On Thu, Oct 24, 2019 at 10:55:14AM +0200, Michal Suchánek wrote: > On Wed, Oct 23, 2019 at 07:22:32PM -0700, Christoph Hellwig wrote: > > On Wed, Oct 23, 2019 at 02:52:45PM +0200, Michal Suchanek wrote: > > > Opening a block device may require a long operation such as waiting for > > > the cdrom tray to close. Performing this operation with locks held locks > > > out other attempts to open the device. These processes waiting to open > > > the device are not killable. You can use mutex_lock_killable() to fix that.