Merge branches 'for-4.4/upstream-fixes', 'for-4.5/async-suspend', 'for-4.5/container...

[mirror_ubuntu-artful-kernel.git] / fs / btrfs / transaction.c

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 418c6a2ad7d88658f8624d99a1ba0e9e84c13d45..3367a3c6f214f5ca248a79fff36c6404a49fbf4f 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -592,6 +592,38 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
        return start_transaction(root, num_items, TRANS_START,
                                 BTRFS_RESERVE_FLUSH_ALL);
 }
+struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
+                                       struct btrfs_root *root,
+                                       unsigned int num_items,
+                                       int min_factor)
+{
+       struct btrfs_trans_handle *trans;
+       u64 num_bytes;
+       int ret;
+
+       trans = btrfs_start_transaction(root, num_items);
+       if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
+               return trans;
+
+       trans = btrfs_start_transaction(root, 0);
+       if (IS_ERR(trans))
+               return trans;
+
+       num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
+       ret = btrfs_cond_migrate_bytes(root->fs_info,
+                                      &root->fs_info->trans_block_rsv,
+                                      num_bytes,
+                                      min_factor);
+       if (ret) {
+               btrfs_end_transaction(trans, root);
+               return ERR_PTR(ret);
+       }
+
+       trans->block_rsv = &root->fs_info->trans_block_rsv;
+       trans->bytes_reserved = num_bytes;
+
+       return trans;
+}
 
 struct btrfs_trans_handle *btrfs_start_transaction_lflush(
                                        struct btrfs_root *root,