[CRIU] [PATCH 15/37] files: save mnt_id for reg files

[Andrew Vagin]

On Fri, Apr 18, 2014 at 07:30:04PM +0400, Pavel Emelyanov wrote:
> On 04/18/2014 06:42 PM, Andrey Vagin wrote:
> > Signed-off-by: Andrey Vagin <avagin at openvz.org>
> > ---
> >  files-reg.c            | 6 ++++++
> >  protobuf/regfile.proto | 1 +
> >  2 files changed, 7 insertions(+)
> > 
> > diff --git a/files-reg.c b/files-reg.c
> > index 5b6c4a3..3d316ec 100644
> > --- a/files-reg.c
> > +++ b/files-reg.c
> > @@ -22,6 +22,7 @@
> >  #include "util.h"
> >  #include "fs-magic.h"
> >  #include "asm/atomic.h"
> > +#include "namespaces.h"
> >  
> >  #include "protobuf.h"
> >  #include "protobuf/regfile.pb-c.h"
> > @@ -557,6 +558,11 @@ int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
> >  	} else
> >  		link = p->link;
> >  
> > +	if (p->mnt_id >= 0 && (root_ns_mask & CLONE_NEWNS)) {
> > +		rfe.mnt_id = p->mnt_id;
> > +		rfe.has_mnt_id = true;
> > +	}
> 
> I would also expect a check like this
> 
> if (p->mnt_id < 0 && (root_ns_mask & CLONE_NEWNS)) {
> 	pr_err("Mount namespaces w/o mount ids\n");
> 	return -1;
> }
> 
> Do we have such?

I think you don't want this, because it will break dumping and restoring
containers on 3.11.

> 
> 
> And also
> 
> if (find_mount_by_id(p->mnt_id) == NULL) {
> 	pr_err("No mount for this file in this namespace\n");
> 	return -1;
> }
> 
> How about this?

This looks reasonable. Thanks.
> 
> > +
> >  	pr_info("Dumping path for %d fd via self %d [%s]\n",
> >  			p->fd, lfd, &link->name[1]);
> >  
> > diff --git a/protobuf/regfile.proto b/protobuf/regfile.proto
> > index d975ab0..e91dc44 100644
> > --- a/protobuf/regfile.proto
> > +++ b/protobuf/regfile.proto
> > @@ -6,4 +6,5 @@ message reg_file_entry {
> >  	required uint64		pos	= 3;
> >  	required fown_entry	fown	= 5;
> >  	required string		name	= 6;
> > +	optional sint32		mnt_id	= 7 [default = -1];
> >  }
> > 
> 
>