81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
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{
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struct btrfs_path *path;
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int ret;
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struct extent_buffer *l;
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struct btrfs_key search_key;
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struct btrfs_key found_key;
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int slot;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
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search_key.type = -1;
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search_key.offset = (u64)-1;
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ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
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if (ret < 0)
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goto error;
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BUG_ON(ret == 0);
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if (path->slots[0] > 0) {
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slot = path->slots[0] - 1;
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l = path->nodes[0];
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btrfs_item_key_to_cpu(l, &found_key, slot);
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*objectid = max_t(u64, found_key.objectid,
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BTRFS_FIRST_FREE_OBJECTID - 1);
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} else {
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*objectid = BTRFS_FIRST_FREE_OBJECTID - 1;
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}
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ret = 0;
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error:
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btrfs_free_path(path);
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return ret;
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}
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int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 dirid, u64 *objectid)
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{
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int ret;
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mutex_lock(&root->objectid_mutex);
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if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) {
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ret = btrfs_find_highest_inode(root, &root->highest_objectid);
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if (ret)
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goto out;
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}
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if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) {
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ret = -ENOSPC;
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goto out;
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}
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*objectid = ++root->highest_objectid;
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ret = 0;
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out:
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mutex_unlock(&root->objectid_mutex);
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return ret;
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}
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