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
  49         btrfs_init_path(&path);
  50         ret = btrfs_search_slot(trans, root, key, &path, 0, 1);
  51         if (ret < 0)
  52                 goto out;
  53         BUG_ON(ret != 0);
  54         l = btrfs_buffer_leaf(path.nodes[0]);
  55         slot = path.slots[0];
  56         memcpy(btrfs_item_ptr(l, slot, struct btrfs_root_item), item,
  57                 sizeof(*item));
  58         mark_buffer_dirty(path.nodes[0]);
  59 out:
  60         btrfs_release_path(root, &path);
  61         return ret;
  62 }
  63
  64 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
  65                       *root, struct btrfs_key *key, struct btrfs_root_item
  66                       *item)
  67 {
  68         int ret;
  69         ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
  70         BUG_ON(ret);
  71         return ret;
  72 }
  73
  74 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
  75                    struct btrfs_key *key)
  76 {
  77         struct btrfs_path path;
  78         int ret;
  79
  80         btrfs_init_path(&path);
  81         ret = btrfs_search_slot(trans, root, key, &path, -1, 1);
  82         if (ret < 0)
  83                 goto out;
  84         BUG_ON(ret != 0);
  85         ret = btrfs_del_item(trans, root, &path);
  86 out:
  87         btrfs_release_path(root, &path);
  88         return ret;
  89 }