[md-6.14,00/13] md/md-bitmap: support to build md-bitmap as kernel module

Message

Yu Kuai Dec. 25, 2024, 11:15 a.m. UTC

From: Yu Kuai <[e-mail]>

Due to known performance issues with md-bitmap and the unreasonable
implementations like following:

 - self-managed pages, bitmap_storage->filemap;
 - self-managed IO submitting like filemap_write_page();
 - global spin_lock
 ...

I have decided not to continue optimizing based on the current bitmap
implementation, and plan to invent a new lock-less bitmap. And build
the bitmap as kernel module is a good way for isolation. However, we
still encourage anyone who wants to continue optimizing the current
implementation, the new bitmap will take some time to be ready.

Yu Kuai (13):
  md/md-bitmap: remove the parameter 'init' for bitmap_ops->resize()
  md/md-bitmap: merge md_bitmap_group into bitmap_operations
  md/md-bitmap: add md_bitmap_registered/enabled() helper
  md/md-bitmap: handle the case bitmap is not enabled before
    start_sync()
  md/md-bitmap: handle the case bitmap is not enabled before end_sync()
  md/dm-raid: check if bitmap is registered in raid_ctr()
  md/raid1: check bitmap before behind write
  md/raid1: check before deferencing mddev->bitmap_ops
  md/raid10: check before deferencing mddev->bitmap_ops
  md/raid5: check before deferencing mddev->bitmap_ops
  md: check before deferencing mddev->bitmap_ops
  md: export some helpers
  md/md-bitmap: support to build md-bitmap as kernel module

 drivers/md/Kconfig      |  18 ++++
 drivers/md/Makefile     |   4 +-
 drivers/md/dm-raid.c    |   5 +-
 drivers/md/md-bitmap.c  |  72 ++++++++--------
 drivers/md/md-bitmap.h  |  54 +++++++++++-
 drivers/md/md-cluster.c |   2 +-
 drivers/md/md.c         | 183 +++++++++++++++++++++++++++++++---------
 drivers/md/md.h         |  12 ++-
 drivers/md/raid1-10.c   |   2 +-
 drivers/md/raid1.c      |  79 ++++++++++-------
 drivers/md/raid10.c     |  48 +++++------
 drivers/md/raid5.c      |  30 ++++---
 12 files changed, 352 insertions(+), 157 deletions(-)