btrfs-progs: Record orphan data extent ref to corresponding root.

Before this patch, when a extent's data ref points to a invalid key in
fs tree, this happens if a leaf/node of fs tree is corrupted, btrfsck
can't do any repair and just exit.

In fact, such problem can be handled in fs tree repair routines, rebuild
the inode item(if missing) and add back the extent data (with some
assumption).

So this patch records such data extent refs for later fs tree recovery
routine.

TODO:
    Restore orphan data extent refs into btrfs_root is not the best
    method. It's best to directly restore it into inode_record, however
    current extent tree and fs tree can't cooperate together, so use
    btrfs_root as a temporary storage until inode_cache is built.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

1 files changed, 10 insertions, 0 deletions

diff --git a/ctree.h b/ctree.h
index c069a95a..a8b99422 100644
--- a/ctree.h
+++ b/ctree.h
@@ -1039,6 +1039,16 @@ struct btrfs_root {
 	u64 highest_inode;
 	u64 last_inode_alloc;
 
+	/*
+	 * Record orphan data extent ref
+	 *
+	 * TODO: Don't restore things in btrfs_root.
+	 * Directly record it into inode_record, which needs a lot of
+	 * infrastructure change to allow cooperation between extent
+	 * and fs tree scan.
+	 */
+	struct list_head orphan_data_extents;
+
 	/* the dirty list is only used by non-reference counted roots */
 	struct list_head dirty_list;
 	struct rb_node rb_node;