> FILE_SUPPORTS_REPARSE_POINTS, which breaks against samba because itisn't set. IOW, we should skip this check for SMB3.1.1 POSIX mounts. We did add this patch to 6.16 in mainline https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/smb/client?id=8767cb3fbd514c4cf85b4f516ca30388e846f540 And it should be backported to some stable kernels by now Thanks, Steve On Thu, Jul 31, 2025, 1:15?PM Paulo Alcantara <pc at manguebit.org> wrote:> Matthew Richardson <m.richardson at ed.ac.uk> writes: > > > Thanks for spotting this. I can confirm that I see different behaviour > > with different kernels: > > > > 6.13.0 - mkfifo and ln-s work as expected. > > 6.14.0 - mkfifo works, ln-s gives 'operation not supported'. > > >=6.15.7 - both give 'operation not supported'. > > > > Which implies possibly more than one regression? > > Yes. It used to work on older kernels because the client used to create > special files with NFS reparse points by default, which is required for > SMB3.1.1 POSIX mounts. 6c06be908ca1 ("cifs: Check if server supports > reparse points before using them") then added a check for > FILE_SUPPORTS_REPARSE_POINTS, which breaks against samba because it > isn't set. IOW, we should skip this check for SMB3.1.1 POSIX mounts. >
Matthew Richardson
2025-Jul-31 19:24 UTC
[Samba] SMB3 Unix Extensions - creating special files
I've just tried the 6.16 kernel from mainline (Linux vm-b 6.16.0-061600-generic #202507272138 SMP PREEMPT_DYNAMIC Sun Jul 27 22:00:36 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux) and while mkfifo works again, ln -s is still giving 'operation not supported'. Thanks, Matthew On 31/07/2025 19:53, Steve French wrote:> > You don't often get email from smfrench at gmail.com. Learn why this is > important <https://aka.ms/LearnAboutSenderIdentification> > > >> FILE_SUPPORTS_REPARSE_POINTS, which breaks against samba because it > isn't set.? IOW, we should skip this check for SMB3.1.1 POSIX mounts. > > We did add this patch to 6.16 in mainline > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ > commit/fs/smb/client?id=8767cb3fbd514c4cf85b4f516ca30388e846f540 > <https://eur02.safelinks.protection.outlook.com/? > url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%2Fcommit%2Ffs%2Fsmb%2Fclient%3Fid%3D8767cb3fbd514c4cf85b4f516ca30388e846f540&data=05%7C02%7C%7Cc29b9828335c42fa54f908ddd0638746%7C2e9f06b016694589878910a06934dc61%7C0%7C0%7C638895848082756770%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=hQdSVaqJFPIjiwDPuN%2FlOn%2FSqGlqg8Sts1yH272svtA%3D&reserved=0> > > And it should be backported to some stable kernels by now > Thanks, > > Steve > > On Thu, Jul 31, 2025, 1:15?PM Paulo Alcantara <pc at manguebit.org > <mailto:pc at manguebit.org>> wrote: > > Matthew Richardson <m.richardson at ed.ac.uk > <mailto:m.richardson at ed.ac.uk>> writes: > > > Thanks for spotting this. I can confirm that I see different > behaviour > > with different kernels: > > > > 6.13.0 - mkfifo and ln-s work as expected. > > 6.14.0 - mkfifo works, ln-s gives 'operation not supported'. > >? >=6.15.7 - both give 'operation not supported'. > > > > Which implies possibly more than one regression? > > Yes.? It used to work on older kernels because the client used to create > special files with NFS reparse points by default, which is required for > SMB3.1.1 POSIX mounts.? 6c06be908ca1 ("cifs: Check if server supports > reparse points before using them") then added a check for > FILE_SUPPORTS_REPARSE_POINTS, which breaks against samba because it > isn't set.? IOW, we should skip this check for SMB3.1.1 POSIX mounts. >-------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature.asc Type: application/pgp-signature Size: 203 bytes Desc: OpenPGP digital signature URL: <http://lists.samba.org/pipermail/samba/attachments/20250731/147aab8b/OpenPGP_signature.sig>
Paulo Alcantara
2025-Jul-31 19:59 UTC
[Samba] SMB3 Unix Extensions - creating special files
Steve French <smfrench at gmail.com> writes:>> FILE_SUPPORTS_REPARSE_POINTS, which breaks against samba because it > isn't set. IOW, we should skip this check for SMB3.1.1 POSIX mounts. > > We did add this patch to 6.16 in mainline > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/smb/client?id=8767cb3fbd514c4cf85b4f516ca30388e846f540This patch doesn't fix the problem with creating symlinks reported by Matthew. Note that I've run the tests with v6.16 kernel. I'll send a follow-up patch soon that fixes both socket and symlink issues.