[RFC][PATCH 8/8] check files for checkpointability

Serge E. Hallyn serue at us.ibm.com
Mon Mar 2 10:35:22 PST 2009


Quoting Dave Hansen (dave at linux.vnet.ibm.com):
> On Mon, 2009-03-02 at 11:44 -0600, Serge E. Hallyn wrote:
> > Quoting Dave Hansen (dave at linux.vnet.ibm.com):
> > > On Mon, 2009-03-02 at 11:22 -0600, Nathan Lynch wrote:
> > > > No.. I mean what if a process 1234 does
> > > > 
> > > > f = fopen("/proc/1234/stat", "r");
> > > > 
> > > > and is then checkpointed.  Can that path be resolved during restart,
> > > > before pid 1234 is alive?
> > > 
> > > Heh, that's a good one.
> > > 
> > > It does mean that we can't do restore like this:
> > > 
> > > 	for_each_cr_task()
> > > 		restore_task_struct()
> > > 		restore_files()
> > > 		...
> > > 
> > > We have to do:
> > > 
> > > 	for_each_cr_task()
> > > 		restore_task_struct()
> > > 	for_each_cr_task()
> > > 		restore_files()
> > >
> > Which is what we actually do, right?
> 
> OK, I have a really evil one.
> 
> What if task 1234 does:
> 
> 	open(O_RDONLY, "/proc/5678/fdinfo/44");
> 
> and task 5678 does:
> 
> 	open(O_RDONLY, "/proc/5678/fdinfo/55");

Nice one.  Let's make fdinfo files uncheckpointable for now :)

-serge


More information about the Containers mailing list