Messages in this thread | | | Date | Mon, 11 Aug 2014 10:13:08 -0400 | From | Matthew Wilcox <> | Subject | Re: [PATCH v7 07/22] Replace the XIP page fault handler with the DAX page fault handler |
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On Mon, Aug 11, 2014 at 10:51:47AM +0200, Jan Kara wrote: > So I'm afraid we'll have to find some other way to synchronize > page faults and truncate / punch hole in DAX.
What if we don't? If we hit the race (which is vanishingly unlikely with real applications), the consequence is simply that after a truncate, a file may be left with one or two blocks allocated somewhere after i_size. As I understand it, that's not a real problem; they're temporarily unavailable for allocation but will be freed on file removal or the next truncation of that file.
I'm also still considering the possibility of having truncate-down block until all mmaps that extend after the new i_size have been removed ...
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