On Fri, May 19, 2017 at 10:00:31AM -0400, Colin Walters wrote: > On Thu, May 18, 2017, at 08:20 PM, Darrick J. Wong wrote: > > > Therefore, add a reboot hook to freeze all filesystems (which in general > > will induce ext4/xfs/btrfs to checkpoint the log) just prior to reboot. > > This is an unfortunate and insufficient workaround for multiple layers > > of inadequate external software, but at least it will reduce boot time > > surprises for the "OS updater failed to disengage the filesystem before > > rebooting" case. > > As a maintainer of one of those userspace tools > (https://github.com/ostreedev/ostree), which I don't think is the one > in question here, but likely has the same issue - I'd like to have > some sort of API to fix this - maybe flush the journal *without* > remounting r/o? The convention (at least among ext4 and xfs) is that fs freeze should be checkpointing the journal. > Unlike the case you're talking about with rebooting into a special > update mode, libostree constructs a new root with hardlinks while > the system is running. Hence, system downtime is just reboot, like > dual-partition update systems, except we're more flexible. > > Although hm...I guess an API to flush the journal would only narrow > the race. > > Is the single partition case really just doomed? Probably. TBH given the current behavior of grub, I would always have a separate /boot to minimize the amount it's allowed to touch. :) --D > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html
