ReiserFS Officially Declared "Obsolete"
The linux-fs merge for the Linux 6.6 cycle now treats ReiserFS as obsolete, the file-system long ago used by default on the likes of SUSE Linux.
Last year with Linux 5.18 ReiserFS was deprecated and now with it being obsolete, it will likely be dropped from the mainline Linux kernel within the next two to three years. Last year openSUSE Tumbleweed also ended ReiserFS support as one of the few distributions supporting it as an option.
ReiserFS is obsolete compared to modern Linux file-systems like EXT4, Btrfs, XFS, and other modern options like F2FS and the forthcoming Bcachefs. Reiser4 development never resulted in its mainline inclusion with no major corporate backers of the effort and others distancing themselves from the Reiser file-systems following the murder conviction of ReiserFS creator Hans Reiser. There's been some occasional work around the Reiser5 file-system led by former Namesys developer Edward Shishkin, but at this stage it doesn't look like Reiser5 will be mainlined in the near-term.
So while it's hardly surprising, with Linux 6.6 ReiserFS is now marked as obsolete. If you have any ReiserFS partitions around, it's past time to move to another file-system option if you are actively using them with modern versions of the Linux kernel.