Re: selective block polling and preadv2/pwritev2 revisited

Hi Christoph,

Note that there are plenty of other use cases for preadv2/pwritev2 as well,
but I'd like to concentrate on this one for now.  Example are: non-blocking
reads (the original purpose), per-I/O O_SYNC, user space support for T10
DIF/DIX applications tags and probably some more.

So I'm trying to understand how can integrity metadata be used here.
Will the user-app append the meta-data to the data iovec (given there
is no metadata iovec)? If so, how will we separate data from metadata?

Cheers,
Sagi.