Re: [PATCH v2 3/3] btrfs: add validation for extent states

On Tue, Jul 28, 2026 at 10:36 AM Qu Wenruo <[email protected]> wrote:
>
> Extent maps have the extra validation since commit 3f255ece2f1e ("btrfs:
> introduce extra sanity checks for extent maps"), but extent states do
> not have a similar check.
>
> Introduce a basic alignment check for the following call sites, so that
> we can cover all extent states inserted into the tree:
>
> - insert_state_fast()
> - insert_state()
> - split_state()
>
> Signed-off-by: Qu Wenruo <[email protected]>
> ---
>  fs/btrfs/extent-io-tree.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c
> index c18ea5ef2974..c6e639d0fcc1 100644
> --- a/fs/btrfs/extent-io-tree.c
> +++ b/fs/btrfs/extent-io-tree.c
> @@ -334,6 +334,21 @@ static inline struct extent_state *tree_search(struct extent_io_tree *tree, u64
>         return tree_search_for_insert(tree, offset, NULL, NULL);
>  }
>
> +static void validate_extent_state(const struct extent_io_tree *tree,
> +                                 struct extent_state *state)

Why isn't state marked as const as well?

With that change:

Reviewed-by: Filipe Manana <[email protected]>

Thanks.

> +{
> +       u32 blocksize;
> +
> +       if (tree->owner != IO_TREE_INODE_IO)
> +               return;
> +
> +       blocksize = btrfs_extent_io_tree_to_fs_info(tree)->sectorsize;
> +       ASSERT(IS_ALIGNED(state->start, blocksize) &&
> +              IS_ALIGNED(state->end + 1, blocksize),
> +              "unaligned extent state, blocksize=%u start=%llu end=%llu state=0x%x",
> +              blocksize, state->start, state->end, state->state);
> +}
> +
>  #define extent_io_tree_panic(tree, state, opname, err)                      \
>         btrfs_panic(btrfs_extent_io_tree_to_fs_info((tree)), (err),         \
>                     "extent io tree error on %s state start %llu end %llu", \
> @@ -429,6 +444,8 @@ static struct extent_state *insert_state(struct extent_io_tree *tree,
>         const u64 end = state->end + 1;
>         const bool try_merge = !(bits & (EXTENT_LOCK_BITS | EXTENT_BOUNDARY));
>
> +       validate_extent_state(tree, state);
> +
>         set_state_bits(tree, state, bits, changeset);
>
>         node = &tree->state.rb_node;
> @@ -481,6 +498,8 @@ static void insert_state_fast(struct extent_io_tree *tree,
>                               struct rb_node *parent, unsigned bits,
>                               struct extent_changeset *changeset)
>  {
> +       validate_extent_state(tree, state);
> +
>         set_state_bits(tree, state, bits, changeset);
>         rb_link_node(&state->rb_node, parent, node);
>         rb_insert_color(&state->rb_node, &tree->state);
> @@ -533,6 +552,8 @@ static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
>                 }
>         }
>
> +       validate_extent_state(tree, orig);
> +       validate_extent_state(tree, prealloc);
>         rb_link_node(&prealloc->rb_node, parent, node);
>         rb_insert_color(&prealloc->rb_node, &tree->state);
>
> --
> 2.54.0
>
>