On Fri, Feb 26, 2021 at 11:05 AM Darrick J. Wong <djwong@xxxxxxxxxx> wrote: > > On Fri, Feb 26, 2021 at 09:45:45AM +0000, ruansy.fnst@xxxxxxxxxxx wrote: > > Hi, guys > > > > Beside this patchset, I'd like to confirm something about the > > "EXPERIMENTAL" tag for dax in XFS. > > > > In XFS, the "EXPERIMENTAL" tag, which is reported in waring message > > when we mount a pmem device with dax option, has been existed for a > > while. It's a bit annoying when using fsdax feature. So, my initial > > intention was to remove this tag. And I started to find out and solve > > the problems which prevent it from being removed. > > > > As is talked before, there are 3 main problems. The first one is "dax > > semantics", which has been resolved. The rest two are "RMAP for > > fsdax" and "support dax reflink for filesystem", which I have been > > working on. > > <nod> > > > So, what I want to confirm is: does it means that we can remove the > > "EXPERIMENTAL" tag when the rest two problem are solved? > > Yes. I'd keep the experimental tag for a cycle or two to make sure that > nothing new pops up, but otherwise the two patchsets you've sent close > those two big remaining gaps. Thank you for working on this! > > > Or maybe there are other important problems need to be fixed before > > removing it? If there are, could you please show me that? > > That remains to be seen through QA/validation, but I think that's it. > > Granted, I still have to read through the two patchsets... I've been meaning to circle back here as well. My immediate concern is the issue Jason recently highlighted [1] with respect to invalidating all dax mappings when / if the device is ripped out from underneath the fs. I don't think that will collide with Ruan's implementation, but it does need new communication from driver to fs about removal events. [1]: http://lore.kernel.org/r/CAPcyv4i+PZhYZiePf2PaH0dT5jDfkmkDX-3usQy1fAhf6LPyfw@xxxxxxxxxxxxxx
