Btrfs: Fixup reference counting on cows

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

fs/btrfs/Makefile

 
 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

@@ -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

@@ -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

@@ -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

@@ -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);

fs/btrfs/print-tree.c

@@ -21,9 +21,11 @@ void print_leaf(struct leaf *l)
 			item->key.objectid, item->key.flags, item->key.offset,
 			item->offset, item->size);
 		fflush(stdout);
-		printf("\t\titem data %.*s\n", item->size, l->data+item->offset);
+		printf("\t\titem data %.*s\n", item->size,
+			l->data+item->offset);
 		ei = (struct extent_item *)(l->data + item->offset);
-		printf("\t\textent data %u %Lu\n", ei->refs, ei->owner);
+		printf("\t\textent data refs %u owner %Lu\n", ei->refs,
+			ei->owner);
 		fflush(stdout);
 	}
 }

fs/btrfs/quick-test.c

@@ -19,7 +19,7 @@ int main(int ac, char **av) {
 	int i;
 	int num;
 	int ret;
-	int run_size = 1024;
+	int run_size = 100000;
 	int max_key =  100000000;
 	int tree_size = 0;
 	struct ctree_path path;
@@ -44,9 +44,9 @@ int main(int ac, char **av) {
 		if (!ret)
 			tree_size++;
 		free(buf);
+
 	}
-	write_ctree_super(root, &super);
-	close_ctree(root);
+	close_ctree(root, &super);
 
 	root = open_ctree("dbfile", &super);
 	printf("starting search\n");
@@ -65,8 +65,7 @@ int main(int ac, char **av) {
 		}
 		release_path(root, &path);
 	}
-	write_ctree_super(root, &super);
-	close_ctree(root);
+	close_ctree(root, &super);
 	root = open_ctree("dbfile", &super);
 	printf("node %p level %d total ptrs %d free spc %lu\n", root->node,
 	        node_level(root->node->node.header.flags),
@@ -90,8 +89,7 @@ int main(int ac, char **av) {
 		}
 		release_path(root, &path);
 	}
-	write_ctree_super(root, &super);
-	close_ctree(root);
+	close_ctree(root, &super);
 	root = open_ctree("dbfile", &super);
 	srand(128);
 	for (i = 0; i < run_size; i++) {
@@ -106,8 +104,7 @@ int main(int ac, char **av) {
 			tree_size++;
 		free(buf);
 	}
-	write_ctree_super(root, &super);
-	close_ctree(root);
+	close_ctree(root, &super);
 	root = open_ctree("dbfile", &super);
 	srand(128);
 	printf("starting search2\n");
@@ -156,10 +153,17 @@ int main(int ac, char **av) {
 		}
 		release_path(root, &path);
 	}
+	/*
+	printf("previous tree:\n");
+	print_tree(root, root->commit_root);
+	printf("map before commit\n");
+	print_tree(root->extent_root, root->extent_root->node);
+	*/
+	commit_transaction(root, &super);
 	printf("tree size is now %d\n", tree_size);
+	printf("root %p commit root %p\n", root->node, root->commit_root);
 	printf("map tree\n");
 	print_tree(root->extent_root, root->extent_root->node);
-	write_ctree_super(root, &super);
-	close_ctree(root);
+	close_ctree(root, &super);
 	return 0;
 }

fs/btrfs/random-test.c

@@ -8,6 +8,7 @@
 #include "print-tree.h"
 
 int keep_running = 1;
+struct ctree_super_block super;
 
 static int setup_key(struct radix_tree_root *root, struct key *key, int exists)
 {
@@ -59,11 +60,6 @@ static int ins_one(struct ctree_root *root, struct radix_tree_root *radix)
 	return -1;
 }
 
-static int run_commit(struct ctree_root *root, struct radix_tree_root *radix)
-{
-	return commit_transaction(root);
-}
-
 static int insert_dup(struct ctree_root *root, struct radix_tree_root *radix)
 {
 	struct ctree_path path;
@@ -210,7 +206,7 @@ static int fill_tree(struct ctree_root *root, struct radix_tree_root *radix,
 			goto out;
 		}
 		if (i % 1000 == 0) {
-			ret = commit_transaction(root);
+			ret = commit_transaction(root, &super);
 			if (ret) {
 				fprintf(stderr, "fill commit failed\n");
 				return ret;
@@ -229,7 +225,7 @@ static int fill_tree(struct ctree_root *root, struct radix_tree_root *radix,
 static int bulk_op(struct ctree_root *root, struct radix_tree_root *radix)
 {
 	int ret;
-	int nr = rand() % 20000;
+	int nr = rand() % 5000;
 	static int run_nr = 0;
 
 	/* do the bulk op much less frequently */
@@ -247,7 +243,7 @@ static int bulk_op(struct ctree_root *root, struct radix_tree_root *radix)
 
 int (*ops[])(struct ctree_root *root, struct radix_tree_root *radix) =
 	{ ins_one, insert_dup, del_one, lookup_item,
-	  lookup_enoent, bulk_op, run_commit };
+	  lookup_enoent, bulk_op };
 
 static int fill_radix(struct ctree_root *root, struct radix_tree_root *radix)
 {
@@ -314,7 +310,6 @@ int print_usage(void)
 int main(int ac, char **av)
 {
 	RADIX_TREE(radix, GFP_KERNEL);
-	struct ctree_super_block super;
 	struct ctree_root *root;
 	int i;
 	int ret;
@@ -365,8 +360,7 @@ int main(int ac, char **av)
 			printf("open & close, root level %d nritems %d\n",
 				node_level(root->node->node.header.flags),
 				root->node->node.header.nritems);
-			write_ctree_super(root, &super);
-			close_ctree(root);
+			close_ctree(root, &super);
 			root = open_ctree("dbfile", &super);
 		}
 		while(count--) {
@@ -380,7 +374,7 @@ int main(int ac, char **av)
 				err = ret;
 				goto out;
 			}
-			if (ops[op] == bulk_op || ops[op] == run_commit)
+			if (ops[op] == bulk_op)
 				break;
 			if (keep_running == 0) {
 				err = 0;
@@ -389,8 +383,7 @@ int main(int ac, char **av)
 		}
 	}
 out:
-	write_ctree_super(root, &super);
-	close_ctree(root);
+	close_ctree(root, &super);
 	return err;
 }