On Fri, 17 Feb 2012, Lukas Czerner wrote: > On Fri, 17 Feb 2012, Ted Ts'o wrote: > > > On Fri, Feb 17, 2012 at 10:17:43AM +0100, Lukas Czerner wrote: > > > > > > So the problem actually is that I have made some assumptions, like for > > > example that all data are laid out sequentially (because it is how we > > > are creating the qcow2 images with e2image) and possibly more. > > > > So if your code doesn't work correctly if the block numbers are > > monotonically increasing in the qcow2 image, I would *have* to assume > > there would be plenty of qemu-generated images files that don't have > > this constraint (i.e., suppose you write blocks 10000, 42, 16, and 24 > > while running under qemu, presumably that is the order the blocks > > would be written and would show up in the qcow2 file). > > > > Or am I misunderstanding what you are saying here; is it that you are > > fairly sure the code will break if the data is not laid out > > sequentially, or that you've never tested this case? > > Hi Ted, > > as I said I have never tested this. Well, actually I did some very > limited testing, but since this was not (and still is not right?) the > scope of e2image I did not care enough to test that extensively enough > to be sure that it generally works with qcow2 images other than those > generated with e2image. But I think it should work. > > Also I suppose that qemu is being a bit smarter than just writing every > extent out so it does not seek madly back and forth when the image is > not laid out sequentially. e2image does not do that. ehm..I meant, e2image does not do any smart things there, just seek and write. > > Thanks! > -Lukas > > > > > Regards, > > > > - Ted > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
