Thank you Arai-san, Your method with loopback device worked to reproduce the issue even where the bug doesn't easily hit for physical devices. Regards, Ryusuke Konishi On Sun, Feb 16, 2020 at 11:11 AM ARAI Shun-ichi <hermes@xxxxxxxxxxxxxxx> wrote: > > And, > > In <20200210.224609.499887311281343618.hermes@xxxxxxxxxxxxxxx>; > ARAI Shun-ichi <hermes@xxxxxxxxxxxxxxx> wrote > as Subject "Re: BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 in nilfs_segctor_do_construct": > > > Hi, > > > > FYI, reporting additional test results. > > > > I reproduced this problem with clean NILFS2 fs in previous mail. > > "clean" means that "make filesystem before every tests." > > In this mail, I tried to reproduct with/without VG/LV, LUKS, loopback. > > > > * Not reproduced > > USB stick - primary partition - NILFS2 > > USB stick - primary partition - VG/LV - NILFS2 > > USB stick - primary partition - VG/LV - LUKS - NILFS2 > > USB stick - primary partition - LUKS - VG/LV - NILFS2 > > USB stick - primary partition - LUKS - VG/LV - LUKS - NILFS2 > > /tmp (tmpfs) - regular file - NILFS2 (loopback mount, kernel 4.19.82) > > USB stick - primary partition(512MiB) - NILFS2 > > > > * Reproduced (always, immediately) > > /tmp (tmpfs) - regular file - NILFS2 (loopback mount) > > USB stick - primary partition - ext4 - regular file - NILFS2 (loopback mount) > > this loopback problem is seen in Kernel 5.5.4. > > > Test conditions: > > kernel 4.19.86 (same as previous test) > > NILFS2/ext4 filesystem, VG/LV, LUKS were made with default parameters > > size of "primary partition" in USB stick is approx. 14GiB > > size of "regular file" is approx. 512MiB > > "reproduce": mount NILFS2, touch file, sync
