Re: question about crypto module dependency

On Wed, Jan 18, 2012 at 6:39 AM, Herbert Xu [off-list ref] wrote:

Francis Moreau [off-list ref] wrote:

quoted

Hello,

I'm wondering how this scenario is supposed to work: let's say a
module A uses 'crc32c' function in lib/libcrc32c.c. In its turn this
function calls crypto_shash_update() which is exported by
crypto/shash.c. But now no module implementing "crc32c" has still been
loaded although crc32c.ko is available. Therefore the initial load of
module A fails although all required modules by the system are
present.

If the above is correct, how should it be handled ?

We'd need to adjust the init priority of libcrc32c and whatever
it depends on.

Could you give me some details beacause I don't see how that would work...

Currently we have this : libcrc32c -> shash

where '->' means depend on.

However I think we should have this: libcrc32c -> shash -> crc32c, to
get all modules properly loaded when using libcrc32c.

But it seems not possible because of the way shash is doing the load
of its backends dynamically: it requires that the backend has already
been registered.

What is the user in question?

btrfs

Thanks.
-- 
Francis