This series improves mballoc statistics reporting and control by adding
blocks_allocated to /proc/fs/ext4/<dev>/mb_stats, using
READ_ONCE()/WRITE_ONCE() for concurrent accesses to s_mb_stats, and 
allowing mballoc stats to be controlled through
/proc/fs/ext4/<dev>/mb_stats.

Changes in v5: 
 - Use READ_ONCE()/WRITE_ONCE() for s_mb_stats accesses instead of
   converting s_mb_stats to atomic_t, as suggested in review.
 - For proc mb_stats writes of -1, disable stats collection before
   clearing the counters, then re-enable it.

Baolin Liu (3):
  ext4: add blocks_allocated to mb_stats output
  ext4: use READ_ONCE/WRITE_ONCE for s_mb_stats
  ext4: allow controlling mballoc stats through proc mb_stats

 Documentation/ABI/testing/sysfs-fs-ext4 |  3 +-
 Documentation/admin-guide/ext4.rst      |  9 ++-
 Documentation/filesystems/proc.rst      | 13 +----
 fs/ext4/ext4.h                          |  1 +
 fs/ext4/mballoc.c                       | 57 ++++++++++++++-----
 fs/ext4/sysfs.c                         | 73 ++++++++++++++++++++++++-
 6 files changed, 126 insertions(+), 30 deletions(-)

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2.51.0