openzfs/zfs

Add dirsync support

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#4,366 opened on Feb 24, 2016

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Type: Featuregood first issue

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Description

Add support for the Linux dirsync mount option as described in the mount(8) man page.

       dirsync
              All  directory updates within the filesystem should be done syn‐
              chronously.  This affects the  following  system  calls:  creat,
              link, unlink, symlink, mkdir, rmdir, mknod and rename.

It would be nice to support this standard Linux mount option. The most logical place to to go about this would be to extend the existing filesystem sync property to include a directory setting. Of course the downside is that this would result in a compatibility issue with the other openZFS platforms. Other solutions are definitely possible and should be investigated.

Contributor guide

Research direction
Study the existing filesystem sync property in the ZFS codebase and extend it to add a 'directory' setting. Investigate how the mount option is passed from userspace to the kernel module, and modify the relevant structures and functions to handle dirsync. Test the changes with a filesystem mounted with dirsync option and verify that directory updates (creat, link, unlink, symlink, mkdir, rmdir, mknod, rename) are performed synchronously.
Tech stack
c
Domain
backend
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.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
CLinuxZFS
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30