On 12/8/19 3:51 PM, Mike Christie wrote: > This fixes a regression added with: > > commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4 > Author: Mike Christie <mchristi@xxxxxxxxxx> > Date: Sun Aug 4 14:10:06 2019 -0500 > > nbd: fix max number of supported devs > > where we can deadlock during device shutdown. The problem occurs if > the recv_work's nbd_config_put occurs after nbd_start_device_ioctl has > returned and the userspace app has droppped its reference via closing > the device and running nbd_release. The recv_work nbd_config_put call > would then drop the refcount to zero and try to destroy the config which > would try to do destroy_workqueue from the recv work. > > This patch just has nbd_start_device_ioctl do a flush_workqueue when it > wakes so we know after the ioctl returns running works have exited. This > also fixes a possible race where we could try to reuse the device while > old recv_works are still running. Applied, thanks Mike. -- Jens Axboe
