Messages in this thread | | | Date | Thu, 2 Jun 2022 17:42:13 +0800 | Subject | Re: [PATCHSETS] v14 fsdax-rmap + v11 fsdax-reflink | From | Shiyang Ruan <> |
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Hi,
Is there any other work I should do with these two patchsets? I think they are good for now. So... since the 5.19-rc1 is coming, could the notify_failure() part be merged as your plan?
-- Thanks, Ruan.
在 2022/5/12 20:27, Shiyang Ruan 写道: > > > 在 2022/5/11 23:46, Dan Williams 写道: >> On Wed, May 11, 2022 at 8:21 AM Darrick J. Wong <djwong@kernel.org> >> wrote: >>> >>> Oan Tue, May 10, 2022 at 10:24:28PM -0700, Andrew Morton wrote: >>>> On Tue, 10 May 2022 19:43:01 -0700 "Darrick J. Wong" >>>> <djwong@kernel.org> wrote: >>>> >>>>> On Tue, May 10, 2022 at 07:28:53PM -0700, Andrew Morton wrote: >>>>>> On Tue, 10 May 2022 18:55:50 -0700 Dan Williams >>>>>> <dan.j.williams@intel.com> wrote: >>>>>> >>>>>>>> It'll need to be a stable branch somewhere, but I don't think it >>>>>>>> really matters where al long as it's merged into the xfs for-next >>>>>>>> tree so it gets filesystem test coverage... >>>>>>> >>>>>>> So how about let the notify_failure() bits go through -mm this >>>>>>> cycle, >>>>>>> if Andrew will have it, and then the reflnk work has a clean >>>>>>> v5.19-rc1 >>>>>>> baseline to build from? >>>>>> >>>>>> What are we referring to here? I think a minimal thing would be the >>>>>> memremap.h and memory-failure.c changes from >>>>>> https://lkml.kernel.org/r/20220508143620.1775214-4-ruansy.fnst@fujitsu.com >>>>>> ? >>>>>> >>>>>> Sure, I can scoot that into 5.19-rc1 if you think that's best. It >>>>>> would probably be straining things to slip it into 5.19. >>>>>> >>>>>> The use of EOPNOTSUPP is a bit suspect, btw. It *sounds* like the >>>>>> right thing, but it's a networking errno. I suppose livable with >>>>>> if it >>>>>> never escapes the kernel, but if it can get back to userspace then a >>>>>> user would be justified in wondering how the heck a filesystem >>>>>> operation generated a networking errno? >>>>> >>>>> <shrug> most filesystems return EOPNOTSUPP rather enthusiastically >>>>> when >>>>> they don't know how to do something... >>>> >>>> Can it propagate back to userspace? >>> >>> AFAICT, the new code falls back to the current (mf_generic_kill_procs) >>> failure code if the filesystem doesn't provide a ->memory_failure >>> function or if it returns -EOPNOSUPP. mf_generic_kill_procs can also >>> return -EOPNOTSUPP, but all the memory_failure() callers (madvise, etc.) >>> convert that to 0 before returning it to userspace. >>> >>> I suppose the weirder question is going to be what happens when madvise >>> starts returning filesystem errors like EIO or EFSCORRUPTED when pmem >>> loses half its brains and even the fs can't deal with it. >> >> Even then that notification is not in a system call context so it >> would still result in a SIGBUS notification not a EOPNOTSUPP return >> code. The only potential gap I see are what are the possible error >> codes that MADV_SOFT_OFFLINE might see? The man page is silent on soft >> offline failure codes. Shiyang, that's something to check / update if >> necessary. > > According to the code around MADV_SOFT_OFFLINE, it will return -EIO when > the backend is NVDIMM. > > Here is the logic: > madvise_inject_error() { > ... > if (MADV_SOFT_OFFLINE) { > ret = soft_offline_page() { > ... > /* Only online pages can be soft-offlined (esp., not > ZONE_DEVICE). */ > page = pfn_to_online_page(pfn); > if (!page) { > put_ref_page(ref_page); > return -EIO; > } > ... > } > } else { > ret = memory_failure() > } > return ret > } > > > -- > Thanks, > Ruan. > >
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