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/*
* 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"
/*
* 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;
path = btrfs_alloc_path();
BUG_ON(!path);
search_start = root->last_inode_alloc;
search_start = max((unsigned long long)search_start,
BTRFS_FIRST_FREE_OBJECTID);
search_key.objectid = search_start;
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;
if (path->slots[0] > 0)
path->slots[0]--;
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;
}
}
}
start_found = 1;
last_ino = key.objectid + 1;
path->slots[0]++;
}
// FIXME -ENOSPC
found:
root->last_inode_alloc = *objectid;
btrfs_free_path(path);
BUG_ON(*objectid < search_start);
return 0;
error:
btrfs_free_path(path);
return ret;
}
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