Messages in this thread | | | Date | Mon, 24 Apr 2023 20:17:11 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v2] mm/gup: disallow GUP writing to file-backed mappings by default |
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On Tue, Apr 25, 2023 at 12:03:34AM +0100, Lorenzo Stoakes wrote:
> Except you dirty a page that is mapped elsewhere that thought everything > was cleaned and... not sure the PTLs really help you much?
If we have a writable PTE then while the PTE's PTL is held it is impossible for a FS to make the page clean as any cleaning action has to also take the PTL to make the PTE non-present or non-writable.
> If we want to be more adventerous the opt-in variant could default to on > for FOLL_LONGTERM too, but that discussion can be had over on that patch > series.
I think you should at least do this too to explain why io_uring code is moving into common code..
Jason
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