Hi Matthew, as a starting point: can you send us a network trace of this? Iirc the mailing list server is not particularily fond of attachements, so either put it somewhere to grab it or file a Samba bug and attach it there. Cheers! -slow -- SerNet Samba Team Lead https://sernet.de/ Samba Team Member https://samba.org/ Samba Support and Dev https://samba.plus/services/ SAMBA+ packages https://samba.plus/products/samba On 7/29/25 4:21 PM, Matthew Richardson via samba wrote:> Hi, > > I'm currently investigating using the smb3 unix extensions. I can list/ > stat special files in the samba mount, and can create and delete > 'ordinary' files, but when I try to create special files I get an error: > > $ ln -s b.txt sym_b > ln: failed to create symbolic link 'a.sym': Operation not supported > > or > > $ mkfifo b.fifo > mkfifo: cannot create fifo 'b.fifo': Operation not supported > > > My test setup is as follows: > > Samba - Docker samba.org/samba-server:devbuilds-centos-amd64 (publishing > to host port 445) > Host Ubuntu Noble with kernel 6.15.7 (cifs.ko v2.54) > cifs-utils v7.0 > > > Samba config: > > [global] > ?? workgroup = WORKGROUP > ?? security = user > ?? map to guest = never > ?? log level = 3 > ?? guest ok = no > ?? smb3 unix extensions = yes > > [myshare] > ?? path = /opt/smb > ?? browsable = yes > ?? writable = yes > ?? read only = no > ?? valid users = sambauser #uid/gid 1000 > ?? create mask = 0777 > ?? directory mask = 0777 > > > I'm mounting the share as follows: > > mount -t cifs //localhost/myshare /mnt -o > user=sambauser,pass=samba,unix,uid=1000,gid=1000 > > Resulting in mount: > //localhost/myshare on /mnt type cifs > (rw,relatime,vers=3.1.1,cache=strict,upcall_target=app,username=sambauser,uid=1000,forceuid,gid=1000,forcegid,addr=127.0.0.1,file_mode=0755,dir_mode=0755,soft,posix,posixpaths,serverino,mapposix,reparse=nfs,nativesocket,symlink=unix,rsize=4194304,wsize=4194304,bsize=1048576,retrans=1,echo_interval=60,actimeo=1,closetimeo=1) > > There's nothing immediately obvious in the server logs which might add > more information. > > I'm not sure if I'm missing something in my config that is limiting the > creation of special files, or if this is a limitation in the current > development of the smb3 unix extensions code, and I just need to be > patient. > > Any advice appreciated! > > Thanks, > > Matthew >-------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature.asc Type: application/pgp-signature Size: 840 bytes Desc: OpenPGP digital signature URL: <http://lists.samba.org/pipermail/samba/attachments/20250729/48dded6d/OpenPGP_signature.sig>
Matthew Richardson
2025-Jul-30 12:31 UTC
[Samba] SMB3 Unix Extensions - creating special files
Hi, I've created a few network traces which will hopefully help. Each one contains the initial mount command, followed by a single command. They're hosted here: https://filebin.net/zvdx07i2m3lta129 Working: samba_stat_symlink.pcap = stat /mnt/sym_a_local Not working: samba_ln_s.pcap = ln -s /mnt/a.txt /mnt/a.symlink samba_mkfifo.pcap = mkfifo /mnt/fifo_new Hopefully that will give some idea about what's happening but let me know if you need any other traces or debug info. Thanks, Matthew On 29/07/2025 18:22, Ralph Boehme wrote:> Hi Matthew, > > as a starting point: can you send us a network trace of this? > > Iirc the mailing list server is not particularily fond of attachements, > so either put it somewhere to grab it or file a Samba bug and attach it > there. > > Cheers! > -slow >-------------- 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/20250730/0cdcd6c9/OpenPGP_signature.sig>