On Fri, May 27, 2022 at 10:01:48AM +0300, Amir Goldstein wrote: > On Fri, May 27, 2022 at 9:06 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > > > FYI, below is the 5.10-stable backport I have been testing earlier this > > week that fixes a bugzilla reported hang: > > > > https://bugzilla.kernel.org/show_bug.cgi?id=214767 > > > > I was just going to submit it to the stable maintaines today after > > beeing out of the holiday, but if you want to add it to this queue > > that is fine with me as well. > > > > Let me take it for a short spin in out xfs stable test environment, since > this env has caught one regression with an allegedly safe fix. > This env has also VMs with old xfsprogs, which is kind of important to > test since those LTS patches may end up in distros with old xfsprogs. > > If all is well, I'll send your patch later today to stable maintainers > with this first for-5.10 series. > > > --- > > From 8e0464752b24f2b3919e8e92298759d116b283eb Mon Sep 17 00:00:00 2001 > > From: Dave Chinner <dchinner@xxxxxxxxxx> > > Date: Fri, 18 Jun 2021 08:21:51 -0700 > > Subject: xfs: Fix CIL throttle hang when CIL space used going backwards > > > > Damn! this patch slipped through my process (even though I did see > the correspondence on the list). > > My (human) process has eliminated the entire 38 patch series > https://lore.kernel.org/linux-xfs/20210603052240.171998-1-david@xxxxxxxxxxxxx/ > without noticing the fix that was inside it. The first two times it was in much smaller patch series (5 and 8 patches total). Also, you probably need to search for commit IDs on the list, too, because this discussion was held in November about backporting the fix to 5.10 stable kernels: Subject: Help deciding about backported patch (kernel bug 214767, 19f4e7cc8197 xfs: Fix CIL throttle hang when CIL space used going backwards) https://lore.kernel.org/linux-xfs/C1EC87A2-15B4-45B1-ACE2-F225E9E30DA9@xxxxxxxxxxxxxxx/ > In this case, I guess Dave was not aware of the severity of the bug fixed I was very aware of the severity of the problem, and I don't need anyone trying to tell me what I should have been doing 18 months ago. It simply wasn't a severe bug. We had one user reporting it, and the when I found the bug I realised that it was a zero-day thinko in delayed logging accounting I made back in 2010 (~2.6.38 timeframe, IIRC). IOWs, it took 10 years before we got the first indication there was a deep, dark corner case bug lurking in that code. The time between first post of the bug fix and merge was about 6 months, so it also wasn't considered serious by anyone at the time as it missed 2 whole kernel releases before it was reviewed and merged... There's been a small handful of user reports of this bug since (e.g the bz above and the backport discussions), but it's pretty clear that this bug is not (and never has been) a widespread issue. It just doesn't fit any of the criteria for a severe bug. Backport candidate: yes. Severe: absolutely not. -Dave. -- Dave Chinner david@xxxxxxxxxxxxx
