On Thu, Jul 12, 2018 at 07:32:19AM +0000, Petr Pisar wrote: > On 2018-07-11, Zbigniew Jędrzejewski-Szmek <zbys...@in.waw.pl> wrote: > > The effects of fsync are impossible to see unless you hard-reboot the > > machine. > > Are you sure non-fsynced changes are are guaranteed to be visible on > block cache level? E.g. if you mix read/write and mmaped I/O from > different processes?
Block cache — no, I don't think so. But do we have packages that do anything like this during build? It'd require low-level fs support and would be probably pretty fragile anyway. > > I wonder if it wouldn't be more robust to use nspawn's syscall filter > > to filter the fsync calls. > > Can the syscall filter fake a success of the syscall return value? > Correctly written applications check fsync() return value and forward > the error. It can, e.g. something like system-nspawn --system-call-filter='~sync:0 fsync:0' should be a good start. Zbyszek _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/XPYRD7LMNLJGXCYUF5HTSJZIP6P5VOOV/