[PATCH v2 00/12] ubi: fastmap: Fix a series of wear leveling problems

[Zhihao Cheng]

This series of patches fix three problems:
1. Inconsistent erase counter from wl entry and disk, for patches 1~4.
2. Same PEB is always resued for fastmap data, for patches 5~9.
3. First 64 PEBs have large erase counter than others, for patches 10~12.

Besides, patches 4/5 bring an improvement of the UBI service life.

Regression tests are in [Link].

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217787.

v1->v2:
  Patch 6: Change wait condition in wait_free_pebs_for_pool(), there are
	   two situations that cause waiting infinately:
	   1. __erase_worker schedules itself if -EBUSY returned when
	      shutting down system.
	   2. The 'min_expect_free' cannot be satisfied when bad block
	      occurs and ubi becomes ro(The erased PEB should be the
              last one of 'min_expect_free', but it becomes bad in
	      __erase_worker).
 PS: After re-testing, the testing results in [Link] is not affected.


Zhihao Cheng (12):
  ubi: fastmap: Fix missed ec updating after erasing old fastmap data
    block
  ubi: fastmap: erase_block: Get erase counter from wl_entry rather than
    flash
  ubi: fastmap: Allocate memory with GFP_NOFS in ubi_update_fastmap
  ubi: Replace erase_block() with sync_erase()
  ubi: fastmap: Use free pebs reserved for bad block handling
  ubi: fastmap: Wait until there are enough free PEBs before filling
    pools
  ubi: fastmap: Remove unneeded break condition while filling pools
  ubi: fastmap: may_reserve_for_fm: Don't reserve PEB if fm_anchor
    exists
  ubi: fastmap: Get wl PEB even ec beyonds the 'max' if free PEBs are
    run out
  ubi: fastmap: Fix lapsed wear leveling for first 64 PEBs
  ubi: fastmap: Add module parameter to control reserving filling pool
    PEBs
  ubi: fastmap: Add control in 'UBI_IOCATT' ioctl to reserve PEBs for
    filling pools

 drivers/mtd/ubi/build.c      |  25 +++++++-
 drivers/mtd/ubi/cdev.c       |   3 +-
 drivers/mtd/ubi/eba.c        |   3 -
 drivers/mtd/ubi/fastmap-wl.c | 112 +++++++++++++++++++++++++++--------
 drivers/mtd/ubi/fastmap.c    |  66 +++------------------
 drivers/mtd/ubi/ubi.h        |  10 +++-
 drivers/mtd/ubi/wl.c         |  48 +++++++++------
 drivers/mtd/ubi/wl.h         |   6 +-
 include/uapi/mtd/ubi-user.h  |   4 +-
 9 files changed, 164 insertions(+), 113 deletions(-)

-- 
2.39.2