Btrfs: early reference counting

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

fs/btrfs/ctree.h

@@ -142,8 +142,9 @@ struct ctree_path {
 };
 
 struct tree_buffer *alloc_free_block(struct ctree_root *root);
+int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf);
 int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks);
-int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p, int ins_len);
+int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p, int ins_len, int cow);
 void release_path(struct ctree_root *root, struct ctree_path *p);
 void init_path(struct ctree_path *p);
 int del_item(struct ctree_root *root, struct ctree_path *path);

fs/btrfs/disk-io.c

@@ -260,6 +260,8 @@ void tree_block_release(struct ctree_root *root, struct tree_buffer *buf)
 	if (buf->count < 0)
 		BUG();
 	if (buf->count == 0) {
+		BUG_ON(!list_empty(&buf->cache));
+		BUG_ON(!list_empty(&buf->dirty));
 		if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
 			BUG();
 		radix_tree_delete(&root->cache_radix, buf->blocknr);

fs/btrfs/extent-tree.c

@@ -15,6 +15,39 @@
  */
 #define CTREE_EXTENT_PENDING 0
 
+static int inc_block_ref(struct ctree_root *root, u64 blocknr)
+{
+	struct ctree_path path;
+	int ret;
+	struct key key;
+	struct leaf *l;
+	struct extent_item *item;
+	init_path(&path);
+	key.objectid = blocknr;
+	key.flags = 0;
+	key.offset = 1;
+	ret = search_slot(root->extent_root, &key, &path, 0, 1);
+	BUG_ON(ret != 0);
+	l = &path.nodes[0]->leaf;
+	item = (struct extent_item *)(l->data +
+				      l->items[path.slots[0]].offset);
+	item->refs++;
+	BUG_ON(list_empty(&path.nodes[0]->dirty));
+	release_path(root->extent_root, &path);
+	return 0;
+}
+
+int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf)
+{
+	u64 blocknr;
+	int i;
+	for (i = 0; i < buf->node.header.nritems; i++) {
+		blocknr = buf->node.blockptrs[i];
+		inc_block_ref(root, blocknr);
+	}
+	return 0;
+}
+
 /*
  * find all the blocks marked as pending in the radix tree and remove
  * them from the extent map
@@ -39,7 +72,7 @@ static int del_pending_extents(struct ctree_root *extent_root)
 			key.flags = 0;
 			key.offset = 1;
 			init_path(&path);
-			ret = search_slot(extent_root, &key, &path, -1);
+			ret = search_slot(extent_root, &key, &path, -1, 1);
 			if (ret) {
 				print_tree(extent_root, extent_root->node);
 				printf("unable to find %Lu\n", key.objectid);
@@ -83,7 +116,7 @@ int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
 		return 0;
 	}
 	init_path(&path);
-	ret = search_slot(extent_root, &key, &path, -1);
+	ret = search_slot(extent_root, &key, &path, -1, 1);
 	if (ret) {
 		print_tree(extent_root, extent_root->node);
 		printf("failed to find %Lu\n", key.objectid);
@@ -124,7 +157,7 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
 	ins->offset = 0;
 	ins->flags = 0;
 	start_found = 0;
-	ret = search_slot(root, ins, &path, 0);
+	ret = search_slot(root, ins, &path, 0, 0);
 	if (ret < 0)
 		goto error;
 
@@ -221,6 +254,8 @@ static int insert_pending_extents(struct ctree_root *extent_root)
 			ret = insert_item(extent_root, &key, &item,
 					  sizeof(item));
 			if (ret) {
+				printf("%Lu already in tree\n", key.objectid);
+				print_tree(extent_root, extent_root->node);
 				BUG();
 				// FIXME undo it and return sane
 				return ret;
@@ -228,6 +263,7 @@ static int insert_pending_extents(struct ctree_root *extent_root)
 			radix_tree_tag_clear(&extent_root->cache_radix,
 					     gang[i]->blocknr,
 					     CTREE_EXTENT_PENDING);
+			printf("%Lu is not pending\n", gang[i]->blocknr);
 			tree_block_release(extent_root, gang[i]);
 		}
 	}
@@ -266,15 +302,18 @@ int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
 		if (pending_ret)
 			return pending_ret;
 		*buf = find_tree_block(root, ins->objectid);
+		dirty_tree_block(root, *buf);
 		return 0;
 	}
 	/* we're allocating an extent for the extent tree, don't recurse */
 	BUG_ON(ins->offset != 1);
 	*buf = find_tree_block(root, ins->objectid);
 	BUG_ON(!*buf);
+	printf("%Lu is pending\n", ins->objectid);
 	radix_tree_tag_set(&root->cache_radix, ins->objectid,
 			   CTREE_EXTENT_PENDING);
 	(*buf)->count++;
+	dirty_tree_block(root, *buf);
 	return 0;
 
 }

fs/btrfs/quick-test.c

@@ -19,7 +19,7 @@ int main(int ac, char **av) {
 	int i;
 	int num;
 	int ret;
-	int run_size = 100000;
+	int run_size = 1024;
 	int max_key =  100000000;
 	int tree_size = 0;
 	struct ctree_path path;
@@ -57,7 +57,7 @@ int main(int ac, char **av) {
 		init_path(&path);
 		if (i % 10000 == 0)
 			fprintf(stderr, "search %d:%d\n", num, i);
-		ret = search_slot(root, &ins, &path, 0);
+		ret = search_slot(root, &ins, &path, 0, 0);
 		if (ret) {
 			print_tree(root, root->node);
 			printf("unable to find %d\n", num);
@@ -79,7 +79,7 @@ int main(int ac, char **av) {
 		num = next_key(i, max_key);
 		ins.objectid = num;
 		init_path(&path);
-		ret = search_slot(root, &ins, &path, -1);
+		ret = search_slot(root, &ins, &path, -1, 1);
 		if (!ret) {
 			if (i % 10000 == 0)
 				fprintf(stderr, "del %d:%d\n", num, i);
@@ -117,7 +117,7 @@ int main(int ac, char **av) {
 		init_path(&path);
 		if (i % 10000 == 0)
 			fprintf(stderr, "search %d:%d\n", num, i);
-		ret = search_slot(root, &ins, &path, 0);
+		ret = search_slot(root, &ins, &path, 0, 0);
 		if (ret) {
 			print_tree(root, root->node);
 			printf("unable to find %d\n", num);
@@ -131,7 +131,7 @@ int main(int ac, char **av) {
 		int slot;
 		ins.objectid = (u64)-1;
 		init_path(&path);
-		ret = search_slot(root, &ins, &path, -1);
+		ret = search_slot(root, &ins, &path, -1, 1);
 		if (ret == 0)
 			BUG();
 

fs/btrfs/random-test.c

@@ -93,7 +93,7 @@ static int del_one(struct ctree_root *root, struct radix_tree_root *radix)
 	ret = setup_key(radix, &key, 1);
 	if (ret < 0)
 		return 0;
-	ret = search_slot(root, &key, &path, -1);
+	ret = search_slot(root, &key, &path, -1, 1);
 	if (ret)
 		goto error;
 	ret = del_item(root, &path);
@@ -118,7 +118,7 @@ static int lookup_item(struct ctree_root *root, struct radix_tree_root *radix)
 	ret = setup_key(radix, &key, 1);
 	if (ret < 0)
 		return 0;
-	ret = search_slot(root, &key, &path, 0);
+	ret = search_slot(root, &key, &path, 0, 1);
 	release_path(root, &path);
 	if (ret)
 		goto error;
@@ -137,7 +137,7 @@ static int lookup_enoent(struct ctree_root *root, struct radix_tree_root *radix)
 	ret = setup_key(radix, &key, 0);
 	if (ret < 0)
 		return ret;
-	ret = search_slot(root, &key, &path, 0);
+	ret = search_slot(root, &key, &path, 0, 0);
 	release_path(root, &path);
 	if (ret <= 0)
 		goto error;
@@ -163,7 +163,7 @@ static int empty_tree(struct ctree_root *root, struct radix_tree_root *radix,
 	key.objectid = (unsigned long)-1;
 	while(nr-- >= 0) {
 		init_path(&path);
-		ret = search_slot(root, &key, &path, -1);
+		ret = search_slot(root, &key, &path, -1, 1);
 		if (ret < 0) {
 			release_path(root, &path);
 			return ret;
@@ -216,7 +216,7 @@ static int fill_tree(struct ctree_root *root, struct radix_tree_root *radix,
 				return ret;
 			}
 		}
-		if (i % 10000 == 0) {
+		if (i && i % 10000 == 0) {
 			printf("bigfill %d\n", i);
 		}
 		if (!keep_running)
@@ -263,7 +263,7 @@ static int fill_radix(struct ctree_root *root, struct radix_tree_root *radix)
 	key.objectid = (unsigned long)-1;
 	while(1) {
 		init_path(&path);
-		ret = search_slot(root, &key, &path, 0);
+		ret = search_slot(root, &key, &path, 0, 0);
 		if (ret < 0) {
 			release_path(root, &path);
 			return ret;