Btrfs-progs: add -b to btrfsck to look at backup roots

In some cases the tree root is so hosed we can't get anything useful out of it.
So add the -b option to btrfsck to make us look for the most recent backup tree
root to use for repair.  Then we can hopefully get ourselves into a working
state.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/disk-io.h b/disk-io.h
index 6f2d4f41..b0292db2 100644
--- a/disk-io.h
+++ b/disk-io.h
@@ -53,7 +53,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info);
 struct btrfs_fs_info *btrfs_new_fs_info(int writable, u64 sb_bytenr);
 int btrfs_check_fs_compatibility(struct btrfs_super_block *sb, int writable);
 int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info,
-			  u64 root_tree_bytenr, int partial);
+			  u64 root_tree_bytenr, int partial, int backup_root);
 void btrfs_release_all_roots(struct btrfs_fs_info *fs_info);
 void btrfs_cleanup_all_caches(struct btrfs_fs_info *fs_info);
 int btrfs_scan_fs_devices(int fd, const char *path,
@@ -69,7 +69,8 @@ struct btrfs_fs_info *open_ctree_fs_info_restore(const char *filename,
 					 int writes, int partial);
 struct btrfs_fs_info *open_ctree_fs_info(const char *filename,
 					 u64 sb_bytenr, u64 root_tree_bytenr,
-					 int writes, int partial);
+					 int writes, int partial,
+					 int backup_root);
 struct btrfs_root *open_ctree_with_broken_super(const char *filename,
 					u64 sb_bytenr, int writes);
 int close_ctree(struct btrfs_root *root);