Re: [PATCH v8 5/5] generic: test fs-verity EFBIG scenarios

[Eric Biggers <ebiggers@kernel.org>]

On Wed, Mar 16, 2022 at 01:25:15PM -0700, Boris Burkov wrote:
> btrfs, ext4, and f2fs cache the Merkle tree past EOF, which restricts
> the maximum file size beneath the normal maximum. Test the logic in
> those filesystems against files with sizes near the maximum.
> 
> To work properly, this does require some understanding of the practical
> but not standardized layout of the Merkle tree. This is a bit unpleasant
> and could make the test incorrect in the future, if the implementation
> changes. On the other hand, it feels quite useful to test this tricky
> edge case. It could perhaps be made more generic by adding some ioctls
> to let the file system communicate the maximum file size for a verity
> file or some information about the storage of the Merkle tree.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  common/verity         | 11 ++++++++
>  tests/generic/690     | 64 +++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/690.out |  7 +++++
>  3 files changed, 82 insertions(+)
>  create mode 100755 tests/generic/690
>  create mode 100644 tests/generic/690.out
> 

Reviewed-by: Eric Biggers <ebiggers@google.com>

- Eric