| Message ID | ef1023fa-25e4-8ce7-945e-bc210e635e10@gentoo.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | nfs-utils: v3 mounts broken due to statx() returning EINVAL | expand |
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. I might also try looking through the kernel logs for nfs or the stat code to see if there's a mention of this (didn't see it on a quick look.) Or try bisecting kernel versions to find the one where this was fixed. --b. > > Any help is appreciated. Thanks! > > > -- > Regards, > Thomas Deutschmann / Gentoo Linux Developer > C4DD 695F A713 8F24 2AA1 5638 5849 7EE5 1D5D 74A5 >
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. Doug
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.
--- 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