On Fri, Apr 27, 2018 at 12:03 PM, J. Bruce Fields <bfields@xxxxxxxxxx> wrote: > On Tue, Apr 24, 2018 at 04:29:14PM -0400, Olga Kornievskaia wrote: >> On Wed, Apr 18, 2018 at 3:08 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: >> > On Tue, Apr 17, 2018 at 11:19:25AM -0400, Olga Kornievskaia wrote: >> >> Yes I agree. Let’s please decide if this will go in (with whatever code improvements are required) or let’s drop it. >> > >> > Well, my vote is very clearly to drop it. >> >> Bruce, when will you make a decision about this? Is there something >> more that needs to happen before it can be decided if the "async" >> patches are moving forward (and then "inter" patches). > > I'm OK with the patches. > > It could help to have some more information about actual customer use > cases: who specifically is asking for this, and what about their > situation makes them believe they'll benefit? I'm really not involved with customer or know of how exactly they will benefit. I have some knowledge of some company that is interested in using copy offload functionality in game development. I have no details. It has been talked about a case scenario of copying VM images. I don't know if VMware uses copy offload or not. > But to me it seems obvious that server-to-server copy will be faster in > some cases as long there's not some screwup preventing it from using the > server-to-server bandwidth (and your numbers don't show any). So I'm > not terribly worried about this. > > If we wanted to simplify I think we could ditch the asynchronous > protocol and still make server-to-server copy work as a series of > synchronous calls. (Or maybe that would make getting good performance > the complicated part.) I'm not in favor of dropping asynchronous piece as I think it's an important performance improvement. It's likely it won't be must of an improvement due to an overhead of establishing clientid/session for every "chuck" of the copy that will be sent synchronously. > The only security issue I'm worried about is the fact that you can make > it try to copy from any arbitrary IP address. I'd be satisfied if we > document the issue and make server-to-server-copy support require a > runtime switch that defaults to off. (And with that in place I don't > see a need to also provide a build option.) Ok, runtime option, I'll work on it. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
