On Mon, Mar 26, 2018 at 08:46:49AM -0400, Brian Foster wrote: > On Sat, Mar 24, 2018 at 09:20:49AM -0700, Darrick J. Wong wrote: > > On Wed, Mar 07, 2018 at 05:33:48PM -0600, Eric Sandeen wrote: > > > Now that unlinked inode recovery is done outside of > > > log recovery, there is no need to dirty the log on > > > snapshots just to handle unlinked inodes. This means > > > that readonly snapshots can be mounted without requiring > > > -o ro,norecovery to avoid the log replay that can't happen > > > on a readonly block device. > > > > > > (unlinked inodes will just hang out in the agi buckets until > > > the next writable mount) > > > > FWIW I put these two in a test kernel to see what would happen and > > generic/311 failures popped up. It looked like the _check_scratch_fs > > found incorrect block counts on the snapshot(?) > > > > Interesting. Just a wild guess, but perhaps it has something to do with > lazy sb accounting..? I see we call xfs_initialize_perag_data() when > mounting an unclean fs. The freeze is calls xfs_log_sbcount() which should update the superblock counters from the in-memory counters and write them to disk. If they are out, I'm guessing it's because the in-memory per-ag reservations are not being returned to the global pool before the in-memory counters are summed during a freeze.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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
