Messages in this thread | | | Date | Tue, 2 Feb 2021 09:32:50 -0500 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH v4 1/2] drivers/misc: sysgenid: add system generation id driver |
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On Wed, Jan 27, 2021 at 11:15:05PM +0100, Pavel Machek wrote: > Hi! > > > - Solution > > > > The System Generation ID is a simple concept meant to alleviate the > > issue by providing a monotonically increasing u32 counter that changes > > each time the VM or container is restored from a snapshot. > > I'd make it u64. > > But as people explained, this has race problems that may be impossible > to solve?
Well the read/write interface could be used in a safe way thinkably:
- application checks VM gen id - application sends a transaction e.g. to database - application re-checks VM gen id - if id changed, application checks the database for duplicate transactions
not sure how can the mmap interface be used safely. Drop it for now?
> Best regards, > Pavel > > -- > http://www.livejournal.com/~pavelmachek
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