Note to self: don't forget about "the other" fs-attrs!

[pjotrek-b]

There's not only xattrs for key/value metadata, but also other sysadmin-used attrs on linux filesystems:
https://wiki.archlinux.org/title/File_permissions_and_attributes#File_attributes

Quote from ArchLinux wiki:

These are a few useful attributes. Not all filesystems support every attribute.

a - append only: File can only be opened for appending.
c - compressed: Enable filesystem-level compression for the file.
i - immutable: Cannot be modified, deleted, renamed, linked to. Can only be set by root.
j - data [journal](https://wiki.archlinux.org/title/File_systems#Journaling)ing: Use the journal for file data writes as well as metadata.
m - no compression: Disable filesystem-level compression for the file.
A - no atime update: The file's atime will not be modified.
C - no copy on write: Disable copy-on-write, for filesystems that support it.

See chattr(1) for a complete list of attributes and for more info on what each attribute does.

[pjotrek-b]

Note No.2:
Also don't forget about the namespaces of xattrs:
Currently everything I'm able to use is "user."

I expect other namespaces to be supported and used to set order and standards apart from "unmoderated user. namespace" 😄

[grexe]

this is by design and intended behavior. Custom attributes specified by users should always be prefixed with the user namespace, which is also used in all examples, see:
https://wiki.archlinux.org/title/Extended_attributes
as also documented by freedesktop.org:
https://www.freedesktop.org/wiki/CommonExtendedAttributes/