Update statx constants and types (Linux 6.8-6.14)

[rusty-snake]

Description

This PR updates statx constants and types for features added in Linux 6.8 to 6.14.

Sources

• https://github.com/torvalds/linux/blob/3bde70a2c82712f05c7220b8b94fc2cbdf7fbfe0/include/uapi/linux/stat.h#L168-L186
• https://github.com/torvalds/linux/blob/3bde70a2c82712f05c7220b8b94fc2cbdf7fbfe0/include/uapi/linux/stat.h#L213-L217
• https://github.com/torvalds/linux/blob/3bde70a2c82712f05c7220b8b94fc2cbdf7fbfe0/include/uapi/linux/stat.h#L253

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

---

@rustbot label +stable-nominated

[rustbot]

r? @tgross35

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[rusty-snake]

No idea why CI is failing.

[tgross35]

LGTM as long as CI passes

[tgross35]

Looks like some of this may not be available on arm32 Android, can you check this against the bionic headers? https://cs.android.com/android/platform/superproject/main, cc @maurer

[rusty-snake]

I'm not familiar with bionic/their source tree or how to check. Do we know it works on non-arm32 android (e.g. armv8)? Because the CI skipping it's sometimes hard to tell whether it broken because of architecture or libc or both. I can #[cfg] them out it this is wanted but I suspect it is more likely that they were added to recent. Android 15 uses Linux 6.6 as the "main-kernel" right now AFAIK. These were all added in Linux 6.8 and later. Bionic supports statx so I suspect it will also support these new flags.

[maurer]

tl;dr:

• Remove support for statx_dio_read_align on Android; it won't arrive for at least a year.
• Bump the NDK version to 28, and the rest of your stuff should work.

This is going to be compatible from the Android PoV - only STATX_DIO_READ_ALIGN is not yet present in bionic, and that's likely because the latest kernel version Android uses is 6.12 right now.

The reason you're getting an error from offsetof for stx_subvol is not because of the architecture, it's because NDK 27 (current LTS NDK) does not yet have that field. NDK 28 (stable and released, but not LTS) does.

Probably (subject to @tgross35 agreement) we should switch to NDK 28b in this PR.

Support in bionic for statx_dio_read_align is probably more than a year out, because Android needs to release a kernel >= 6.14, and then needs to have an NDK release. I don't anticipate any differences between our support and anyone else's, but no Android device will exist that supports it for at least a year, so it'd be a mistake to try to use it. I'd suggest configuring out statx_dio_read_align both field and constant.

[maurer]

This constant is not yet present in bionic, likely because it was introduced to Linux in 6.14, and the latest Android kernel is 6.12.

[tgross35]

Probably (subject to @tgross35 agreement) we should switch to NDK 28b in this PR.

I have no objections to bumping the version. Is there any chance you, or anyone else from the android team / more familiar, might be able to do it in a separate PR? We have been having some pretty consistent intermittent failures (#4297), it would be good for somebody more familiar with the platform to double check that the way we are setting up and testing actually makes sense.