From 22c32850798c264b6a20539b9cd1699228368ce9 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Thu, 7 Jul 2022 02:51:57 -0600
Subject: write btrfs-clear-bad-nodes

---
 pkg/btrfs/io3_btree.go | 44 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

(limited to 'pkg/btrfs/io3_btree.go')

diff --git a/pkg/btrfs/io3_btree.go b/pkg/btrfs/io3_btree.go
index 01da746..3c1535b 100644
--- a/pkg/btrfs/io3_btree.go
+++ b/pkg/btrfs/io3_btree.go
@@ -19,9 +19,49 @@ import (
 // - For .Item() callbacks, the last element will always have a
 //   NodeAddr of 0.
 //
-// ex:
+// For example, given the tree structure
 //
-//     {-1, 0x01, 3}→{9, 0x02, 2}→{9, 0x03, 1}→{9, 0x04, 0}→{9, 0, 0}
+//   [superblock]
+//        |
+//        | <------------------------------------------ pathElem={idx:-1, addr:0x01, lvl:3}
+//        |
+//     +[0x01]-----------+
+//     | lvl=3           |
+//     +-+-+-+-+-+-+-+-+-+
+//     |1|2|3|4|5|6|7|8|9|
+//     +---+---+---+---+-+
+//                    |
+//                    | <------------------------------ pathElem={idx:8, addr:0x02, lvl:2}
+//                    |
+//                 +[0x02]-----------+
+//                 | lvl=2           |
+//                 +-+-+-+-+-+-+-+-+-+
+//                 |1|2|3|4|5|6|7|8|9|
+//                 +---+---+---+---+-+
+//                              |
+//                              | <-------------------- pathElem={idx:7, addr:0x03, lvl:1}
+//                              |
+//                           +[0x03]-----------+
+//                           | lvl=1           |
+//                           +-+-+-+-+-+-+-+-+-+
+//                           |1|2|3|4|5|6|7|8|9|
+//                           +---+---+---+---+-+
+//                                  |
+//                                  | <---------------- pathElem={idx:4, addr:0x04, lvl:0}
+//                                  |
+//                                +[0x04]-----------+
+//                                | lvl=0           |
+//                                +-+-+-+-+-+-+-+-+-+
+//                                |1|2|3|4|5|6|7|8|9|
+//                                +---+---+---+---+-+
+//                                   |
+//                                   | <--------------- pathElem={idx:5, addr:0, lvl:0}
+//                                   |
+//                                 [item]
+//
+// the path would be
+//
+//     {-1, 0x01, 3}→{8, 0x02, 2}→{7, 0x03, 1}→{4, 0x04, 0}→{2, 0, 0}
 type TreePath []TreePathElem
 
 // A TreePathElem essentially represents a KeyPointer.
-- 
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