[Samba] vfs_shadow_copy2 cannot read/find snapshots

[Sebastian Neustein]

Hi

I am trying to get shadow_copy2 to read gluster snapshots and provide 
the users with previous versions of their files.

Here is my smb.conf:

[global]
         security = ADS
         workgroup = AD
         realm = AD.XXX.XX
         netbios name = A32X
         log file = /var/log/samba/%m
         log level = 1
         idmap config * : backend = tdb
         idmap config * : range = 10000-10100
         idmap config AD:backend = rid
         idmap config AD:range = 1000000-1999999
         vfs objects = acl_xattr
         map acl inherit = yes
         inherit acls = yes
         store dos attributes = yes
         winbind use default domain = yes

[admin]
         path = /srv/glvol_samba/admin
         guest ok = no
         read only = no
         browseable = no
         administrative share = yes
         vfs objects = acl_xattr glusterfs_fuse

[projects]
         path = /srv/glvol_samba/admin/projects
         comment = ARC Projekte
         guest ok = no
         read only = no
         shadow:snapdir = /srv/glvol_samba/admin/projects/.snaps
         shadow:basedir = /srv/glvol_samba/admin/projects
         shadow:sort = desc
         shadow:snapprefix = ^snap$
         shadow:format = _GMT-%Y.%m.%d-%H.%M.%S
         vfs objects = acl_xattr shadow_copy2 glusterfs_fuse


I can go to a shared directory on the samba server and enter the .snaps 
subdirectory, in there I can see:

root at XXX:~# cd /srv/glvol_samba/admin/projects/.snaps

root at XXX:/srv/glvol_samba/admin/projects/.snaps# ls -ld
drwxr-xr-x 2 root root 4096  1. Jan 1970  .

root at XXX:/srv/glvol_samba/admin/projects/.snaps# ls -l
insgesamt 28
drwxrwx---+ 3 domadmin.sn domänen-benutzer 4096 16. Mai 16:31 
snap_GMT-2023.05.16-19.14.01
drwxrwx---+ 3 domadmin.sn domänen-benutzer 4096 16. Mai 16:31 
snap_GMT-2023.05.17-19.14.01
drwxrwx---+ 3 domadmin.sn domänen-benutzer 4096 16. Mai 16:31 
snap_GMT-2023.05.18-19.14.01
drwxrwx---+ 3 domadmin.sn domänen-benutzer 4096 16. Mai 16:31 
snap_GMT-2023.05.19-19.14.01
drwxrwx---+ 3 domadmin.sn domänen-benutzer 4096 16. Mai 16:31 
snap_GMT-2023.05.20-19.14.01
drwxrwx---+ 3 domadmin.sn domänen-benutzer 4096 16. Mai 16:31 
snap_GMT-2023.05.21-19.14.01

Until here, from my point of view, everything works as expected.

But when I try to access a previous version of a file from a windows 
client, samba logs:
[2023/05/22 10:39:52.278407,  1] 
../../source3/modules/vfs_shadow_copy2.c:2222(shadow_copy2_get_shadow_copy_data)
   shadow_copy2_get_shadow_copy_data: SMB_VFS_NEXT_OPEN failed for 
'/srv/glvol_samba/admin/projects/.snaps' - Permission denied
Even though the file has changed, the user cannot see a previous 
version. The list is empty.

I can mount a single snapshot on a linux client into /mnt and see all 
files as expected:
root at YYY:~# mount.glusterfs 
B741:/snaps/snap_GMT-2023.05.21-19.14.01/glvol_samba /mnt/

On the samba server the gluster share is mounted with:
root at XXX:~# mount -t fuse.glusterfs
B741:/glvol_samba on /srv/glvol_samba type fuse.glusterfs 
(rw,relatime,user_id=0,group_id=0,allow_other,max_read=131072,_netdev)

The systemd unit for this is:
root at XXX:~# cat /etc/systemd/system/srv-glvol_samba.mount
[Unit]
Description=Data Dir
After=network.target
Requires=network-online.target

[Mount]
What=B741:/glvol_samba
Where=/srv/glvol_samba
Type=glusterfs
Options=defaults,_netdev,negative-timeout=10,attribute-timeout=30,fopen-keep-cache,direct-io-mode=enable,acl

[Install]
WantedBy=multi-user.target


The OS is debian 11.7 with sernet samba packages (4.17.8).

Regards
Sebastian

-- 
Sebastian Neustein

Airport Research Center GmbH
Bismarckstraße 61
52066 Aachen
Germany

Phone: +49 241 16843-23
Fax: +49 241 16843-19
e-mail:sebastian.neustein at arc-aachen.de
Website:http://www.airport-consultants.com

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