yaffs: Clean up as per Ryan's comments

Clean up a whole lot of code issues raised by Ryan.

Some further reformatting etc to be mor kernel friendly.

Signed-off-by: Charles Manning <cdhmanning@gmail.com>

1 files changed, 64 insertions, 45 deletions

diff --git a/yaffs_allocator.c b/yaffs_allocator.c
index 1dd0c27..695c254 100644
--- a/yaffs_allocator.c
+++ b/yaffs_allocator.c
@@ -16,6 +16,19 @@
 #include "yaffs_trace.h"
 #include "yportenv.h"
 
+/*
+ * 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;
@@ -34,7 +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;
@@ -68,14 +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 {
+	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)
@@ -183,17 +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 {
+	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)
@@ -210,11 +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;
 }
@@ -249,13 +269,9 @@ static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
 	}
 
 	/* 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;
 
@@ -271,6 +287,7 @@ 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) {
@@ -279,13 +296,13 @@ struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
 	}
 
 	/* 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--;
 	}
 
@@ -297,42 +314,44 @@ void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
 
 	struct yaffs_allocator *allocator = dev->allocator;
 
-	if (!allocator)
+	if (!allocator) {
 		BUG();
-	else {
-		/* Link into the free list. */
-		obj->siblings.next = (struct list_head *)(allocator->free_objs);
-		allocator->free_objs = obj;
-		allocator->n_free_objects++;
+		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 {
+	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 {
+	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);
 	}
 }