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

[Zhihao Cheng]

在 2023/8/28 14:38, Zhihao Cheng 写道:
> 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.
> 

Hi, Richard. I hope you can take some time(when you have free time) to 
have a glance of this series of patches, I have made some tests on 
virtual machine for 2+ months(and half month for physical nand flash), 
so far ubi works fine with patches applied.

> 
> 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(-)
>