[CRIU] Dumping a FUSE mount

[Jonathan 'Wolf' Rentzsch]

> On Oct 8, 2015, at 5:12 AM, Pavel Emelyanov <xemul at parallels.com> wrote:
>> However I’m not abel to successfully restore. do_mount_one() ends up calling do_new_mount(), which fails with 
>> 
>> 1: Error (mount.c:1480): Can't mount at ./app/available_modules: No such device
> 
> Heh... Why does it do so? If the mountpoint in question is external from the
> do_mount_one() it should go into do_bind_mount(). Do you specify the --ext-mount-map
> option at restore?

I can’t directly since criu in this case is being invoked by docker, so I hard-coded it in setup_opts_from_req(). The restore log seems to indicate it’s in place:

> root at ip-172-31-46-108:/tmp/checkpoints/ab1241c25194b1b3dc363107daa35c7d# cat a642fd071935064d48dbacf58c6d84a7a00c3e08 at 4/restore-work-1444313084740/restore.log 
> (00.000039) Added eth0:veth1c94e82 veth map
> (00.000069) Added /app/available_modules:/mnt/stretch/all_modules_dupe ext mount mapping
> (00.000077) Added /etc/resolv.conf:/var/lib/evaldocker/containers/481dbca5f31fee14608f1bb90b331df29fb915d59eccb8a7f2c049945f1d9907/resolv.conf ext mount mapping
> (00.000082) Added /etc/hostname:/var/lib/evaldocker/containers/481dbca5f31fee14608f1bb90b331df29fb915d59eccb8a7f2c049945f1d9907/hostname ext mount mapping
> (00.000086) Added /etc/hosts:/var/lib/evaldocker/containers/481dbca5f31fee14608f1bb90b331df29fb915d59eccb8a7f2c049945f1d9907/hosts ext mount mapping
> (00.000090) Added ./app/available_modules:/mnt/stretch/all_modules_dupe ext mount mapping
> (00.000199) TCP recv queue memory limit is 3145728
> (00.000234) cpu: fpu:1 fxsr:1 xsave:1
> (00.000373) vdso: Parsing at 7fff50fc1000 7fff50fc3000

The "/app/available_modules:/mnt/stretch/all_modules_dupe" external mount was already in place.

I went further and manually added a hard-coded “./app/available_modules:/mnt/stretch/all_modules_dupe” to make sure that leading period wasn’t tripping things up some how.

Same error: 

Error (mount.c:1480): Can't mount at ./app/available_modules: No such device

Obviously I’m missing something else.

-Wolf