Add fsx-style randomized tree tester

Add debug-tree command to print the tree
Add extent-tree.c to the repo
Comment ctree.h

1 files changed, 296 insertions, 0 deletions

diff --git a/extent-tree.c b/extent-tree.c
new file mode 100644
index 00000000..2b663ef8
--- /dev/null
+++ b/extent-tree.c
@@ -0,0 +1,296 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "kerncompat.h"
+#include "radix-tree.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "print-tree.h"
+
+/*
+ * pending extents are blocks that we're trying to allocate in the extent
+ * map while trying to grow the map because of other allocations.  To avoid
+ * recursing, they are tagged in the radix tree and cleaned up after
+ * other allocations are done.  The pending tag is also used in the same
+ * manner for deletes.
+ */
+#define CTREE_EXTENT_PENDING 0
+
+/*
+ * find all the blocks marked as pending in the radix tree and remove
+ * them from the extent map
+ */
+static int del_pending_extents(struct ctree_root *extent_root)
+{
+	int ret;
+	struct key key;
+	struct tree_buffer *gang[4];
+	int i;
+	struct ctree_path path;
+
+	while(1) {
+		ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
+						 (void **)gang, 0,
+						 ARRAY_SIZE(gang),
+						 CTREE_EXTENT_PENDING);
+		if (!ret)
+			break;
+		for (i = 0; i < ret; i++) {
+			key.objectid = gang[i]->blocknr;
+			key.flags = 0;
+			key.offset = 1;
+			init_path(&path);
+			ret = search_slot(extent_root, &key, &path, 0);
+			if (ret) {
+				print_tree(extent_root, extent_root->node);
+				printf("unable to find %lu\n", key.objectid);
+				BUG();
+				// FIXME undo it and return sane
+				return ret;
+			}
+			ret = del_item(extent_root, &path);
+			if (ret) {
+				BUG();
+				return ret;
+			}
+			release_path(extent_root, &path);
+			radix_tree_tag_clear(&extent_root->cache_radix,
+						gang[i]->blocknr,
+						CTREE_EXTENT_PENDING);
+			tree_block_release(extent_root, gang[i]);
+		}
+	}
+	return 0;
+}
+
+/*
+ * remove an extent from the root, returns 0 on success
+ */
+int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
+{
+	struct ctree_path path;
+	struct key key;
+	struct ctree_root *extent_root = root->extent_root;
+	struct tree_buffer *t;
+	int pending_ret;
+	int ret;
+	key.objectid = blocknr;
+	key.flags = 0;
+	key.offset = num_blocks;
+	if (root == extent_root) {
+		t = read_tree_block(root, key.objectid);
+		radix_tree_tag_set(&root->cache_radix, key.objectid,
+				   CTREE_EXTENT_PENDING);
+		return 0;
+	}
+	init_path(&path);
+	ret = search_slot(extent_root, &key, &path, 0);
+	if (ret) {
+		print_tree(extent_root, extent_root->node);
+		printf("failed to find %lu\n", key.objectid);
+		BUG();
+	}
+	ret = del_item(extent_root, &path);
+	if (ret)
+		BUG();
+	release_path(extent_root, &path);
+	pending_ret = del_pending_extents(root->extent_root);
+	return ret ? ret : pending_ret;
+}
+
+/*
+ * walks the btree of allocated extents and find a hole of a given size.
+ * The key ins is changed to record the hole:
+ * ins->objectid == block start
+ * ins->flags = 0
+ * ins->offset == number of blocks
+ * Any available blocks before search_start are skipped.
+ */
+int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
+		     u64 search_start, u64 search_end, struct key *ins)
+{
+	struct ctree_path path;
+	struct key *key;
+	int ret;
+	u64 hole_size = 0;
+	int slot = 0;
+	u64 last_block;
+	int start_found;
+	struct leaf *l;
+	struct ctree_root * root = orig_root->extent_root;
+
+check_failed:
+	init_path(&path);
+	ins->objectid = search_start;
+	ins->offset = 0;
+	ins->flags = 0;
+	start_found = 0;
+	ret = search_slot(root, ins, &path, 0);
+	while (1) {
+		l = &path.nodes[0]->leaf;
+		slot = path.slots[0];
+		if (slot >= l->header.nritems) {
+			ret = next_leaf(root, &path);
+			if (ret == 0)
+				continue;
+			if (!start_found) {
+				ins->objectid = search_start;
+				ins->offset = num_blocks;
+				start_found = 1;
+				goto check_pending;
+			}
+			ins->objectid = last_block > search_start ?
+					last_block : search_start;
+			ins->offset = num_blocks;
+			goto check_pending;
+		}
+		key = &l->items[slot].key;
+		if (key->objectid >= search_start) {
+			if (start_found) {
+				hole_size = key->objectid - last_block;
+				if (hole_size > num_blocks) {
+					ins->objectid = last_block;
+					ins->offset = num_blocks;
+					goto check_pending;
+				}
+			} else
+				start_found = 1;
+			last_block = key->objectid + key->offset;
+		}
+		path.slots[0]++;
+	}
+	// FIXME -ENOSPC
+check_pending:
+	/* we have to make sure we didn't find an extent that has already
+	 * been allocated by the map tree or the original allocation
+	 */
+	release_path(root, &path);
+	BUG_ON(ins->objectid < search_start);
+	if (orig_root->extent_root == orig_root) {
+		BUG_ON(num_blocks != 1);
+		if ((root->current_insert.objectid <= ins->objectid &&
+		    root->current_insert.objectid +
+		    root->current_insert.offset > ins->objectid) ||
+		   (root->current_insert.objectid > ins->objectid &&
+		    root->current_insert.objectid <= ins->objectid +
+		    ins->offset) ||
+		   radix_tree_tag_get(&root->cache_radix, ins->objectid,
+				      CTREE_EXTENT_PENDING)) {
+			search_start = ins->objectid + 1;
+			goto check_failed;
+		}
+	}
+	if (ins->offset != 1)
+		BUG();
+	return 0;
+}
+
+/*
+ * insert all of the pending extents reserved during the original
+ * allocation.  (CTREE_EXTENT_PENDING).  Returns zero if it all worked out
+ */
+static int insert_pending_extents(struct ctree_root *extent_root)
+{
+	int ret;
+	struct key key;
+	struct extent_item item;
+	struct tree_buffer *gang[4];
+	int i;
+
+	// FIXME -ENOSPC
+	item.refs = 1;
+	item.owner = extent_root->node->node.header.parentid;
+	while(1) {
+		ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
+						 (void **)gang, 0,
+						 ARRAY_SIZE(gang),
+						 CTREE_EXTENT_PENDING);
+		if (!ret)
+			break;
+		for (i = 0; i < ret; i++) {
+			key.objectid = gang[i]->blocknr;
+			key.flags = 0;
+			key.offset = 1;
+			ret = insert_item(extent_root, &key, &item,
+					  sizeof(item));
+			if (ret) {
+				BUG();
+				// FIXME undo it and return sane
+				return ret;
+			}
+			radix_tree_tag_clear(&extent_root->cache_radix,
+					     gang[i]->blocknr,
+					     CTREE_EXTENT_PENDING);
+			tree_block_release(extent_root, gang[i]);
+		}
+	}
+	return 0;
+}
+
+/*
+ * finds a free extent and does all the dirty work required for allocation
+ * returns the key for the extent through ins, and a tree buffer for
+ * the first block of the extent through buf.
+ *
+ * returns 0 if everything worked, non-zero otherwise.
+ */
+int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
+			 u64 search_end, u64 owner, struct key *ins,
+			 struct tree_buffer **buf)
+{
+	int ret;
+	int pending_ret;
+	struct extent_item extent_item;
+	extent_item.refs = 1;
+	extent_item.owner = owner;
+
+	ret = find_free_extent(root, num_blocks, search_start, search_end, ins);
+	if (ret)
+		return ret;
+	if (root != root->extent_root) {
+		memcpy(&root->extent_root->current_insert, ins, sizeof(*ins));
+		ret = insert_item(root->extent_root, ins, &extent_item,
+				  sizeof(extent_item));
+		memset(&root->extent_root->current_insert, 0,
+		       sizeof(struct key));
+		pending_ret = insert_pending_extents(root->extent_root);
+		if (ret)
+			return ret;
+		if (pending_ret)
+			return pending_ret;
+		*buf = find_tree_block(root, ins->objectid);
+		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);
+	radix_tree_tag_set(&root->cache_radix, ins->objectid,
+			   CTREE_EXTENT_PENDING);
+	(*buf)->count++;
+	return 0;
+
+}
+
+/*
+ * helper function to allocate a block for a given tree
+ * returns the tree buffer or NULL.
+ */
+struct tree_buffer *alloc_free_block(struct ctree_root *root)
+{
+	struct key ins;
+	int ret;
+	struct tree_buffer *buf = NULL;
+
+	ret = alloc_extent(root, 1, 0, (unsigned long)-1,
+			   root->node->node.header.parentid,
+			   &ins, &buf);
+
+	if (ret) {
+		BUG();
+		return NULL;
+	}
+	if (root != root->extent_root)
+		BUG_ON(radix_tree_tag_get(&root->extent_root->cache_radix,
+					  buf->blocknr, CTREE_EXTENT_PENDING));
+	return buf;
+}