48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0+
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#include "ctree.h"
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int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
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struct btrfs_root_item *item, struct btrfs_key *key)
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{
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struct btrfs_path *path;
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struct btrfs_key search_key;
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struct btrfs_key found_key;
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struct extent_buffer *l;
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int ret;
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int slot;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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search_key.objectid = objectid;
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search_key.type = BTRFS_ROOT_ITEM_KEY;
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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 out;
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if (path->slots[0] == 0) {
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ret = -ENOENT;
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goto out;
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}
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BUG_ON(ret == 0);
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l = path->nodes[0];
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slot = path->slots[0] - 1;
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btrfs_item_key_to_cpu(l, &found_key, slot);
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if (found_key.type != BTRFS_ROOT_ITEM_KEY ||
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found_key.objectid != objectid) {
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ret = -ENOENT;
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goto out;
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}
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read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
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sizeof(*item));
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memcpy(key, &found_key, sizeof(found_key));
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ret = 0;
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out:
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btrfs_free_path(path);
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return ret;
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}
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