Re: [PATCH 04/16] fscrypt: Fully disallow IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE

Christoph Hellwig <[email protected]> Fri, 26 Jun 2026 07:18:51 +0200

Newsgroups	org.kernel.vger.linux-fscrypt,net.sourceforge.lists.linux-f2fs-devel,org.kernel.vger.linux-block,org.kernel.vger.linux-ext4,org.kernel.vger.linux-fsdevel
Message-ID	<[email protected]>

On Tue, Jun 23, 2026 at 10:03:22PM -0700, Eric Biggers wrote:
> FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE works
> only with the fs-layer implementation of file contents encryption, not
> blk-crypto.  This is a problem for standardizing on blk-crypto.
> 
> Fortunately, no one should be using this combination anyway.  It doesn't
> make sense because the entire point of IV_INO_LBLK_32 is to support
> inline encryption hardware that is limited to 32-bit DUNs.
> 
> Thus, fully disallow IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE.

Looks good:

Reviewed-by: Christoph Hellwig <[email protected]>