Btrfs: Metadata reservation for orphan inodes

[linux-2.6-block.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index cb814a71800d97a168f56a277e5658dc4b92abe8..a713f69f0c7ac2311998578f74b57c8d6e91cf92 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3626,6 +3626,34 @@ void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
        trans->bytes_reserved = 0;
 }
 
+int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
+                                 struct inode *inode)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
+       struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
+
+       /*
+        * one for deleting orphan item, one for updating inode and
+        * two for calling btrfs_truncate_inode_items.
+        *
+        * btrfs_truncate_inode_items is a delete operation, it frees
+        * more space than it uses in most cases. So two units of
+        * metadata space should be enough for calling it many times.
+        * If all of the metadata space is used, we can commit
+        * transaction and use space it freed.
+        */
+       u64 num_bytes = calc_trans_metadata_size(root, 4);
+       return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
+}
+
+void btrfs_orphan_release_metadata(struct inode *inode)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       u64 num_bytes = calc_trans_metadata_size(root, 4);
+       btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
+}
+
 int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
                                struct btrfs_pending_snapshot *pending)
 {