Caja: segfault 4 from usb drive unmount

[TuxVinyards]

Unmounting a usb drive causes whole of Caja to crash.

(Caja 1.20.2 with Ubuntu Mate 18.04)

Using `cat /var/log/kern.log | grep caja ` yielded constant ` segfault 4 ` references

Following this link: [ https://stackoverflow.com/a/26638899 ] I traced the fault with `addr2line` to here:

"caja_path_bar_get_button_from_button_list_entry"

My main HDD is set as 3 ext4 partitions which all mount on boot and should remain open in Caja, usually in tabs, when unmounting the usb. Is this Ubuntu or Caja? Or something else?

Hope this trace helps. Bests.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

I have done a bit more research:

1. This doesn't happen with PcManFM. The default Lubuntu file manager will install quite happily onto U.Mate and both USB HDD's and sticks will mount and unmount without problems.

2. I have noticed that if using a USB stick that Caja holds up if selecting 'eject'. It only fails if selecting 'safely remove drive'. The latter is of course the only option with external HDD.

3. I would caution anyone trying to replicate this error not to have important data on the drive as it does seem to cause damage the external drive file system. (Gnome Disks does repair this though).

4. Synaptic lists pcmanfm as using GVFS for removable media, which I think is the same as Caja.

5. Of note, I have had this problem for quite a while, certainly since 18.04 but not sure about before that. I originally thought it was the drive, not the software .... I have also carried out re-installs of Caja, gvfs and other components too.

I now think this problem centres on the 'safely remove drive' button function of Caja and probably an upstream fix will be needed.

Hope someone familiar with Caja's inner workings can fix this.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

Of note, I can't duplicate this issue by using the 18.04 live ISO.

Also upstream report: [ https://github.com/mate-desktop/caja/issues/1046 ]

[Dr Steve Brule (drstevebrule)]

I have spent many days looking at this problem on and off with several distros. At first I thought it was an upstream problem with MATE's caja but after seeing for myself that Fedora's live does not have this issue (newer kernel and the same caja 1.20.2), I'm more inclined to think this is a downstream issue affecting Ubuntu, Linux Mint and Manjaro. You can view my comments on the upstream report.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

I am away from my desktop at present but recall that I found the original 18.04 live didn't have the problems.

I don't have access to my notes. I noticed that the order of installation of the update packages madea difference. If gvfs was installed before certain other packages it worked. But with all the updates it eventually produced failure.

In the end I decided to wait till others reported this problem. I concluded that it was possibly a problem specific to my particular hardware and to wait for 18.10.

Has anyone else managed to replicate yet?

[Dr Steve Brule (drstevebrule)]

Just a note, I get the same results on two different laptops; ASUS G1Sn with single Nvidia GPU and a Dell Precision M4600 with Intel/Nvidia. It many be possible that new users coming from Windows to MATE Mint & MATE Ubuntu might be thing this is normal behaviour for a Linux distro when they see the file manager drop out or they might find it confusing to figure out why and how to report such an issue. I find it hard to believe we are the only individuals with this issue give that I've manage to repeat the problem so easily on these two computers with Mint, Ubuntu and Manjaro but not on Fedoria or Debian. You could be right about gvfs but most of my testing was with live boots without updating anything.
                      Extra Panel Extra Panel Kernel Kernel & Caja
                 Caja blank info loc.bar focus Version “sigfault at 4”
Linux Mint 18.3 Mate 1.18.5 n n 4.10.0-38 n
Linux Mint 19.2 Mate 1.20.2 y y 4.15.0-20 n
Linux Mint 19.2 Mate 1.20.2 y y 4.15.0-33 y
Ubuntu 18.04 Mate 1.20.2 n y 4.15.0-29 y
Manjaro 17.1.12 Mate 1.20.2 y n 4.14.65-1 y
Debian 9.5 Mate 1.16.6 n n 4.9.0-7 n
Fedora-MATE...28-1.1 1.20.2 n n 4.16.3-301 n

n: no issue
y: fault bug

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

@drstevebrule much thanks for looking at this. Agree with your comments about new users.

I was so impressed with 'Timeshift' (after seeing that Mint have adopted it as standard when you do an HDD install) that I installed it to my Ubuntu desktop.

Anyone not seen it yet needs to give it a go.

https://github.com/teejee2008/timeshift

Really great for incremental installs and un-installs. (18.0 wishlist?)

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

Woo! Not at my desktop but good work. Thanks.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

:( Just did the upgrade with libmount1, mount, libblkid1, uuid-runtime, fdisk and others. Even after a machine restart, the problem is still present.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

Paste from [ https://github.com/mate-desktop/caja/issues/1046#issuecomment-431685452 ]

"@emanuele-f Yes, this works for me. Well spotted. Places > Computer > right click. At last the correct 'safely remove' behaviour and no corrupted usb file system. Finally.

Small observation, I am seeing variable behaviour drop down menu over the mount/unmount toggle. It seems to be getting this bit wrong.

Both PCManFM and the Mate panel utilities don't the power down after the unmount. Places-computer has it right, almost. But why not the side bar ... ?

(Still using Ubuntu Mate 18.04 LTS, at present)"

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ivnitskii Andrei (ivnitsky-a)]

Same problem after "safely remove drive"

[Shegon (shegon)]

I confirm this bug.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

@drstevebrule & others,

We now have a new Caja release which includes fixes for this issue:

https://github.com/mate-desktop/caja/releases (1.20.3)

Refs:

https://github.com/mate-desktop/caja/pull/1084

https://github.com/mate-desktop/caja/commit/df49a00d53e7b874f8146a73329b6f0a0a88e5df

I haven't personally tested a build but I suspect/hope one will be working it's way downstream before long and that we can close this.

[TuxVinyards (0cs935kb517-k5db-wz6bkyhu4uq)]

I have now marked this as 'fix-released' as Ubuntu Mate 19.04 contains the upgraded files and I can confirm that this works for me.

Hopefully other people are finding similar.