Hi all, Back when I originally designed xfs_scrub, all filesystem metadata checks were complete by the end of phase 3, and phase 4 was where all the metadata repairs occurred. On the grounds that the filesystem should be fully consistent by then, I made a call to FITRIM at the end of phase 4 to discard empty space in the filesystem. Unfortunately, that's no longer the case -- summary counters, link counts, and quota counters are not checked until phase 7. It's not safe to instruct the storage to unmap "empty" areas if we don't know where those empty areas are, so we need to create a phase 8 to trim the fs. While we're at it, make it more obvious that fstrim only gets to run if there are no unfixed corruptions and no other runtime errors have occurred. Finally, reduce the latency impacts on the rest of the system by breaking up the fstrim work into a loop that targets only 16GB per call. This enables better progress reporting for interactive runs and cgroup based resource constraints for background runs. 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 xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=scrub-fstrim-phase --- scrub/Makefile | 1 scrub/phase4.c | 30 +---------- scrub/phase8.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++++++ scrub/vfs.c | 22 +++++--- scrub/vfs.h | 2 - scrub/xfs_scrub.c | 11 ++++ scrub/xfs_scrub.h | 3 + 7 files changed, 183 insertions(+), 37 deletions(-) create mode 100644 scrub/phase8.c
