yaffs: Fix yaffsfs xattr error handling, add yaffs_lsetxattr and friends
[yaffs2.git] / yaffs_guts.c
index df66ec89860585636ffbfdaf0c80e7b90186493c..385b26778fbff66aa1e872800f4452ae5773ed17 100644 (file)
@@ -1,7 +1,7 @@
 /*
  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
  *
- * Copyright (C) 2002-2007 Aleph One Ltd.
+ * Copyright (C) 2002-2010 Aleph One Ltd.
  *   for Toby Churchill Ltd and Brightstar Engineering
  *
  * Created by Charles Manning <charles@aleph1.co.uk>
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-
-const char *yaffs_guts_c_version =
-    "$Id: yaffs_guts.c,v 1.119 2010-03-12 02:48:34 charles Exp $";
-
 #include "yportenv.h"
 #include "yaffs_trace.h"
 
@@ -33,12 +29,34 @@ const char *yaffs_guts_c_version =
 #include "yaffs_nand.h"
 #include "yaffs_packedtags2.h"
 
+#include "yaffs_nameval.h"
+
+
+/* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */
+#define YAFFS_GC_GOOD_ENOUGH 2
+#define YAFFS_GC_PASSIVE_THRESHOLD 4
 
-#define YAFFS_PASSIVE_GC_CHUNKS 2
 #define YAFFS_SMALL_HOLE_THRESHOLD 3
 
+/*
+ * Checkpoints are really no benefit on very small partitions.
+ *
+ * To save space on small partitions don't bother with checkpoints unless
+ * the partition is at least this big.
+ */
+#define YAFFS_CHECKPOINT_MIN_BLOCKS 60
+
 #include "yaffs_ecc.h"
 
+/* Private structure for doing xattr modifications */
+typedef struct {
+       int set; /* If 0 then this is a deletion */
+       const char *name;
+       const void *data;
+       int size;
+       int flags;
+       int result;
+} yaffs_XAttrMod;
 
 /* Robustification (if it ever comes about...) */
 static void yaffs_RetireBlock(yaffs_Device *dev, int blockInNAND);
@@ -69,11 +87,11 @@ static yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev, int number,
 static void yaffs_AddObjectToDirectory(yaffs_Object *directory,
                                yaffs_Object *obj);
 static int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name,
-                               int force, int isShrink, int shadows);
+                               int force, int isShrink, int shadows, yaffs_XAttrMod *xop);
+static int yaffs_ApplyXMod(yaffs_Device *dev, char *buffer, yaffs_XAttrMod *xmod);
+
 static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj);
 static int yaffs_CheckStructures(void);
-static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
-                       int chunkOffset, int *limit);
 static int yaffs_DoGenericObjectDeletion(yaffs_Object *in);
 
 static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device *dev, int blockNo);
@@ -181,7 +199,7 @@ static __u32 ShiftsGE(__u32 x)
 
 static __u32 Shifts(__u32 x)
 {
-       int nShifts;
+       __u32 nShifts;
 
        nShifts =  0;
 
@@ -608,7 +626,8 @@ static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh,
 }
 
 
-
+#if 0
+/* Not being used, but don't want to throw away yet */
 static int yaffs_VerifyTnodeWorker(yaffs_Object *obj, yaffs_Tnode *tn,
                                        __u32 level, int chunkOffset)
 {
@@ -654,6 +673,7 @@ static int yaffs_VerifyTnodeWorker(yaffs_Object *obj, yaffs_Tnode *tn,
 
 }
 
+#endif
 
 static void yaffs_VerifyFile(yaffs_Object *obj)
 {
@@ -1058,41 +1078,41 @@ static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
  * yaffs_FindOldestDirtySequence()
  * Calculate the oldest dirty sequence number if we don't know it.
  */
-static int yaffs_CalcOldestDirtySequence(yaffs_Device *dev)
+static void yaffs_CalcOldestDirtySequence(yaffs_Device *dev)
 {
        int i;
-       __u32 seq;
+       unsigned seq;
+       unsigned blockNo = 0;
        yaffs_BlockInfo *b;
 
        if(!dev->param.isYaffs2)
-               return 0;
+               return;
 
        /* Find the oldest dirty sequence number. */
-       seq = dev->sequenceNumber;
+       seq = dev->sequenceNumber + 1;
        b = dev->blockInfo;
        for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
                if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
-                   (b->pagesInUse - b->softDeletions) < dev->param.nChunksPerBlock &&
-                   b->sequenceNumber < seq) 
-                               seq = b->sequenceNumber;
+                       (b->pagesInUse - b->softDeletions) < dev->param.nChunksPerBlock &&
+                       b->sequenceNumber < seq) {
+                       seq = b->sequenceNumber;
+                       blockNo = i;
+               }
                b++;
        }
-       return seq;
+
+       if(blockNo){
+               dev->oldestDirtySequence = seq;
+               dev->oldestDirtyBlock = blockNo;
+       }
+
 }
 
 
 static void yaffs_FindOldestDirtySequence(yaffs_Device *dev)
 {
        if(dev->param.isYaffs2 && !dev->oldestDirtySequence)
-               dev->oldestDirtySequence = 
-                       yaffs_CalcOldestDirtySequence(dev);
-
-#if 0
-       if(!yaffs_SkipVerification(dev) &&
-               dev->oldestDirtySequence != yaffs_CalcOldestDirtySequence(dev))
-               YBUG();
-
-#endif
+               yaffs_CalcOldestDirtySequence(dev);
 }
 
 /*
@@ -1107,8 +1127,10 @@ static void yaffs_ClearOldestDirtySequence(yaffs_Device *dev, yaffs_BlockInfo *b
        if(!dev->param.isYaffs2)
                return;
 
-       if(!bi || bi->sequenceNumber == dev->oldestDirtySequence)
+       if(!bi || bi->sequenceNumber == dev->oldestDirtySequence){
                dev->oldestDirtySequence = 0;
+               dev->oldestDirtyBlock = 0;
+       }
 }
 
 /*
@@ -1116,11 +1138,13 @@ static void yaffs_ClearOldestDirtySequence(yaffs_Device *dev, yaffs_BlockInfo *b
  * Update the oldest dirty sequence number whenever we dirty a block.
  * Only do this if the oldestDirtySequence is actually being tracked.
  */
-static void yaffs_UpdateOldestDirtySequence(yaffs_Device *dev, yaffs_BlockInfo *bi)
+static void yaffs_UpdateOldestDirtySequence(yaffs_Device *dev, unsigned blockNo, yaffs_BlockInfo *bi)
 {
        if(dev->param.isYaffs2 && dev->oldestDirtySequence){
-               if(dev->oldestDirtySequence > bi->sequenceNumber)
+               if(dev->oldestDirtySequence > bi->sequenceNumber){
                        dev->oldestDirtySequence = bi->sequenceNumber;
+                       dev->oldestDirtyBlock = blockNo;
+               }
        }
 }
  
@@ -1702,9 +1726,10 @@ static int yaffs_FindChunkInGroup(yaffs_Device *dev, int theChunk,
        return -1;
 }
 
-
+#if 0
+/* Experimental code not being used yet. Might speed up file deletion */
 /* DeleteWorker scans backwards through the tnode tree and deletes all the
- * chunks and tnodes in the file
+ * chunks and tnodes in the file.
  * Returns 1 if the tree was deleted.
  * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
  */
@@ -1796,17 +1821,21 @@ static int yaffs_DeleteWorker(yaffs_Object *in, yaffs_Tnode *tn, __u32 level,
 
 }
 
+#endif
+
 static void yaffs_SoftDeleteChunk(yaffs_Device *dev, int chunk)
 {
        yaffs_BlockInfo *theBlock;
+       unsigned blockNo;
 
        T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
 
-       theBlock = yaffs_GetBlockInfo(dev, chunk / dev->param.nChunksPerBlock);
+       blockNo =  chunk / dev->param.nChunksPerBlock;
+       theBlock = yaffs_GetBlockInfo(dev, blockNo);
        if (theBlock) {
                theBlock->softDeletions++;
                dev->nFreeChunks++;
-               yaffs_UpdateOldestDirtySequence(dev,theBlock);
+               yaffs_UpdateOldestDirtySequence(dev, blockNo, theBlock);
        }
 }
 
@@ -2503,7 +2532,7 @@ static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
                        break;
                }
 
-               if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
+               if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0, NULL) < 0) {
                        /* Could not create the object header, fail the creation */
                        yaffs_DeleteObject(in);
                        in = NULL;
@@ -2611,7 +2640,7 @@ static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir,
                        obj->unlinked = 1;
 
                /* If it is a deletion then we mark it as a shrink for gc purposes. */
-               if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows) >= 0)
+               if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows, NULL) >= 0)
                        return YAFFS_OK;
        }
 
@@ -2667,12 +2696,12 @@ int yaffs_RenameObject(yaffs_Object *oldDir, const YCHAR *oldName,
                         * Note we must disable gc otherwise it can mess up the shadowing.
                         *
                         */
-                       dev->isDoingGC=1;
+                       dev->gcDisable=1;
                        yaffs_ChangeObjectName(obj, newDir, newName, force,
                                                existingTarget->objectId);
                        existingTarget->isShadowed = 1;
                        yaffs_UnlinkObject(existingTarget);
-                       dev->isDoingGC=0;
+                       dev->gcDisable=0;
                }
 
                result = yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
@@ -2789,10 +2818,8 @@ static __u32 yaffs_FindRefreshBlock(yaffs_Device *dev)
         if(dev->refreshSkip > dev->param.refreshPeriod)
                 dev->refreshSkip = dev->param.refreshPeriod;
 
-       if(dev->refreshSkip > 0){
-               dev->refreshSkip--;
+       if(dev->refreshSkip > 0)
                return oldest;
-       }
 
        /*
         * Refresh skip is now zero.
@@ -2824,106 +2851,6 @@ static __u32 yaffs_FindRefreshBlock(yaffs_Device *dev)
        return oldest;
 }
 
-/*
- * FindDiretiestBlock is used to select the dirtiest block (or close enough)
- * for garbage collection.
- */
-
-static int yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
-                                       int aggressive)
-{
-       int b = dev->currentDirtyChecker;
-
-       int i;
-       int iterations;
-       int dirtiest = -1;
-       int pagesInUse = 0;
-       int prioritised = 0;
-       yaffs_BlockInfo *bi;
-       int pendingPrioritisedExist = 0;
-
-       /* First let's see if we need to grab a prioritised block */
-       if (dev->hasPendingPrioritisedGCs) {
-               bi = dev->blockInfo;
-               for (i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++) {
-
-                       if (bi->gcPrioritise) {
-                               pendingPrioritisedExist = 1;
-                               if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
-                                  yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
-                                       pagesInUse = (bi->pagesInUse - bi->softDeletions);
-                                       dirtiest = i;
-                                       prioritised = 1;
-                                       aggressive = 1; /* Fool the non-aggressive skip logiv below */
-                               }
-                       }
-                       bi++;
-               }
-
-               if (!pendingPrioritisedExist) /* None found, so we can clear this */
-                       dev->hasPendingPrioritisedGCs = 0;
-       }
-
-       /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
-        * search harder.
-        * else (we're doing a leasurely gc), then we only bother to do this if the
-        * block has only a few pages in use.
-        */
-
-       dev->nonAggressiveSkip--;
-
-       if (!aggressive && (dev->nonAggressiveSkip > 0))
-               return -1;
-
-       if (!prioritised)
-               pagesInUse =
-                       (aggressive) ? dev->param.nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
-
-       if (aggressive)
-               iterations =
-                   dev->internalEndBlock - dev->internalStartBlock + 1;
-       else {
-               iterations =
-                   dev->internalEndBlock - dev->internalStartBlock + 1;
-               iterations = iterations / 16;
-               if (iterations > 200)
-                       iterations = 200;
-       }
-
-       for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
-               b++;
-               if (b < dev->internalStartBlock || b > dev->internalEndBlock)
-                       b = dev->internalStartBlock;
-
-               if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
-                       T(YAFFS_TRACE_ERROR,
-                         (TSTR("**>> Block %d is not valid" TENDSTR), b));
-                       YBUG();
-               }
-
-               bi = yaffs_GetBlockInfo(dev, b);
-
-               if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
-                       (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
-                               yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
-                       dirtiest = b;
-                       pagesInUse = (bi->pagesInUse - bi->softDeletions);
-               }
-       }
-
-       dev->currentDirtyChecker = b;
-
-       if (dirtiest > 0) {
-               T(YAFFS_TRACE_GC,
-                 (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
-                  dev->param.nChunksPerBlock - pagesInUse, prioritised));
-       }
-
-       if (dirtiest > 0)
-               dev->nonAggressiveSkip = 4;
-
-       return dirtiest;
-}
 
 static void yaffs_BlockBecameDirty(yaffs_Device *dev, int blockNo)
 {
@@ -2943,6 +2870,16 @@ static void yaffs_BlockBecameDirty(yaffs_Device *dev, int blockNo)
 
        bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
 
+       /* If this is the block being garbage collected then stop gc'ing this block */
+       if(blockNo == dev->gcBlock)
+               dev->gcBlock = 0;
+
+       /* If this block is currently the best candidate for gc then drop as a candidate */
+       if(blockNo == dev->gcDirtiest){
+               dev->gcDirtiest = 0;
+               dev->gcPagesInUse = 0;
+       }
+
        if (!bi->needsRetiring) {
                yaffs_InvalidateCheckpoint(dev);
                erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
@@ -3040,10 +2977,17 @@ static int yaffs_FindBlockForAllocation(yaffs_Device *dev)
 
 
 
+static int yaffs_CheckpointRequired(yaffs_Device *dev)
+{
+       int nblocks = dev->internalEndBlock - dev->internalStartBlock + 1 ;
+       return dev->param.isYaffs2 &&
+               !dev->param.skipCheckpointWrite &&
+               (nblocks >= YAFFS_CHECKPOINT_MIN_BLOCKS);
+}
 static int yaffs_CalcCheckpointBlocksRequired(yaffs_Device *dev)
 {
        if (!dev->nCheckpointBlocksRequired &&
-          dev->param.isYaffs2) {
+               yaffs_CheckpointRequired(dev)){
                /* Not a valid value so recalculate */
                int nBytes = 0;
                int nBlocks;
@@ -3215,13 +3159,7 @@ static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
        
        bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
 
-       /* Take off the number of soft deleted entries because
-        * they're going to get really deleted during GC.
-        */
-       if(dev->gcChunk == 0) /* first time through for this block */
-               dev->nFreeChunks -= bi->softDeletions;
-
-       dev->isDoingGC = 1;
+       dev->gcDisable = 1;
 
        if (isCheckpointBlock ||
                        !yaffs_StillSomeChunkBits(dev, block)) {
@@ -3236,7 +3174,7 @@ static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
 
                yaffs_VerifyBlock(dev, bi, block);
 
-               maxCopies = (wholeBlock) ? dev->param.nChunksPerBlock : 10;
+               maxCopies = (wholeBlock) ? dev->param.nChunksPerBlock : 5;
                oldChunk = block * dev->param.nChunksPerBlock + dev->gcChunk;
 
                for (/* init already done */;
@@ -3300,6 +3238,13 @@ static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
                                         * No need to copy this, just forget about it and
                                         * fix up the object.
                                         */
+                                        
+                                       /* Free chunks already includes softdeleted chunks.
+                                        * How ever this chunk is going to soon be really deleted
+                                        * which will increment free chunks.
+                                        * We have to decrement free chunks so this works out properly.
+                                        */
+                                       dev->nFreeChunks--;
 
                                        object->nDataChunks--;
 
@@ -3420,8 +3365,14 @@ static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
 
 
 
-       /* If the gc completed then clear the current gcBlock so that we find another. */
-       if (bi->blockState != YAFFS_BLOCK_STATE_COLLECTING) {
+       if (bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
+               /*
+                * The gc did not complete. Set block state back to FULL
+                * because checkpointing does not restore gc.
+                */
+               bi->blockState = YAFFS_BLOCK_STATE_FULL;
+       } else {
+               /* The gc completed. */
                chunksAfter = yaffs_GetErasedChunks(dev);
                if (chunksBefore >= chunksAfter) {
                        T(YAFFS_TRACE_GC,
@@ -3429,15 +3380,165 @@ static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
                           ("gc did not increase free chunks before %d after %d"
                            TENDSTR), chunksBefore, chunksAfter));
                }
-               dev->gcBlock = -1;
+               dev->gcBlock = 0;
                dev->gcChunk = 0;
        }
 
-       dev->isDoingGC = 0;
+       dev->gcDisable = 0;
 
        return retVal;
 }
 
+/*
+ * FindBlockForgarbageCollection is used to select the dirtiest block (or close enough)
+ * for garbage collection.
+ */
+
+static unsigned yaffs_FindBlockForGarbageCollection(yaffs_Device *dev,
+                                       int aggressive,
+                                       int background)
+{
+       int i;
+       int iterations;
+       unsigned selected = 0;
+       int prioritised = 0;
+       int prioritisedExists = 0;
+       yaffs_BlockInfo *bi;
+       int threshold;
+
+       /* First let's see if we need to grab a prioritised block */
+       if (dev->hasPendingPrioritisedGCs && !aggressive) {
+               dev->gcDirtiest = 0;
+               bi = dev->blockInfo;
+               for (i = dev->internalStartBlock;
+                       i <= dev->internalEndBlock && !selected;
+                       i++) {
+
+                       if (bi->gcPrioritise) {
+                               prioritisedExists = 1;
+                               if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
+                                  yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
+                                       selected = i;
+                                       prioritised = 1;
+                               }
+                       }
+                       bi++;
+               }
+
+               /*
+                * If there is a prioritised block and none was selected then
+                * this happened because there is at least one old dirty block gumming
+                * up the works. Let's gc the oldest dirty block.
+                */
+
+               if(prioritisedExists &&
+                       !selected &&
+                       dev->oldestDirtyBlock > 0)
+                       selected = dev->oldestDirtyBlock;
+
+               if (!prioritisedExists) /* None found, so we can clear this */
+                       dev->hasPendingPrioritisedGCs = 0;
+       }
+
+       /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
+        * search harder.
+        * else (we're doing a leasurely gc), then we only bother to do this if the
+        * block has only a few pages in use.
+        */
+
+       if (!selected){
+               int pagesUsed;
+               int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
+               if (aggressive){
+                       threshold = dev->param.nChunksPerBlock;
+                       iterations = nBlocks;
+               } else {
+                       int maxThreshold = dev->param.nChunksPerBlock/2;
+                       threshold = background ?
+                               (dev->gcNotDone + 2) * 2 : 0;
+                       if(threshold <YAFFS_GC_PASSIVE_THRESHOLD)
+                               threshold = YAFFS_GC_PASSIVE_THRESHOLD;
+                       if(threshold > maxThreshold)
+                               threshold = maxThreshold;
+
+                       iterations = nBlocks / 16 + 1;
+                       if (iterations > 100)
+                               iterations = 100;
+               }
+
+               for (i = 0;
+                       i < iterations &&
+                       (dev->gcDirtiest < 1 ||
+                               dev->gcPagesInUse > YAFFS_GC_GOOD_ENOUGH);
+                       i++) {
+                       dev->gcBlockFinder++;
+                       if (dev->gcBlockFinder < dev->internalStartBlock ||
+                               dev->gcBlockFinder > dev->internalEndBlock)
+                               dev->gcBlockFinder = dev->internalStartBlock;
+
+                       bi = yaffs_GetBlockInfo(dev, dev->gcBlockFinder);
+
+                       pagesUsed = bi->pagesInUse - bi->softDeletions;
+
+                       if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
+                               pagesUsed < dev->param.nChunksPerBlock &&
+                               (dev->gcDirtiest < 1 || pagesUsed < dev->gcPagesInUse) &&
+                               yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
+                               dev->gcDirtiest = dev->gcBlockFinder;
+                               dev->gcPagesInUse = pagesUsed;
+                       }
+               }
+
+               if(dev->gcDirtiest > 0 && dev->gcPagesInUse <= threshold)
+                       selected = dev->gcDirtiest;
+       }
+
+       /*
+        * If nothing has been selected for a while, try selecting the oldest dirty
+        * because that's gumming up the works.
+        */
+
+       if(!selected && dev->param.isYaffs2 &&
+               dev->gcNotDone >= ( background ? 10 : 20)){
+               yaffs_FindOldestDirtySequence(dev);
+               if(dev->oldestDirtyBlock > 0) {
+                       selected = dev->oldestDirtyBlock;
+                       dev->gcDirtiest = selected;
+                       dev->oldestDirtyGCs++;
+                       bi = yaffs_GetBlockInfo(dev, selected);
+                       dev->gcPagesInUse =  bi->pagesInUse - bi->softDeletions;
+               } else
+                       dev->gcNotDone = 0;
+       }
+
+       if(selected){
+               T(YAFFS_TRACE_GC,
+                 (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR),
+                 selected,
+                 dev->param.nChunksPerBlock - dev->gcPagesInUse,
+                 prioritised));
+
+               if(background)
+                       dev->backgroundGCs++;
+               dev->gcDirtiest = 0;
+               dev->gcPagesInUse = 0;
+               dev->gcNotDone = 0;
+               if(dev->refreshSkip > 0)
+                       dev->refreshSkip--;
+       } else{
+               dev->gcNotDone++;
+               T(YAFFS_TRACE_GC,
+                 (TSTR("GC none: finder %d skip %d threshold %d dirtiest %d using %d oldest %d%s" TENDSTR),
+                 dev->gcBlockFinder, dev->gcNotDone,
+                 threshold,
+                 dev->gcDirtiest, dev->gcPagesInUse,
+                 dev->oldestDirtyBlock,
+                 background ? " bg" : ""));
+       }
+
+       return selected;
+}
+
 /* New garbage collector
  * If we're very low on erased blocks then we do aggressive garbage collection
  * otherwise we do "leasurely" garbage collection.
@@ -3447,22 +3548,28 @@ static int yaffs_GarbageCollectBlock(yaffs_Device *dev, int block,
  * The idea is to help clear out space in a more spread-out manner.
  * Dunno if it really does anything useful.
  */
-static int yaffs_CheckGarbageCollection(yaffs_Device *dev)
+static int yaffs_CheckGarbageCollection(yaffs_Device *dev, int background)
 {
-       int block;
-       int aggressive;
+       int aggressive = 0;
        int gcOk = YAFFS_OK;
        int maxTries = 0;
 
+       int minErased;
+       int erasedChunks;
+
        int checkpointBlockAdjust;
 
-       if (dev->isDoingGC) {
+       if(dev->param.gcControl &&
+               (dev->param.gcControl(dev) & 1) == 0)
+               return YAFFS_OK;
+
+       if (dev->gcDisable) {
                /* Bail out so we don't get recursive gc */
                return YAFFS_OK;
        }
 
        /* This loop should pass the first time.
-        * We'll only see looping here if the erase of the collected block fails.
+        * We'll only see looping here if the collection does not increase space.
         */
 
        do {
@@ -3472,11 +3579,26 @@ static int yaffs_CheckGarbageCollection(yaffs_Device *dev)
                if (checkpointBlockAdjust < 0)
                        checkpointBlockAdjust = 0;
 
+               minErased  = dev->param.nReservedBlocks + checkpointBlockAdjust + 1;
+               erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
+
                /* If we need a block soon then do aggressive gc.*/
-               if (dev->nErasedBlocks < (dev->param.nReservedBlocks + checkpointBlockAdjust + 2))
+               if (dev->nErasedBlocks < minErased)
                        aggressive = 1;
-               else
-                       aggressive = 0;
+               else {
+                       if(dev->gcSkip > 20)
+                               dev->gcSkip = 20;
+                       if(erasedChunks < dev->nFreeChunks/2 ||
+                               dev->gcSkip < 1 ||
+                               background)
+                               aggressive = 0;
+                       else {
+                               dev->gcSkip--;
+                               break;
+                       }
+               }
+
+               dev->gcSkip = 5;
 
                 /* If we don't already have a block being gc'd then see if we should start another */
 
@@ -3485,38 +3607,51 @@ static int yaffs_CheckGarbageCollection(yaffs_Device *dev)
                        dev->gcChunk = 0;
                }
                if (dev->gcBlock < 1) {
-                       dev->gcBlock = yaffs_FindBlockForGarbageCollection(dev, aggressive);
+                       dev->gcBlock = yaffs_FindBlockForGarbageCollection(dev, aggressive, background);
                        dev->gcChunk = 0;
                }
 
-               block = dev->gcBlock;
-
-               if (block > 0) {
-                       dev->garbageCollections++;
+               if (dev->gcBlock > 0) {
+                       dev->allGCs++;
                        if (!aggressive)
-                               dev->passiveGarbageCollections++;
+                               dev->passiveGCs++;
 
                        T(YAFFS_TRACE_GC,
                          (TSTR
                           ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
                           dev->nErasedBlocks, aggressive));
 
-                       gcOk = yaffs_GarbageCollectBlock(dev, block, aggressive);
+                       gcOk = yaffs_GarbageCollectBlock(dev, dev->gcBlock, aggressive);
                }
 
-               if (dev->nErasedBlocks < (dev->param.nReservedBlocks) && block > 0) {
+               if (dev->nErasedBlocks < (dev->param.nReservedBlocks) && dev->gcBlock > 0) {
                        T(YAFFS_TRACE_GC,
                          (TSTR
                           ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
-                           TENDSTR), dev->nErasedBlocks, maxTries, block));
+                           TENDSTR), dev->nErasedBlocks, maxTries, dev->gcBlock));
                }
        } while ((dev->nErasedBlocks < dev->param.nReservedBlocks) &&
-                (block > 0) &&
+                (dev->gcBlock > 0) &&
                 (maxTries < 2));
 
        return aggressive ? gcOk : YAFFS_OK;
 }
 
+/*
+ * yaffs_BackgroundGarbageCollect()
+ * Garbage collects. Intended to be called from a background thread.
+ * Returns non-zero if at least half the free chunks are erased.
+ */
+int yaffs_BackgroundGarbageCollect(yaffs_Device *dev, unsigned urgency)
+{
+       int erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
+
+       T(YAFFS_TRACE_BACKGROUND, (TSTR("Background gc %u" TENDSTR),urgency));
+
+       yaffs_CheckGarbageCollection(dev, 1);
+       return erasedChunks > dev->nFreeChunks/2;
+}
+
 /*-------------------------  TAGS --------------------------------*/
 
 static int yaffs_TagsMatch(const yaffs_ExtendedTags *tags, int objectId,
@@ -3820,7 +3955,7 @@ void yaffs_DeleteChunk(yaffs_Device *dev, int chunkId, int markNAND, int lyn)
 
        bi = yaffs_GetBlockInfo(dev, block);
        
-       yaffs_UpdateOldestDirtySequence(dev,bi);
+       yaffs_UpdateOldestDirtySequence(dev, block, bi);
 
        T(YAFFS_TRACE_DELETION,
          (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));
@@ -3879,7 +4014,7 @@ static int yaffs_WriteChunkDataToObject(yaffs_Object *in, int chunkInInode,
 
        yaffs_Device *dev = in->myDev;
 
-       yaffs_CheckGarbageCollection(dev);
+       yaffs_CheckGarbageCollection(dev,0);
 
        /* Get the previous chunk at this location in the file if it exists.
         * If it does not exist then put a zero into the tree. This creates
@@ -3926,7 +4061,7 @@ static int yaffs_WriteChunkDataToObject(yaffs_Object *in, int chunkInInode,
  * If name is not NULL, then that new name is used.
  */
 int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name, int force,
-                            int isShrink, int shadows)
+                            int isShrink, int shadows, yaffs_XAttrMod *xmod)
 {
 
        yaffs_BlockInfo *bi;
@@ -3952,9 +4087,9 @@ int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name, int force,
 
        if (!in->fake ||
                in == dev->rootDir || /* The rootDir should also be saved */
-               force) {
+               force  || xmod) {
 
-               yaffs_CheckGarbageCollection(dev);
+               yaffs_CheckGarbageCollection(dev,0);
                yaffs_CheckObjectDetailsLoaded(in);
 
                buffer = yaffs_GetTempBuffer(in->myDev, __LINE__);
@@ -3969,9 +4104,9 @@ int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name, int force,
                        yaffs_VerifyObjectHeader(in, oh, &oldTags, 0);
 
                        memcpy(oldName, oh->name, sizeof(oh->name));
-               }
-
-               memset(buffer, 0xFF, dev->nDataBytesPerChunk);
+                       memset(buffer, 0xFF, sizeof(yaffs_ObjectHeader));
+               } else
+                       memset(buffer, 0xFF, dev->nDataBytesPerChunk);
 
                oh->type = in->variantType;
                oh->yst_mode = in->yst_mode;
@@ -4039,6 +4174,11 @@ int yaffs_UpdateObjectHeader(yaffs_Object *in, const YCHAR *name, int force,
                        break;
                }
 
+               /* process any xattrib modifications */
+               if(xmod)
+                       yaffs_ApplyXMod(dev, (char *)buffer, xmod);
+
+
                /* Tags */
                yaffs_InitialiseTags(&newTags);
                in->serial++;
@@ -4773,7 +4913,7 @@ static int yaffs_WriteCheckpointData(yaffs_Device *dev)
 {
        int ok = 1;
 
-       if (dev->param.skipCheckpointWrite || !dev->param.isYaffs2) {
+       if (!yaffs_CheckpointRequired(dev)) {
                T(YAFFS_TRACE_CHECKPOINT, (TSTR("skipping checkpoint write" TENDSTR)));
                ok = 0;
        }
@@ -5029,8 +5169,6 @@ int yaffs_DoWriteDataToFile(yaffs_Object *in, const __u8 *buffer, loff_t offset,
        dev = in->myDev;
 
        while (n > 0 && chunkWritten >= 0) {
-               /* chunk = offset / dev->nDataBytesPerChunk + 1; */
-               /* start = offset % dev->nDataBytesPerChunk; */
                yaffs_AddrToChunk(dev, offset, &chunk, &start);
 
                if (chunk * dev->nDataBytesPerChunk + start != offset ||
@@ -5040,7 +5178,7 @@ int yaffs_DoWriteDataToFile(yaffs_Object *in, const __u8 *buffer, loff_t offset,
                           TENDSTR),
                           (int)offset, chunk, start));
                }
-               chunk++;
+               chunk++; /* File pos to chunk in file offset */
 
                /* OK now check for the curveball where the start and end are in
                 * the same chunk.
@@ -5349,7 +5487,7 @@ static int yaffs_HandleHole(yaffs_Object *obj, loff_t newSize)
                obj->parent->objectId != YAFFS_OBJECTID_UNLINKED &&
                obj->parent->objectId != YAFFS_OBJECTID_DELETED){
                /* Write a hole start header with the old file size */
-               yaffs_UpdateObjectHeader(obj, NULL, 0,1,0);
+               yaffs_UpdateObjectHeader(obj, NULL, 0, 1, 0, NULL);
        }
 
        return result;
@@ -5364,7 +5502,7 @@ int yaffs_ResizeFile(yaffs_Object *in, loff_t newSize)
        yaffs_FlushFilesChunkCache(in);
        yaffs_InvalidateWholeChunkCache(in);
 
-       yaffs_CheckGarbageCollection(dev);
+       yaffs_CheckGarbageCollection(dev,0);
 
        if (in->variantType != YAFFS_OBJECT_TYPE_FILE)
                return YAFFS_FAIL;
@@ -5389,7 +5527,7 @@ int yaffs_ResizeFile(yaffs_Object *in, loff_t newSize)
            !in->isShadowed &&
            in->parent->objectId != YAFFS_OBJECTID_UNLINKED &&
            in->parent->objectId != YAFFS_OBJECTID_DELETED)
-               yaffs_UpdateObjectHeader(in, NULL, 0,0,0);
+               yaffs_UpdateObjectHeader(in, NULL, 0, 0, 0, NULL);
 
 
        return YAFFS_OK;
@@ -5433,7 +5571,7 @@ int yaffs_FlushFile(yaffs_Object *in, int updateTime, int dataSync)
 #endif
                        }
 
-                       retVal = (yaffs_UpdateObjectHeader(in, NULL, 0, 0, 0) >=
+                       retVal = (yaffs_UpdateObjectHeader(in, NULL, 0, 0, 0, NULL) >=
                                0) ? YAFFS_OK : YAFFS_FAIL;
                }
        } else {
@@ -5474,6 +5612,7 @@ static int yaffs_UnlinkFileIfNeeded(yaffs_Object *in)
 
        int retVal;
        int immediateDeletion = 0;
+       yaffs_Device *dev = in->myDev;
 
        if (!in->myInode)
                immediateDeletion = 1;
@@ -5487,7 +5626,7 @@ static int yaffs_UnlinkFileIfNeeded(yaffs_Object *in)
                   in->objectId));
                in->deleted = 1;
                in->myDev->nDeletedFiles++;
-               if (1 || in->myDev->param.isYaffs2)
+               if (dev->param.disableSoftDelete || dev->param.isYaffs2)
                        yaffs_ResizeFile(in, 0);
                yaffs_SoftDeleteFile(in);
        } else {
@@ -5503,9 +5642,11 @@ static int yaffs_UnlinkFileIfNeeded(yaffs_Object *in)
 int yaffs_DeleteFile(yaffs_Object *in)
 {
        int retVal = YAFFS_OK;
-       int deleted = in->deleted;
+       int deleted; /* Need to cache value on stack if in is freed */
+       yaffs_Device *dev = in->myDev;
 
-       yaffs_ResizeFile(in, 0);
+       if (dev->param.disableSoftDelete || dev->param.isYaffs2)
+               yaffs_ResizeFile(in, 0);
 
        if (in->nDataChunks > 0) {
                /* Use soft deletion if there is data in the file.
@@ -5514,6 +5655,8 @@ int yaffs_DeleteFile(yaffs_Object *in)
                if (!in->unlinked)
                        retVal = yaffs_UnlinkFileIfNeeded(in);
 
+               deleted = in->deleted;
+
                if (retVal == YAFFS_OK && in->unlinked && !in->deleted) {
                        in->deleted = 1;
                        deleted = 1;
@@ -6353,7 +6496,7 @@ static int yaffs_Scan(yaffs_Device *dev)
                        obj = yaffs_FindObjectByNumber(dev, fixer->objectId);
 
                        if (obj)
-                               yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0);
+                               yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0, NULL);
 
                        YFREE(fixer);
                }
@@ -6661,7 +6804,7 @@ static int yaffs_ScanBackwards(yaffs_Device *dev)
                                                         * the current allocation block.
                                                         */
 
-                                                        T(YAFFS_TRACE_ALWAYS,
+                                                        T(YAFFS_TRACE_SCAN,
                                                         (TSTR("Partially written block %d detected" TENDSTR),
                                                         blk));
                                                }
@@ -7187,7 +7330,7 @@ static void yaffs_UpdateParent(yaffs_Object *obj)
                }
 
        } else
-               yaffs_UpdateObjectHeader(obj,NULL,0,0,0);
+               yaffs_UpdateObjectHeader(obj, NULL, 0, 0, 0, NULL);
 }
 
 void yaffs_UpdateDirtyDirectories(yaffs_Device *dev)
@@ -7210,7 +7353,7 @@ void yaffs_UpdateDirtyDirectories(yaffs_Device *dev)
                T(YAFFS_TRACE_BACKGROUND, (TSTR("Update directory %d" TENDSTR), obj->objectId));
 
                if(obj->dirty)
-                       yaffs_UpdateObjectHeader(obj,NULL,0,0,0);
+                       yaffs_UpdateObjectHeader(obj, NULL, 0, 0, 0, NULL);
        }
 }
 
@@ -7541,7 +7684,7 @@ int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr)
        if (valid & ATTR_SIZE)
                yaffs_ResizeFile(obj, attr->ia_size);
 
-       yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0);
+       yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0, NULL);
 
        return YAFFS_OK;
 
@@ -7574,6 +7717,104 @@ int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr)
 
 #endif
 
+
+static int yaffs_DoXMod(yaffs_Object *obj, int set, const char *name, const void *value, int size, int flags)
+{
+       yaffs_XAttrMod xmod;
+
+       int result;
+
+       xmod.set = set;
+       xmod.name = name;
+       xmod.data = value;
+       xmod.size =  size;
+       xmod.flags = flags;
+       xmod.result = -ENOSPC;
+
+       result = yaffs_UpdateObjectHeader(obj, NULL, 0, 0, 0, &xmod);
+
+       if(result > 0)
+               return xmod.result;
+       else
+               return -ENOSPC;
+}
+
+static int yaffs_ApplyXMod(yaffs_Device *dev, char *buffer, yaffs_XAttrMod *xmod)
+{
+       int retval = 0;
+       int x_offs = sizeof(yaffs_ObjectHeader);
+       int x_size = dev->nDataBytesPerChunk - sizeof(yaffs_ObjectHeader);
+
+       char * x_buffer = buffer + x_offs;
+
+       if(xmod->set)
+               retval = nval_set(x_buffer, x_size, xmod->name, xmod->data, xmod->size, xmod->flags);
+       else
+               retval = nval_del(x_buffer, x_size, xmod->name);
+
+       xmod->result = retval;
+
+       return retval;
+}
+
+static int yaffs_DoXFetch(yaffs_Object *obj, const char *name, void *value, int size)
+{
+       char *buffer = NULL;
+       int result;
+       yaffs_ExtendedTags tags;
+       yaffs_Device *dev = obj->myDev;
+       int x_offs = sizeof(yaffs_ObjectHeader);
+       int x_size = dev->nDataBytesPerChunk - sizeof(yaffs_ObjectHeader);
+
+       __u8 * x_buffer;
+
+       int retval = 0;
+
+       if(obj->hdrChunk < 1)
+               return -ENOENT;
+
+       buffer = yaffs_GetTempBuffer(dev, __LINE__);
+       if(!buffer)
+               return -ENOMEM;
+
+       result = yaffs_ReadChunkWithTagsFromNAND(dev,obj->hdrChunk, buffer, &tags);
+
+       if(result != YAFFS_OK)
+               retval = -ENOENT;
+       else{
+               x_buffer =  buffer + x_offs;
+
+               if(name)
+                       retval = nval_get(x_buffer, x_size, name, value, size);
+               else
+                       retval = nval_list(x_buffer, x_size, value,size);
+       }
+       yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
+       return retval;
+}
+
+int yaffs_SetXAttribute(yaffs_Object *obj, const char *name, const void * value, int size, int flags)
+{
+       return yaffs_DoXMod(obj, 1, name, value, size, flags);
+}
+
+int yaffs_RemoveXAttribute(yaffs_Object *obj, const char *name)
+{
+       return yaffs_DoXMod(obj, 0, name, NULL, 0, 0);
+}
+
+int yaffs_GetXAttribute(yaffs_Object *obj, const char *name, void *value, int size)
+{
+       return yaffs_DoXFetch(obj, name, value, size);
+}
+
+int yaffs_ListXAttributes(yaffs_Object *obj, char *buffer, int size)
+{
+       return yaffs_DoXFetch(obj, NULL, buffer,size);
+}
+
+
+
 #if 0
 int yaffs_DumpObject(yaffs_Object *obj)
 {
@@ -7677,7 +7918,7 @@ int yaffs_GutsInitialise(yaffs_Device *dev)
        dev->chunkOffset = 0;
        dev->nFreeChunks = 0;
 
-       dev->gcBlock = -1;
+       dev->gcBlock = 0;
 
        if (dev->param.startBlock == 0) {
                dev->internalStartBlock = dev->param.startBlock + 1;
@@ -7806,9 +8047,11 @@ int yaffs_GutsInitialise(yaffs_Device *dev)
        /* OK, we've finished verifying the device, lets continue with initialisation */
 
        /* More device initialisation */
-       dev->garbageCollections = 0;
-       dev->passiveGarbageCollections = 0;
-       dev->currentDirtyChecker = 0;
+       dev->allGCs = 0;
+       dev->passiveGCs = 0;
+       dev->oldestDirtyGCs = 0;
+       dev->backgroundGCs = 0;
+       dev->gcBlockFinder = 0;
        dev->bufferedBlock = -1;
        dev->doingBufferedBlockRewrite = 0;
        dev->nDeletedFiles = 0;
@@ -7820,10 +8063,11 @@ int yaffs_GutsInitialise(yaffs_Device *dev)
        dev->tagsEccUnfixed = 0;
        dev->nErasureFailures = 0;
        dev->nErasedBlocks = 0;
-       dev->isDoingGC = 0;
+       dev->gcDisable= 0;
        dev->hasPendingPrioritisedGCs = 1; /* Assume the worst for now, will get fixed on first GC */
        YINIT_LIST_HEAD(&dev->dirtyDirectories);
        dev->oldestDirtySequence = 0;
+       dev->oldestDirtyBlock = 0;
 
        /* Initialise temporary buffers and caches. */
        if (!yaffs_InitialiseTempBuffers(dev))