Quoting Dave Hansen (dave@xxxxxxxxxxxxxxxxxx): > Christoph's suggestion that we go add f_ops individually is a really > good way to get people thinking about individual cases that we have to > deal with. > > Can we checkpoint an *open* /proc/mounts? I don't think we want to. It > could get really nasty really fast. But, what if the f_pos is 0? That > makes it a lot easier. > > If the "may checkpoint" flag is per-container (as Alexey has said) and > one-way (as Ingo has said), does a single 'cat /proc/mounts' 5 days ago > keep a container from being checkpointed today? > > I just don't think the container-wide flag works if it is one way. > > I think making it per-process or per-resource (so it can be more easily > tracked at fork()/clone()/exec()) is the only way to go. It makes it so > simple since only the 'cat /proc/mounts' process becomes > uncheckpointable. Once it exits, we are OK and can checkpoint again. > That all seems right to me. > > -- Dave Well one way to look at it: the files_struct may_checkpoint is the short-term big stick to put pressure on us to fix things that are fixable. the per-file ->checkpoint() will (I guess) always be able to return an error. So for now an open /proc/mounts fd will irreversibly make the process non-checkpointable. But eventually the files_struct may_checkpoint flag will go away, and we'll just let each fd decide at checkpoint time whether it's ok to checkpoint. -serge _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
