Btrfs: Integrate metadata reservation with start_transaction

[net-next-2.6.git] / fs / btrfs / inode-item.c

diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 72ce3c173d6a3d111826e40ce8421b8f7f57f9b1..64f1150bb48d1fb1cd5b7c7d29742b3f9afff7cd 100644 (file)
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -49,6 +49,33 @@ static int find_name_in_backref(struct btrfs_path *path, const char *name,
        return 0;
 }
 
+struct btrfs_inode_ref *
+btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root,
+                       struct btrfs_path *path,
+                       const char *name, int name_len,
+                       u64 inode_objectid, u64 ref_objectid, int mod)
+{
+       struct btrfs_key key;
+       struct btrfs_inode_ref *ref;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+       int ret;
+
+       key.objectid = inode_objectid;
+       key.type = BTRFS_INODE_REF_KEY;
+       key.offset = ref_objectid;
+
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       if (ret > 0)
+               return NULL;
+       if (!find_name_in_backref(path, name, name_len, &ref))
+               return NULL;
+       return ref;
+}
+
 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           const char *name, int name_len,