fs/btrfs/root-tree.c

   1 #include <linux/module.h>
   2 #include "ctree.h"
   3 #include "disk-io.h"
   4 #include "print-tree.h"
   5
   6 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
   7                         struct btrfs_root_item *item, struct btrfs_key *key)
   8 {
   9         struct btrfs_path path;
  10         struct btrfs_key search_key;
  11         struct btrfs_leaf *l;
  12         int ret;
  13         int slot;
  14
  15         search_key.objectid = objectid;
  16         search_key.flags = (u32)-1;
  17         search_key.offset = (u32)-1;
  18
  19         btrfs_init_path(&path);
  20         ret = btrfs_search_slot(NULL, root, &search_key, &path, 0, 0);
  21         if (ret < 0)
  22                 goto out;
  23         BUG_ON(ret == 0);
  24         l = btrfs_buffer_leaf(path.nodes[0]);
  25         BUG_ON(path.slots[0] == 0);
  26         slot = path.slots[0] - 1;
  27         if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
  28                 ret = 1;
  29                 goto out;
  30         }
  31         memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
  32                 sizeof(*item));
  33         btrfs_disk_key_to_cpu(key, &l->items[slot].key);
  34         btrfs_release_path(root, &path);
  35         ret = 0;
  36 out:
  37         return ret;
  38 }
  39
  40 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
  41                       *root, struct btrfs_key *key, struct btrfs_root_item
  42                       *item)
  43 {
  44         struct btrfs_path path;
  45         struct btrfs_leaf *l;
  46         int ret;
  47         int slot;
  48         struct btrfs_root_item *update_item;
  49
  50         btrfs_init_path(&path);
  51         ret = btrfs_search_slot(trans, root, key, &path, 0, 1);
  52         if (ret < 0)
  53                 goto out;
  54         BUG_ON(ret != 0);
  55         l = btrfs_buffer_leaf(path.nodes[0]);
  56         slot = path.slots[0];
  57         update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
  58         btrfs_memcpy(root, l, update_item, item, sizeof(*item));
  59         btrfs_mark_buffer_dirty(path.nodes[0]);
  60 out:
  61         btrfs_release_path(root, &path);
  62         return ret;
  63 }
  64
  65 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
  66                       *root, struct btrfs_key *key, struct btrfs_root_item
  67                       *item)
  68 {
  69         int ret;
  70         ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
  71         BUG_ON(ret);
  72         return ret;
  73 }
  74
  75 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
  76                    struct btrfs_key *key)
  77 {
  78         struct btrfs_path path;
  79         int ret;
  80
  81         btrfs_init_path(&path);
  82         ret = btrfs_search_slot(trans, root, key, &path, -1, 1);
  83         if (ret < 0)
  84                 goto out;
  85         BUG_ON(ret != 0);
  86         ret = btrfs_del_item(trans, root, &path);
  87 out:
  88         btrfs_release_path(root, &path);
  89         return ret;
  90 }