Pavel Machek <pavel@xxxxxx> writes: [snip] > I don't know how to do that mechanism... but if we knew where to trap > filesystem writes, we could simply freeze at that point, and at that > point only, no? Any operation at all that has an external effect must not occur after the snapshot is made; otherwise, there will be random hard-to-find corruptions and other problems occurring as a result. Thus, for example, any writes (either directly or indirectly through e.g. a filesystem) to non-volatile storage, any network traffic, any communication with hardware like a printer must be prevented after the snapshot. It seems, though, that in general the kernel will have no way to know which operations are safe, and which are not safe. (This is why the whole "proper filesystem snapshot support is the solution" argument is bogus.) -- Jeremy Maitin-Shepard _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
