Re: [PATCHSET DELUGE v11] xfs: Parent Pointers

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Apr 06, 2023 at 11:10:38AM -0700, Darrick J. Wong wrote:
> Hi everyone,
> 
> This submission contains all of the changes to the parent pointers
> patchset that I've been working since last month's deluge.  The kernel
> and xfsprogs patchsets are based on Allison's v10 tag from some time
> ago.  To recap Allison's cover letter:
> 
> "The goal of this patch set is to add a parent pointer attribute to each
> inode.  The attribute name containing the parent inode, generation, and
> directory offset, while the  attribute value contains the file name.
> This feature will enable future optimizations for online scrub, shrink,
> nfs handles, verity, or any other feature that could make use of quickly
> deriving an inodes path from the mount point."
> 
> v11 rebases everything against 6.3-rc5, and weaves all the changes that
> I had made against v10 into Allison's original series.  The new xattr
> NVLOOKUP mode that I introduced for v10 is critical for handling parent
> pointer attr name collisions with grace, so that has been retained from
> v10.  With that in place, I've replaced the diroffset in the ondisk
> parent pointer with the dirent hash of the name.
> 
> Parent pointers now look like this:
> 
> 	(parent_ino, parent_gen, namehash) -> (name[])
> 
> I experimented with replacing the dahash with crc32c for this patchset
> but left it out, having concluded that checksum operation has higher
> overhead (thanks, crypto api!), would require someone to figure out crc
> spoofing sufficiently well to keep metadump name obfuscation working,
> and doesn't seem to improve collision resistance sufficiently to be
> worth the added engineering cost.
> 
> As of this submission, I think this feature is ready to go once we've
> merged the online repair code and rebased the online repair code to
> actually commit the repaired directories.
> 
> If you want to pull the whole thing, use these links:
> https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=pptrs
> https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=pptrs-drop-unnecessary

<sigh> Apparently vim undid my edit here; the correct URL is:
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=pptrs

--D

> https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfstests-dev.git/log/?h=pptrs
> 
> --D