Add dependencies to the VirtioFsSvc service

[jwatt]

The service has two dependencies (WinFsp.Launcher and VirtioFsDrv) as noted, for example, at:

https://virtio-fs.gitlab.io/howto-windows.html https://github.com/virtio-win/kvm-guest-drivers-windows/issues/550#issuecomment-779047192

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[jwatt]

Thanks for taking a look at this pull request, @viktor-prutyanov.

Maybe @hammerg or @xiagao can comment since they have both previously said that WinFsp.Launcher is a dependency (hammerg's comment) (xiagao's comment).

virtiofs is built on top of WinFsp, as you'll know, and my (possibly incorrect) understanding from the discussion on some virtiofs issues is that if WinFsp isn't fully ready when VirtioFsSvc is started, then virtiofs sharing may (or may not - racey?) fail for certain tasks (such as opening files in subdirectories of the shared directory, I think). To fix that, VirtioFsSvc needs to be manually restarted after boot. So I'm guessing marking WinFsp.Launcher as a dependency isn't because it's needed to launch VirtioFsSvc, but instead it may be a convenient way to have Service Manager wait until it's safe before it starts VirtioFsSvc.

[xiagao]

Thanks for taking a look at this pull request, @viktor-prutyanov.

Maybe @hammerg or @xiagao can comment since they have both previously said that WinFsp.Launcher is a dependency (hammerg's comment) (xiagao's comment).

Actually I config VirtioFsSvc according to https://virtio-fs.gitlab.io/howto-windows.html . And I tried without any dependecy, virtiofs still works.

virtiofs is built on top of WinFsp, as you'll know, and my (possibly incorrect) understanding from the discussion on some virtiofs issues is that if WinFsp isn't fully ready when VirtioFsSvc is started, then virtiofs sharing may (or may not - racey?) fail for certain tasks (such as opening files in subdirectories of the shared directory, I think). To fix that, VirtioFsSvc needs to be manually restarted after boot. So I'm guessing marking WinFsp.Launcher as a dependency isn't because it's needed to launch VirtioFsSvc, but instead it may be a convenient way to have Service Manager wait until it's safe before it starts VirtioFsSvc.

[viktor-prutyanov]

Hi @jwatt

Do you plan to send a new version of the patch?