"Can't dump file 12 of that type" upon dumping a simple test.sh

[Hi-Angel]

I'm following this tutorial, and the dumping step fails for me. Error in description is the first one I see.

Steps to reproduce

$ cat test.sh
#!/bin/sh
while :; do
    sleep 1
    date
done
$ setsid ./test.sh < /dev/null &> test.log &
$ ls
dump.log  fdinfo-2.img  files.img  ids-425213.img  seccomp.img  test.log  test.sh
$ sudo criu dump -t $(pgrep test.sh) -v4 -o dump.log && echo OK

Expected

A print "OK"

Actual

Nothing printed

Additional information

• Crio version is 3.14
• log is attached: dump.log

[adrianreber]

Can you try on a non-btrfs based system: https://criu.org/Filesystems_pecularities

[Hi-Angel]

Can you try on a non-btrfs based system: https://criu.org/Filesystems_pecularities

Hmm… Okay, though I'm unsure on one detail. I reproduce it in /tmp/foo dir, and per this output:

$ mount | grep /tmp
tmpfs on /tmp type tmpfs (rw,nosuid,nodev)

I do it on tmpfs, not on btrfs. Do I need to completely exclude btrfs from mount points? If so, that would be problematic as both computers I have have use it as their root filesystem.

[rppt]

The log says that criu had troubles with a chardev:

(00.005326) Error (criu/files-ext.c:95): Can't dump file 12 of that type [20660] (chr 226:0)

Can you check what is this device?

[Hi-Angel]

The log says that criu had troubles with a chardev:

(00.005326) Error (criu/files-ext.c:95): Can't dump file 12 of that type [20660] (chr 226:0)

Can you check what is this device?

It is drm.

$ grep 226 /proc/devices                                                                                           
226 drm

If that matters, I have two GPUs, Intel and AMD.

[rppt]

criu cannot handle open /dev/drm.
I don't know why bash has it open though...

[Hi-Angel]

criu cannot handle open /dev/drm.

Oh, this is sad. I was mainly interested in criu to save state of a wine game. Oh, well…

I don't know why bash has it open though...

[rppt]

criu cannot handle open /dev/drm.

Oh, this is sad. I was mainly interested in criu to save state of a wine game. Oh, well…

Yeah, it is. This topic returns from time to time (eg #384, #436), but there is no solution for checkpointing the state of a GPU device.

[Hi-Angel]

I don't know why bash has it open though...

Btw, I confirm that running the test.sh and looking through file descriptors there's /dev/dri/card0 for some reason is opened:

$ ll /proc/$(pgrep test.sh)/fd         
total 0
lrwx------ 1 constantine constantine 64 июн 21 12:39 0 -> /dev/pts/4
lrwx------ 1 constantine constantine 64 июн 21 12:39 1 -> /dev/pts/4
lrwx------ 1 constantine constantine 64 июн 21 12:39 12 -> /dev/dri/card0
lrwx------ 1 constantine constantine 64 июн 21 12:39 2 -> /dev/pts/4
lr-x------ 1 constantine constantine 64 июн 21 12:39 255 -> /tmp/test.sh

Indeed this is odd.

criu cannot handle open /dev/drm.

Oh, this is sad. I was mainly interested in criu to save state of a wine game. Oh, well…

Yeah, it is. This topic returns from time to time (eg #384, #436), but there is no solution for checkpointing the state of a GPU device.

Thanks!

[Hi-Angel]

Okay, so I figured the /dev/dri/card0 being opened is inherited from Konsole application. If I look through /proc/self/fd in gnome-terminal, I do not see this device opened.

Okay, so, since it all comes down to a DRM device being opened, and there already are issues for this, current one would be a duplicate, so I'm closing it