[mikhailt]

They do plan to document it fully later:

> Is APFS open source?

> An open source implementation is not available at this time. Apple plans to document and publish the APFS volume format specification.

Source: https://developer.apple.com/library/archive/documentation/Fi...

My theory is that Apple rushed APFS and its implementation isn't in a great shape for the public review. APFS doesn't feel any faster on my SSDs on macOS. I suspect they'll add it in a few years, after a few iterations.

[mbell]

> My theory is that Apple rushed APFS and its implementation isn't in a great shape for the public review.

The rollout of APFS was _incredibly_ well done; I don't think there is even a remote comparison to how successful it was. A new file system was rolled out to millions of devices in an automated fashion with very few issues. I don't think anyone else has even considered such a thing. I highly doubt the code is that rough, I can't imagine pulling this off without fairly solid core code in place.

[eridius]

Agreed. For iOS, the rollout was so smooth that most people weren't even aware it was taking place, with the only observable effect being that the iOS upgrade took a bit longer than usual. For the macOS rollout, there were more hiccups, but still, extremely smooth. In fact, I just had to launch Disk Utility to double-check that this computer was in fact migrated to APFS because I couldn't recall actually seeing anything specific about it (as this computer has a fusion drive, as well as a Bootcamp partition).

[romed]

Mojave update trashed my Fusion Drive to the extent that plugging any other mac into my imac in target disk mode made the host mac instantly kernel panic. And I lost all my files obv.

[stansm]

But you did backup before update, didn’t you?

[lultimouomo]

You mean besides the fact that the volume encryption password was stored in plain text in the disk?

https://thehackernews.com/2018/03/macos-apfs-password.html

[twotwotwo]

They released the format spec here: https://developer.apple.com/support/apple-file-system/Apple-...

[MBCook]

What makes you think it’s a rush job?

Perhaps it’s just the lawyer reviews holding it up.

[asveikau]

> What makes you think it’s a rush job?

A global lock on readdir().

[mrpippy]

My personal guess is that they wanted to release the printed spec before they released the code. The spec has now been released, the 10.14 source has not, maybe apfs.kext will be in the 10.14 source drop.

(also, HFS+ and its fsck have always been open-source with OS X)

[pfranz]

HFS+ was first released for Mac OS 8.1 in 1998. The earliest source code I see is from Mac OS X 10.0, which was released in March of 2001 (not sure when the source was released). The first iPod was released in October of 2001 which used HFS+. I imagine by the time that code was released it had been battle hardened quite a bit.

[mikhailt]

Because on two separate occasions, APFS ate all of my free space resulting into me reinstalling macOS as the system was locking up. (Yes, I filed a radar, and yes they fixed it, only to regress 6-8 months later).

[JadeNB]

> They do plan to document it fully later:

> > Is APFS open source?

> > An open source implementation is not available at this time. Apple plans to document and publish the APFS volume format specification.

They claim to plan to document it fully later.

[monocasa]

The spec has already been released.

[loeg]

It's a partial spec.