This patch series adds a new mtdchar ioctl, MEMREAD. Its purpose is to
serve as a read counterpart of the MEMWRITE ioctl, exposing a broader
set of capabilities for read operations (e.g. use of MTD_OPS_AUTO_OOB,
access to ECC statistics) to user-space applications making use of MTD
devices via /dev/mtd* character devices.
Changes from v3:
- Fixed two issues found by Richard Weinberger [1]:
- prevent integer overflow,
- use kvmalloc() for potentially large allocations.
(Identical fixes have already been applied to mtdchar_write_ioctl(),
i.e. the write counterpart of the ioctl proposed in this patch
series, in mtd/next. [2] [3])
Changes from v2:
- Squashed patch 1/5 into patch 5/5 to prevent breaking bisectability
due to an incompatible ABI change between those two patches.
Revised commit messages accordingly.
Changes from v1:
- Added patches 2-5 which enable the new MEMREAD ioctl to report ECC
statistics for the read operation back to user space. (There are
obviously different ways these changes can be split up into separate
commits; I was aiming for maximum ease of review.)
- The 'retlen' and 'oobretlen' fields were not set in the struct
mtd_read_req returned to userspace. This was done properly in
Boris' original draft patch [1], but I missed it in my v1.
- Invalid IS_ERR() checks were replaced with NULL checks. This was an
artifact of copy-pasting mtdchar_write_ioctl() in v1: unlike
memdup_user() used therein, kmalloc() always returns NULL on error.
- Minor subject prefix adjustment for patch 1/5 ("mtd" -> "mtdchar").
[1] http://lists.infradead.org/pipermail/linux-mtd/2022-February/091276.html
[2] http://lists.infradead.org/pipermail/linux-mtd/2022-June/093829.html
[3] http://lists.infradead.org/pipermail/linux-mtd/2022-June/093828.html
Michał Kępień (4):
mtd: track maximum number of bitflips for each read request
mtd: always initialize 'stats' in struct mtd_oob_ops
mtd: add ECC error accounting for each read request
mtdchar: add MEMREAD ioctl
drivers/mtd/devices/docg3.c | 8 ++
drivers/mtd/inftlcore.c | 6 +-
drivers/mtd/mtdchar.c | 139 ++++++++++++++++++++++++
drivers/mtd/mtdcore.c | 5 +
drivers/mtd/mtdswap.c | 6 +-
drivers/mtd/nand/onenand/onenand_base.c | 16 ++-
drivers/mtd/nand/onenand/onenand_bbt.c | 2 +-
drivers/mtd/nand/raw/nand_base.c | 10 ++
drivers/mtd/nand/raw/nand_bbt.c | 8 +-
drivers/mtd/nand/raw/sm_common.c | 2 +-
drivers/mtd/nand/spi/core.c | 10 ++
drivers/mtd/nftlcore.c | 6 +-
drivers/mtd/sm_ftl.c | 4 +-
drivers/mtd/ssfdc.c | 2 +-
drivers/mtd/tests/nandbiterrs.c | 2 +-
drivers/mtd/tests/oobtest.c | 8 +-
drivers/mtd/tests/readtest.c | 2 +-
fs/jffs2/wbuf.c | 6 +-
include/linux/mtd/mtd.h | 7 ++
include/uapi/mtd/mtd-abi.h | 64 ++++++++++-
20 files changed, 279 insertions(+), 34 deletions(-)
--
2.37.0