Hi,
This is to report that after jumping from generic kernel 5.15.167 to 5.15.170 I apparently observe ext4 damage.
After some few days of regular daily use of 5.15.170, one morning my ext4 partition refused to mount complaining about corrupted system area (-117). There were no unusual events preceding this. The device in question is a laptop with healthy battery, also connected to AC permanently. The laptop is privately owned by me, in daily use at home, so I am 100% aware of everything happening with it. The filesystem in question lives on md raid1 with very assymmetric members (ssd+hdd) so one would not possibly expect that in the event of emergency cpu halt or some other abnormal stop while filesystem was actively writing data, raid members could stay in perfect sync. After the incident, I've run raid1 check multiple times and run memtest multiple times from different boot media and certainly consulted startctl. Nothing. No issues whatsoever except for this spontaneous ext4 damage.
Looking at git log for ext4 changes between 5.15.167 and 5.15.170 shows a few commits. All landed in 5.15.168. Interestingly, one of them is a comeback of the (in)famous 91562895f803 "properly sync file size update after O_SYNC ..." which caused some blowup 1 year ago due to "subtle interaction". I've no idea if 91562895f803 is related to damage this time or not, but most definitely it looks like some problem was introduced between 5.15.167 and 5.15.170 anyway. And because there are apparently 0 commits to ext4 in 5.15 since 5.15.168 at the moment, I thought I'd report.
Please CC me if you want me to see your reply and/or need more info (I'm not subscribed to the normal flow).
Take care,
Nick