On Thu, Oct 21, 2010 at 08:32:12PM -0500, C Anthony Risinger wrote: > On Thu, Oct 21, 2010 at 8:05 PM, Josef Bacik <josef@xxxxxxxxxx> wrote: > > On Thu, Oct 21, 2010 at 05:21:06PM -0500, Mitch Harder wrote: > >> On Thu, Oct 21, 2010 at 5:09 PM, Diego Calleja <diegocg@xxxxxxxxx> wrote: > >> > On Jueves, 21 de Octubre de 2010 17:46:58 David Nicol escribió: > >> >> Does this mixing constitute a forbidden change of on-disk format, and > >> >> if not how not? > >> > > >> > It doesn't need a format change. The difference between a data and > >> > a metadata block group is just an allocation hint AFAIK. > >> > -- > >> > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > >> > the body of a message to majordomo@xxxxxxxxxxxxxxx > >> > More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > > >> > >> Let me know if the problems with an un-patched kernel were un-expected. > >> > >> I can provide more information on the crash when booting an older kernel. > > > > Nope they are expected, it's not a disk format change, but older kernels won't > > deal with mixed block groups. > > When something like this goes mainline, is it used by default/automatically? > > I ask because I maintain a btrfs-based rollback initramfs hook [1], > and am currently updating it for extlinux, enabling kernel-level > system rollbacks via `btrfs set-default` + reboot (or maybe > `kexec`)... > > rolling back to an old kernel will then blow up my machine > (figuratively of course :-)? > The only way you get this feature is if you mkfs with the feature enabled, and is only meant for small filesystems (1 gig or smaller). Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
