On Wed, Dec 04, 2024 at 10:48:39PM -0800, Christoph Hellwig wrote: > On Wed, Dec 04, 2024 at 09:54:51PM -0800, Darrick J. Wong wrote: > > > This really should be libxfs so tht it can be shared with > > > secondary_sb_whack in xfsrepair. The comment at the end of > > > the xfs_dsb definition should also be changed to point to this > > > libxfs version. > > > > The xfs_repair version of this is subtlely different -- given a > > secondary ondisk superblock, it figures out the size of the ondisk > > superblock given the features set *in that alleged superblock*. From > > there it validates the secondary superblock. The featureset in the > > alleged superblock doesn't even have to match the primary super, but > > it'll go zero things all the same before copying the incore super back > > to disk: > > > > if (xfs_sb_version_hasmetadir(sb)) > > size = offsetofend(struct xfs_dsb, sb_pad); > > else if (xfs_sb_version_hasmetauuid(sb)) > > size = offsetofend(struct xfs_dsb, sb_meta_uuid); > > > > This version in online computes the size of the secondary ondisk > > superblock object given the features set in the *primary* superblock > > that we used to mount the filesystem. > > Well, it considers the size for the passed in superblock. Where the > passed in one happens to be the primary one and the usage is for the > second. > > > Also if I did that we'd have to recopy the xfs_sb_version_hasXXXX > > functions back into libxfs after ripping most of them out. Or we'd have > > to encode the logic manually. But even then, the xfs_repair and > > xfs_scrub functions are /not quite/ switching on the same thing. > > We don't really need the helpers and could just check the flag vs > the field directly. > > I'd personally prefer to share this code, but I also don't want to > hold off the fix for it. So if you prefer to stick to this > version maybe just clearly document why these two are different > with a comment that has the above information? Ok. I was thinking this hoist is a reasonable cleanup for 6.14 anyway, not a bugfix to apply to 6.13. --D
