Messages in this thread | | | Subject | Re: NFS 4.2 client support broken on 5.10.5 | From | Kurt Garloff <> | Date | Fri, 8 Jan 2021 16:49:53 +0100 |
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Hi Trond,
Am 08.01.21 um 15:39 schrieb Kurt Garloff: > Hi Trond, > > On 08/01/2021 12:58, Trond Myklebust wrote: >> On Fri, 2021-01-08 at 12:41 +0100, Kurt Garloff wrote: >>> [...] >>> The kernel tree is on an NFS share, and I run 5.10.5 client kernel >>> against the kernel NFS (4.2) server, running a 5.10.3 kernel. >>> >>> The issue does NOT occur on a 5.10.3 client kernel, but is easily >>> reproducible on 5.10.5. Note that 5.10.5 on a local file system or >>> against an NFSv3 server does not show the issue. >>> >>> Test program that reproduces this on the first pwrite64() is >>> attached. >>> Note that the call to ftruncate() is required to make the problem >>> happen. >>> >>> I could go on bisecting this to a particular patch, but you'll >>> probably be able to see right away what's wrong. >>> >> Hmm... If this is NFSv4.2 do you have READ_PLUS turned on or off in >> .config? It really is not safe to enable READ_PLUS on 5.10 kernels >> since that can cause random memory corruption. > OK, it is turned on in my kernel -- looks like I have not read the > warning in the config option help text carefully enough ... > > I'll test what happens if I switch it off and report back.
OK, I compiled a kernel without support for READ_PLUS and the test program magically succeeds.
So take my report as input to the developers that work on making READ_PLUS work. Maybe they want to add my little program to their CI suite.
Thanks,
-- Kurt Garloff <kurt@garloff.de>, Cologne, Germany
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