[CRIU] [PATCH 2/2] introduce --skip-mnt cli option

[Oleg Nesterov]

On 04/01, Pavel Emelyanov wrote:
>
> On 03/31/2015 07:24 PM, Oleg Nesterov wrote:
>
> > @@ -1004,6 +1035,13 @@ struct mount_info *parse_mountinfo(pid_t pid, struct ns_id *nsid, bool for_dump)
> >  			goto end;
> >  		}
> >
> > +		if (for_dump && should_skip_mount(new->mountpoint + 1)) {
>
> This check is not enough. If we have a file opened on skipped mountpoint, then
> dump will succeed, but we will fail on restore.

I thought about this case. dump_one_reg_file()->lookup_nsid_by_mnt_id()
should fail correctly.

Let me test... yes,

	$ perl -e 'close STDOUT; close STDERR; sleep' < /boot/System.map

and "dump --skip-mnt /boot" fails with "Unable to look up the %d mount".

Hmm. but I think this error message deserves another cosmetic cleanup.
Perhaps it should print link->name? Otherwise it is absolutely not clear
what this message actually means.

But,

> Such behavior is actually not
> good, restore shouldn't fail due to badly created images :)

Sure ;) And probably this option can cause such kind of problem. But again,
the user should know what he does or do not use this option. This is like
--enable-fs, use at your own risk.

> Other than this I have no objections against the feature.

So what do you think I should change in this patch?

I forgot about the "Usage:" string, it should include the new option...

Anything else? Apart from RPC which I didn't look at yet, will try to
do later.

Oleg.