Fixing the Filesystem Freeze API

on YouTube ↗36m

" summary

Filesystem freeze in Linux currently lacks a reliable check API and lets a frozen filesystem be unmounted with no way to thaw it, breaks multi-device filesystems (BTRFS) and misbehaves with DM snapshot. Patches add a new get_freeze_fd ioctl that keeps a freeze held while the FD is open so a crashed guest agent auto‑unfreezes, export freeze count via /proc/fs and a hand‑task‑watchdog hint flag so sleeping writers don’t trigger panics. BTRFS gets a superblock pointer in struct block_device, and there’s work on VSS support and user‑namespace fixes.

AI-written summary · about

" chapters (8)

1. 0:00Intro
2. 1:12Filesystem freeze in Linux
3. 1:57Linux filesystem freeze API
4. 3:57Filesystem freeze warts
5. 15:05Filesystem freeze and virtualization
6. 19:04New filesystem freeze API
7. 20:59Future work
8. 25:20Hypervisor initiated live-snapshots

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