[PATCH] D39464: Define fs::allocate_file which preallocates disk blocks.

[Rafael Avila de Espindola via llvm-commits]

Kamil Rytarowski via Phabricator <reviews at reviews.llvm.org> writes:

> krytarowski added inline comments.
>
>
> ================
> Comment at: llvm/lib/Support/Unix/Path.inc:436
>        return std::error_code(Err, std::generic_category());
> +    return make_error_code(errc::function_not_supported);
>    }
> ----------------
> NetBSD needs `ftruncate`(2) as a fallback for `posix_fallocate`(2).
>
> In the default setup `posix_fallocate`() returns EOPNOTSUPP.

Will ftruncate allocate space on netbsd? Note that it is OK for
allocate_file to fail. The user then has to use a buffer and write(2)
instead of mmap for output.

Cheers,
Rafael