diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index e6d9384..31e4289 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -70,14 +70,14 @@
 			/* Entire transaction goes into this subdev */
 			size = len;
 
-		err = subdev->read(subdev, from, size, &retsize, buf);
+		err = mtd_read(subdev, from, size, &retsize, buf);
 
 		/* Save information about bitflips! */
 		if (unlikely(err)) {
-			if (err == -EBADMSG) {
+			if (mtd_is_eccerr(err)) {
 				mtd->ecc_stats.failed++;
 				ret = err;
-			} else if (err == -EUCLEAN) {
+			} else if (mtd_is_bitflip(err)) {
 				mtd->ecc_stats.corrected++;
 				/* Do not overwrite -EBADMSG !! */
 				if (!ret)
@@ -105,9 +105,6 @@
 	int err = -EINVAL;
 	int i;
 
-	if (!(mtd->flags & MTD_WRITEABLE))
-		return -EROFS;
-
 	*retlen = 0;
 
 	for (i = 0; i < concat->num_subdev; i++) {
@@ -124,11 +121,7 @@
 		else
 			size = len;
 
-		if (!(subdev->flags & MTD_WRITEABLE))
-			err = -EROFS;
-		else
-			err = subdev->write(subdev, to, size, &retsize, buf);
-
+		err = mtd_write(subdev, to, size, &retsize, buf);
 		if (err)
 			break;
 
@@ -165,16 +158,16 @@
 		if (from + devops.len > subdev->size)
 			devops.len = subdev->size - from;
 
-		err = subdev->read_oob(subdev, from, &devops);
+		err = mtd_read_oob(subdev, from, &devops);
 		ops->retlen += devops.retlen;
 		ops->oobretlen += devops.oobretlen;
 
 		/* Save information about bitflips! */
 		if (unlikely(err)) {
-			if (err == -EBADMSG) {
+			if (mtd_is_eccerr(err)) {
 				mtd->ecc_stats.failed++;
 				ret = err;
-			} else if (err == -EUCLEAN) {
+			} else if (mtd_is_bitflip(err)) {
 				mtd->ecc_stats.corrected++;
 				/* Do not overwrite -EBADMSG !! */
 				if (!ret)
@@ -225,7 +218,7 @@
 		if (to + devops.len > subdev->size)
 			devops.len = subdev->size - to;
 
-		err = subdev->write_oob(subdev, to, &devops);
+		err = mtd_write_oob(subdev, to, &devops);
 		ops->retlen += devops.retlen;
 		if (err)
 			return err;
@@ -271,7 +264,7 @@
 	 * FIXME: Allow INTERRUPTIBLE. Which means
 	 * not having the wait_queue head on the stack.
 	 */
-	err = mtd->erase(mtd, erase);
+	err = mtd_erase(mtd, erase);
 	if (!err) {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		add_wait_queue(&waitq, &wait);
@@ -294,15 +287,6 @@
 	uint64_t length, offset = 0;
 	struct erase_info *erase;
 
-	if (!(mtd->flags & MTD_WRITEABLE))
-		return -EROFS;
-
-	if (instr->addr > concat->mtd.size)
-		return -EINVAL;
-
-	if (instr->len + instr->addr > concat->mtd.size)
-		return -EINVAL;
-
 	/*
 	 * Check for proper erase block alignment of the to-be-erased area.
 	 * It is easier to do this based on the super device's erase
@@ -350,8 +334,6 @@
 			return -EINVAL;
 	}
 
-	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
-
 	/* make a local copy of instr to avoid modifying the caller's struct */
 	erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
 
@@ -390,10 +372,6 @@
 		else
 			erase->len = length;
 
-		if (!(subdev->flags & MTD_WRITEABLE)) {
-			err = -EROFS;
-			break;
-		}
 		length -= erase->len;
 		if ((err = concat_dev_erase(subdev, erase))) {
 			/* sanity check: should never happen since
@@ -429,9 +407,6 @@
 	struct mtd_concat *concat = CONCAT(mtd);
 	int i, err = -EINVAL;
 
-	if ((len + ofs) > mtd->size)
-		return -EINVAL;
-
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
 		uint64_t size;
@@ -446,7 +421,7 @@
 		else
 			size = len;
 
-		err = subdev->lock(subdev, ofs, size);
+		err = mtd_lock(subdev, ofs, size);
 
 		if (err)
 			break;
@@ -467,9 +442,6 @@
 	struct mtd_concat *concat = CONCAT(mtd);
 	int i, err = 0;
 
-	if ((len + ofs) > mtd->size)
-		return -EINVAL;
-
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
 		uint64_t size;
@@ -484,7 +456,7 @@
 		else
 			size = len;
 
-		err = subdev->unlock(subdev, ofs, size);
+		err = mtd_unlock(subdev, ofs, size);
 
 		if (err)
 			break;
@@ -507,7 +479,7 @@
 
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
-		subdev->sync(subdev);
+		mtd_sync(subdev);
 	}
 }
 
@@ -516,12 +488,9 @@
 	struct mtd_concat *concat = CONCAT(mtd);
 	int i, res = 0;
 
-	if (!concat->subdev[0]->block_isbad)
+	if (!mtd_can_have_bb(concat->subdev[0]))
 		return res;
 
-	if (ofs > mtd->size)
-		return -EINVAL;
-
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
 
@@ -530,7 +499,7 @@
 			continue;
 		}
 
-		res = subdev->block_isbad(subdev, ofs);
+		res = mtd_block_isbad(subdev, ofs);
 		break;
 	}
 
@@ -542,12 +511,9 @@
 	struct mtd_concat *concat = CONCAT(mtd);
 	int i, err = -EINVAL;
 
-	if (!concat->subdev[0]->block_markbad)
+	if (!mtd_can_have_bb(concat->subdev[0]))
 		return 0;
 
-	if (ofs > mtd->size)
-		return -EINVAL;
-
 	for (i = 0; i < concat->num_subdev; i++) {
 		struct mtd_info *subdev = concat->subdev[i];
 
@@ -556,7 +522,7 @@
 			continue;
 		}
 
-		err = subdev->block_markbad(subdev, ofs);
+		err = mtd_block_markbad(subdev, ofs);
 		if (!err)
 			mtd->ecc_stats.badblocks++;
 		break;
@@ -609,14 +575,14 @@
 	concat->mtd.subpage_sft = subdev[0]->subpage_sft;
 	concat->mtd.oobsize = subdev[0]->oobsize;
 	concat->mtd.oobavail = subdev[0]->oobavail;
-	if (subdev[0]->read_oob)
-		concat->mtd.read_oob = concat_read_oob;
-	if (subdev[0]->write_oob)
-		concat->mtd.write_oob = concat_write_oob;
-	if (subdev[0]->block_isbad)
-		concat->mtd.block_isbad = concat_block_isbad;
-	if (subdev[0]->block_markbad)
-		concat->mtd.block_markbad = concat_block_markbad;
+	if (subdev[0]->_read_oob)
+		concat->mtd._read_oob = concat_read_oob;
+	if (subdev[0]->_write_oob)
+		concat->mtd._write_oob = concat_write_oob;
+	if (subdev[0]->_block_isbad)
+		concat->mtd._block_isbad = concat_block_isbad;
+	if (subdev[0]->_block_markbad)
+		concat->mtd._block_markbad = concat_block_markbad;
 
 	concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
 
@@ -653,8 +619,8 @@
 		if (concat->mtd.writesize   !=  subdev[i]->writesize ||
 		    concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
 		    concat->mtd.oobsize    !=  subdev[i]->oobsize ||
-		    !concat->mtd.read_oob  != !subdev[i]->read_oob ||
-		    !concat->mtd.write_oob != !subdev[i]->write_oob) {
+		    !concat->mtd._read_oob  != !subdev[i]->_read_oob ||
+		    !concat->mtd._write_oob != !subdev[i]->_write_oob) {
 			kfree(concat);
 			printk("Incompatible OOB or ECC data on \"%s\"\n",
 			       subdev[i]->name);
@@ -669,12 +635,12 @@
 	concat->num_subdev = num_devs;
 	concat->mtd.name = name;
 
-	concat->mtd.erase = concat_erase;
-	concat->mtd.read = concat_read;
-	concat->mtd.write = concat_write;
-	concat->mtd.sync = concat_sync;
-	concat->mtd.lock = concat_lock;
-	concat->mtd.unlock = concat_unlock;
+	concat->mtd._erase = concat_erase;
+	concat->mtd._read = concat_read;
+	concat->mtd._write = concat_write;
+	concat->mtd._sync = concat_sync;
+	concat->mtd._lock = concat_lock;
+	concat->mtd._unlock = concat_unlock;
 
 	/*
 	 * Combine the erase block size info of the subdevices: