SOLVED! qbittorrent-nox download to different folder permission issue?

[fuhaoda]

I am using qbittorrent-nox v4.4.3.1 on Linux Ubuntu 22.04 LTS

I have setup daemon service and service config file is used as below

[Unit]
Description=qBittorrent Command Line Client
After=network.target
 
[Service]
#Type=forking
User=btdl
Group=family
UMask=002
ExecStart=/usr/bin/qbittorrent-nox --webui-port=8080
Restart=always
 
[Install]
WantedBy=multi-user.target

The download works perfectly to download items into my family folder

drwxrwx--- 3 emily parent 4.0K Jun 21 21:28 private
drwxrwxr-x 5 emily family 4.0K Jul  8 10:34 public

But when I try to save items into private folder, it has an error in the web UI.

I have added btdl user to both parent and family group.
I also tried to change private fold into 775, there is still an issue.

1. Did I do anything incorrectly? How can I fix the issue?
2. The web UI only has an error showing in the status. How can I know which exactly the error so that it can give me a hit on the potential issues?

[fuhaoda]

After a few tries, I found that removing Group=family from the configure file can resolve the issue.

BUT

The only downside is that when a new file is created. It is under name AND user group as btdl, previously I prefer to have newly created file as btdl as user and family as group. Any suggestions?

[Kolcha]

try this systemd service config key https://www.freedesktop.org/software/systemd/man/systemd.exec.html#SupplementaryGroups=
leave Group=family as it was and just add SupplementaryGroups=parent , this should do the trick (not tested).
as a fallback solution, you can run script on download completion and change files ownership to desired. this will not require any sudo privileges as so as only group changes and user is a member of both old (aka user-specific) and new (aka desired) group.

[fuhaoda]

It works like a magic. Could you please explain a little bit more why it works?

[Kolcha]

this is because how Linux permissions work. your user btdl is a member of both groups parent and family, private folder has a write access for parent group. systemd assign user/group to the process (more correctly launch process as given user/group) according to your configuration (i.e. btdl/family), but information about any other groups membership is lost in this case (very likely it uses seteuid()/setegid() internally). supplying SupplementaryGroups config key returns "default shell behavior" when all groups are considered (don't know what exact system call can be used for that).
in most cases exactly euid/egid values are used when dealing with files, and at least they are set in ownership fields for new files (don't know exact theory, just based on my own experience when wrote my own filesystem, see this function for details).

P.S> if your question is solved, please mark my comment as solution and this discussion as solved. thank you!

[fuhaoda]

THANK YOU so much. It seems that systemd didn't pass all the groups information into of btdl which causing this issue. So that we have to manually pass it through SupplementaryGroups information.

BTW, I have marked the title as solve. Since your reply is just reply my previous reply, I can't mark what you said as an answer. Can you reply it formally, so that I can mark it as an answer to give you the full credit? I really appreciate that you pointed me to the right direction.

[Kolcha]

try this systemd service config key https://www.freedesktop.org/software/systemd/man/systemd.exec.html#SupplementaryGroups=
leave Group=family as it was and just add SupplementaryGroups=parent , this should do the trick (not tested).
as a fallback solution, you can run script on download completion and change files ownership to desired. this will not require any sudo privileges as so as only group changes and user is a member of both old (aka user-specific) and new (aka desired) group.

[fuhaoda]

You are awesome!

[d47081]

I have fixed this issue by append qbittirrent-nox to the family group,
then allowed login to bash in /etc/passwd

qbittorrent-nox:...:/home/qbittorrent-nox:/usr/bin/bash

Shared folders have 0770 permission

Don't know this idea is safe

[svetoslav-s]

Hello Guys,

I have the same problem, but the solution described here does not work:

I have a separate drive intended for downloads. I have a dir called video, which contains two other dirs that should be used for downloading video content. I cannot make qbittorrent save to any of them. I get the error message "Cannot make save path", when I try to move a torrent to the video folder

I've created a separate group and added qbtuser the account I use to run qbittorrent user with. My main account vitaminx is the owner of that dir.
I even used setfacl to try to set the permissions for qbtuser , which I did, but to no avail.
Here is the output of ls -ld :

drwxrwxr-x+ 3 vitaminx video-users 4096 сеп 12 23:51 video/

also here is the output of getfacl :

# file: video
# owner: vitaminx
# group: video-users
user::rwx
user:qbtuser:rwx
group::rwx
mask::rwx
other::r-x

Output of members video-users:

qbtuser

Here is the content of my [email protected] file:

[Unit]
Description=qBittorrent-nox service for user %I
Documentation=man:qbittorrent-nox(1)
Wants=network-online.target
After=local-fs.target network-online.target nss-lookup.target

[Service]
#Type=forking
#PrivateTmp=false
User=qbtuser
Group=video-users
#SupplementaryGroups=video-users
ExecStart=/usr/bin/qbittorrent-nox
TimeoutStopSec=1800
Restart=on-failure


[Install]
WantedBy=multi-user.target

I tried adding and removing Group, SupplementaryGroups and their parameters, but to no avail. I am kind of a newbie and I'd appreciate your help. Thanks!

[svetoslav-s]

OK, I solved my issue.

it looks like it is very trivial, but nonetheless... All the dirs leading to the end folder must have at least execute permissions.
One of the parent folders did not, therefore, I couldn't save anything in the child directory, regardless of its own permissions.