OpenZFS on OS X

The result of Finder copies, copies via commandline, or ChronoSync, the xattr "com.apple.FinderInfo" does not seem to be entirely faithful.

My understanding is that it's a binary fixed length of 32 bytes.
When I copy using the Finder, using the command line, or via ChronoSync the result is that there is extra "info" added to the 32 bytes.
For example:

the ORIGINAL SOURCE might be:
com.apple.FinderInfo (32 bytes):
<50545820 5054756c 00000000 00000000 00000000 00000000 00000000 00000000>

String content:
PTX PTul


And the RESULTANT COPY would be:
com.apple.FinderInfo (32 bytes):

<50545820 5054756c 00000000 00000000 00000000 5ceae387 00000000 00000000>
Binary data as string:
«PTX PTul\êㇻ


See the screenshot where I used the xattred application to compare two files, one on an original APFS volumes, the other on a O3X zfs volume.

Also, using "rsync -rlptDvnihxHEXN" to compare the directories, it also reveals a difference in the xattr consistent with this assessment.

Platform:
OS X 10.14.5 (Mojave)

Tested using release:
O3X 1.8.2

Also tested using Beta:
O3X 1.9.0 RC3

Same result with both.

Thanks!

-- madison

Yes, we update the ADDTIME field before returning it:

Code: Select all

      extinfo->date_added = OSSwapBigToHostInt32(va_crtime.tv_sec);


as was required by something. It could be it should only be updated under certain circumstances though, but never did come across an official documentation on it.

Thanks for this reply.

Yes, copies from the same volume to an APFS volume via the various methods mentioned do not trigger this update, at least for the conditions I tried.

I'm not a developer, but maybe I can poke around to see if there's more information.

If you off-hand know of any pointers as to docs where to start looking, or open-source Apple code aside from what I might uncover in Google searches and the like -- feel free to share.

Again, thanks.

-- madison

I read the sources for HFS the most, to see what they do - the logic around ADDTIME wasn't entirely clear. I would consider that to be the definitive source, especially since apfs has no sources for us to peruse.

Thanks.