[weblacky]

XFS is open source, Linux distributions, or well I guess Slackware at least, provide the option of using XFS as the filesystem upon installation.

 
You are CORRECT that MODERN XFS is supported, it will use XFS v5 (3rd Gen XFS Inode format). Inode version 3 and higher is supported in Linux NOW. 

You're welcome to try this for yourself. All you have to do is get an XFS disk image from IRIX and try to mount it. You'll get an inode v3 warning that claims the file system is corrupt and it doesn't know what it's doing.

IRIX XFS before 6.5.5 (https://web.archive.org/web/202303241808....6.5.5.pdf) was XFS inode v1, 6.5.5 introduced XFS Inode v2, see link on Page 8.  Before that was v1.

Inode V1 and v2 support was PULLED from xfsprogs when I indicated (Feb 2017) because they didn't want to maintain and support the older inode format anymore. So Linux "used to" support all inode revisions of XFS. As of early 2017, it only supports the "modern" versions.  Irix NEVER supported XFS inode v3.

See Section 18.1 "Inode Core" :https://ftp.ntu.edu.tw/linux/utils/fs/xfs/docs/xfs_filesystem_structure.pdf.

Old XFS inode support was discarded due to maintenance decisions as the old UNIX OS was considered a dead platform and therefore they didn't care about data archiving or reading old disks or tapes. They didn't want to maintain the code base that had to know the old XFS Inode format algorithm behavior in the Linux Kernel driver.