Messages in this thread | | | Date | Fri, 11 Jun 2021 14:41:50 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 2/3] s390/vfio-ap: introduce two new r/w locks to replace wait_queue_head_t |
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On Fri, Jun 11, 2021 at 07:11:50PM +0200, David Hildenbrand wrote:
> > Also, not convinced down_write_trylock() is appropriate from a sysfs > > callback, it should block and wait, surely? Otherwise userspace gets > > random racy failures depending on what the kernel is doing?? > > It might we worth exploring lock_device_hotplug_sysfs() which does a > > "return restart_syscall()" with some delay.
The ideal design from a sysfs should be a single down_write_killable().
restart_syscall will just create a weird spinlock that is hopefully unlikely to spin :\
Jason
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