Why do we need to log to block (mtd) device? 1. Most embedded intelligent equipment have no persistent ram, which increases costs. We perfer to cheaper solutions, like block devices. 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. Why do we need mtdpstore instead of mtdoops? 1. repetitive jobs between pstore and mtdoops Both of pstore and mtdoops do the same jobs that store panic/oops log. 2. do what a driver should do To me, a driver should provide methods instead of policies. What MTD should do is to provide read/write/erase operations, geting rid of codes about chunk management, kmsg dumper and configuration. 3. enhanced feature Not only store log, but also show it as files. Not only log, but also trigger time and trigger count. Not only panic/oops log, but also log recorder for pmsg, console and ftrace in the future. Before upstream submission, pstore/blk is tested on arch ARM and x84_64, block device and mtd device, built as modules and in kernel. Here are the details: https://github.com/gmpy/articles/blob/master/pstore/Test-Pstore-Block.md [PATCH v3]: 1. patch 1~10: a lot of improvements according to Kees Cook <keescook@xxxxxxxxxxxx> including rename module, typo, reorder, rewrite document, bugs and so on. 2. patch 11: rename funtions of pstore/blk and update document. [PATCH v2]: 1. fix syntax error in documents. Thank Randy Dunlap <rdunlap@xxxxxxxxxxxxx> 2. replace pr_* with dev_* for mtdpstore. Thank Vignesh Raghavendra <vigneshr@xxxxxx> 3. improve mtdpstore. Thank Miquel Raynal <mraynal@xxxxxxxxxx> [PATCH v1]: 1. fix errors and warnings reported by kbuild test robot. WeiXiong Liao (11): pstore/zone: a common layer to manage storage as zones pstore/blk: new support logger for block devices pstore/blk: respect for driver to pick pstore front-ends pstore/blk: pstore/zone: support pmsg recorder pstore/blk: blkoops: support console recorder pstore/blk: blkoops: support ftrace recorder Documentation: create document for pstore/blk pstore/zone: skip broken zone for MTD device pstore/blk: a way to get user configure about pstore front-ends. pstore/zone: pstore/blk: support non-block devices mtd: new support oops logger based on pstore/blk Documentation/admin-guide/pstore-block.rst | 237 +++++ MAINTAINERS | 1 + drivers/mtd/Kconfig | 10 + drivers/mtd/Makefile | 1 + drivers/mtd/mtdpstore.c | 564 +++++++++++ fs/pstore/Kconfig | 107 ++ fs/pstore/Makefile | 4 + fs/pstore/platform.c | 3 +- fs/pstore/pstore_blk.c | 480 +++++++++ fs/pstore/pstore_zone.c | 1511 ++++++++++++++++++++++++++++ include/linux/pstore.h | 1 + include/linux/pstore_blk.h | 77 ++ include/linux/pstore_zone.h | 60 ++ 13 files changed, 3055 insertions(+), 1 deletion(-) create mode 100644 Documentation/admin-guide/pstore-block.rst create mode 100644 drivers/mtd/mtdpstore.c create mode 100644 fs/pstore/pstore_blk.c create mode 100644 fs/pstore/pstore_zone.c create mode 100644 include/linux/pstore_blk.h create mode 100644 include/linux/pstore_zone.h -- 1.9.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/