On Fri, Nov 08, 2019 at 07:01:15AM +0100, Arkadiusz Miśkiewicz wrote: > > Hello. > > I have two servers: > > backup4 - one with Adaptec ASR8885Q (that's the one which breaks so > often but this time adaptes works) > > backup3 - other with software raid only > > Both are now running 5.3.8 kernels and both end up like this log below. > It takes ~ up to day to reproduce. The WARN_ON means that conversion of delalloc blocks failed to find free space. Something that should not be possible due to the delalloc reservations. What as the last kernel where you did not see something like this?