Commit a28ec197 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse
Browse files

Btrfs: Fixup reference counting on cows 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 02217ed2

fs/btrfs/Makefile

+1 −1
Original line number Diff line number Diff line 


CC=gcc

CFLAGS = -g -Wall

headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h

headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h list.h

objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o



# if you don't have sparse installed, use ls instead

fs/btrfs/ctree.c

+4 −5
Original line number Diff line number Diff line
@@ -50,16 +50,17 @@ int btrfs_cow_block(struct ctree_root *root, 
	memcpy(&cow->node, &buf->node, sizeof(buf->node));

	cow->node.header.blocknr = cow->blocknr;

	*cow_ret = cow;

	btrfs_inc_ref(root, buf);

	if (buf == root->node) {

		root->node = cow;

		cow->count++;

		if (buf != root->commit_root)

			free_extent(root, buf->blocknr, 1);

		tree_block_release(root, buf);

	} else {

		parent->node.blockptrs[parent_slot] = cow->blocknr;

		BUG_ON(list_empty(&parent->dirty));

	}

	if (0 && root != root->extent_root && !is_leaf(cow->node.header.flags)) {

		btrfs_inc_ref(root, cow);

		free_extent(root, buf->blocknr, 1);

	}

	tree_block_release(root, buf);

	return 0;
@@ -1018,7 +1019,6 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path, 
	slot = path->slots[0];

	nritems = l->header.nritems;

	mid = (nritems + 1)/ 2;



	right_buffer = alloc_free_block(root);

	BUG_ON(!right_buffer);

	BUG_ON(mid == nritems);
@@ -1170,7 +1170,6 @@ static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, 


	node = &parent->node;

	nritems = node->header.nritems;



	if (slot != nritems -1) {

		memmove(node->keys + slot, node->keys + slot + 1,

			sizeof(struct key) * (nritems - slot - 1));

fs/btrfs/ctree.h

+4 −0
Original line number Diff line number Diff line
@@ -51,10 +51,12 @@ struct tree_buffer; 
 */

struct ctree_root {

	struct tree_buffer *node;

	struct tree_buffer *commit_root;

	struct ctree_root *extent_root;

	struct key current_insert;

	int fp;

	struct radix_tree_root cache_radix;

	struct radix_tree_root pinned_radix;

	struct list_head trans;

	struct list_head cache;

	int cache_size;
@@ -151,4 +153,6 @@ int del_item(struct ctree_root *root, struct ctree_path *path); 
int insert_item(struct ctree_root *root, struct key *key, void *data, int data_size);

int next_leaf(struct ctree_root *root, struct ctree_path *path);

int leaf_free_space(struct leaf *leaf);

int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap);

int btrfs_finish_extent_commit(struct ctree_root *root);

#endif

fs/btrfs/disk-io.c

+26 −5
Original line number Diff line number Diff line
@@ -153,13 +153,24 @@ static int __commit_transaction(struct ctree_root *root) 
	return ret;

}



int commit_transaction(struct ctree_root *root)

int commit_transaction(struct ctree_root *root, struct ctree_super_block *s)

{

	int ret;

	int ret = 0;



	ret = __commit_transaction(root);

	if (!ret && root != root->extent_root)

		ret = __commit_transaction(root->extent_root);

	BUG_ON(ret);

	if (root->commit_root != root->node) {

		struct tree_buffer *snap = root->commit_root;

		root->commit_root = root->node;

		root->node->count++;

		ret = btrfs_drop_snapshot(root, snap);

		BUG_ON(ret);

		tree_block_release(root, snap);

	}

        write_ctree_super(root, s);

	btrfs_finish_extent_commit(root);

	return ret;

}
@@ -168,10 +179,13 @@ static int __setup_root(struct ctree_root *root, struct ctree_root *extent_root, 
{

	INIT_LIST_HEAD(&root->trans);

	INIT_LIST_HEAD(&root->cache);

	root->cache_size = 0;

	root->fp = fp;

	root->node = NULL;

	root->node = read_tree_block(root, info->tree_root);

	root->extent_root = extent_root;

	root->commit_root = NULL;

	root->node = read_tree_block(root, info->tree_root);

	memset(&root->current_insert, 0, sizeof(root->current_insert));

	return 0;

}
@@ -188,6 +202,8 @@ struct ctree_root *open_ctree(char *filename, struct ctree_super_block *super) 
		return NULL;

	}

	INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL);

	INIT_RADIX_TREE(&root->pinned_radix, GFP_KERNEL);

	INIT_RADIX_TREE(&extent_root->pinned_radix, GFP_KERNEL);

	INIT_RADIX_TREE(&extent_root->cache_radix, GFP_KERNEL);

	ret = pread(fp, super, sizeof(struct ctree_super_block),

		     CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
@@ -204,6 +220,8 @@ struct ctree_root *open_ctree(char *filename, struct ctree_super_block *super) 
	BUG_ON(ret < 0);

	__setup_root(root, extent_root, &super->root_info, fp);

	__setup_root(extent_root, extent_root, &super->extent_info, fp);

	root->commit_root = root->node;

	root->node->count++;

	return root;

}
@@ -236,9 +254,11 @@ static int drop_cache(struct ctree_root *root) 
	}

	return 0;

}

int close_ctree(struct ctree_root *root)

int close_ctree(struct ctree_root *root, struct ctree_super_block *s)

{

	commit_transaction(root);

	commit_transaction(root, s);

	__commit_transaction(root->extent_root);

	write_ctree_super(root, s);

	drop_cache(root->extent_root);

	drop_cache(root);

	BUG_ON(!list_empty(&root->trans));
@@ -249,6 +269,7 @@ int close_ctree(struct ctree_root *root) 
		tree_block_release(root, root->node);

	if (root->extent_root->node)

		tree_block_release(root->extent_root, root->extent_root->node);

	tree_block_release(root, root->commit_root);

	free(root);

	printf("on close %d blocks are allocated\n", allocated_blocks);

	return 0;

fs/btrfs/disk-io.h

+2 −2
Original line number Diff line number Diff line
@@ -18,9 +18,9 @@ struct tree_buffer *find_tree_block(struct ctree_root *root, u64 blocknr); 
int write_tree_block(struct ctree_root *root, struct tree_buffer *buf);

int dirty_tree_block(struct ctree_root *root, struct tree_buffer *buf);

int clean_tree_block(struct ctree_root *root, struct tree_buffer *buf);

int commit_transaction(struct ctree_root *root);

int commit_transaction(struct ctree_root *root, struct ctree_super_block *s);

struct ctree_root *open_ctree(char *filename, struct ctree_super_block *s);

int close_ctree(struct ctree_root *root);

int close_ctree(struct ctree_root *root, struct ctree_super_block *s);

void tree_block_release(struct ctree_root *root, struct tree_buffer *buf);

int write_ctree_super(struct ctree_root *root, struct ctree_super_block *s);

int mkfs(int fd);