MTD partition we are attaching (ubi->mtd).
+	 */
+	device_size = mtd_get_device_size(ubi->mtd);
+	device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
+	limit = mult_frac(device_pebs, max_beb_per1024, 1024);
 
-	err = ubi_wl_init_scan(ubi, si);
-	if (err)
-		goto out_eba;
+	/* Round it up */
+	if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
+		limit += 1;
 
-	ubi_scan_destroy_si(si);
-	return 0;
-
-out_eba:
-	ubi_eba_close(ubi);
-out_vtbl:
-	vfree(ubi->vtbl);
-out_si:
-	ubi_scan_destroy_si(si);
-	return err;
+	return limit;
 }
 
 /**
- * io_init - initialize I/O unit for a given UBI device.
+ * io_init - initialize I/O sub-system for a given UBI device.
  * @ubi: UBI device description object
+ * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
  *
  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
  * assumed:
@@ -499,8 +660,11 @@ out_si:
  * 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)
+static int io_init(struct ubi_device *ubi, int max_beb_per1024)
 {
+	dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
+	dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
+
 	if (ubi->mtd->numeraseregions != 0) {
 		/*
 		 * Some flashes have several erase regions. Different regions
@@ -527,8 +691,15 @@ static int io_init(struct ubi_device *ubi)
 	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
 	ubi->flash_size = ubi->mtd->size;
 
-	if (mtd_can_have_bb(ubi->mtd))
+	if (mtd_can_have_bb(ubi->mtd)) {
 		ubi->bad_allowed = 1;
+		ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
+	}
+
+	if (ubi->mtd->type == MTD_NORFLASH) {
+		ubi_assert(ubi->mtd->writesize == 1);
+		ubi->nor_flash = 1;
+	}
 
 	ubi->min_io_size = ubi->mtd->writesize;
 	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
@@ -548,14 +719,28 @@ static int io_init(struct ubi_device *ubi)
 	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
 	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
 
+	ubi->max_write_size = ubi->mtd->writebufsize;
+	/*
+	 * Maximum write size has to be greater or equivalent to min. I/O
+	 * size, and be multiple of min. I/O size.
+	 */
+	if (ubi->max_write_size < ubi->min_io_size ||
+	    ubi->max_write_size % ubi->min_io_size ||
+	    !is_power_of_2(ubi->max_write_size)) {
+		ubi_err("bad write buffer size %d for %d min. I/O unit",
+			ubi->max_write_size, ubi->min_io_size);
+		return -EINVAL;
+	}
+
 	/* 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);
+	dbg_gen("min_io_size      %d", ubi->min_io_size);
+	dbg_gen("max_write_size   %d", ubi->max_write_size);
+	dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
+	dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
+	dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
 
 	if (ubi->vid_hdr_offset == 0)
 		/* Default offset */
@@ -569,13 +754,13 @@ static int io_init(struct ubi_device *ubi)
 	}
 
 	/* Similar for the data offset */
-	ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
+	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_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);
+	dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
+	dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
+	dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
+	dbg_gen("leb_start        %d", ubi->leb_start);
 
 	/* The shift must be aligned to 32-bit boundary */
 	if (ubi->vid_hdr_shift % 4) {
@@ -595,41 +780,38 @@ static int io_init(struct ubi_device *ubi)
 	}
 
 	/*
+	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
+	 * Erroneous PEB are those which have read errors.
+	 */
+	ubi->max_erroneous = ubi->peb_count / 10;
+	if (ubi->max_erroneous < 16)
+		ubi->max_erroneous = 16;
+	dbg_gen("max_erroneous    %d", ubi->max_erroneous);
+
+	/*
 	 * 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_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_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
+	 * 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.
+	 * each physical eraseblock. So, we leave @ubi->bad_peb_count
+	 * uninitialized so far.
 	 */
 
 	return 0;
@@ -640,7 +822,7 @@ static int io_init(struct ubi_device *ubi)
  * @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
+ * 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.
@@ -651,9 +833,14 @@ static int autoresize(struct ubi_device *ubi, int vol_id)
 	struct ubi_volume *vol = ubi->volumes[vol_id];
 	int err, old_reserved_pebs = vol->reserved_pebs;
 
+	if (ubi->ro_mode) {
+		ubi_warn("skip auto-resize because of R/O mode");
+		return 0;
+	}
+
 	/*
 	 * Clear the auto-resize flag in the volume in-memory copy of the
-	 * volume table, and 'ubi_resize_volume()' will propogate this change
+	 * volume table, and 'ubi_resize_volume()' will propagate this change
 	 * to the flash.
 	 */
 	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
@@ -662,11 +849,10 @@ static int autoresize(struct ubi_device *ubi, int vol_id)
 		struct ubi_vtbl_record vtbl_rec;
 
 		/*
-		 * No avalilable PEBs to re-size the volume, clear the flag on
+		 * No available 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));
+		vtbl_rec = ubi->vtbl[vol_id];
 		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 		if (err)
 			ubi_err("cannot clean auto-resize flag for volume %d",
@@ -689,23 +875,31 @@ static int autoresize(struct ubi_device *ubi, int vol_id)
 
 /**
  * ubi_attach_mtd_dev - attach an MTD device.
- * @mtd_dev: MTD device description object
+ * @mtd: MTD device description object
  * @ubi_num: number to assign to the new UBI device
  * @vid_hdr_offset: VID header offset
+ * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
  *
  * 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
+ * which case this function finds a vacant device number and assigns 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)
+int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
+		       int vid_hdr_offset, int max_beb_per1024)
 {
 	struct ubi_device *ubi;
-	int i, err;
+	int i, err, ref = 0;
+
+	if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
+		return -EINVAL;
+
+	if (!max_beb_per1024)
+		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
 
 	/*
 	 * Check if we already have the same MTD device attached.
@@ -716,7 +910,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	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",
+			ubi_err("mtd%d is already attached to ubi%d",
 				mtd->index, i);
 			return -EEXIST;
 		}
@@ -731,8 +925,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	 * 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);
+		ubi_err("refuse attaching mtd%d - it is already emulated on top of UBI",
+			mtd->index);
 		return -EINVAL;
 	}
 
@@ -742,7 +936,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 			if (!ubi_devices[ubi_num])
 				break;
 		if (ubi_num == UBI_MAX_DEVICES) {
-			dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES);
+			ubi_err("only %d UBI devices may be created",
+				UBI_MAX_DEVICES);
 			return -ENFILE;
 		}
 	} else {
@@ -751,7 +946,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 
 		/* Make sure ubi_num is not busy */
 		if (ubi_devices[ubi_num]) {
-			dbg_err("ubi%d already exists", ubi_num);
+			ubi_err("ubi%d already exists", ubi_num);
 			return -EEXIST;
 		}
 	}
@@ -765,36 +960,61 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 	ubi->vid_hdr_offset = vid_hdr_offset;
 	ubi->autoresize_vol_id = -1;
 
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	ubi->fm_pool.used = ubi->fm_pool.size = 0;
+	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
+
+	/*
+	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
+	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
+	 */
+	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
+		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
+	if (ubi->fm_pool.max_size < UBI_FM_MIN_POOL_SIZE)
+		ubi->fm_pool.max_size = UBI_FM_MIN_POOL_SIZE;
+
+	ubi->fm_wl_pool.max_size = UBI_FM_WL_POOL_SIZE;
+	ubi->fm_disabled = !fm_autoconvert;
+
+	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
+	    <= UBI_FM_MAX_START) {
+		ubi_err("More than %i PEBs are needed for fastmap, sorry.",
+			UBI_FM_MAX_START);
+		ubi->fm_disabled = 1;
+	}
+
+	ubi_msg("default fastmap pool size: %d", ubi->fm_pool.max_size);
+	ubi_msg("default fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
+#else
+	ubi->fm_disabled = 1;
+#endif
 	mutex_init(&ubi->buf_mutex);
 	mutex_init(&ubi->ckvol_mutex);
-	mutex_init(&ubi->volumes_mutex);
+	mutex_init(&ubi->device_mutex);
 	spin_lock_init(&ubi->volumes_lock);
+	mutex_init(&ubi->fm_mutex);
+	init_rwsem(&ubi->fm_sem);
 
 	ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
 
-	err = io_init(ubi);
+	err = io_init(ubi, max_beb_per1024);
 	if (err)
 		goto out_free;
 
 	err = -ENOMEM;
-	ubi->peb_buf1 = vmalloc(ubi->peb_size);
-	if (!ubi->peb_buf1)
+	ubi->peb_buf = vmalloc(ubi->peb_size);
+	if (!ubi->peb_buf)
 		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)
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	ubi->fm_size = ubi_calc_fm_size(ubi);
+	ubi->fm_buf = vzalloc(ubi->fm_size);
+	if (!ubi->fm_buf)
 		goto out_free;
 #endif
-
-	err = attach_by_scanning(ubi);
+	err = ubi_attach(ubi, 0);
 	if (err) {
-		dbg_err("failed to attach by scanning, error %d", err);
+		ubi_err("failed to attach mtd%d, error %d", mtd->index, err);
 		goto out_free;
 	}
 
@@ -804,56 +1024,71 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 			goto out_detach;
 	}
 
-	err = uif_init(ubi);
+	err = uif_init(ubi, &ref);
 	if (err)
 		goto out_detach;
 
-	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
+	err = ubi_debugfs_init_dev(ubi);
+	if (err)
+		goto out_uif;
+
+	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", 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;
+		goto out_debugfs;
 	}
 
-	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_msg("attached mtd%d (name \"%s\", size %llu MiB) to ubi%d",
+		mtd->index, mtd->name, ubi->flash_size >> 20, ubi_num);
+	ubi_msg("PEB size: %d bytes (%d KiB), LEB size: %d bytes",
+		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
+	ubi_msg("min./max. I/O unit sizes: %d/%d, sub-page size %d",
+		ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
+	ubi_msg("VID header offset: %d (aligned %d), data offset: %d",
+		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
+	ubi_msg("good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
+		ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
+	ubi_msg("user volume: %d, internal volumes: %d, max. volumes count: %d",
+		ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
+		ubi->vtbl_slots);
+	ubi_msg("max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
+		ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
+		ubi->image_seq);
+	ubi_msg("available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
+		ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
+
+	/*
+	 * The below lock makes sure we do not race with 'ubi_thread()' which
+	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
+	 */
+	spin_lock(&ubi->wl_lock);
+	ubi->thread_enabled = 1;
+	wake_up_process(ubi->bgt_thread);
+	spin_unlock(&ubi->wl_lock);
 
 	ubi_devices[ubi_num] = ubi;
+	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
 	return ubi_num;
 
+out_debugfs:
+	ubi_debugfs_exit_dev(ubi);
 out_uif:
+	get_device(&ubi->dev);
+	ubi_assert(ref);
 	uif_close(ubi);
 out_detach:
-	ubi_eba_close(ubi);
 	ubi_wl_close(ubi);
+	ubi_free_internal_volumes(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);
+	vfree(ubi->peb_buf);
+	vfree(ubi->fm_buf);
+	if (ref)
+		put_device(&ubi->dev);
+	else
+		kfree(ubi);
 	return err;
 }
 
@@ -877,13 +1112,13 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	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);
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
 		return -EINVAL;
-	}
 
+	spin_lock(&ubi_devices_lock);
+	put_device(&ubi->dev);
+	ubi->ref_count -= 1;
 	if (ubi->ref_count) {
 		if (!anyway) {
 			spin_unlock(&ubi_devices_lock);
@@ -897,8 +1132,13 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	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);
-
+	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
+	ubi_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
+#ifdef CONFIG_MTD_UBI_FASTMAP
+	/* If we don't write a new fastmap at detach time we lose all
+	 * EC updates that have been made since the last written fastmap. */
+	ubi_update_fastmap(ubi);
+#endif
 	/*
 	 * Before freeing anything, we have to stop the background thread to
 	 * prevent it from doing anything on this device while we are freeing.
@@ -906,29 +1146,73 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	if (ubi->bgt_thread)
 		kthread_stop(ubi->bgt_thread);
 
+	/*
+	 * Get a reference to the device in order to prevent 'dev_release()'
+	 * from freeing the @ubi object.
+	 */
+	get_device(&ubi->dev);
+
+	ubi_debugfs_exit_dev(ubi);
 	uif_close(ubi);
-	ubi_eba_close(ubi);
+
 	ubi_wl_close(ubi);
+	ubi_free_internal_volumes(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
+	vfree(ubi->peb_buf);
+	vfree(ubi->fm_buf);
 	ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
-	kfree(ubi);
+	put_device(&ubi->dev);
 	return 0;
 }
 
+#ifndef __UBOOT__
 /**
- * find_mtd_device - open an MTD device by its name or number.
- * @mtd_dev: name or number of the device
+ * open_mtd_by_chdev - open an MTD device by its character device node path.
+ * @mtd_dev: MTD character device node path
+ *
+ * This helper function opens an MTD device by its character node device path.
+ * 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_by_chdev(const char *mtd_dev)
+{
+	int err, major, minor, mode;
+	struct path path;
+
+	/* Probably this is an MTD character device node path */
+	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
+	if (err)
+		return ERR_PTR(err);
+
+	/* MTD device number is defined by the major / minor numbers */
+	major = imajor(path.dentry->d_inode);
+	minor = iminor(path.dentry->d_inode);
+	mode = path.dentry->d_inode->i_mode;
+	path_put(&path);
+	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
+		return ERR_PTR(-EINVAL);
+
+	if (minor & 1)
+		/*
+		 * Just do not think the "/dev/mtdrX" devices support is need,
+		 * so do not support them to avoid doing extra work.
+		 */
+		return ERR_PTR(-EINVAL);
+
+	return get_mtd_device(NULL, minor / 2);
+}
+#endif
+
+/**
+ * open_mtd_device - open MTD device by name, character device path, or number.
+ * @mtd_dev: name, character device node path, or MTD device device number
  *
  * 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.
+ * which is first treated as ASCII MTD device number, and if it is not true, it
+ * is treated as MTD device name, and if that is also not true, it is treated
+ * as MTD character device node path. 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)
 {
@@ -943,13 +1227,22 @@ static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
 		 * MTD device name.
 		 */
 		mtd = get_mtd_device_nm(mtd_dev);
+#ifndef __UBOOT__
+		if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
+			/* Probably this is an MTD character device node path */
+			mtd = open_mtd_by_chdev(mtd_dev);
+#endif
 	} else
 		mtd = get_mtd_device(NULL, mtd_num);
 
 	return mtd;
 }
 
-int __init ubi_init(void)
+#ifndef __UBOOT__
+static int __init ubi_init(void)
+#else
+int ubi_init(void)
+#endif
 {
 	int err, i, k;
 
@@ -982,13 +1275,18 @@ int __init ubi_init(void)
 		goto out_version;
 	}
 
-#ifdef UBI_LINUX
 	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
 					      sizeof(struct ubi_wl_entry),
 					      0, 0, NULL);
-	if (!ubi_wl_entry_slab)
+	if (!ubi_wl_entry_slab) {
+		err = -ENOMEM;
 		goto out_dev_unreg;
-#endif
+	}
+
+	err = ubi_debugfs_init();
+	if (err)
+		goto out_slab;
+
 
 	/* Attach MTD devices */
 	for (i = 0; i < mtd_devs; i++) {
@@ -1000,17 +1298,36 @@ int __init ubi_init(void)
 		mtd = open_mtd_device(p->name);
 		if (IS_ERR(mtd)) {
 			err = PTR_ERR(mtd);
-			goto out_detach;
+			ubi_err("cannot open mtd %s, error %d", p->name, err);
+			/* See comment below re-ubi_is_module(). */
+			if (ubi_is_module())
+				goto out_detach;
+			continue;
 		}
 
 		mutex_lock(&ubi_devices_mutex);
-		err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
-					 p->vid_hdr_offs);
+		err = ubi_attach_mtd_dev(mtd, p->ubi_num,
+					 p->vid_hdr_offs, p->max_beb_per1024);
 		mutex_unlock(&ubi_devices_mutex);
 		if (err < 0) {
-			put_mtd_device(mtd);
 			ubi_err("cannot attach mtd%d", mtd->index);
-			goto out_detach;
+			put_mtd_device(mtd);
+
+			/*
+			 * Originally UBI stopped initializing on any error.
+			 * However, later on it was found out that this
+			 * behavior is not very good when UBI is compiled into
+			 * the kernel and the MTD devices to attach are passed
+			 * through the command line. Indeed, UBI failure
+			 * stopped whole boot sequence.
+			 *
+			 * To fix this, we changed the behavior for the
+			 * non-module case, but preserved the old behavior for
+			 * the module case, just for compatibility. This is a
+			 * little inconsistent, though.
+			 */
+			if (ubi_is_module())
+				goto out_detach;
 		}
 	}
 
@@ -1023,23 +1340,26 @@ out_detach:
 			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
 			mutex_unlock(&ubi_devices_mutex);
 		}
-#ifdef UBI_LINUX
+	ubi_debugfs_exit();
+out_slab:
 	kmem_cache_destroy(ubi_wl_entry_slab);
 out_dev_unreg:
-#endif
 	misc_deregister(&ubi_ctrl_cdev);
 out_version:
 	class_remove_file(ubi_class, &ubi_version);
 out_class:
 	class_destroy(ubi_class);
 out:
-	mtd_devs = 0;
-	ubi_err("UBI error: cannot initialize UBI, error %d", err);
+	ubi_err("cannot initialize UBI, error %d", err);
 	return err;
 }
-module_init(ubi_init);
+late_initcall(ubi_init);
 
-void __exit ubi_exit(void)
+#ifndef __UBOOT__
+static void __exit ubi_exit(void)
+#else
+void ubi_exit(void)
+#endif
 {
 	int i;
 
@@ -1049,17 +1369,16 @@ void __exit ubi_exit(void)
 			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
 			mutex_unlock(&ubi_devices_mutex);
 		}
+	ubi_debugfs_exit();
 	kmem_cache_destroy(ubi_wl_entry_slab);
 	misc_deregister(&ubi_ctrl_cdev);
 	class_remove_file(ubi_class, &ubi_version);
 	class_destroy(ubi_class);
-	mtd_devs = 0;
 }
 module_exit(ubi_exit);
 
 /**
- * bytes_str_to_int - convert a string representing number of bytes to an
- * integer.
+ * bytes_str_to_int - convert a number of bytes string into an integer.
  * @str: the string to convert
  *
  * This function returns positive resulting integer in case of success and a
@@ -1071,9 +1390,8 @@ static int __init bytes_str_to_int(const char *str)
 	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);
+	if (str == endp || result >= INT_MAX) {
+		ubi_err("incorrect bytes count: \"%s\"\n", str);
 		return -EINVAL;
 	}
 
@@ -1089,14 +1407,24 @@ static int __init bytes_str_to_int(const char *str)
 	case '\0':
 		break;
 	default:
-		printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
-		       str);
+		ubi_err("incorrect bytes count: \"%s\"\n", str);
 		return -EINVAL;
 	}
 
 	return result;
 }
 
+int kstrtoint(const char *s, unsigned int base, int *res)
+{
+	unsigned long long tmp;
+
+	tmp = simple_strtoull(s, NULL, base);
+	if (tmp != (unsigned long long)(int)tmp)
+		return -ERANGE;
+
+	return (int)tmp;
+}
+
 /**
  * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
  * @val: the parameter value to parse
@@ -1105,33 +1433,36 @@ static int __init bytes_str_to_int(const char *str)
  * 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)
+#ifndef __UBOOT__
+static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
+#else
+int ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
+#endif
 {
 	int i, len;
 	struct mtd_dev_param *p;
 	char buf[MTD_PARAM_LEN_MAX];
 	char *pbuf = &buf[0];
-	char *tokens[2] = {NULL, NULL};
+	char *tokens[MTD_PARAM_MAX_COUNT], *token;
 
 	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);
+		ubi_err("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);
+		ubi_err("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");
+		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
 		return 0;
 	}
 
@@ -1141,40 +1472,69 @@ int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
 	if (buf[len - 1] == '\n')
 		buf[len - 1] = '\0';
 
-	for (i = 0; i < 2; i++)
+	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
 		tokens[i] = strsep(&pbuf, ",");
 
 	if (pbuf) {
-		printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
-		       val);
+		ubi_err("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]);
+	token = tokens[1];
+	if (token) {
+		p->vid_hdr_offs = bytes_str_to_int(token);
+
+		if (p->vid_hdr_offs < 0)
+			return p->vid_hdr_offs;
+	}
 
-	if (p->vid_hdr_offs < 0)
-		return p->vid_hdr_offs;
+	token = tokens[2];
+	if (token) {
+		int err = kstrtoint(token, 10, &p->max_beb_per1024);
+
+		if (err) {
+			ubi_err("bad value for max_beb_per1024 parameter: %s",
+				token);
+			return -EINVAL;
+		}
+	}
+
+	token = tokens[3];
+	if (token) {
+		int err = kstrtoint(token, 10, &p->ubi_num);
+
+		if (err) {
+			ubi_err("bad value for ubi_num parameter: %s", token);
+			return -EINVAL;
+		}
+	} else
+		p->ubi_num = UBI_DEV_NUM_AUTO;
 
 	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"
+MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\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.");
-
+		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
+		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
+		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
+		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
+		      "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
+		      "\n"
+		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
+		      "Example 2: 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.\n"
+		      "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
+		      "Example 4: mtd=/dev/mtd1,0,0,5 - attach MTD device /dev/mtd1 to UBI 5 and using default values for the other fields.\n"
+		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
+#ifdef CONFIG_MTD_UBI_FASTMAP
+module_param(fm_autoconvert, bool, 0644);
+MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
+#endif
 MODULE_VERSION(__stringify(UBI_VERSION));
 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
 MODULE_AUTHOR("Artem Bityutskiy");