Miklos, Following your feedback on v2 [1], I moved the iostats to per-sb. Thanks, Amir. [1] https://lore.kernel.org/linux-unionfs/20220228113910.1727819-1-amir73il@xxxxxxxxx/ Changes since v2: - Change from per-mount to per-sb io stats (szeredi) - Avoid percpu loop when reading mountstats (dchinner) Changes since v1: - Opt-in for per-mount io stats for overlayfs and fuse Amir Goldstein (6): lib/percpu_counter: add helpers for arrays of counters fs: add optional iostats counters to struct super_block fs: collect per-sb io stats fs: report per-sb io stats ovl: opt-in for per-sb io stats fuse: opt-in for per-sb io stats fs/Kconfig | 8 +++ fs/fuse/inode.c | 5 ++ fs/nfsd/export.c | 7 +- fs/nfsd/nfscache.c | 5 +- fs/nfsd/stats.c | 37 +--------- fs/nfsd/stats.h | 3 - fs/overlayfs/super.c | 5 ++ fs/proc_namespace.c | 16 +++++ fs/read_write.c | 88 ++++++++++++++++------- fs/super.c | 2 + include/linux/fs.h | 10 ++- include/linux/fs_iostats.h | 127 +++++++++++++++++++++++++++++++++ include/linux/percpu_counter.h | 28 ++++++++ lib/percpu_counter.c | 27 +++++++ 14 files changed, 300 insertions(+), 68 deletions(-) create mode 100644 include/linux/fs_iostats.h -- 2.25.1