On Thu, Jun 02, 2022 at 05:42:13PM +0800, Shiyang Ruan wrote: > 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? Hmm. I don't see any of the patches 1-5,7-13 in current upstream, so I'm guessing this means Andrew isn't taking it for 5.19? --D > > > -- > 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@xxxxxxxxxx> > > > 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@xxxxxxxxxx> 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@xxxxxxxxx> 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@xxxxxxxxxxx > > > > > > > ? > > > > > > > > > > > > > > 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. > > > > > >
