Created attachment 847976 [details]
/dev/sda3 is the corrupted partition.

Background...

Recently, my btrfs root partition started mounting read-only after I had tried a "btrfs balance" to free up some space. I couldn't fix things quickly (e.g., with reboots, "btrfs check --repair", etc.), so I decided just to reinstall Tumbleweed in a different partition.

Things worked well for a day or two, but then my system performance degraded severely in the middle of a "zypper dup" removing the current kernel before installing a new kernel. Looking around, I noticed in the log that os-prober was running on the corrupted partition, along with a lot of btrfs activity in the corrupted partition. (I've attached some log records. /dev/sda3 is the corrupted partition. /dev/sda2 is the newly-installed one.)

Unfortunately, I ended up with a partially-removed kernel package (with no older kernel, since it was a new installation), so I recovered by rolling back to the "pre" snapshot for the "zypper dup". After that, I used Yast Partitioner to reformat the corrupted btrfs partition as XFS. Things have been fine since.

The issue...

I suspect the degradation I saw was due to os-prober mounting the corrupted partition, which then triggered the system degradation. I suggest modifying os-prober to use mount options like skip_balance to avoid triggering situations like this.