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[md-6.15,v4,00/11] md/md-bitmap: introduce CONFIG_MD_BITMAP

Message ID 20250219083456.941760-1-yukuai1@huaweicloud.com (mailing list archive)
Headers show
Series md/md-bitmap: introduce CONFIG_MD_BITMAP | expand

Message

Yu Kuai Feb. 19, 2025, 8:34 a.m. UTC
From: Yu Kuai <yukuai3@huawei.com>

Changes in v4:
 - rebase on the top of other patchset [1].
Changes in v3:
 - update commit message.
Changes in v2:
 - don't export apis, and don't support build md-bitmap as module

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 a new
kconfig option 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.
Please refer to the RFC version [2] if interested.

[1] https://lore.kernel.org/all/20250215092225.2427977-1-yukuai1@huaweicloud.com/
[2] https://lore.kernel.org/all/20250126083624.1675849-1-yukuai1@huaweicloud.com/

Yu Kuai (11):
  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/raid1: check bitmap before behind write
  md/raid1: check before referencing mddev->bitmap_ops
  md/raid10: check before referencing mddev->bitmap_ops
  md/raid5: check before referencing mddev->bitmap_ops
  md: check before referencing mddev->bitmap_ops
  md/md-bitmap: introduce CONFIG_MD_BITMAP

 drivers/md/Kconfig      |  18 +++++++
 drivers/md/Makefile     |   3 +-
 drivers/md/dm-raid.c    |   2 +-
 drivers/md/md-bitmap.c  |  67 ++++++++++++------------
 drivers/md/md-bitmap.h  |  62 ++++++++++++++++++++--
 drivers/md/md-cluster.c |   2 +-
 drivers/md/md.c         | 112 ++++++++++++++++++++++++++++------------
 drivers/md/md.h         |   4 +-
 drivers/md/raid1-10.c   |   2 +-
 drivers/md/raid1.c      |  79 ++++++++++++++++------------
 drivers/md/raid10.c     |  48 ++++++++---------
 drivers/md/raid5.c      |  30 ++++++-----
 12 files changed, 281 insertions(+), 148 deletions(-)