Hi all, This is the sixteenth revision of a patchset that adds to XFS kernel support for online metadata scrubbing and repair. There aren't any on-disk format changes. New for this version of the patch series are: a renaming of the 'repair freeze' code into the 'scrub freeze' code so that scrubbers can freeze the filesystem to check or repair metadata; a new ioctl flag for userspace to grant the kernel permission to freeze the filesystem to do work; a centralized iput helper that delays iput processing until after the scrub freeze is lifted; and a new fs summary counter scrub/repair function that can check the global icount/ifree/fdblock counters. The first patch fixes a soon-to-be-invalid assumption in the rmap code that the rmapbt can never be empty. This won't be true at all for realtime rmap and is briefly untrue for rmap repairs, so we might as well restructure that assumption out of the code. The next two patches create two predicates that decide if an inode has CoW staging blocks that need to be freed or post-eof blocks that need to be freed. Patches 4-7 implement reconstruction of the AGF/AGI/AGFL headers, the free space btrees, and the inode btrees. These are the same patches as v15. Patches 8-9 implement the deferred iput code -- first the scrub-specific iput helper that enables us delay iputting of inodes that have post-eof or CoW blocks that need to be freed until we no longer have a transaction and can let the iput work proceed. The second patch fleshes out the scrub iget/iput tracepoints for easier debugging. Next comes the scrub freeze code which enables us to pause all other work in the filesystem and introduces the FREEZE_OK ioctl flag for userspace to control freeze policy. Patch 11-19 implement online rmap, refcount, inode, ifork, bmap, symlink, extended attribute, and quota repairs. Patch 20 implements online quotacheck via the scrub freezer. Patch 21 implements the filesystem summary counter check and repair code. This turned out to be easier to implement than I had thought -- we gather the icount, ifree, and fdblocks counts from each of the AGs. Next we adjust fdblocks by all the in-core reservations: resblks, per-AG reservations, and all delayed allocation blocks of all in-core inodes. Then we can compare our counts against the superblock's counts and adjust accordingly. 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 4.18-rc2. 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 -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
