Messages in this thread | | | Subject | Re: [PATCH 0/3] iopmem : A block device for PCIe memory | From | Sagi Grimberg <> | Date | Thu, 27 Oct 2016 13:22:49 +0300 |
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>> You do realise that local filesystems can silently change the >> location of file data at any point in time, so there is no such >> thing as a "stable mapping" of file data to block device addresses >> in userspace? >> >> If you want remote access to the blocks owned and controlled by a >> filesystem, then you need to use a filesystem with a remote locking >> mechanism to allow co-ordinated, coherent access to the data in >> those blocks. Anything else is just asking for ongoing, unfixable >> filesystem corruption or data leakage problems (i.e. security >> issues). > > And at least for XFS we have such a mechanism :) E.g. I have a > prototype of a pNFS layout that uses XFS+DAX to allow clients to do > RDMA directly to XFS files, with the same locking mechanism we use > for the current block and scsi layout in xfs_pnfs.c.
Christoph, did you manage to leap to the future and solve the RDMA persistency hole? :)
e.g. what happens with O_DSYNC in this model? Or you did a message exchange for commits?
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