[Solved] Samba share no write access

Thomas_Do · 2017-09-29 19:16:48

In my home LAN I run a Samba file server. Since the last kernel update I have no longer write access to the shares because all files belong to root (permistion 755). Kernel 4.13 apparently uses SMB3 as standard and unix extension seem not to work (?). How can I get write permission for normal users?

My smb.conf looks like this:

[global]
	bind interfaces only = Yes
	interfaces = 172.17.2.23/255.255.255.0
	server string = server
	workgroup = GROUP
	os level = 2
	log file = /var/log/samba/log.%m
	max log size = 1000
	syslog = 0
	panic action = /usr/share/samba/panic-action %d
	guest account = root
	map to guest = Bad User
	security = USER
	keepalive = 30
	dns proxy = No
	idmap config * : backend = tdb
...

[Scanner]
	comment = My Scanner
	path = /mnt/Data/Data/Scanner
	guest ok = Yes
	read only = No

...

The corresponding line in the fstab:

//172.17.2.23/Scanner   /home/thomas/Scanner  cifs password=  0 0

Last edited by Thomas_Do (2017-10-03 11:03:00)

seth · 2017-09-29 20:54:38

https://bbs.archlinux.org/viewtopic.php?id=230324

Edit: is arch / 4.13 client, server or both?

Last edited by seth (2017-09-29 20:55:44)

Thomas_Do · 2017-09-30 08:56:28

https://bbs.archlinux.org/viewtopic.php?id=230324

My problem is different, I can connect but read-only due to changed file permissions.

Edit: is arch / 4.13 client, server or both?

The problem appeared when the client was updated. Meanwhile the server runs 4.13, too. No difference.
I have an other client with 4.12 that works fine.

seth · 2017-09-30 11:37:04

Tried to explicitly add "mapposix" to the options?

Thomas_Do · 2017-09-30 12:38:41

Tried to explicitly add "mapposix" to the options?

Just tried, no difference.

seth · 2017-09-30 13:51:32

This random google up suggest it might relate to the protocol version. https://forum.synology.com/enu/viewtopic.php?t=120065
So I'd still suggest to try eg. "vers=2.0" (resp. any version < 3.0, maybe even 1.0 - just to isolate the problem)

Thomas_Do · 2017-09-30 17:31:11

I tried this already. But after your suggestion I tried again with a reboot instead of unmount & remount. And really, "vers=1.0" works (2.0 does not). Thanks a lot for your help! However, I will leave this thread unsolved, hoping for sugestions how to configure samba with up-to-date protocols.

seth · 2017-09-30 20:25:53

I'd though suggest to mark this as resolved and open a new thread that focuses on the actual problem (seems this has been a problem before) in subject and first post.
Alternatively edit this one, but the following discussion might distract readers.

loqs · 2017-09-30 20:42:04

Try setting log level in smb.conf default = 0 max = 10 and examine the log output for vers=1.0 compared to vers=2.0?

Janusz11 · 2017-10-01 10:14:01

Thomas_Do wrote:

I tried this already. But after your suggestion I tried again with a reboot instead of unmount & remount. And really, "vers=1.0" works (2.0 does not). Thanks a lot for your help!

That helped me as well. Thanks, seth.

I am running samba on a Banana Pi Pro with bananian, by the way.

Thomas_Do · 2017-10-01 12:21:15

seth wrote:

I'd though suggest to mark this as resolved and open a new thread that focuses on the actual problem (seems this has been a problem before) in subject and first post.
Alternatively edit this one, but the following discussion might distract readers.

I am not sure I understand what you mean with "the actual problem (seems this has been a problem before)". As I stated in my first post, I think that the recent change in the samba protocol leads to a different handling of unix file permissions. This led in my case to the observed read-only restriction.
What I would like to find out is, how to pass the original file permissions to a samba share using SMB2 and SMB3. If this is not possible, I would like to know, what alternatives could be used to get a simlar result.

loqs wrote:

Try setting log level in smb.conf default = 0 max = 10 and examine the log output for vers=1.0 compared to vers=2.0?

I did that but can not find any hint to solve the problem.

seth · 2017-10-01 18:33:07

The actual problem is that, as we figured, this does not work in higher SMB versions (at all) - so your problem is that mapposix (resp. "something" in the unix extensions) does not work on higher level SMB, not that the latest kernel release introduced a technical regression. The only reason for your problem is the altered SMB version default (1.0 -> 2.x)

The idea is that stressing this a bit more prominent w/o the noise of the following comments in this thread might help to get a better response on the issue.

loqs · 2017-10-01 22:15:55

You might also want to review these settings

	guest account = root
	map to guest = Bad User

Even if it is not a security issue for your system this appears to be a relatively unusual combination that may not see much testing.

Thomas_Do · 2017-10-02 11:38:09

loqs wrote:

Even if it is not a security issue for your system this appears to be a relatively unusual combination that may not see much testing.

Thanks for your comment. You are right, this configuration it is a little unusual. Changing these settings has no effect on the problem, though.

Thomas_Do · 2017-10-03 11:02:06

I mark this thread as solved because I found a workaround. Thanks all who helped!

SMB2 and SMB3 apparently have no implementation for the unix extensions:

Release Notes for Samba 4.1.0 wrote:

Note that when connecting using SMB2 or SMB3 protocols
the UNIX extensions are no longer available inside the
smbclient command set. This is due to UNIX extensions
not yet being defined for the SMB2 or SMB3 protocols.

jiak · 2017-10-04 09:45:04

Do tell us what is the workwaround...

seth · 2017-10-04 09:51:06

read the thread? esp. post #7 ...

jiak · 2017-10-09 15:16:28

Thanks!

Arch Linux

#1 2017-09-29 19:16:48

[Solved] Samba share no write access

#2 2017-09-29 20:54:38

Re: [Solved] Samba share no write access

#3 2017-09-30 08:56:28

Re: [Solved] Samba share no write access

#4 2017-09-30 11:37:04

Re: [Solved] Samba share no write access

#5 2017-09-30 12:38:41

Re: [Solved] Samba share no write access

#6 2017-09-30 13:51:32

Re: [Solved] Samba share no write access

#7 2017-09-30 17:31:11

Re: [Solved] Samba share no write access

#8 2017-09-30 20:25:53

Re: [Solved] Samba share no write access

#9 2017-09-30 20:42:04

Re: [Solved] Samba share no write access

#10 2017-10-01 10:14:01

Re: [Solved] Samba share no write access

#11 2017-10-01 12:21:15

Re: [Solved] Samba share no write access

#12 2017-10-01 18:33:07

Re: [Solved] Samba share no write access

#13 2017-10-01 22:15:55

Re: [Solved] Samba share no write access

#14 2017-10-02 11:38:09

Re: [Solved] Samba share no write access

#15 2017-10-03 11:02:06

Re: [Solved] Samba share no write access

#16 2017-10-04 09:45:04

Re: [Solved] Samba share no write access

#17 2017-10-04 09:51:06

Re: [Solved] Samba share no write access

#18 2017-10-09 15:16:28

Re: [Solved] Samba share no write access

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