# Linux 7.4 block layer merges Apple M4 NVMe support and floppy driver fixes

> **Key takeaway:** The Linux 7.4 merge window brought block subsystem updates spanning from Apple M4 NVMe support to decades-old floppy driver bug fixes.

**Published:** 2026-10-25T00:42:28+00:00 
**Source:** Phoronix Benchmarks & Drivers 
**Category:** kernel-os 
**Canonical URL:** https://fosswire.org/news/linux-74-block-layer-merges-apple-m4-nvme-support-and-floppy.html 

## Summary
The Linux 7.4 block/storage and IO_uring updates have been merged during the current merge window, demonstrating the kernel's unusually wide hardware support timeline. On the vintage hardware side, Oracle's Denis Efremov fixed a stack out-of-bounds issue in the floppy driver detected by Kernel Address Sanitizer, plus a regression from 2017 code refactoring that mishandled drive struct flags. Cen Zhang also addressed data races in the same driver. The SWIM driver for old Apple Macintosh floppy controllers received 33 fixes from Finn Thain of the Linux m68k community after he found it too buggy for use; testing confirmed functionality on Mac Quadra 650, LC III, Quadra 700, and IIvx systems. For modern hardware, the merge adds NVMe support for Apple M4 devices using the T8132 ANS2 controller.

## What changed in Linux 7.4 block layer
- **Floppy driver hardening:** Denis Efremov fixed a Kernel Address Sanitizer-reported stack out-of-bounds condition and resolved a long-standing regression from 2017 refactoring where floppy drive struct flags were improperly handled.
- **Floppy driver concurrency:** Cen Zhang identified and fixed data races in the floppy driver, with the discovery attributed to unspecified automated tooling.
- **SWIM Macintosh floppy controller revival:** Finn Thain delivered 33 fixes to the SWIM driver after finding it non-functional for his use case; validated on four 68k Mac models including Quadra 650 and IIvx.
- **Apple M4 NVMe enablement:** The T8132 ANS2 NVMe controller found in Apple M4 devices now has kernel support, extending Apple Silicon storage coverage in mainline Linux.
- **IO_uring inclusion:** The pull request also carried IO_uring updates alongside the block subsystem changes, though specific IO_uring details were not itemized in the source.

## Why it matters
This merge illustrates how Linux kernel maintenance spans extreme hardware generations simultaneously, from 1990s Macintosh systems to 2024 Apple Silicon. For users and developers, the Apple M4 NVMe support removes a storage barrier for Linux on newer Macs, while the floppy and SWIM fixes preserve retrocomputing and emulation workflows that depend on accurate vintage hardware behavior. The continued investment in legacy drivers also signals that mainline Linux remains viable for preservation projects and museum-grade hardware restoration.