- https://man.netbsd.org/setsockopt.2
- DragonFlyBSD/DragonFlyBSD@89233cf

* io-uring API updates.

Add the `addr_len` field to `splice_fd_in_or_file_index_union`, define
the `io_uring_sync_cancel_reg` struct, and export the various flags
types used in the public API from the `io_uring` module so that users
don't need to enable "fs" or "net" themselves just to work with
`io_uring`.

* Make `Nsecs` be 64-bit on 32-bit x86 Linux.

* Fixes needed by io_uring.

 - Have the `io_uring` module export more types used in opcode entries.
 - Define a conversion from `SocketAddr` to `SocketAddrAny`.
 - Add comments to the `fadvise` implementation.

* Pin regex to 1.9 in Rust 1.63 builds.

* Make more `Epoll` types available to io_uring too.

This enables most of the epoll module without needing "alloc". It
doesn't enable `epoll_wait`, because that needs `Vec`, but this
does potentially open up a path to having a non-allocating opetion
for waiting on an epoll.

* Fix `rustix::fs::Dir` to avoid unbounded buffer growth.

Fix `Dir`'s buffer size computation to avoid resizing past a fixed
upper limit. This prevents it from growing without bound, such as in
the case of `Dir::rewind` for repeated iterations with the same `Dir`.

* Don't let `Dir` continue to try to iterate after a failure.

* Handle `io::Errno::INTR` gracefully.

* Write a more detailed comment on the buffer growth policy.

* Also mention that no buffer can ever be big enough for everything.

* Add tests against over-allocation & stuck iterator

* Rm `dir_iterator_does_not_overallocate` unit test in favour of docs

* Extend `test_dir` to cover `rewind`.

* Consistently handle directory removal as ending the stream.

libc implementations of directory iteration handle directory removal
by just ending the stream. In the linux_raw backend, this looks like
`ENOENT` from `getdents64`, so change the code to check for `ENOENT`
and end the stream.

This requires changing the `dir_iterator_does_not_get_stuck_on_io_error`
test to no longer expect a failure, so it's now renamed to
`dir_iterator_handles_dir_removal`.

To test the error case, add a new `dir_iterator_handles_io_errors`
test which uses `dup2` to induce an error, in both the linux_raw and
libc backends.

This exposes the fact that the libc `Dir` implementation was also
assuming that users would stop iterating after hitting a failure, so
add a `any_errors` flag to the libc backend as well.

* Add a test for removing the directory after doing `read_from`.

* In the libc backend, handle `ENOENT` when opening ".".

---------

Co-authored-by: cyqsimon <[email protected]>