Hi all, 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. We start by creating xfs_imeta_* functions to mediate access to metadata inode pointers. This enables the imeta code to abstract inode pointers, whether they're the classic five in the superblock, or the much more complex directory tree. All current users of metadata inodes (rt+quota) are converted to use the boilerplate code. Next, we define the metadir on-disk format, which consists of marking inodes with a new iflag that says they're metadata. This we use to prevent bulkstat and friends from ever getting their hands on fs metadata. Finally, we implement metadir operations so that clients can create, delete, zap, and look up metadata inodes by path. Beware that much of this code is only lightly used, because the five current users of metadata inodes don't tend to change them very often. This is likely to change if and when the subvolume and multiple-rt-volume features get written/merged/etc. If you're going to start using this mess, you probably ought to just pull from my git trees. The kernel patches[1] should apply against 4.20. xfsprogs[2] and xfstests[3] can be found in their usual places. The git trees contain all four series' worth of changes. This is an extraordinary way to destroy everything. Enjoy! Comments and questions are, as always, welcome. --D [1] https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=djwong-devel [2] https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=djwong-devel [3] https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=djwong-devel
