From: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
After call of check_inode_item(), path may point to the last unchecked
slot of the leaf. The outer walk_up_tree() always treats the position
as checked item then skips to next item.
If the last item was an inode item, yes, it was unchecked.
Then walk_up_tree() will think the leaf is checked and walk up to
upper node, process_one_leaf() in walk_down_tree() would skip to
check next inode item. Which means, the inode item won't be checked.
Solution:
After check_inode_item returns, if found path point to the last item
of a leaf, decrease path slot manually, so walk_up_tree() will stay
on the leaf.
Fixes: 5e2dc770471b ("btrfs-progs: check: skip shared node or leaf check for low_memory mode")
Signed-off-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
---
check/mode-lowmem.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index b665c700328c..bec2ee185cc8 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -2677,6 +2677,18 @@ again:
if (cur->start == cur_bytenr)
goto again;
+ /*
+ * path may point at the last item(a inode item maybe) in a leaf.
+ * Without below lines, walk_up_tree() will skip the item which
+ * means all items related to the inode will never be checked.
+ * Decrease the slot manually, walk_up_tree won't skip to next node
+ * if it occurs.
+ */
+ if (path->slots[0] + 1 >= btrfs_header_nritems(path->nodes[0])) {
+ if (path->slots[0])
+ path->slots[0]--;
+ }
+
/*
* we have switched to another leaf, above nodes may
* have changed, here walk down the path, if a node
--
2.18.0
