Re: [PATCH 5/9 next] scsi: Use iovec_import() instead of import_iovec().

[Christoph Hellwig]

So looking at the various callers I'm not sure this API is the
best.  If we want to do something fancy I'd hide the struct iovec
instances entirely with something like:

struct iov_storage {
        struct iovec stack[UIO_FASTIOV], *vec;
}

int iov_iter_import_iovec(struct iov_iter *iter, struct iov_storage *s,
                const struct iovec __user *vec, unsigned long nr_segs,
                int type);

and then add a new helper to free the thing if needed:

void iov_iter_release_iovec(struct iov_storage *s)
{
        if (s->vec != s->stack)
                kfree(s->vec);
}