-#include <stdio.h>
-#include <stdlib.h>
-#include "kerncompat.h"
-#include "radix-tree.h"
+/*
+ * 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 "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
struct btrfs_root_item *item, struct btrfs_key *key)
{
- struct btrfs_path path;
+ struct btrfs_path *path;
struct btrfs_key search_key;
- struct btrfs_leaf *l;
+ struct btrfs_key found_key;
+ struct extent_buffer *l;
int ret;
int slot;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
search_key.objectid = objectid;
- search_key.flags = (u32)-1;
- search_key.offset = (u32)-1;
+ search_key.type = BTRFS_ROOT_ITEM_KEY;
+ search_key.offset = (u64)-1;
- btrfs_init_path(&path);
- ret = btrfs_search_slot(NULL, root, &search_key, &path, 0, 0);
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
+ if (path->slots[0] == 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
BUG_ON(ret == 0);
- l = &path.nodes[0]->leaf;
- BUG_ON(path.slots[0] == 0);
- slot = path.slots[0] - 1;
- if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
- ret = 1;
+ l = path->nodes[0];
+ slot = path->slots[0] - 1;
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+ if (found_key.type != BTRFS_ROOT_ITEM_KEY ||
+ found_key.objectid != objectid) {
+ ret = -ENOENT;
goto out;
}
- memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
- sizeof(*item));
- btrfs_disk_key_to_cpu(key, &l->items[slot].key);
- btrfs_release_path(root, &path);
+ read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
+ sizeof(*item));
+ memcpy(key, &found_key, sizeof(found_key));
ret = 0;
out:
+ btrfs_free_path(path);
return ret;
}
*root, struct btrfs_key *key, struct btrfs_root_item
*item)
{
- struct btrfs_path path;
- struct btrfs_leaf *l;
+ struct btrfs_path *path;
+ struct extent_buffer *l;
int ret;
int slot;
+ unsigned long ptr;
+ u32 old_len;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
- btrfs_init_path(&path);
- ret = btrfs_search_slot(trans, root, key, &path, 0, 1);
+ ret = btrfs_search_slot(trans, root, key, path, 0, 1);
if (ret < 0)
goto out;
BUG_ON(ret != 0);
- l = &path.nodes[0]->leaf;
- slot = path.slots[0];
- memcpy(btrfs_item_ptr(l, slot, struct btrfs_root_item), item,
- sizeof(*item));
+ l = path->nodes[0];
+ slot = path->slots[0];
+ ptr = btrfs_item_ptr_offset(l, slot);
+ old_len = btrfs_item_size_nr(l, slot);
+
+ /*
+ * If this is the first time we update the root item which originated
+ * from an older kernel, we need to enlarge the item size to make room
+ * for the added fields.
+ */
+ if (old_len < sizeof(*item)) {
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(trans, root, key, path,
+ -1, 1);
+ if (ret < 0) {
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret < 0) {
+ goto out;
+ }
+ btrfs_release_path(path);
+ ret = btrfs_insert_empty_item(trans, root, path,
+ key, sizeof(*item));
+ if (ret < 0) {
+ goto out;
+ }
+ l = path->nodes[0];
+ slot = path->slots[0];
+ ptr = btrfs_item_ptr_offset(l, slot);
+ }
+
+ /*
+ * Update generation_v2 so at the next mount we know the new root
+ * fields are valid.
+ */
+ btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
+
+ write_extent_buffer(l, item, ptr, sizeof(*item));
+ btrfs_mark_buffer_dirty(path->nodes[0]);
out:
- btrfs_release_path(root, &path);
+ btrfs_free_path(path);
return ret;
}
*item)
{
int ret;
+
+ /*
+ * Make sure generation v1 and v2 match. See update_root for details.
+ */
+ btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
- BUG_ON(ret);
return ret;
}
+/* drop the root item for 'key' from 'root' */
int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_key *key)
{
- struct btrfs_path path;
+ struct btrfs_path *path;
int ret;
- btrfs_init_path(&path);
- ret = btrfs_search_slot(trans, root, key, &path, -1, 1);
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ ret = btrfs_search_slot(trans, root, key, path, -1, 1);
if (ret < 0)
goto out;
- BUG_ON(ret != 0);
- ret = btrfs_del_item(trans, root, &path);
+
+ if (ret != 0) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
out:
- btrfs_release_path(root, &path);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
+ * or BTRFS_ROOT_BACKREF_KEY.
+ *
+ * The dirid, sequence, name and name_len refer to the directory entry
+ * that is referencing the root.
+ *
+ * For a forward ref, the root_id is the id of the tree referencing
+ * the root and ref_id is the id of the subvol or snapshot.
+ *
+ * For a back ref the root_id is the id of the subvol or snapshot and
+ * ref_id is the id of the tree referencing it.
+ */
+int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *tree_root,
+ u64 root_id, u8 type, u64 ref_id,
+ u64 dirid, u64 sequence,
+ const char *name, int name_len)
+{
+ struct btrfs_key key;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root_ref *ref;
+ struct extent_buffer *leaf;
+ unsigned long ptr;
+
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = root_id;
+ key.type = type;
+ key.offset = ref_id;
+
+ ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
+ sizeof(*ref) + name_len);
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
+ btrfs_set_root_ref_dirid(leaf, ref, dirid);
+ btrfs_set_root_ref_sequence(leaf, ref, sequence);
+ btrfs_set_root_ref_name_len(leaf, ref, name_len);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(leaf, name, ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_free_path(path);
return ret;
}
projects / platform / upstream / btrfs-progs.git / blobdiff