ZFS needs a lazytime property to set lazytime mount option

Description

Contributor guide

Tech stack

c

Domain

backendperformance

Issue type

feature

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

3-5 days

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

ZFS property systemC programmingLinux mount options

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

30

Research direction

The issue requests adding a 'lazytime' property to ZFS datasets, similar to existing properties like 'atime'. Investigate how mount options are currently implemented as properties in ZFS, focusing on files such as 'module/zfs/zfs prop.c' and 'lib/libzfs/libzfs mount.c'. The existing support for 'lazytime' via manual remount indicates the kernel feature is available; the task is to expose it as a dataset property. Review the property definitions and mount code to understand how to add a new property that triggers the lazytime mount option during 'zfs mount'.