Btrfs: variable block size support

Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/ctree.h

@@ -5,7 +5,6 @@
 #include "kerncompat.h"
 
 #define BTRFS_MAGIC "_BtRfS_M"
-#define BTRFS_BLOCKSIZE 1024
 
 #define BTRFS_ROOT_TREE_OBJECTID 1
 #define BTRFS_EXTENT_TREE_OBJECTID 2
@@ -52,8 +51,11 @@ struct btrfs_header {
 } __attribute__ ((__packed__));
 
 #define BTRFS_MAX_LEVEL 8
-#define NODEPTRS_PER_BLOCK ((BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)) / \
-			    (sizeof(struct btrfs_disk_key) + sizeof(u64)))
+#define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->blocksize - \
+			        sizeof(struct btrfs_header)) / \
+			       (sizeof(struct btrfs_disk_key) + sizeof(u64)))
+#define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
+#define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->blocksize))
 
 struct btrfs_buffer;
 
@@ -86,6 +88,7 @@ struct btrfs_root {
 	int ref_cows;
 	struct btrfs_root_item root_item;
 	struct btrfs_key root_key;
+	u32 blocksize;
 };
 
 /*
@@ -97,7 +100,7 @@ struct btrfs_super_block {
 	__le64 blocknr; /* this block number */
 	__le32 csum;
 	__le64 magic;
-	__le16 blocksize;
+	__le32 blocksize;
 	__le64 generation;
 	__le64 root;
 	__le64 total_blocks;
@@ -111,7 +114,7 @@ struct btrfs_super_block {
  */
 struct btrfs_item {
 	struct btrfs_disk_key key;
-	__le16 offset;
+	__le32 offset;
 	__le16 size;
 } __attribute__ ((__packed__));
 
@@ -122,24 +125,23 @@ struct btrfs_item {
  * The data is separate from the items to get the keys closer together
  * during searches.
  */
-#define LEAF_DATA_SIZE (BTRFS_BLOCKSIZE - sizeof(struct btrfs_header))
 struct btrfs_leaf {
 	struct btrfs_header header;
-	union {
-		struct btrfs_item items[LEAF_DATA_SIZE/
-				        sizeof(struct btrfs_item)];
-		u8 data[BTRFS_BLOCKSIZE - sizeof(struct btrfs_header)];
-	};
+	struct btrfs_item items[];
 } __attribute__ ((__packed__));
 
 /*
  * all non-leaf blocks are nodes, they hold only keys and pointers to
  * other blocks
  */
+struct btrfs_key_ptr {
+	struct btrfs_disk_key key;
+	__le64 blockptr;
+} __attribute__ ((__packed__));
+
 struct btrfs_node {
 	struct btrfs_header header;
-	struct btrfs_disk_key keys[NODEPTRS_PER_BLOCK];
-	__le64 blockptrs[NODEPTRS_PER_BLOCK];
+	struct btrfs_key_ptr ptrs[];
 } __attribute__ ((__packed__));
 
 /*
@@ -186,28 +188,28 @@ static inline void btrfs_set_extent_refs(struct btrfs_extent_item *ei, u32 val)
 
 static inline u64 btrfs_node_blockptr(struct btrfs_node *n, int nr)
 {
-	return le64_to_cpu(n->blockptrs[nr]);
+	return le64_to_cpu(n->ptrs[nr].blockptr);
 }
 
 static inline void btrfs_set_node_blockptr(struct btrfs_node *n, int nr,
 					   u64 val)
 {
-	n->blockptrs[nr] = cpu_to_le64(val);
+	n->ptrs[nr].blockptr = cpu_to_le64(val);
 }
 
-static inline u16 btrfs_item_offset(struct btrfs_item *item)
+static inline u32 btrfs_item_offset(struct btrfs_item *item)
 {
-	return le16_to_cpu(item->offset);
+	return le32_to_cpu(item->offset);
 }
 
-static inline void btrfs_set_item_offset(struct btrfs_item *item, u16 val)
+static inline void btrfs_set_item_offset(struct btrfs_item *item, u32 val)
 {
-	item->offset = cpu_to_le16(val);
+	item->offset = cpu_to_le32(val);
 }
 
-static inline u16 btrfs_item_end(struct btrfs_item *item)
+static inline u32 btrfs_item_end(struct btrfs_item *item)
 {
-	return le16_to_cpu(item->offset) + le16_to_cpu(item->size);
+	return le32_to_cpu(item->offset) + le16_to_cpu(item->size);
 }
 
 static inline u16 btrfs_item_size(struct btrfs_item *item)
@@ -390,20 +392,26 @@ static inline void btrfs_set_super_blocks_used(struct btrfs_super_block *s,
 	s->blocks_used = cpu_to_le64(val);
 }
 
-static inline u16 btrfs_super_blocksize(struct btrfs_super_block *s)
+static inline u32 btrfs_super_blocksize(struct btrfs_super_block *s)
 {
-	return le16_to_cpu(s->blocksize);
+	return le32_to_cpu(s->blocksize);
 }
 
 static inline void btrfs_set_super_blocksize(struct btrfs_super_block *s,
-						u16 val)
+						u32 val)
+{
+	s->blocksize = cpu_to_le32(val);
+}
+
+static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l)
 {
-	s->blocksize = cpu_to_le16(val);
+	return (u8 *)l->items;
 }
 
 /* helper function to cast into the data area of the leaf. */
 #define btrfs_item_ptr(leaf, slot, type) \
-	((type *)((leaf)->data + btrfs_item_offset((leaf)->items + (slot))))
+	((type *)(btrfs_leaf_data(leaf) + \
+	btrfs_item_offset((leaf)->items + (slot))))
 
 struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root);
 int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf);
@@ -416,7 +424,7 @@ int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *key,
 		void *data, int data_size);
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
-int btrfs_leaf_free_space(struct btrfs_leaf *leaf);
+int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf);
 int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap);
 int btrfs_finish_extent_commit(struct btrfs_root *root);
 int btrfs_del_root(struct btrfs_root *root, struct btrfs_key *key);

fs/btrfs/disk-io.c

@@ -46,7 +46,8 @@ struct btrfs_buffer *alloc_tree_block(struct btrfs_root *root, u64 blocknr)
 {
 	struct btrfs_buffer *buf;
 	int ret;
-	buf = malloc(sizeof(struct btrfs_buffer));
+
+	buf = malloc(sizeof(struct btrfs_buffer) + root->blocksize);
 	if (!buf)
 		return buf;
 	allocated_blocks++;
@@ -84,7 +85,7 @@ struct btrfs_buffer *find_tree_block(struct btrfs_root *root, u64 blocknr)
 
 struct btrfs_buffer *read_tree_block(struct btrfs_root *root, u64 blocknr)
 {
-	loff_t offset = blocknr * BTRFS_BLOCKSIZE;
+	loff_t offset = blocknr * root->blocksize;
 	struct btrfs_buffer *buf;
 	int ret;
 
@@ -95,8 +96,8 @@ struct btrfs_buffer *read_tree_block(struct btrfs_root *root, u64 blocknr)
 		buf = alloc_tree_block(root, blocknr);
 		if (!buf)
 			return NULL;
-		ret = pread(root->fp, &buf->node, BTRFS_BLOCKSIZE, offset);
-		if (ret != BTRFS_BLOCKSIZE) {
+		ret = pread(root->fp, &buf->node, root->blocksize, offset);
+		if (ret != root->blocksize) {
 			free(buf);
 			return NULL;
 		}
@@ -127,13 +128,13 @@ int clean_tree_block(struct btrfs_root *root, struct btrfs_buffer *buf)
 int write_tree_block(struct btrfs_root *root, struct btrfs_buffer *buf)
 {
 	u64 blocknr = buf->blocknr;
-	loff_t offset = blocknr * BTRFS_BLOCKSIZE;
+	loff_t offset = blocknr * root->blocksize;
 	int ret;
 
 	if (buf->blocknr != btrfs_header_blocknr(&buf->node.header))
 		BUG();
-	ret = pwrite(root->fp, &buf->node, BTRFS_BLOCKSIZE, offset);
-	if (ret != BTRFS_BLOCKSIZE)
+	ret = pwrite(root->fp, &buf->node, root->blocksize, offset);
+	if (ret != root->blocksize)
 		return ret;
 	return 0;
 }
@@ -215,7 +216,8 @@ int btrfs_commit_transaction(struct btrfs_root *root,
 	return ret;
 }
 
-static int __setup_root(struct btrfs_root *root, u64 objectid, int fp)
+static int __setup_root(struct btrfs_super_block *super,
+			struct btrfs_root *root, u64 objectid, int fp)
 {
 	INIT_LIST_HEAD(&root->trans);
 	INIT_LIST_HEAD(&root->cache);
@@ -223,6 +225,8 @@ static int __setup_root(struct btrfs_root *root, u64 objectid, int fp)
 	root->fp = fp;
 	root->node = NULL;
 	root->commit_root = NULL;
+	root->blocksize = btrfs_super_blocksize(super);
+	root->ref_cows = 0;
 	memset(&root->current_insert, 0, sizeof(root->current_insert));
 	memset(&root->last_insert, 0, sizeof(root->last_insert));
 	memset(&root->root_key, 0, sizeof(root->root_key));
@@ -230,19 +234,19 @@ static int __setup_root(struct btrfs_root *root, u64 objectid, int fp)
 	return 0;
 }
 
-static int find_and_setup_root(struct btrfs_root *tree_root, u64 objectid,
-			struct btrfs_root *root, int fp)
+static int find_and_setup_root(struct btrfs_super_block *super,
+			       struct btrfs_root *tree_root, u64 objectid,
+			       struct btrfs_root *root, int fp)
 {
 	int ret;
 
-	__setup_root(root, objectid, fp);
+	__setup_root(super, root, objectid, fp);
 	ret = btrfs_find_last_root(tree_root, objectid,
 				   &root->root_item, &root->root_key);
 	BUG_ON(ret);
 
 	root->node = read_tree_block(root,
 				     btrfs_root_blocknr(&root->root_item));
-	root->ref_cows = 0;
 	BUG_ON(!root->node);
 	return 0;
 }
@@ -277,28 +281,28 @@ struct btrfs_root *open_ctree(char *filename, struct btrfs_super_block *super)
 	INIT_RADIX_TREE(&tree_root->cache_radix, GFP_KERNEL);
 
 	ret = pread(fp, super, sizeof(struct btrfs_super_block),
-		     BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE));
+		     BTRFS_SUPER_INFO_OFFSET);
 	if (ret == 0 || btrfs_super_root(super) == 0) {
 		printf("making new FS!\n");
-		ret = mkfs(fp, 0, BTRFS_BLOCKSIZE);
+		ret = mkfs(fp, 0, 1024);
 		if (ret)
 			return NULL;
 		ret = pread(fp, super, sizeof(struct btrfs_super_block),
-			     BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE));
+			     BTRFS_SUPER_INFO_OFFSET);
 		if (ret != sizeof(struct btrfs_super_block))
 			return NULL;
 	}
 	BUG_ON(ret < 0);
 
-	__setup_root(tree_root, BTRFS_ROOT_TREE_OBJECTID, fp);
+	__setup_root(super, tree_root, BTRFS_ROOT_TREE_OBJECTID, fp);
 	tree_root->node = read_tree_block(tree_root, btrfs_super_root(super));
 	BUG_ON(!tree_root->node);
 
-	ret = find_and_setup_root(tree_root, BTRFS_EXTENT_TREE_OBJECTID,
+	ret = find_and_setup_root(super, tree_root, BTRFS_EXTENT_TREE_OBJECTID,
 				  extent_root, fp);
 	BUG_ON(ret);
 
-	ret = find_and_setup_root(tree_root, BTRFS_FS_TREE_OBJECTID,
+	ret = find_and_setup_root(super, tree_root, BTRFS_FS_TREE_OBJECTID,
 				  root, fp);
 	BUG_ON(ret);
 
@@ -313,7 +317,7 @@ int write_ctree_super(struct btrfs_root *root, struct btrfs_super_block *s)
 	int ret;
 	btrfs_set_super_root(s, root->tree_root->node->blocknr);
 	ret = pwrite(root->fp, s, sizeof(*s),
-		     BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE));
+		     BTRFS_SUPER_INFO_OFFSET);
 	if (ret != sizeof(*s)) {
 		fprintf(stderr, "failed to write new super block err %d\n", ret);
 		return ret;

fs/btrfs/disk-io.h

@@ -5,12 +5,12 @@
 struct btrfs_buffer {
 	u64 blocknr;
 	int count;
+	struct list_head dirty;
+	struct list_head cache;
 	union {
 		struct btrfs_node node;
 		struct btrfs_leaf leaf;
 	};
-	struct list_head dirty;
-	struct list_head cache;
 };
 
 struct btrfs_buffer *read_tree_block(struct btrfs_root *root, u64 blocknr);
@@ -24,9 +24,8 @@ struct btrfs_root *open_ctree(char *filename, struct btrfs_super_block *s);
 int close_ctree(struct btrfs_root *root, struct btrfs_super_block *s);
 void btrfs_block_release(struct btrfs_root *root, struct btrfs_buffer *buf);
 int write_ctree_super(struct btrfs_root *root, struct btrfs_super_block *s);
-int mkfs(int fd, u64 num_blocks, u16 blocksize);
-
+int mkfs(int fd, u64 num_blocks, u32 blocksize);
 
-#define BTRFS_SUPER_INFO_OFFSET(bs) (16 * (bs))
+#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)
 
 #endif

fs/btrfs/extent-tree.c

@@ -143,7 +143,6 @@ static int __free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks)
 	struct btrfs_key key;
 	struct btrfs_root *extent_root = root->extent_root;
 	int ret;
-	struct btrfs_item *item;
 	struct btrfs_extent_item *ei;
 	struct btrfs_key ins;
 	u32 refs;
@@ -161,9 +160,8 @@ static int __free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks)
 		printf("failed to find %Lu\n", key.objectid);
 		BUG();
 	}
-	item = path.nodes[0]->leaf.items + path.slots[0];
-	ei = (struct btrfs_extent_item *)(path.nodes[0]->leaf.data +
-				    btrfs_item_offset(item));
+	ei = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
+			    struct btrfs_extent_item);
 	BUG_ON(ei->refs == 0);
 	refs = btrfs_extent_refs(ei) - 1;
 	btrfs_set_extent_refs(ei, refs);

fs/btrfs/mkfs.c

@@ -10,19 +10,20 @@
 #include "ctree.h"
 #include "disk-io.h"
 
-int mkfs(int fd, u64 num_blocks, u16 blocksize)
+int mkfs(int fd, u64 num_blocks, u32 blocksize)
 {
 	struct btrfs_super_block super;
-	struct btrfs_leaf empty_leaf;
+	struct btrfs_leaf *empty_leaf;
 	struct btrfs_root_item root_item;
 	struct btrfs_item item;
 	struct btrfs_extent_item extent_item;
 	char *block;
 	int ret;
-	u16 itemoff;
+	u32 itemoff;
+	u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;
 
-	btrfs_set_super_blocknr(&super, 16);
-	btrfs_set_super_root(&super, 17);
+	btrfs_set_super_blocknr(&super, start_block);
+	btrfs_set_super_root(&super, start_block + 1);
 	strcpy((char *)(&super.magic), BTRFS_MAGIC);
 	btrfs_set_super_blocksize(&super, blocksize);
 	btrfs_set_super_total_blocks(&super, num_blocks);
@@ -32,168 +33,98 @@ int mkfs(int fd, u64 num_blocks, u16 blocksize)
 	memset(block, 0, blocksize);
 	BUG_ON(sizeof(super) > blocksize);
 	memcpy(block, &super, sizeof(super));
-	ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET(blocksize));
+	ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET);
 	BUG_ON(ret != blocksize);
 
 	/* create the tree of root objects */
-	memset(&empty_leaf, 0, sizeof(empty_leaf));
-	btrfs_set_header_parentid(&empty_leaf.header, BTRFS_ROOT_TREE_OBJECTID);
-	btrfs_set_header_blocknr(&empty_leaf.header, 17);
-	btrfs_set_header_nritems(&empty_leaf.header, 2);
+	empty_leaf = malloc(blocksize);
+	memset(empty_leaf, 0, blocksize);
+	btrfs_set_header_parentid(&empty_leaf->header,
+				  BTRFS_ROOT_TREE_OBJECTID);
+	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1);
+	btrfs_set_header_nritems(&empty_leaf->header, 2);
 
 	/* create the items for the root tree */
-	btrfs_set_root_blocknr(&root_item, 18);
+	btrfs_set_root_blocknr(&root_item, start_block + 2);
 	btrfs_set_root_refs(&root_item, 1);
-	itemoff = LEAF_DATA_SIZE - sizeof(root_item);
+	itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
 	btrfs_set_item_offset(&item, itemoff);
 	btrfs_set_item_size(&item, sizeof(root_item));
 	btrfs_set_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
 	btrfs_set_key_offset(&item.key, 0);
 	btrfs_set_key_flags(&item.key, 0);
-	memcpy(empty_leaf.items, &item, sizeof(item));
-	memcpy(empty_leaf.data + itemoff, &root_item, sizeof(root_item));
+	memcpy(empty_leaf->items, &item, sizeof(item));
+	memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
+		&root_item, sizeof(root_item));
 
-	btrfs_set_root_blocknr(&root_item, 19);
+	btrfs_set_root_blocknr(&root_item, start_block + 3);
 	itemoff = itemoff - sizeof(root_item);
 	btrfs_set_item_offset(&item, itemoff);
 	btrfs_set_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
-	memcpy(empty_leaf.items + 1, &item, sizeof(item));
-	memcpy(empty_leaf.data + itemoff, &root_item, sizeof(root_item));
-	ret = pwrite(fd, &empty_leaf, blocksize, 17 * blocksize);
+	memcpy(empty_leaf->items + 1, &item, sizeof(item));
+	memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
+		&root_item, sizeof(root_item));
+	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize);
 
 	/* create the items for the extent tree */
-	btrfs_set_header_parentid(&empty_leaf.header,
+	btrfs_set_header_parentid(&empty_leaf->header,
 				  BTRFS_EXTENT_TREE_OBJECTID);
-	btrfs_set_header_blocknr(&empty_leaf.header, 18);
-	btrfs_set_header_nritems(&empty_leaf.header, 4);
+	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2);
+	btrfs_set_header_nritems(&empty_leaf->header, 4);
 
 	/* item1, reserve blocks 0-16 */
 	btrfs_set_key_objectid(&item.key, 0);
-	btrfs_set_key_offset(&item.key, 17);
+	btrfs_set_key_offset(&item.key, start_block + 1);
 	btrfs_set_key_flags(&item.key, 0);
-	itemoff = LEAF_DATA_SIZE - sizeof(struct btrfs_extent_item);
+	itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) -
+			sizeof(struct btrfs_extent_item);
 	btrfs_set_item_offset(&item, itemoff);
 	btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
 	btrfs_set_extent_refs(&extent_item, 1);
 	btrfs_set_extent_owner(&extent_item, 0);
-	memcpy(empty_leaf.items, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
+	memcpy(empty_leaf->items, &item, sizeof(item));
+	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
+		&extent_item, btrfs_item_size(&item));
 
 	/* item2, give block 17 to the root */
-	btrfs_set_key_objectid(&item.key, 17);
+	btrfs_set_key_objectid(&item.key, start_block + 1);
 	btrfs_set_key_offset(&item.key, 1);
 	itemoff = itemoff - sizeof(struct btrfs_extent_item);
 	btrfs_set_item_offset(&item, itemoff);
 	btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
-	memcpy(empty_leaf.items + 1, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
+	memcpy(empty_leaf->items + 1, &item, sizeof(item));
+	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
+		&extent_item, btrfs_item_size(&item));
 
 	/* item3, give block 18 to the extent root */
-	btrfs_set_key_objectid(&item.key, 18);
+	btrfs_set_key_objectid(&item.key, start_block + 2);
 	btrfs_set_key_offset(&item.key, 1);
 	itemoff = itemoff - sizeof(struct btrfs_extent_item);
 	btrfs_set_item_offset(&item, itemoff);
 	btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID);
-	memcpy(empty_leaf.items + 2, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
+	memcpy(empty_leaf->items + 2, &item, sizeof(item));
+	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
+		&extent_item, btrfs_item_size(&item));
 
 	/* item4, give block 19 to the FS root */
-	btrfs_set_key_objectid(&item.key, 19);
+	btrfs_set_key_objectid(&item.key, start_block + 3);
 	btrfs_set_key_offset(&item.key, 1);
 	itemoff = itemoff - sizeof(struct btrfs_extent_item);
 	btrfs_set_item_offset(&item, itemoff);
 	btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID);
-	memcpy(empty_leaf.items + 3, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
-	ret = pwrite(fd, &empty_leaf, blocksize, 18 * blocksize);
-	if (ret != sizeof(empty_leaf))
+	memcpy(empty_leaf->items + 3, &item, sizeof(item));
+	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
+		&extent_item, btrfs_item_size(&item));
+	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
+	if (ret != blocksize)
 		return -1;
 
 	/* finally create the FS root */
-	btrfs_set_header_parentid(&empty_leaf.header, BTRFS_FS_TREE_OBJECTID);
-	btrfs_set_header_blocknr(&empty_leaf.header, 19);
-	btrfs_set_header_nritems(&empty_leaf.header, 0);
-	ret = pwrite(fd, &empty_leaf, blocksize, 19 * blocksize);
-	if (ret != sizeof(empty_leaf))
+	btrfs_set_header_parentid(&empty_leaf->header, BTRFS_FS_TREE_OBJECTID);
+	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3);
+	btrfs_set_header_nritems(&empty_leaf->header, 0);
+	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize);
+	if (ret != blocksize)
 		return -1;
 	return 0;
 }
-
-#if 0
-int mkfs(int fd)
-{
-	struct btrfs_root_info info[2];
-	struct btrfs_leaf empty_leaf;
-	struct btrfs_item item;
-	struct btrfs_extent_item extent_item;
-	int ret;
-
-	/* setup the super block area */
-	memset(info, 0, sizeof(info));
-	btrfs_set_root_blocknr(info, 16);
-	btrfs_set_root_objectid(info, 1);
-	btrfs_set_root_tree_root(info, 17);
-
-	btrfs_set_root_blocknr(info + 1, 16);
-	btrfs_set_root_objectid(info + 1, 2);
-	btrfs_set_root_tree_root(info + 1, 18);
-
-	ret = pwrite(fd, info, sizeof(info),
-		     BTRFS_SUPER_INFO_OFFSET(BTRFS_BLOCKSIZE));
-	if (ret != sizeof(info))
-		return -1;
-
-	/* create leaves for the tree root and extent root */
-	memset(&empty_leaf, 0, sizeof(empty_leaf));
-	btrfs_set_header_parentid(&empty_leaf.header, 1);
-	btrfs_set_header_blocknr(&empty_leaf.header, 17);
-	ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 17 * BTRFS_BLOCKSIZE);
-	if (ret != sizeof(empty_leaf))
-		return -1;
-
-	btrfs_set_header_parentid(&empty_leaf.header, 2);
-	btrfs_set_header_blocknr(&empty_leaf.header, 18);
-	btrfs_set_header_nritems(&empty_leaf.header, 3);
-
-	/* item1, reserve blocks 0-16 */
-	btrfs_set_key_objectid(&item.key, 0);
-	btrfs_set_key_offset(&item.key, 17);
-	btrfs_set_key_flags(&item.key, 0);
-	btrfs_set_item_offset(&item, LEAF_DATA_SIZE -
-			      sizeof(struct btrfs_extent_item));
-	btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
-	btrfs_set_extent_refs(&extent_item, 1);
-	btrfs_set_extent_owner(&extent_item, 0);
-	memcpy(empty_leaf.items, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
-
-	/* item2, give block 17 to the root */
-	btrfs_set_key_objectid(&item.key, 17);
-	btrfs_set_key_offset(&item.key, 1);
-	btrfs_set_item_offset(&item, LEAF_DATA_SIZE -
-			      sizeof(struct btrfs_extent_item) * 2);
-	btrfs_set_extent_owner(&extent_item, 1);
-	memcpy(empty_leaf.items + 1, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
-
-	/* item3, give block 18 for the extent root */
-	btrfs_set_key_objectid(&item.key, 18);
-	btrfs_set_key_offset(&item.key, 1);
-	btrfs_set_item_offset(&item, LEAF_DATA_SIZE -
-			      sizeof(struct btrfs_extent_item) * 3);
-	btrfs_set_extent_owner(&extent_item, 2);
-	memcpy(empty_leaf.items + 2, &item, sizeof(item));
-	memcpy(empty_leaf.data + btrfs_item_offset(&item), &extent_item,
-		btrfs_item_size(&item));
-	ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 18 * BTRFS_BLOCKSIZE);
-	if (ret != sizeof(empty_leaf))
-		return -1;
-	return 0;
-}
-#endif

fs/btrfs/print-tree.c

@@ -5,7 +5,7 @@
 #include "ctree.h"
 #include "disk-io.h"
 
-void btrfs_print_leaf(struct btrfs_leaf *l)
+void btrfs_print_leaf(struct btrfs_root *root, struct btrfs_leaf *l)
 {
 	int i;
 	u32 nr = btrfs_header_nritems(&l->header);
@@ -13,7 +13,8 @@ void btrfs_print_leaf(struct btrfs_leaf *l)
 	struct btrfs_extent_item *ei;
 	struct btrfs_root_item *ri;
 	printf("leaf %Lu total ptrs %d free space %d\n",
-		btrfs_header_blocknr(&l->header), nr, btrfs_leaf_free_space(l));
+		btrfs_header_blocknr(&l->header), nr,
+		btrfs_leaf_free_space(root, l));
 	fflush(stdout);
 	for (i = 0 ; i < nr ; i++) {
 		item = l->items + i;
@@ -25,7 +26,7 @@ void btrfs_print_leaf(struct btrfs_leaf *l)
 			btrfs_item_offset(item),
 			btrfs_item_size(item));
 		printf("\t\titem data %.*s\n", btrfs_item_size(item),
-			l->data + btrfs_item_offset(item));
+			btrfs_leaf_data(l) + btrfs_item_offset(item));
 		ei = btrfs_item_ptr(l, i, struct btrfs_extent_item);
 		printf("\t\textent data refs %u owner %Lu\n",
 			btrfs_extent_refs(ei), btrfs_extent_owner(ei));
@@ -46,18 +47,18 @@ void btrfs_print_tree(struct btrfs_root *root, struct btrfs_buffer *t)
 	c = &t->node;
 	nr = btrfs_header_nritems(&c->header);
 	if (btrfs_is_leaf(c)) {
-		btrfs_print_leaf((struct btrfs_leaf *)c);
+		btrfs_print_leaf(root, (struct btrfs_leaf *)c);
 		return;
 	}
 	printf("node %Lu level %d total ptrs %d free spc %u\n", t->blocknr,
 	        btrfs_header_level(&c->header), nr,
-		(u32)NODEPTRS_PER_BLOCK - nr);
+		(u32)BTRFS_NODEPTRS_PER_BLOCK(root) - nr);
 	fflush(stdout);
 	for (i = 0; i < nr; i++) {
 		printf("\tkey %d (%Lu %u %Lu) block %Lu\n",
 		       i,
-		       c->keys[i].objectid, c->keys[i].flags, c->keys[i].offset,
-		       btrfs_node_blockptr(c, i));
+		       c->ptrs[i].key.objectid, c->ptrs[i].key.flags,
+		       c->ptrs[i].key.offset, btrfs_node_blockptr(c, i));
 		fflush(stdout);
 	}
 	for (i = 0; i < nr; i++) {

fs/btrfs/print-tree.h

 
-void btrfs_print_leaf(struct btrfs_leaf *l);
+void btrfs_print_leaf(struct btrfs_root *root, struct btrfs_leaf *l);
 void btrfs_print_tree(struct btrfs_root *root, struct btrfs_buffer *t);

fs/btrfs/quick-test.c

@@ -73,7 +73,7 @@ int main(int ac, char **av) {
 	printf("node %p level %d total ptrs %d free spc %lu\n", root->node,
 	        btrfs_header_level(&root->node->node.header),
 		btrfs_header_nritems(&root->node->node.header),
-		NODEPTRS_PER_BLOCK -
+		BTRFS_NODEPTRS_PER_BLOCK(root) -
 		btrfs_header_nritems(&root->node->node.header));
 	printf("all searches good, deleting some items\n");
 	i = 0;

fs/btrfs/root-tree.c

@@ -31,7 +31,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
 		ret = 1;
 		goto out;
 	}
-	memcpy(item, l->data + btrfs_item_offset(l->items + slot),
+	memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
 		sizeof(*item));
 	btrfs_disk_key_to_cpu(key, &l->items[slot].key);
 	btrfs_release_path(root, &path);
@@ -55,7 +55,7 @@ int btrfs_update_root(struct btrfs_root *root, struct btrfs_key *key,
 	BUG_ON(ret != 0);
 	l = &path.nodes[0]->leaf;
 	slot = path.slots[0];
-	memcpy(l->data + btrfs_item_offset(l->items + slot), item,
+	memcpy(btrfs_item_ptr(l, slot, struct btrfs_root_item), item,
 		sizeof(*item));
 out:
 	btrfs_release_path(root, &path);