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113 lines
2.7 KiB
C
113 lines
2.7 KiB
C
#include <linux/module.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "print-tree.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_leaf *l;
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int ret;
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int slot;
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search_key.objectid = objectid;
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search_key.flags = (u32)-1;
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search_key.offset = (u32)-1;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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btrfs_init_path(path);
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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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BUG_ON(ret == 0);
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l = btrfs_buffer_leaf(path->nodes[0]);
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BUG_ON(path->slots[0] == 0);
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slot = path->slots[0] - 1;
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if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
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ret = 1;
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goto out;
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}
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memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
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sizeof(*item));
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btrfs_disk_key_to_cpu(key, &l->items[slot].key);
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ret = 0;
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out:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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return ret;
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}
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int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct btrfs_key *key, struct btrfs_root_item
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*item)
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{
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struct btrfs_path *path;
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struct btrfs_leaf *l;
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int ret;
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int slot;
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struct btrfs_root_item *update_item;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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btrfs_init_path(path);
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ret = btrfs_search_slot(trans, root, key, path, 0, 1);
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if (ret < 0)
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goto out;
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BUG_ON(ret != 0);
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l = btrfs_buffer_leaf(path->nodes[0]);
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slot = path->slots[0];
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update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
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btrfs_memcpy(root, l, update_item, item, sizeof(*item));
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btrfs_mark_buffer_dirty(path->nodes[0]);
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out:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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return ret;
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}
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int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct btrfs_key *key, struct btrfs_root_item
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*item)
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{
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int ret;
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ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
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BUG_ON(ret);
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return ret;
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}
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int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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struct btrfs_key *key)
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{
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struct btrfs_path *path;
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int ret;
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u32 refs;
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struct btrfs_root_item *ri;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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btrfs_init_path(path);
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ret = btrfs_search_slot(trans, root, key, path, -1, 1);
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if (ret < 0)
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goto out;
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BUG_ON(ret != 0);
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ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
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path->slots[0], struct btrfs_root_item);
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refs = btrfs_root_refs(ri);
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BUG_ON(refs == 0);
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if (refs == 1) {
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ret = btrfs_del_item(trans, root, path);
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} else {
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btrfs_set_root_refs(ri, refs - 1);
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printk("ref now %u root %Lu %Lu %u\n", refs -1, key->objectid, key->offset, key->flags);
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mark_buffer_dirty(path->nodes[0]);
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}
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out:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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return ret;
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}
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