--- a/Kconfig
+++ b/Kconfig
@@ -31,9 +31,25 @@ config YAFFS_YAFFS1
 
 	  If unsure, say Y.
 
+config YAFFS_9BYTE_TAGS
+	bool "Use older-style on-NAND data format with pageStatus byte"
+	depends on YAFFS_YAFFS1
+	default n
+	help
+
+	  Older-style on-NAND data format has a "pageStatus" byte to record
+	  chunk/page state.  This byte is zero when the page is discarded.
+	  Choose this option if you have existing on-NAND data using this
+	  format that you need to continue to support.  New data written
+	  also uses the older-style format.  Note: Use of this option
+	  generally requires that MTD's oob layout be adjusted to use the
+	  older-style format.  See notes on tags formats and MTD versions.
+
+	  If unsure, say N.
+
 config YAFFS_DOES_ECC
 	bool "Lets Yaffs do its own ECC"
-	depends on YAFFS_FS && YAFFS_YAFFS1
+	depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
 	default n
 	help
 	  This enables Yaffs to use its own ECC functions instead of using
@@ -43,7 +59,7 @@ config YAFFS_DOES_ECC
 
 config YAFFS_ECC_WRONG_ORDER
 	bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
-	depends on YAFFS_FS && YAFFS_DOES_ECC
+	depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
 	default n
 	help
 	  This makes yaffs_ecc.c use the same ecc byte order as Steven

--- a/Makefile
+++ b/Makefile
@@ -19,6 +19,7 @@ ifneq ($(KERNELRELEASE),)
 	obj-m := yaffs2.o
 
 	yaffs2-objs := yaffs_mtdif.o yaffs_mtdif2.o
+	yaffs2-objs += yaffs_mtdif1.o yaffs_packedtags1.o
 	yaffs2-objs += yaffs_ecc.o yaffs_fs.o yaffs_guts.o
 	yaffs2-objs += yaffs_packedtags2.o yaffs_qsort.o
 	yaffs2-objs += yaffs_tagscompat.o yaffs_tagsvalidity.o

--- a/direct/yaffsfs.c
+++ b/direct/yaffsfs.c
@@ -38,6 +38,9 @@ static void yaffsfs_RemoveObjectCallback
 // Handle management.
 // 
 
+
+unsigned int yaffs_wr_attempts;
+
 typedef struct
 {
 	__u8  inUse:1;		// this handle is in use

--- a/moduleconfig.h
+++ b/moduleconfig.h
@@ -44,7 +44,21 @@
 
 /* Default: 10 */
 /* Meaning: set the count of blocks to reserve for checkpointing */
-#define YAFFS_CHECKPOINT_RESERVED_BLOCKS 10
+#define CONFIG_YAFFS_CHECKPOINT_RESERVED_BLOCKS 10
+
+/*
+Older-style on-NAND data format has a "pageStatus" byte to record
+chunk/page state.  This byte is zeroed when the page is discarded.
+Choose this option if you have existing on-NAND data in this format
+that you need to continue to support.  New data written also uses the
+older-style format.
+Note: Use of this option generally requires that MTD's oob layout be
+adjusted to use the older-style format.  See notes on tags formats and
+MTD versions.
+*/
+/* Default: Not selected */
+/* Meaning: Use older-style on-NAND data format with pageStatus byte */
+#define CONFIG_YAFFS_9BYTE_TAGS
 
 #endif /* YAFFS_OUT_OF_TREE */
 

--- a/yaffs_fs.c
+++ b/yaffs_fs.c
@@ -89,13 +89,23 @@ extern const char *yaffs_guts_c_version;
 #include "yportenv.h"
 #include "yaffs_guts.h"
 
-unsigned yaffs_traceMask = YAFFS_TRACE_BAD_BLOCKS
-			   /* | 0xFFFFFFFF */; 
-
 #include <linux/mtd/mtd.h>
 #include "yaffs_mtdif.h"
+#include "yaffs_mtdif1.h"
 #include "yaffs_mtdif2.h"
 
+unsigned int yaffs_traceMask = YAFFS_TRACE_BAD_BLOCKS;
+unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
+
+/* Module Parameters */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+module_param(yaffs_traceMask,uint,0644);
+module_param(yaffs_wr_attempts,uint,0644);
+#else
+MODULE_PARM(yaffs_traceMask,"i");
+MODULE_PARM(yaffs_wr_attempts,"i");
+#endif
+
 /*#define T(x) printk x */
 
 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18))
@@ -1778,8 +1788,18 @@ static struct super_block *yaffs_interna
 		dev->startBlock = 0;
 		dev->endBlock = nBlocks - 1;
 	} else {
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+		/* use the MTD interface in yaffs_mtdif1.c */
+		dev->writeChunkWithTagsToNAND =
+			nandmtd1_WriteChunkWithTagsToNAND;
+		dev->readChunkWithTagsFromNAND =
+			nandmtd1_ReadChunkWithTagsFromNAND;
+		dev->markNANDBlockBad = nandmtd1_MarkNANDBlockBad;
+		dev->queryNANDBlock = nandmtd1_QueryNANDBlock;
+#else
 		dev->writeChunkToNAND = nandmtd_WriteChunkToNAND;
 		dev->readChunkFromNAND = nandmtd_ReadChunkFromNAND;
+#endif
 		dev->isYaffs2 = 0;
 	}
 	/* ... and common functions */

--- a/yaffs_guts.c
+++ b/yaffs_guts.c
@@ -920,86 +920,88 @@ static int yaffs_WriteNewChunkWithTagsTo
 					     yaffs_ExtendedTags * tags,
 					     int useReserve)
 {
-	int chunk;
-
+	int attempts = 0;
 	int writeOk = 0;
-	int erasedOk = 1;
-	int attempts = 0;
-	yaffs_BlockInfo *bi;
-	
+	int chunk;
+
 	yaffs_InvalidateCheckpoint(dev);
 
 	do {
-		chunk = yaffs_AllocateChunk(dev, useReserve,&bi);
-
-		if (chunk >= 0) {
-			/* First check this chunk is erased, if it needs checking.
-			 * The checking policy (unless forced always on) is as follows:
-			 * Check the first page we try to write in a block.
-			 * - If the check passes then we don't need to check any more.
-			 * - If the check fails, we check again...
-			 * If the block has been erased, we don't need to check.
-			 *
-			 * However, if the block has been prioritised for gc, then
-			 * we think there might be something odd about this block
-			 * and stop using it.
-			 *
-			 * Rationale:
-			 * We should only ever see chunks that have not been erased
-			 * if there was a partially written chunk due to power loss
-			 * This checking policy should catch that case with very
-			 * few checks and thus save a lot of checks that are most likely not
-			 * needed.
-			 */
-			 
-			 if(bi->gcPrioritise){
-			 		yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
-			} else {
+		yaffs_BlockInfo *bi = 0;
+		int erasedOk = 0;
+
+		chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
+		if (chunk < 0) {
+			/* no space */
+			break;
+		}
+
+		/* First check this chunk is erased, if it needs
+		 * checking.  The checking policy (unless forced
+		 * always on) is as follows:
+		 *
+		 * Check the first page we try to write in a block.
+		 * If the check passes then we don't need to check any
+		 * more.	If the check fails, we check again...
+		 * If the block has been erased, we don't need to check.
+		 *
+		 * However, if the block has been prioritised for gc,
+		 * then we think there might be something odd about
+		 * this block and stop using it.
+		 *
+		 * Rationale: We should only ever see chunks that have
+		 * not been erased if there was a partially written
+		 * chunk due to power loss.  This checking policy should
+		 * catch that case with very few checks and thus save a
+		 * lot of checks that are most likely not needed.
+		 */
+		if (bi->gcPrioritise) {
+			yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
+			/* try another chunk */
+			continue;
+		}
+
+		/* let's give it a try */
+		attempts++;
+
 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
-
-				bi->skipErasedCheck = 0;
-
+		bi->skipErasedCheck = 0;
 #endif
-				if(!bi->skipErasedCheck){
-					erasedOk = yaffs_CheckChunkErased(dev, chunk);
-					if(erasedOk && !bi->gcPrioritise)
-						bi->skipErasedCheck = 1;
-				}
-
-				if (!erasedOk) {
-					T(YAFFS_TRACE_ERROR,
-					  (TSTR
-					   ("**>> yaffs chunk %d was not erased"
-					    TENDSTR), chunk));
-				} else {
-					writeOk =
-					    yaffs_WriteChunkWithTagsToNAND(dev, chunk,
-									   data, tags);
-				}
-			
-				attempts++;
-
-				if (writeOk) {
-					/*
-					 *  Copy the data into the robustification buffer.
-					 *  NB We do this at the end to prevent duplicates in the case of a write error.
-					 *  Todo
-					 */
-					yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
-				
-				} else {
-					/* The erased check or write failed */
-					yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
-				}
+		if (!bi->skipErasedCheck) {
+			erasedOk = yaffs_CheckChunkErased(dev, chunk);
+			if (erasedOk != YAFFS_OK) {
+				T(YAFFS_TRACE_ERROR,
+				(TSTR ("**>> yaffs chunk %d was not erased"
+				TENDSTR), chunk));
+
+				/* try another chunk */
+				continue;
 			}
+			bi->skipErasedCheck = 1;
 		}
 
-	} while (chunk >= 0 && !writeOk);
+		writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
+				data, tags);
+		if (writeOk != YAFFS_OK) {
+			yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
+			/* try another chunk */
+			continue;
+		}
+
+		/* Copy the data into the robustification buffer */
+		yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
+
+	} while (writeOk != YAFFS_OK && 
+	        (yaffs_wr_attempts <= 0 || attempts <= yaffs_wr_attempts));
+	
+	if(!writeOk)
+		chunk = -1;
 
 	if (attempts > 1) {
 		T(YAFFS_TRACE_ERROR,
-		  (TSTR("**>> yaffs write required %d attempts" TENDSTR),
-		   attempts));
+			(TSTR("**>> yaffs write required %d attempts" TENDSTR),
+			attempts));
+
 		dev->nRetriedWrites += (attempts - 1);
 	}
 
@@ -2591,7 +2593,6 @@ static int yaffs_FindBlockForGarbageColl
 	int pagesInUse = 0;
 	int prioritised=0;
 	yaffs_BlockInfo *bi;
-	static int nonAggressiveSkip = 0;
 	int pendingPrioritisedExist = 0;
 	
 	/* First let's see if we need to grab a prioritised block */
@@ -2623,9 +2624,9 @@ static int yaffs_FindBlockForGarbageColl
 	 * block has only a few pages in use.
 	 */
 
-	nonAggressiveSkip--;
-
-	if (!aggressive && (nonAggressiveSkip > 0)) {
+	dev->nonAggressiveSkip--;
+
+	if (!aggressive && (dev->nonAggressiveSkip > 0)) {
 		return -1;
 	}
 
@@ -2686,7 +2687,7 @@ static int yaffs_FindBlockForGarbageColl
 	dev->oldestDirtySequence = 0;
 
 	if (dirtiest > 0) {
-		nonAggressiveSkip = 4;
+		dev->nonAggressiveSkip = 4;
 	}
 
 	return dirtiest;

--- a/yaffs_guts.h
+++ b/yaffs_guts.h
@@ -92,6 +92,12 @@
 
 #define YAFFS_N_TEMP_BUFFERS		4
 
+/* We limit the number attempts at sucessfully saving a chunk of data.
+ * Small-page devices have 32 pages per block; large-page devices have 64.
+ * Default to something in the order of 5 to 10 blocks worth of chunks.
+ */
+#define YAFFS_WR_ATTEMPTS		(5*64)
+
 /* Sequence numbers are used in YAFFS2 to determine block allocation order.
  * The range is limited slightly to help distinguish bad numbers from good.
  * This also allows us to perhaps in the future use special numbers for
@@ -271,7 +277,7 @@ typedef struct {
 
 	int softDeletions:10;	/* number of soft deleted pages */
 	int pagesInUse:10;	/* number of pages in use */
-	__u32 blockState:4;	/* One of the above block states. NB use unsigned because enum is sometimes an int */
+	unsigned blockState:4;	/* One of the above block states. NB use unsigned because enum is sometimes an int */
 	__u32 needsRetiring:1;	/* Data has failed on this block, need to get valid data off */
                         	/* and retire the block. */
 	__u32 skipErasedCheck: 1; /* If this is set we can skip the erased check on this block */
@@ -692,6 +698,7 @@ struct yaffs_DeviceStruct {
 	int currentDirtyChecker;	/* Used to find current dirtiest block */
 
 	__u32 *gcCleanupList;	/* objects to delete at the end of a GC. */
+	int nonAggressiveSkip;	/* GC state/mode */
 
 	/* Statistcs */
 	int nPageWrites;

new file mode 100644
--- /dev/null
+++ b/yaffs_mtdif1.c
@@ -0,0 +1,363 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_mtdif1.c  NAND mtd interface functions for small-page NAND.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This module provides the interface between yaffs_nand.c and the
+ * MTD API.  This version is used when the MTD interface supports the
+ * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
+ * and we have small-page NAND device.
+ *
+ * These functions are invoked via function pointers in yaffs_nand.c.
+ * This replaces functionality provided by functions in yaffs_mtdif.c
+ * and the yaffs_TagsCompatability functions in yaffs_tagscompat.c that are
+ * called in yaffs_mtdif.c when the function pointers are NULL.
+ * We assume the MTD layer is performing ECC (useNANDECC is true).
+ */
+
+#include "yportenv.h"
+#include "yaffs_guts.h"
+#include "yaffs_packedtags1.h"
+#include "yaffs_tagscompat.h"	// for yaffs_CalcTagsECC
+
+#include "linux/kernel.h"
+#include "linux/version.h"
+#include "linux/types.h"
+#include "linux/mtd/mtd.h"
+
+/* Don't compile this module if we don't have MTD's mtd_oob_ops interface */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+
+const char *yaffs_mtdif1_c_version = "$Id$";
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+# define YTAG1_SIZE 8
+#else
+# define YTAG1_SIZE 9
+#endif
+
+#if 0
+/* Use the following nand_ecclayout with MTD when using
+ * CONFIG_YAFFS_9BYTE_TAGS and the older on-NAND tags layout.
+ * If you have existing Yaffs images and the byte order differs from this,
+ * adjust 'oobfree' to match your existing Yaffs data.
+ *
+ * This nand_ecclayout scatters/gathers to/from the old-yaffs layout with the
+ * pageStatus byte (at NAND spare offset 4) scattered/gathered from/to
+ * the 9th byte.
+ *
+ * Old-style on-NAND format: T0,T1,T2,T3,P,B,T4,T5,E0,E1,E2,T6,T7,E3,E4,E5
+ * We have/need PackedTags1 plus pageStatus: T0,T1,T2,T3,T4,T5,T6,T7,P
+ * where Tn are the tag bytes, En are MTD's ECC bytes, P is the pageStatus
+ * byte and B is the small-page bad-block indicator byte.
+ */
+static struct nand_ecclayout nand_oob_16 = {
+	.eccbytes = 6,
+	.eccpos = { 8, 9, 10, 13, 14, 15 },
+	.oobavail = 9,
+	.oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
+};
+#endif
+
+/* Write a chunk (page) of data to NAND.
+ *
+ * Caller always provides ExtendedTags data which are converted to a more
+ * compact (packed) form for storage in NAND.  A mini-ECC runs over the
+ * contents of the tags meta-data; used to valid the tags when read.
+ *
+ *  - Pack ExtendedTags to PackedTags1 form
+ *  - Compute mini-ECC for PackedTags1
+ *  - Write data and packed tags to NAND.
+ *
+ * Note: Due to the use of the PackedTags1 meta-data which does not include
+ * a full sequence number (as found in the larger PackedTags2 form) it is
+ * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
+ * discarded and dirty.  This is not ideal: newer NAND parts are supposed
+ * to be written just once.  When Yaffs performs this operation, this
+ * function is called with a NULL data pointer -- calling MTD write_oob
+ * without data is valid usage (2.6.17).
+ *
+ * Any underlying MTD error results in YAFFS_FAIL.
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_WriteChunkWithTagsToNAND(yaffs_Device *dev,
+	int chunkInNAND, const __u8 * data, const yaffs_ExtendedTags * etags)
+{
+	struct mtd_info * mtd = dev->genericDevice;
+	int chunkBytes = dev->nDataBytesPerChunk;
+	loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
+	struct mtd_oob_ops ops;
+	yaffs_PackedTags1 pt1;
+	int retval;
+
+	/* we assume that PackedTags1 and yaffs_Tags are compatible */
+	compile_time_assertion(sizeof(yaffs_PackedTags1) == 12);
+	compile_time_assertion(sizeof(yaffs_Tags) == 8);
+
+	yaffs_PackTags1(&pt1, etags);
+	yaffs_CalcTagsECC((yaffs_Tags *)&pt1);
+
+	/* When deleting a chunk, the upper layer provides only skeletal
+	 * etags, one with chunkDeleted set.  However, we need to update the
+	 * tags, not erase them completely.  So we use the NAND write property
+	 * that only zeroed-bits stick and set tag bytes to all-ones and
+	 * zero just the (not) deleted bit.
+	 */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+	if (etags->chunkDeleted) {
+		memset(&pt1, 0xff, 8);
+		/* clear delete status bit to indicate deleted */
+		pt1.deleted = 0;
+	}
+#else
+	((__u8 *)&pt1)[8] = 0xff;
+	if (etags->chunkDeleted) {
+		memset(&pt1, 0xff, 8);
+		/* zero pageStatus byte to indicate deleted */
+		((__u8 *)&pt1)[8] = 0;
+	}
+#endif
+
+	memset(&ops, 0, sizeof(ops));
+	ops.mode = MTD_OOB_AUTO;
+	ops.len = (data) ? chunkBytes : 0;
+	ops.ooblen = YTAG1_SIZE;
+	ops.datbuf = (__u8 *)data;
+	ops.oobbuf = (__u8 *)&pt1;
+
+	retval = mtd->write_oob(mtd, addr, &ops);
+	if (retval) {
+		yaffs_trace(YAFFS_TRACE_MTD,
+			"write_oob failed, chunk %d, mtd error %d\n",
+			chunkInNAND, retval);
+	}
+	return retval ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Return with empty ExtendedTags but add eccResult.
+ */
+static int rettags(yaffs_ExtendedTags * etags, int eccResult, int retval)
+{
+	if (etags) {
+		memset(etags, 0, sizeof(*etags));
+		etags->eccResult = eccResult;
+	}
+	return retval;
+}
+
+/* Read a chunk (page) from NAND.
+ *
+ * Caller expects ExtendedTags data to be usable even on error; that is,
+ * all members except eccResult and blockBad are zeroed.
+ *
+ *  - Check ECC results for data (if applicable)
+ *  - Check for blank/erased block (return empty ExtendedTags if blank)
+ *  - Check the PackedTags1 mini-ECC (correct if necessary/possible)
+ *  - Convert PackedTags1 to ExtendedTags
+ *  - Update eccResult and blockBad members to refect state.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device *dev,
+	int chunkInNAND, __u8 * data, yaffs_ExtendedTags * etags)
+{
+	struct mtd_info * mtd = dev->genericDevice;
+	int chunkBytes = dev->nDataBytesPerChunk;
+	loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
+	int eccres = YAFFS_ECC_RESULT_NO_ERROR;
+	struct mtd_oob_ops ops;
+	yaffs_PackedTags1 pt1;
+	int retval;
+	int deleted;
+
+	memset(&ops, 0, sizeof(ops));
+	ops.mode = MTD_OOB_AUTO;
+	ops.len = (data) ? chunkBytes : 0;
+	ops.ooblen = YTAG1_SIZE;
+	ops.datbuf = data;
+	ops.oobbuf = (__u8 *)&pt1;
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
+	/* In MTD 2.6.18 to 2.6.19 nand_base.c:nand_do_read_oob() has a bug;
+	 * help it out with ops.len = ops.ooblen when ops.datbuf == NULL.
+	 */
+	ops.len = (ops.datbuf) ? ops.len : ops.ooblen;
+#endif
+	/* Read page and oob using MTD.
+	 * Check status and determine ECC result.
+	 */
+	retval = mtd->read_oob(mtd, addr, &ops);
+	if (retval) {
+		yaffs_trace(YAFFS_TRACE_MTD,
+			"read_oob failed, chunk %d, mtd error %d\n",
+			chunkInNAND, retval);
+	}
+
+	switch (retval) {
+	case 0:
+		/* no error */
+		break;
+
+	case -EUCLEAN:
+		/* MTD's ECC fixed the data */
+		eccres = YAFFS_ECC_RESULT_FIXED;
+		dev->eccFixed++;
+		break;
+
+	case -EBADMSG:
+		/* MTD's ECC could not fix the data */
+		dev->eccUnfixed++;
+		/* fall into... */
+	default:
+		rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
+		etags->blockBad = (mtd->block_isbad)(mtd, addr);
+		return YAFFS_FAIL;
+	}
+
+	/* Check for a blank/erased chunk.
+	 */
+	if (yaffs_CheckFF((__u8 *)&pt1, 8)) {
+		/* when blank, upper layers want eccResult to be <= NO_ERROR */
+		return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
+	}
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+	/* Read deleted status (bit) then return it to it's non-deleted
+	 * state before performing tags mini-ECC check. pt1.deleted is
+	 * inverted.
+	 */
+	deleted = !pt1.deleted;
+	pt1.deleted = 1;
+#else
+	(void) deleted; /* not used */
+#endif
+
+	/* Check the packed tags mini-ECC and correct if necessary/possible.
+	 */
+	retval = yaffs_CheckECCOnTags((yaffs_Tags *)&pt1);
+	switch (retval) {
+	case 0:
+		/* no tags error, use MTD result */
+		break;
+	case 1:
+		/* recovered tags-ECC error */
+		dev->tagsEccFixed++;
+		eccres = YAFFS_ECC_RESULT_FIXED;
+		break;
+	default:
+		/* unrecovered tags-ECC error */
+		dev->tagsEccUnfixed++;
+		return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
+	}
+
+	/* Unpack the tags to extended form and set ECC result.
+	 * [set shouldBeFF just to keep yaffs_UnpackTags1 happy]
+	 */
+	pt1.shouldBeFF = 0xFFFFFFFF;
+	yaffs_UnpackTags1(etags, &pt1);
+	etags->eccResult = eccres;
+
+	/* Set deleted state.
+	 */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+	etags->chunkDeleted = deleted;
+#else
+	etags->chunkDeleted = (yaffs_CountBits(((__u8 *)&pt1)[8]) < 7);
+#endif
+	return YAFFS_OK;
+}
+
+/* Mark a block bad.
+ *
+ * This is a persistant state.
+ * Use of this function should be rare.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
+{
+	struct mtd_info * mtd = dev->genericDevice;
+	int blocksize = dev->nChunksPerBlock * dev->nDataBytesPerChunk;
+	int retval;
+
+	yaffs_trace(YAFFS_TRACE_BAD_BLOCKS, "marking block %d bad", blockNo);
+
+	retval = mtd->block_markbad(mtd, (loff_t)blocksize * blockNo);
+	return (retval) ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Check any MTD prerequists.
+ * 
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+static int nandmtd1_TestPrerequists(struct mtd_info * mtd)
+{
+	/* 2.6.18 has mtd->ecclayout->oobavail */
+	/* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
+	int oobavail = mtd->ecclayout->oobavail;
+
+	if (oobavail < YTAG1_SIZE) {
+		yaffs_trace(YAFFS_TRACE_ERROR,
+			"mtd device has only %d bytes for tags, need %d",
+			oobavail, YTAG1_SIZE);
+		return YAFFS_FAIL;
+	}
+	return YAFFS_OK;
+}
+
+/* Query for the current state of a specific block.
+ *
+ * Examine the tags of the first chunk of the block and return the state:
+ *  - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
+ *  - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
+ *  - YAFFS_BLOCK_STATE_EMPTY, the block is clean
+ *
+ * Always returns YAFFS_OK.
+ */
+int nandmtd1_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+	yaffs_BlockState * pState, int *pSequenceNumber)
+{
+	struct mtd_info * mtd = dev->genericDevice;
+	int chunkNo = blockNo * dev->nChunksPerBlock;
+	yaffs_ExtendedTags etags;
+	int state = YAFFS_BLOCK_STATE_DEAD;
+	int seqnum = 0;
+	int retval;
+
+	/* We don't yet have a good place to test for MTD config prerequists.
+	 * Do it here as we are called during the initial scan.
+	 */
+	if (nandmtd1_TestPrerequists(mtd) != YAFFS_OK) {
+		return YAFFS_FAIL;
+	}
+
+	retval = nandmtd1_ReadChunkWithTagsFromNAND(dev, chunkNo, NULL, &etags);
+	if (etags.blockBad) {
+		yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+			"block %d is marked bad", blockNo);
+		state = YAFFS_BLOCK_STATE_DEAD;
+	}
+	else if (etags.chunkUsed) {
+		state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+		seqnum = etags.sequenceNumber;
+	}
+	else {
+		state = YAFFS_BLOCK_STATE_EMPTY;
+	}
+
+	*pState = state;
+	*pSequenceNumber = seqnum;
+
+	/* query always succeeds */
+	return YAFFS_OK;
+}
+
+#endif /*KERNEL_VERSION*/

--- a/yaffs_qsort.c
+++ b/yaffs_qsort.c
@@ -74,9 +74,13 @@ med3(char *a, char *b, char *c, int (*cm
               :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
 }
 
+#ifndef min
 #define min(a,b) (((a) < (b)) ? (a) : (b))
+#endif
+
 void
-qsort(void *aa, size_t n, size_t es, int (*cmp)(const void *, const void *))
+yaffs_qsort(void *aa, size_t n, size_t es,
+	int (*cmp)(const void *, const void *))
 {
 	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
 	int d, r, swaptype, swap_cnt;
@@ -145,12 +149,12 @@ loop:	SWAPINIT(a, es);
 	r = min((long)(pd - pc), (long)(pn - pd - es));
 	vecswap(pb, pn - r, r);
 	if ((r = pb - pa) > es)
-		qsort(a, r / es, es, cmp);
+		yaffs_qsort(a, r / es, es, cmp);
 	if ((r = pd - pc) > es) { 
 		/* Iterate rather than recurse to save stack space */
 		a = pn - r;
 		n = r / es;
 		goto loop;
 	}
-/*		qsort(pn - r, r / es, es, cmp);*/
+/*		yaffs_qsort(pn - r, r / es, es, cmp);*/
 }

--- a/yaffs_qsort.h
+++ b/yaffs_qsort.h
@@ -17,7 +17,7 @@
 #ifndef __YAFFS_QSORT_H__
 #define __YAFFS_QSORT_H__
 
-extern void qsort (void *const base, size_t total_elems, size_t size,
+extern void yaffs_qsort (void *const base, size_t total_elems, size_t size,
                    int (*cmp)(const void *, const void *));
 
 #endif

--- a/yaffs_tagscompat.c
+++ b/yaffs_tagscompat.c
@@ -45,7 +45,7 @@ static const char yaffs_countBitsTable[2
 	4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
 };
 
-static int yaffs_CountBits(__u8 x)
+int yaffs_CountBits(__u8 x)
 {
 	int retVal;
 	retVal = yaffs_countBitsTable[x];

--- a/yaffs_tagscompat.h
+++ b/yaffs_tagscompat.h
@@ -33,4 +33,8 @@ int yaffs_TagsCompatabilityQueryNANDBloc
 					  int blockNo, yaffs_BlockState *
 					  state, int *sequenceNumber);
 
+void yaffs_CalcTagsECC(yaffs_Tags * tags);
+int yaffs_CheckECCOnTags(yaffs_Tags * tags);
+int yaffs_CountBits(__u8 byte);
+
 #endif

--- a/yportenv.h
+++ b/yportenv.h
@@ -79,6 +79,14 @@
 #define TSTR(x) KERN_WARNING x
 #define TOUT(p) printk p
 
+#define yaffs_trace(mask, fmt, args...) \
+	do { if ((mask) & (yaffs_traceMask|YAFFS_TRACE_ERROR)) \
+		printk(KERN_WARNING "yaffs: " fmt, ## args); \
+	} while (0)
+
+#define compile_time_assertion(assertion) \
+	({ int x = __builtin_choose_expr(assertion, 0, (void)0); (void) x; })
+
 #elif defined CONFIG_YAFFS_DIRECT
 
 /* Direct interface */
@@ -133,7 +141,9 @@
 
 #endif
 
-extern unsigned yaffs_traceMask;
+/* see yaffs_fs.c */
+extern unsigned int yaffs_traceMask;
+extern unsigned int yaffs_wr_attempts;
 
 /*
  * Tracing flags.