+static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ u64 min_size)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+ int failures = 0;
+
+ for (;;) {
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ ret = btrfs_block_rsv_refill(root, rsv, min_size,
+ BTRFS_RESERVE_FLUSH_LIMIT);
+
+ if (ret && ++failures > 2) {
+ btrfs_warn(fs_info,
+ "could not allocate space for a delete; will truncate on mount");
+ return ERR_PTR(-ENOSPC);
+ }
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans) || !ret)
+ return trans;
+
+ /*
+ * Try to steal from the global reserve if there is space for
+ * it.
+ */
+ if (!btrfs_check_space_for_delayed_refs(trans, fs_info) &&
+ !btrfs_block_rsv_migrate(global_rsv, rsv, min_size, 0))
+ return trans;
+
+ /* If not, commit and try again. */
+ ret = btrfs_commit_transaction(trans);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+}
+