On Sun, Jun 29, 2025 at 01:28:08PM -0400, Michael S. Tsirkin wrote: > On Sun, Jun 29, 2025 at 03:36:27PM +0200, Lukas Wunner wrote: > > On Sat, Jun 28, 2025 at 02:58:49PM -0400, Michael S. Tsirkin wrote: > > > > 1/ The device_lock() will reintroduce the issues solved by 74ff8864cc84. > > I see. What other way is there to prevent dev->driver from going away, > though? I guess I can add a new spinlock and take it both here and when > dev->driver changes? Acceptable? You're already holding the pci_bus_sem here, so the final device 'put' can't have been called yet, so the device is valid and thread safe in this context. I think maintaining the desired lifetime of the instantiated driver is just a matter of reference counting within your driver. Just a thought on your patch, instead of introducing a new callback, you could call the existing '->error_detected()' callback with the previously set 'pci_channel_io_perm_failure' status. That would totally work for nvme to kick its cleanup much quicker than the blk_mq timeout handling we currently rely on for this scenario.
