Hi all, This patch series introduces a totally new filesystem summary counter online scrub feature. Whereas previous iterations froze the filesystem to count inodes and free blocks, this one drastically reduces overhead by loosening its precision somewhat. Instead of freezing the fs, we race the expected summary counter calculation with normal fs operations and use thresholding to check that the counters are in the ballpark, where ballpark means "off by less than 6% or so". If you're going to start using this mess, you probably ought to just pull from my git trees, which are linked below. This is an extraordinary way to destroy everything. Enjoy! Comments and questions are, as always, welcome. --D kernel git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=scrub-summary-counters xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=scrub-summary-counters
