Btrfs: Block sized tree extents and extent deletion
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/mkfs.c b/fs/btrfs/mkfs.c
index 584aba4..fd4e5de 100644
--- a/fs/btrfs/mkfs.c
+++ b/fs/btrfs/mkfs.c
@@ -23,17 +23,10 @@
info[0].blocknr = 16;
info[0].objectid = 1;
info[0].tree_root = 17;
- info[0].alloc_extent.blocknr = 0;
- info[0].alloc_extent.num_blocks = 64;
- /* 0-17 are used (inclusive) */
- info[0].alloc_extent.num_used = 18;
info[1].blocknr = 16;
info[1].objectid = 2;
- info[1].tree_root = 64;
- info[1].alloc_extent.blocknr = 64;
- info[1].alloc_extent.num_blocks = 64;
- info[1].alloc_extent.num_used = 1;
+ info[1].tree_root = 18;
ret = pwrite(fd, info, sizeof(info),
CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
if (ret != sizeof(info))
@@ -48,24 +41,36 @@
return -1;
empty_leaf.header.parentid = 2;
- empty_leaf.header.blocknr = 64;
- empty_leaf.header.nritems = 2;
+ empty_leaf.header.blocknr = 18;
+ empty_leaf.header.nritems = 3;
+
+ /* item1, reserve blocks 0-16 */
item.key.objectid = 0;
- item.key.offset = 64;
+ item.key.offset = 17;
item.key.flags = 0;
item.offset = LEAF_DATA_SIZE - sizeof(struct extent_item);
item.size = sizeof(struct extent_item);
extent_item.refs = 1;
- extent_item.owner = 1;
+ extent_item.owner = 0;
memcpy(empty_leaf.items, &item, sizeof(item));
memcpy(empty_leaf.data + item.offset, &extent_item, item.size);
- item.key.objectid = 64;
- item.key.offset = 64;
+
+ /* item2, give block 17 to the root */
+ item.key.objectid = 17;
+ item.key.offset = 1;
item.offset = LEAF_DATA_SIZE - sizeof(struct extent_item) * 2;
- extent_item.owner = 2;
+ extent_item.owner = 1;
memcpy(empty_leaf.items + 1, &item, sizeof(item));
memcpy(empty_leaf.data + item.offset, &extent_item, item.size);
- ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 64 * CTREE_BLOCKSIZE);
+
+ /* item3, give block 18 for the extent root */
+ item.key.objectid = 18;
+ item.key.offset = 1;
+ item.offset = LEAF_DATA_SIZE - sizeof(struct extent_item) * 3;
+ extent_item.owner = 2;
+ memcpy(empty_leaf.items + 2, &item, sizeof(item));
+ memcpy(empty_leaf.data + item.offset, &extent_item, item.size);
+ ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 18 * CTREE_BLOCKSIZE);
if (ret != sizeof(empty_leaf))
return -1;
return 0;