1 files changed, 141 insertions, 0 deletions
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
new file mode 100644
index 000000000000..cd6171c2da42
--- /dev/null
+++ b/fs/btrfs/inode-map.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
+{
+	struct btrfs_path *path;
+	int ret;
+	struct extent_buffer *l;
+	struct btrfs_key search_key;
+	struct btrfs_key found_key;
+	int slot;
+
+	path = btrfs_alloc_path();
+	BUG_ON(!path);
+
+	search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
+	search_key.type = -1;
+	search_key.offset = (u64)-1;
+	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+	BUG_ON(ret == 0);
+	if (path->slots[0] > 0) {
+		slot = path->slots[0] - 1;
+		l = path->nodes[0];
+		btrfs_item_key_to_cpu(l, &found_key, slot);
+		*objectid = found_key.objectid;
+	} else {
+		*objectid = BTRFS_FIRST_FREE_OBJECTID;
+	}
+	ret = 0;
+error:
+	btrfs_free_path(path);
+	return ret;
+}
+
+/*
+ * walks the btree of allocated inodes and find a hole.
+ */
+int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root,
+			     u64 dirid, u64 *objectid)
+{
+	struct btrfs_path *path;
+	struct btrfs_key key;
+	int ret;
+	int slot = 0;
+	u64 last_ino = 0;
+	int start_found;
+	struct extent_buffer *l;
+	struct btrfs_key search_key;
+	u64 search_start = dirid;
+
+	mutex_lock(&root->objectid_mutex);
+	if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&
+	    root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {
+		*objectid = ++root->last_inode_alloc;
+		mutex_unlock(&root->objectid_mutex);
+		return 0;
+	}
+	path = btrfs_alloc_path();
+	BUG_ON(!path);
+	search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
+	search_key.objectid = search_start;
+	search_key.type = 0;
+	search_key.offset = 0;
+
+	btrfs_init_path(path);
+	start_found = 0;
+	ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
+	if (ret < 0)
+		goto error;
+
+	while (1) {
+		l = path->nodes[0];
+		slot = path->slots[0];
+		if (slot >= btrfs_header_nritems(l)) {
+			ret = btrfs_next_leaf(root, path);
+			if (ret == 0)
+				continue;
+			if (ret < 0)
+				goto error;
+			if (!start_found) {
+				*objectid = search_start;
+				start_found = 1;
+				goto found;
+			}
+			*objectid = last_ino > search_start ?
+				last_ino : search_start;
+			goto found;
+		}
+		btrfs_item_key_to_cpu(l, &key, slot);
+		if (key.objectid >= search_start) {
+			if (start_found) {
+				if (last_ino < search_start)
+					last_ino = search_start;
+				if (key.objectid > last_ino) {
+					*objectid = last_ino;
+					goto found;
+				}
+			}
+		}
+		if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
+			break;
+		start_found = 1;
+		last_ino = key.objectid + 1;
+		path->slots[0]++;
+	}
+	// FIXME -ENOSPC
+	BUG_ON(1);
+found:
+	btrfs_release_path(root, path);
+	btrfs_free_path(path);
+	BUG_ON(*objectid < search_start);
+	mutex_unlock(&root->objectid_mutex);
+	return 0;
+error:
+	btrfs_release_path(root, path);
+	btrfs_free_path(path);
+	mutex_unlock(&root->objectid_mutex);
+	return ret;
+}