On Mon, Aug 26, 2024 at 07:16:09PM -0700, Darrick J. Wong wrote: > > Hmmm. Could we initialise it in memory only for !rtg filesystems, > > and make sure we never write it back via a check in the > > xfs_sb_to_disk() formatter function? > > Only if the incore sb_rgextents becomes u64, which will then cause the > incore and ondisk superblock structures not to match anymore. There's > probably not much reason to keep them the same anymore. That said, up > until recently the metadir patchset actually broke the two apart, but > then hch and I put things back to reduce our own confusion. Note that the incore sb really isn't much of a thing. It's a random structure that only exists embedded into the XFS mount. The only reason we keep adding fields to it is because some of the conversion functions from/to disk are a mess. The RT growfs cleanups earlier in this patchbomb actually take care of a large part of that, so we should be able to retire it in the not too distant future.
