On Thu, Sep 02, 2021 at 01:57:13PM +0000, Christian L?hle wrote: > sd and parent devices must not be removed as sd_open checks for events > > sd_need_revalidate and sd_revalidate_disk traverse the device path > to check for event changes. If during this, e.g. the scsi host is being > removed and its resources freed, this traversal crashes. > Locking with scan_mutex for just a scsi disk open may seem blunt, but there > does not seem to be a more granular option. Also opening /dev/sdX directly > happens rarely enough that this shouldn't cause any issues. Can you please root cause how the device could not be valid, as that should not happen? > > The issue occurred on an older kernel with the following trace: > stack segment: 0000 [#1] PREEMPT SMP PTI > CPU: 1 PID: 121457 Comm: python3 Not tainted 4.14.238hyLinux #1 .. preferably with a current mainline kernel as things changed a lot in this area.