1 files changed, 82 insertions, 121 deletions

diff --git a/yaffs_allocator.c b/yaffs_allocator.c
index f9cd5be..c8f2861 100644
--- a/yaffs_allocator.c
+++ b/yaffs_allocator.c
@@ -1,7 +1,7 @@
 /*
  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
  *
- * Copyright (C) 2002-2010 Aleph One Ltd.
+ * Copyright (C) 2002-2011 Aleph One Ltd.
  *   for Toby Churchill Ltd and Brightstar Engineering
  *
  * Created by Charles Manning <charles@aleph1.co.uk>
@@ -16,53 +16,19 @@
 #include "yaffs_trace.h"
 #include "yportenv.h"
 
-#ifdef CONFIG_YAFFS_KMALLOC_ALLOCATOR
-
-void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
-{
-	dev = dev;
-}
-
-void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
-{
-	dev = dev;
-}
-
-struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
-{
-	return (struct yaffs_tnode *)kmalloc(dev->tnode_size, GFP_NOFS);
-}
-
-void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
-{
-	dev = dev;
-	kfree(tn);
-}
-
-void yaffs_init_raw_objs(struct yaffs_dev *dev)
-{
-	dev = dev;
-}
-
-void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
-{
-	dev = dev;
-}
-
-struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
-{
-	dev = dev;
-	return (struct yaffs_obj *)kmalloc(sizeof(struct yaffs_obj));
-}
-
-void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
-{
-
-	dev = dev;
-	kfree(obj);
-}
-
-#else
+/*
+ * Each entry in yaffs_tnode_list and yaffs_obj_list hold blocks
+ * of approx 100 objects that are themn allocated singly.
+ * This is basically a simplified slab allocator.
+ *
+ * We don't use the Linux slab allocator because slab does not allow
+ * us to dump all the objects in one hit when we do a umount and tear
+ * down  all the tnodes and objects. slab requires that we first free
+ * the individual objects.
+ *
+ * Once yaffs has been mainlined I shall try to motivate for a change
+ * to slab to provide the extra features we need here.
+ */
 
 struct yaffs_tnode_list {
 	struct yaffs_tnode_list *next;
@@ -81,7 +47,7 @@ struct yaffs_allocator {
 	struct yaffs_tnode_list *alloc_tnode_list;
 
 	int n_obj_created;
-	struct yaffs_obj *free_objs;
+	struct list_head free_objs;
 	int n_free_objects;
 
 	struct yaffs_obj_list *allocated_obj_list;
@@ -89,14 +55,12 @@ struct yaffs_allocator {
 
 static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
 {
-
 	struct yaffs_allocator *allocator =
 	    (struct yaffs_allocator *)dev->allocator;
-
 	struct yaffs_tnode_list *tmp;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return;
 	}
 
@@ -106,7 +70,6 @@ static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
 		kfree(allocator->alloc_tnode_list->tnodes);
 		kfree(allocator->alloc_tnode_list);
 		allocator->alloc_tnode_list = tmp;
-
 	}
 
 	allocator->free_tnodes = NULL;
@@ -118,14 +81,15 @@ static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
 {
 	struct yaffs_allocator *allocator = dev->allocator;
 
-	if (allocator) {
-		allocator->alloc_tnode_list = NULL;
-		allocator->free_tnodes = NULL;
-		allocator->n_free_tnodes = 0;
-		allocator->n_tnodes_created = 0;
-	} else {
-		YBUG();
+	if (!allocator) {
+		BUG();
+		return;
 	}
+
+	allocator->alloc_tnode_list = NULL;
+	allocator->free_tnodes = NULL;
+	allocator->n_free_tnodes = 0;
+	allocator->n_tnodes_created = 0;
 }
 
 static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
@@ -140,7 +104,7 @@ static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
 	struct yaffs_tnode_list *tnl;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return YAFFS_FAIL;
 	}
 
@@ -148,7 +112,6 @@ static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
 		return YAFFS_OK;
 
 	/* make these things */
-
 	new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
 	mem = (u8 *) new_tnodes;
 
@@ -176,7 +139,6 @@ static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
 	 * NB If we can't add this to the management list it isn't fatal
 	 * but it just means we can't free this bunch of tnodes later.
 	 */
-
 	tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
 	if (!tnl) {
 		yaffs_trace(YAFFS_TRACE_ERROR,
@@ -188,7 +150,7 @@ static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
 		allocator->alloc_tnode_list = tnl;
 	}
 
-	yaffs_trace(YAFFS_TRACE_ALLOCATE,"Tnodes added");
+	yaffs_trace(YAFFS_TRACE_ALLOCATE, "Tnodes added");
 
 	return YAFFS_OK;
 }
@@ -200,7 +162,7 @@ struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
 	struct yaffs_tnode *tn = NULL;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return NULL;
 	}
 
@@ -223,7 +185,7 @@ void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 	struct yaffs_allocator *allocator = dev->allocator;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return;
 	}
 
@@ -235,17 +197,24 @@ void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
 	dev->checkpoint_blocks_required = 0;	/* force recalculation */
 }
 
+/*--------------- yaffs_obj alloaction ------------------------
+ *
+ * Free yaffs_objs are stored in a list using obj->siblings.
+ * The blocks of allocated objects are stored in a linked list.
+ */
+
 static void yaffs_init_raw_objs(struct yaffs_dev *dev)
 {
 	struct yaffs_allocator *allocator = dev->allocator;
 
-	if (allocator) {
-		allocator->allocated_obj_list = NULL;
-		allocator->free_objs = NULL;
-		allocator->n_free_objects = 0;
-	} else {
-		YBUG();
+	if (!allocator) {
+		BUG();
+		return;
 	}
+
+	allocator->allocated_obj_list = NULL;
+	INIT_LIST_HEAD(&allocator->free_objs);
+	allocator->n_free_objects = 0;
 }
 
 static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
@@ -254,7 +223,7 @@ static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
 	struct yaffs_obj_list *tmp;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return;
 	}
 
@@ -262,11 +231,10 @@ static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
 		tmp = allocator->allocated_obj_list->next;
 		kfree(allocator->allocated_obj_list->objects);
 		kfree(allocator->allocated_obj_list);
-
 		allocator->allocated_obj_list = tmp;
 	}
 
-	allocator->free_objs = NULL;
+	INIT_LIST_HEAD(&allocator->free_objs);
 	allocator->n_free_objects = 0;
 	allocator->n_obj_created = 0;
 }
@@ -274,13 +242,12 @@ static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
 static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
 {
 	struct yaffs_allocator *allocator = dev->allocator;
-
 	int i;
 	struct yaffs_obj *new_objs;
 	struct yaffs_obj_list *list;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return YAFFS_FAIL;
 	}
 
@@ -292,27 +259,19 @@ static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
 	list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
 
 	if (!new_objs || !list) {
-		if (new_objs) {
-			kfree(new_objs);
-			new_objs = NULL;
-		}
-		if (list) {
-			kfree(list);
-			list = NULL;
-		}
+		kfree(new_objs);
+		new_objs = NULL;
+		kfree(list);
+		list = NULL;
 		yaffs_trace(YAFFS_TRACE_ALLOCATE,
 			"Could not allocate more objects");
 		return YAFFS_FAIL;
 	}
 
 	/* Hook them into the free list */
-	for (i = 0; i < n_obj - 1; i++) {
-		new_objs[i].siblings.next =
-		    (struct list_head *)(&new_objs[i + 1]);
-	}
+	for (i = 0; i < n_obj; i++)
+		list_add(&new_objs[i].siblings, &allocator->free_objs);
 
-	new_objs[n_obj - 1].siblings.next = (void *)allocator->free_objs;
-	allocator->free_objs = new_objs;
 	allocator->n_free_objects += n_obj;
 	allocator->n_obj_created += n_obj;
 
@@ -328,21 +287,22 @@ static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
 struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
 {
 	struct yaffs_obj *obj = NULL;
+	struct list_head *lh;
 	struct yaffs_allocator *allocator = dev->allocator;
 
 	if (!allocator) {
-		YBUG();
+		BUG();
 		return obj;
 	}
 
 	/* If there are none left make more */
-	if (!allocator->free_objs)
+	if (list_empty(&allocator->free_objs))
 		yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
 
-	if (allocator->free_objs) {
-		obj = allocator->free_objs;
-		allocator->free_objs =
-		    (struct yaffs_obj *)(allocator->free_objs->siblings.next);
+	if (!list_empty(&allocator->free_objs)) {
+		lh = allocator->free_objs.next;
+		obj = list_entry(lh, struct yaffs_obj, siblings);
+		list_del_init(lh);
 		allocator->n_free_objects--;
 	}
 
@@ -354,43 +314,44 @@ void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
 
 	struct yaffs_allocator *allocator = dev->allocator;
 
-	if (!allocator)
-		YBUG();
-	else {
-		/* Link into the free list. */
-		obj->siblings.next = (struct list_head *)(allocator->free_objs);
-		allocator->free_objs = obj;
-		allocator->n_free_objects++;
+	if (!allocator) {
+		BUG();
+		return;
 	}
+
+	/* Link into the free list. */
+	list_add(&obj->siblings, &allocator->free_objs);
+	allocator->n_free_objects++;
 }
 
 void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
 {
-	if (dev->allocator) {
-		yaffs_deinit_raw_tnodes(dev);
-		yaffs_deinit_raw_objs(dev);
 
-		kfree(dev->allocator);
-		dev->allocator = NULL;
-	} else {
-		YBUG();
+	if (!dev->allocator) {
+		BUG();
+		return;
 	}
+
+	yaffs_deinit_raw_tnodes(dev);
+	yaffs_deinit_raw_objs(dev);
+	kfree(dev->allocator);
+	dev->allocator = NULL;
 }
 
 void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
 {
 	struct yaffs_allocator *allocator;
 
-	if (!dev->allocator) {
-		allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
-		if (allocator) {
-			dev->allocator = allocator;
-			yaffs_init_raw_tnodes(dev);
-			yaffs_init_raw_objs(dev);
-		}
-	} else {
-		YBUG();
+	if (dev->allocator) {
+		BUG();
+		return;
+	}
+
+	allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
+	if (allocator) {
+		dev->allocator = allocator;
+		yaffs_init_raw_tnodes(dev);
+		yaffs_init_raw_objs(dev);
 	}
 }
 
-#endif