From cb7de8ee9c50d86c7ea0f48c6bf50bab84613f22 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 3 Oct 2024 11:43:05 -0400 Subject: [PATCH] btrfs: add a comment for new_bytenr in backref_cache_node Add a comment for this field so we know what it is used for. Previously we used it to update the backref cache, so people may mistakenly think it is useless, but in fact exists to make sure the backref cache makes sense. Reviewed-by: Boris Burkov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/backref.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index a810253d7b8a..7220bde1fc31 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -318,6 +318,12 @@ struct btrfs_backref_node { u64 bytenr; }; /* Use rb_simple_node for search/insert */ + /* + * This is a sanity check, whenever we COW a block we will update + * new_bytenr with it's current location, and we will check this in + * various places to validate that the cache makes sense, it shouldn't + * be used for anything else. + */ u64 new_bytenr; /* Objectid of tree block owner, can be not uptodate */ u64 owner; -- 2.25.1