--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -29,6 +29,8 @@ struct block2mtd_dev {
 	struct block_device *blkdev;
 	struct mtd_info mtd;
 	struct mutex write_mutex;
+	rwlock_t bdev_mutex;
+	char devname[0];
 };
 
 
@@ -81,6 +83,12 @@ static int block2mtd_erase(struct mtd_in
 	size_t len = instr->len;
 	int err;
 
+	read_lock(&dev->bdev_mutex);
+	if (!dev->blkdev) {
+		err = -EINVAL;
+		goto done;
+	}
+
 	instr->state = MTD_ERASING;
 	mutex_lock(&dev->write_mutex);
 	err = _block2mtd_erase(dev, from, len);
@@ -92,6 +100,10 @@ static int block2mtd_erase(struct mtd_in
 		instr->state = MTD_ERASE_DONE;
 
 	mtd_erase_callback(instr);
+
+done:
+	read_unlock(&dev->bdev_mutex);
+
 	return err;
 }
 
@@ -103,7 +115,19 @@ static int block2mtd_read(struct mtd_inf
 	struct page *page;
 	int index = from >> PAGE_SHIFT;
 	int offset = from & (PAGE_SIZE-1);
-	int cpylen;
+	int cpylen, err = 0;
+
+	read_lock(&dev->bdev_mutex);
+	if (!dev->blkdev || (from > mtd->size)) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	if (from + len > mtd->size)
+		len = mtd->size - from;
+
+	if (retlen)
+		*retlen = 0;
 
 	while (len) {
 		if ((offset + len) > PAGE_SIZE)
@@ -113,10 +137,14 @@ static int block2mtd_read(struct mtd_inf
 		len = len - cpylen;
 
 		page = page_read(dev->blkdev->bd_inode->i_mapping, index);
-		if (!page)
-			return -ENOMEM;
-		if (IS_ERR(page))
-			return PTR_ERR(page);
+		if (!page) {
+			err = -ENOMEM;
+			goto done;
+		}
+		if (IS_ERR(page)) {
+			err = PTR_ERR(page);
+			goto done;
+		}
 
 		memcpy(buf, page_address(page) + offset, cpylen);
 		page_cache_release(page);
@@ -127,7 +155,10 @@ static int block2mtd_read(struct mtd_inf
 		offset = 0;
 		index++;
 	}
-	return 0;
+
+done:
+	read_unlock(&dev->bdev_mutex);
+	return err;
 }
 
 
@@ -177,13 +208,33 @@ static int block2mtd_write(struct mtd_in
 		size_t *retlen, const u_char *buf)
 {
 	struct block2mtd_dev *dev = mtd->priv;
-	int err;
+	int err = 0;
+
+	read_lock(&dev->bdev_mutex);
+	if (!dev->blkdev) {
+		err = -EINVAL;
+		goto done;
+	}
+
+	if (!len)
+		goto done;
+
+	if (to >= mtd->size) {
+		err = -ENOSPC;
+		goto done;
+	}
+
+	if (to + len > mtd->size)
+		len = mtd->size - to;
 
 	mutex_lock(&dev->write_mutex);
 	err = _block2mtd_write(dev, buf, to, len, retlen);
 	mutex_unlock(&dev->write_mutex);
 	if (err > 0)
 		err = 0;
+
+done:
+	read_unlock(&dev->bdev_mutex);
 	return err;
 }
 
@@ -226,36 +277,17 @@ static struct block2mtd_dev *add_device(
 	if (!devname)
 		return NULL;
 
-	dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+	dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
 	if (!dev)
 		return NULL;
 
-	/* Get a handle on the device */
-	bdev = blkdev_get_by_path(devname, mode, dev);
-#ifndef MODULE
-	if (IS_ERR(bdev)) {
-
-		/* We might not have rootfs mounted at this point. Try
-		   to resolve the device name by other means. */
-
-		dev_t devt = name_to_dev_t(devname);
-		if (devt)
-			bdev = blkdev_get_by_dev(devt, mode, dev);
-	}
-#endif
+	strcpy(dev->devname, devname);
 
-	if (IS_ERR(bdev)) {
-		ERROR("error: cannot open device %s", devname);
+	if (_open_bdev(dev))
 		goto devinit_err;
-	}
-	dev->blkdev = bdev;
-
-	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
-		ERROR("attempting to use an MTD device as a block device");
-		goto devinit_err;
-	}
 
 	mutex_init(&dev->write_mutex);
+	rwlock_init(&dev->bdev_mutex);
 
 	/* Setup the MTD structure */
 	/* make the name contain the block device in */
@@ -281,6 +313,7 @@ static struct block2mtd_dev *add_device(
 	dev->mtd._read = block2mtd_read;
 	dev->mtd.priv = dev;
 	dev->mtd.owner = THIS_MODULE;
+	dev->mtd.refresh_device = block2mtd_refresh;
 
 	if (mtd_device_register(&dev->mtd, NULL, 0)) {
 		/* Device didn't get added, so free the entry */