On Tue, Nov 26, 2019 at 02:22:40AM -0500, Doug Nazar wrote: > On Fri, Oct 11, 2019 at 17:07:09PM +0000, Bruce Fields wrote: > >On Tue, Oct 08, 2019 at 10:23:56PM +0200, Thomas Deutschmann wrote: > >> Hi, > >> > >> we have some user reporting that NFS v3 mounts are broken > >> when using glibc-2.29 and linux-4.9.x (4.9.128) because > >> statx() with mask=STATX_BASIC_STATS returns EINVAL. > >> > >> Looks like this isn't happening with <nfs-utils-2.4.1 or > >> newer kernels. > >> > >> The following workaround was confirmed to be working: > >> > >> --- a/support/misc/xstat.c 2019-06-24 21:31:55.260371592 +0200 > >> +++ b/support/misc/xstat.c 2019-06-24 21:32:29.098777436 +0200 > >> @@ -47,6 +47,8 @@ > >> statx_copy(statbuf, &stxbuf); > >> return 0; > >> } > >> + if (errno == EINVAL) > >> + errno = ENOSYS; > >> if (errno == ENOSYS) > >> statx_supported = 0; > >> } else > >> > >> > >> Bug: https://bugs.gentoo.org/688644 > >> > >> At the moment I have no clue whether this is kernel/glibc or > >> nfs-utils related; if the patch is safe to apply... > > > >Well, sounds like nfs-utils started using statx in 2.4.1. And just the > >fact that varying the kernel version makes it sound like there was a > >kernel bug causing an EINVAL return in this case, and that bug got > >fixed. > > > >One way to confirm might be running mount under strace and looking for > >that EINVAL return. > > Just to provide an update on this issue, it was tracked down to glibc's > statx emulation not supporting AT_STATX_DONT_SYNC and returning EINVAL. > > So on a kernel without statx support, but a new glibc with statx support, > nfs-utils will always fail to stat any paths. > > Either this or a similar fix is required to support older kernels. OK. So maybe your patch is the best we can do. I'd just add a comment there documenting the situation. --b.
