Tag: samba

Samba – Address family not supported by protocol

After upgrading to Fedora 39, we started having problems with Samba falling over on startup. The server has IPv6 disabled, and (evidently) something is not happy about that. I guess we could enable IPv6, but we don’t really need it.

Adding the following to lines to the GLOBAL section of the smb.conf file and restarting samba sorted it:

bind interfaces only = yes
interfaces = lo eth0


Feb 11 06:26:01 systemd[1]: Started smb.service – Samba SMB Daemon.
Feb 11 06:26:01 smbd[1109]: [2024/02/11 06:26:01.285076, 0] ../../source3/smbd/server.c:1091(smbd_open_one_socket)
Feb 11 06:26:01 smbd[1109]: smbd_open_one_socket: open_socket_in failed: Address family not supported by protocol
Feb 11 06:26:01 smbd[1109]: [2024/02/11 06:26:01.290022, 0] ../../source3/smbd/server.c:1091(smbd_open_one_socket)
Feb 11 06:26:01 smbd[1109]: smbd_open_one_socket: open_socket_in failed: Address family not supported by protocol
Feb 11 08:01:43 systemd[1]: Stopping smb.service – Samba SMB Daemon…
Feb 11 08:01:43 systemd[1]: smb.service: Deactivated successfully.
Feb 11 08:01:43 systemd[1]: Stopped smb.service – Samba SMB Daemon.

Linux – High Load with CIFS Mounts using Kernel 6.5.5

We recently updated our Fedora servers from 36 and 37 to 38. Since the upgrade, we have observed servers with very high load averages – 8+ on a 4-cpu server – but the server didn’t seem unreasonably slow. On the Unix servers I first used, Irix and Solaris, load average counts threads in a Runnable state. Linux, however, includes both Runnable and Uninterruptible states in the load average. This means processes waiting – on network calls using mkdir to a mounted remote server, local disk I/O – are included in the load average. As such, a high load average on Linux may indicate CPU resource contention but it may also indicate I/O contention elsewhere.

But there’s a third possibility – code that opts for the simplicity of the uninterrupted sleep without needing to be uninterruptible for a process. In our upgrade, CIFS mounts have a laundromat that I assume cleans up cache – I see four cifsd-cfid-laundromat threads in an uninterruptible sleep state – which means my load average, when the system is doing absolutely nothing, would be 4.

2023-10-03 11:11:12 [lisa@server01 ~/]# ps aux | grep " [RD]"
root 1150 0.0 0.0 0 0 ? D Sep28 0:01 [cifsd-cfid-laundromat]
root 1151 0.0 0.0 0 0 ? D Sep28 0:01 [cifsd-cfid-laundromat]
root 1152 0.0 0.0 0 0 ? D Sep28 0:01 [cifsd-cfid-laundromat]
root 1153 0.0 0.0 0 0 ? D Sep28 0:01 [cifsd-cfid-laundromat]
root 556598 0.0 0.0 224668 3072 pts/11 R+ 11:11 0:00 ps aux

Looking around the Internet, I see quite a few bug reports regarding this situation … so it seems like a “ignore it and wait” problem – although the load average value is increased by these sleeping threads, it’s cosmetic. Which explains why the server didn’t seem to be running slowly even through the load average was so high.


Date: Tue, 26 Sep 2023 17:54:10 -0700
From: Paul Aurich 
Subject: Re: Possible bug report: kernel 6.5.0/6.5.1 high load when CIFS share is mounted (cifsd-cfid-laundromat in"D" state)

On 2023-09-19 13:23:44 -0500, Steve French wrote:
>On Tue, Sep 19, 2023 at 1:07 PM Tom Talpey <tom@talpey.com> wrote:
>> These changes are good, but I'm skeptical they will reduce the load
>> when the laundromat thread is actually running. All these do is avoid
>> creating it when not necessary, right?
>It does create half as many laundromat threads (we don't need
>laundromat on connection to IPC$) even for the Windows server target
>example, but helps more for cases where server doesn't support
>directory leases.

Perhaps the laundromat thread should be using msleep_interruptible()?

Using an interruptible sleep appears to prevent the thread from contributing
to the load average, and has the happy side-effect of removing the up-to-1s delay
when tearing down the tcon (since a7c01fa93ae, kthread_stop() will return
early triggered by kthread_stop).




We’ve got an old NAS, and after the most recent Windows Update … I lost access to it. Now the NAS is really just a backup, so I never really use the NAS. I don’t generally waste my time fixing things I don’t need, but Scott wasn’t able to use the NAS from Fedora 31 either. So I tried to map the drive again and got told the NAS could only use SMB1 but Windows required 2 or 3.

I ran smb2status and, yeah, the max protocol is SMB 1.0. Simply running smb3enable or smb21enable configures Samba for SMB3 or SMB2.1 and restarts the services. We can use the QNAP Samba share from both Windows 10 and Fedora 31 now.

Samba and SELinux

I had a horrendous time trying to get the Samba share on our new server working. It worked insomuchas I could map a drive to the share … but I couldn’t actually see any files. Increasing the log level (smb.conf)

log level = 10 passdb:5 auth:5

showed that, yeah, I was getting a lot of access denied errors.

[2019/12/14 23:04:53.249959, 10, pid=17854, effective(0, 0), real(0, 0)] ../../source3/smbd/open.c:5438(create_file_unixpath)
create_file_unixpath: NT_STATUS_ACCESS_DENIED
[2019/12/14 23:04:53.249982, 10, pid=17854, effective(0, 0), real(0, 0)] ../../source3/smbd/open.c:5716(create_file_default)
[2019/12/14 23:04:53.250012, 3, pid=17854, effective(0, 0), real(0, 0), class=smb2] ../../source3/smbd/smb2_server.c:3254(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2019/12/14 23:04:53.250038, 10, pid=17854, effective(0, 0), real(0, 0), class=smb2] ../../source3/smbd/smb2_server.c:3142(smbd_smb2_request_done_ex)
smbd_smb2_request_done_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] body[8] dyn[yes:1] at ../../source3/smbd/smb2_server.c:3304

Many, many iterations of samba configs later, I wondered if SELinux was causing a problem. Temporarily disabling SELinux allowed files to be seen in the mapped drive … so that was the problem. I needed to tweak the SELinux settings to allow Samba to actually share files.

semanage fcontext -a -t samba_share_t "/data(/.*)?"


setsebool -P samba_export_all_rw=1