Btrfs: memset to avoid stale content in btree leaf
This is an additional patch to
"Btrfs: memset to avoid stale content in btree node block".
This uses memset to initialize the unused space in a leaf to avoid
potential stale content, which may be incurred by pushing items
between sibling leaves.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index cb0ae90..5f1408b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2293,6 +2293,21 @@
return offsetof(struct btrfs_leaf, items);
}
+/*
+ * The leaf data grows from end-to-front in the node.
+ * this returns the address of the start of the last item,
+ * which is the stop of the leaf data stack
+ */
+static inline unsigned int leaf_data_end(struct btrfs_root *root,
+ struct extent_buffer *leaf)
+{
+ u32 nr = btrfs_header_nritems(leaf);
+
+ if (nr == 0)
+ return BTRFS_LEAF_DATA_SIZE(root);
+ return btrfs_item_offset_nr(leaf, nr - 1);
+}
+
/* struct btrfs_file_extent_item */
BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8);
BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr,