On Mon, Oct 28, 2024 at 08:38:05AM -0600, Keith Busch wrote: > > > + if (bdev_is_partition(bdev) && > > > + !test_bit(hint - 1, bdev->write_hint_mask)) > > > + return file_inode(iocb->ki_filp)->i_write_hint; > > > > I would have expected an error when using an invalid stream identifier. > > It's a hint. fcntl doesn't error if you give an unusable hint, so > neither should this. You get sane default behavior. Well, why does it have to be a hint? If I have a data placement aware application I really want to know into how many buckets I can sort and adjust my algorithm for it. And I'd rather have an error checked interface to pass that down as far as I can. Same for my file system use case. I guess you have a use case where a hint would be enough, at least with good enough knowledge of the underlying implementation. But would there be an actual downside in not having a hint? Because historically speaking everything we've done as a not error checked vaguely defined hint has not been all the useful, but it in hardware or software interfaces.
