1701809 - Firefox maintains v4l device files open after end of video session

Status: RESOLVED FIXED

(Core :: WebRTC: Audio/Video, defect, P2)

Description

[Jérôme Carretero]

User Agent: Mozilla/5.0 (Windows NT 10.0; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

• Start Firefox
• Use camera (eg. https://mozilla.github.io/webrtc-landing/gum_test.html)
• Stop using camera
• for x in $(pidof firefox); do ls -lA /proc/${x}/fd ; done | grep video

Actual results:

Open file descriptors for /dev/video* files

This is an annoyance as it prevents drivers from being unloaded.

Expected results:

No open file descriptor

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::WebRTC: Audio/Video' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Byron Campen [:bwc]]

Marking this P3/S3 because of the annoyance factor, but it is possible there is a more serious problem here. jib?

Comment 3

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Hi Jérôme, thanks for reporting! Would you be able to confirm that it worked in Firefox 77?

I suspect this regressed in bug 1637319 here.

This would mean it broke in Firefox 78 and worked fine in Firefox 77. Unfortunately, I don't have a linux box to check with.

Comment 4

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Attachment: Bug 1701809: Close dev/video* driver file descriptors after camera access on linux.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/161b72a0ff01
Close dev/video* driver file descriptors after camera access on linux. r=ng

Comment 6

[Jérôme Carretero]

Hi Jan-Ivar,

You're right, I tested by installing a Firefox 77 from FlatPak hub:
$ flatpak update --user --commit=74e086c686d4ef166eb55bbf0eac72735235072b04711c6d350242a07a9190e7 org.mozilla.firefox # 77
and the problem did not appear.

And then when I installed a 78-ish in the same way:
$ flatpak update --user --commit=dd97c9d605553f7ea44726e9c6beb4ee8cc821ee0df7c235e01a587e93a92c49 org.mozilla.firefox # 78.0.1
and the problem was there.

Comment 7

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/161b72a0ff01

Comment 8

[Jérôme Carretero]

FYI I just ran Nightly "89.0a1 (2021-04-02) (64-bit)" and the problem is still there; I'm not familiar enough with Firefox's CI to know if it picked up the commit.

Comment 9

[Jérôme Carretero]

My bad. I confirm the problem is fixed. I had another firefox 87 running...

Comment 10

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:jib, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 11

[Giorgia Nichita, Release Desktop QA]

I'm trying to reproduce the issue following the mentioned steps but I'm having trouble getting to the described result. Can you please provide more information? On step 4, do I need to run that command in terminal, could you please be more specific?