On Tue, Sep 03, 2019 at 10:18:51AM -0400, Vivek Goyal wrote: > On Tue, Sep 03, 2019 at 10:12:16AM -0400, Michael S. Tsirkin wrote: > > On Tue, Sep 03, 2019 at 10:07:52AM -0400, Vivek Goyal wrote: > > > On Tue, Sep 03, 2019 at 04:31:38AM -0400, Michael S. Tsirkin wrote: > > > > > > [..] > > > > + /* TODO lock */ > > > > give me pause. > > > > > > > > Cleanup generally seems broken to me - what pauses the FS > > > > > > I am looking into device removal aspect of it now. Thinking of adding > > > a reference count to virtiofs device and possibly also a bit flag to > > > indicate if device is still alive. That way, we should be able to cleanup > > > device more gracefully. > > > > Generally, the way to cleanup things is to first disconnect device from > > linux so linux won't send new requests, wait for old ones to finish. > > I was thinking of following. > > - Set a flag on device to indicate device is dead and not queue new > requests. Device removal call can set this flag. > > - Return errors when fs code tries to queue new request. > > - Drop device creation reference in device removal path. If device is > mounted at the time of removal, that reference will still be active > and device state will not be cleaned up in kernel yet. > > - User unmounts the fs, and that will drop last reference to device and > will lead to cleanup of in kernel state of the device. > > Does that sound reasonable. > > Vivek
Just we aware of the fact that virtio device, all vqs etc will be gone by the time remove returns. -- MST
