Messages in this thread | | | Date | Mon, 12 Sep 2016 08:01:48 -0700 | From | Christoph Hellwig <> | Subject | Re: DAX mapping detection (was: Re: [PATCH] Fix region lost in /proc/self/smaps) |
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On Mon, Sep 12, 2016 at 06:05:07PM +1000, Nicholas Piggin wrote: > It's not fundamentally broken, it just doesn't fit well existing > filesystems.
Or the existing file system architecture for that matter. Which makes it a fundamentally broken model.
> Dave's post of requirements is also wrong. A filesystem does not have > to guarantee all that, it only has to guarantee that is the case for > a given block after it has a mapping and page fault returns, other > operations can be supported by invalidating mappings, etc.
Which doesn't really matter if your use case is manipulating fully mapped files.
But back to the point: if you want to use a full blown Linux or Unix filesystem you will always have to fsync (or variants of it like msync), period.
If you want a volume manager on stereoids that hands out large chunks of storage memory that can't ever be moved, truncated, shared, allocated on demand, etc - implement it in your library on top of a device file.
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