Re: [patch 01/22] update ctime and mtime for mmaped write

From: Miklos Szeredi
Date: Wed Feb 28 2007 - 15:59:49 EST


> What happens if the application overwrites what it had written some
> time later? Nothing. The page is already read-write, the pte dirty,
> so even though the file was clearly modified, there's absolutely no
> way in which this can be used to force an update to the timestamp.

Which, I realize now, actually means, that the patch is wrong. Msync
will have to write protect the page table entries, so that later
dirtyings may have an effect on the timestamp.

Thanks,
Miklos
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