Merge tag 'metadata-directory-tree-6.13_2024-11-05' of...

Merge tag 'metadata-directory-tree-6.13_2024-11-05' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux

 into staging-merge

xfs: metadata inode directory trees [v5.5 03/10]

This series delivers a new feature -- metadata inode directories.  This
is a separate directory tree (rooted in the superblock) that contains
only inodes that contain filesystem metadata.  Different metadata
objects can be looked up with regular paths.

Start by creating xfs_imeta{dir,file}* functions to mediate access to
the metadata directory tree.  By the end of this mega series, all
existing metadata inodes (rt+quota) will use this directory tree instead
of the superblock.

Next, define the metadir on-disk format, which consists of marking
inodes with a new iflag that says they're metadata.  This prevents
bulkstat and friends from ever getting their hands on fs metadata files.

With a bit of luck, this should all go splendidly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>