Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: Writeback threads and freezable | Date | Wed, 18 Dec 2013 23:14:24 +0100 |
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On Wednesday, December 18, 2013 06:43:43 AM Tejun Heo wrote:
[...]
> If filesystems need an indication that the underlying device is no > longer functional, please go ahead and add it, but please keep in mind > all these are completely asynchronous. Nothing guarantees you that > such events would happen in any specific order. IOW, you can be at > *ANY* point in your warm unplug path and the device is hot unplugged, > which essentially forces all the code paths to be ready for the worst, > and that's exactly why there isn't much effort in trying to separate > out warm and hot unplug paths.
Yes. Devices can go away at any point without notice. Even PCI devices that have never been assumed to be hot-removable. Any piece of code in the kernel needs to be prepared to deal with such situations.
Thanks, Rafael
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