Re: [PATCH v14 0/4] pstore/block: new support logger for block devices

[liaoweixiong <liaoweixiong@allwinnertech.com>]

Maybe i have lost my email.

Luckly, it's good chance for me to redisigned pstore/blk and blkoops.
Pstore/blk can now support full recorders of pstore, including console
and ftrace. Besides, there is a series
of patches to make MTD device work on pstore.

Let's drop the old patches of pstore/blk. I will send new patches a few
days later.

On 2019/3/19 PM 11:45, liaoweixiong wrote:
> Why should we need pstore_block?
> 1. Most embedded intelligent equipment have no persistent ram, which
> increases costs. We perfer to cheaper solutions, like block devices.
> In fast, there is already a sample for block device logger in driver
> MTD (drivers/mtd/mtdoops.c).
> 2. Do not any equipment have battery, which means that it lost all data
> on general ram if power failure. Pstore has little to do for these
> equipments.
> 
> [PATCH v14]
> On patch 1:
> 1. flush dirty dmesg zones when write
> On patch 2:
> 1. Support dump_oops for blkoops.
> On patch 3:
> 1. use new apis to flush dirty zone.
> 
> [PATCH v13]
> On patch 1:
> 1. no need to check zone->buffer in blkz_zone_write() since it never be null
> 2. blkz_free_zones should return directly if zones is null
> 3. In blkz_init_zones(), it will causes memory leak if
> blkz_init_zone() return failure because it forget to free zone->buffer.
> 4. In blkz_zone_write(), we copy new data to ram buffer only when buf and
> wlen are valid.
> On pathc 2:
> 1. Fix spelling error on Kconfig
> On patch 3:
> 1. In blkz_pstore_erase(), if there are new but dirty data in pmsg
> zone buffer, we should try to flush them to block device.
> 2. Fix spelling error on Kconfig
> 
> [PATCH v12]
> On patch 4:
> 1. Modify the document according to Randy Dunlap's suggestion.
> 
> [PATCH v11]
> Change patchset label from RFC to PATCH
> 
> [PATCH v10]
> Cancel DT support for blkoops temporarily.
> On patch 1:
> 1. pstore/blk should unlink PSTORE_BLKDEV when unregister.
> On patch 2:
> 1. cancel DT support temporarily. I will submit other patches to support DT
>    when DT maintainers acked.
> 2. add spin lock to protect blkz_info when modify panic operations.
> 3. change default value of total size on Kconfig from 1024 to 0.
> 
> [PATCH v9]
> On patch 1:
> 1. rename part_path/part_size, members of blkz_info, to blkdev/total_size
> 2. if total_size is zero, get size from @blkdev
> 3. support multiple variants for @blkdev, such as partuuid, major with
>    minor, and /dev/xxxx. See details on Documentation.
> 4. get size from block device
> 5. add depends on CONFIG_BLOCK
> On patch 2:
> 1. update document
> On patch 3:
> 1. update codes for new blkzone. Blkoops support insmod without total_size.
>    for example: "insmod ./blkoops.ko blkdev=93:6" (major:minor).
> 2. use late_initcalls rather than module_init, to avoid block device not
> ready.
> 3. support for block driver to add panic apis to blkoops. By this, block
>    driver can do the least work that just provides panic operations.
> On patch 5:
> 1. update document
> 
> [PATCH v8]
> On patch 2:
> 1. move DT to /bindings/pstore
> 2. Delete details for kernel.
> 
> [PATCH v7]
> On patch 1:
> 1. Fix line over 80 characters.
> On patch 2:
> 1. Insert a separate patch for DT bindings.
> 
> [PATCH v6]
> On patch 1:
> 1. Fix according to email from Kees Cook, including spelling mistakes,
>    explicit overflow test, none of the zeroing etc.
> 2. Do not recover data but metadata of dmesg when panic.
> 3. No need to take recovery when do erase.
> 4. Do not use "blkoops" for blkzone any more because "blkoops" is used for
>    other module now. (rename blkbuf to blkoops)
> On patch 2:
> 1. Rename blkbuf to blkoops.
> 2. Add Kconfig/device tree/module parameters settings for blkoops.
> 3. Add document for device tree.
> On patch 3:
> 1. Blkoops support pmsg.
> 2. Fix description for new version patch.
> On patch 4:
> 1. Fix description for new version patch.
> 
> [PATCH v5]
> On patch 1:
> 1. rename pstore/rom to pstore/blk
> 2. Do not allocate any memory in the write path of panic. So, use local
> array instead in function romz_recover_dmesg_meta.
> 3. Add C header file "linux/fs.h" to fix implicit declaration of function
>    'filp_open','kernel_read'...
> On patch 3:
> 1. If panic, do not recover pmsg but flush if it is dirty.
> 2. Fix erase pmsg failed.
> On patch 4:
> 1. Create a document for pstore/blk
> 
> [PATCH v4]
> On patch 1:
> 1. Fix always true condition '(--i >= 0) => (0-u32max >= 0)' in function
>    romz_init_zones by defining variable i to 'int' rahter than
>    'unsigned int'.
> 2. To make codes more easily to read, we use macro READ_NEXT_ZONE for
>    return value of romz_dmesg_read if it need to read next zone.
>    Moveover, we assign READ_NEXT_ZONE -1024 rather than 0.
> 3. Add 'FLUSH_META' to 'enum romz_flush_mode' and rename 'NOT_FLUSH' to
>    'FLUSH_NONE'
> 4. Function romz_zone_write work badly with FLUSH_PART mode as badly
>    address and offset to write.
> On patch 3:
> NEW SUPPORT psmg for pstore_rom.
> 
> [PATCH v3]
> On patch 1:
> Fix build as module error for undefined 'vfs_read' and 'vfs_write'
> Both of 'vfs_read' and 'vfs_write' haven't be exproted yet, so we use
> 'kernel_read' and 'kernel_write' instead.
> 
> [PATCH v2]
> On patch 1:
> Fix build as module error for redefinition of 'romz_unregister' and
> 'romz_register'
> 
> [PATCH v1]
> On patch 1:
> Core codes of pstore_rom, which works well on allwinner(sunxi) platform.
> On patch 2:
> A sample for pstore_rom, using general ram rather than block device.
> 
> liaoweixiong (4):
>   pstore/blk: new support logger for block devices
>   pstore/blk: add blkoops for pstore_blk
>   pstore/blk: support pmsg for pstore block
>   Documentation: pstore/blk: create document for pstore_blk
> 
>  Documentation/admin-guide/pstore-block.rst |  233 +++++
>  MAINTAINERS                                |    3 +-
>  fs/pstore/Kconfig                          |  150 ++++
>  fs/pstore/Makefile                         |    5 +
>  fs/pstore/blkoops.c                        |  219 +++++
>  fs/pstore/blkzone.c                        | 1293 ++++++++++++++++++++++++++++
>  include/linux/pstore_blk.h                 |   87 ++
>  7 files changed, 1989 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/admin-guide/pstore-block.rst
>  create mode 100644 fs/pstore/blkoops.c
>  create mode 100644 fs/pstore/blkzone.c
>  create mode 100644 include/linux/pstore_blk.h
> 

-- 
liaoweixiong