On Wed, 2009-03-04 at 00:50 +0900, hooanon05@xxxxxxxxxxx wrote: > Dave Kleikamp: > > The lower read-only file would not appear to user-space as the same file > > at all. It would have its own address space. It clearly would not see > > the new content. > > > > There wouldn't be any problem with reading pages from the lower file for > > the upper file one at a time as they are faulted. > > I am afraid that I cannot understand fully what you wrote (due to my > poor English). > Do you mean that the entire file copyup will be necessary? No. I was saying the opposite. Nothing that happens to the upper address space would be visible to the lower address space. The upper file could read from the lower file system on-demand as pages are faulted. There is no need to copy everything at once. Shaggy -- David Kleikamp IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
