Btrfs: superblock duplication

This patch implements superblock duplication. Superblocks
are stored at offset 16K, 64M and 256G on every devices.
Spaces used by superblocks are preserved by the allocator,
which uses a reverse mapping function to find the logical
addresses that correspond to superblocks. Thank you,

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 08469ec05850..d3f9c2c663c4 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1996,7 +1996,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
         btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
                        btrfs_header_level(log->fs_info->log_root_tree->node));
 
-        write_ctree_super(trans, log->fs_info->tree_root);
+        write_ctree_super(trans, log->fs_info->tree_root, 2);
         log->fs_info->tree_log_transid++;
         log->fs_info->tree_log_batch = 0;
         atomic_set(&log->fs_info->tree_log_commit, 0);
@@ -2006,7 +2006,6 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 out:
         mutex_unlock(&log->fs_info->tree_log_mutex);
         return 0;
-
 }
 
 /* * free all the extents used by the tree log.  This should be called