From patchwork Mon Aug 20 16:00:15 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v3,5/6] UBI: add ioctl for max_beb_per1024 Date: Mon, 20 Aug 2012 06:00:15 -0000 From: Richard Genoud X-Patchwork-Id: 178869 Message-Id: <1345478416-23900-6-git-send-email-richard.genoud@gmail.com> To: Artem Bityutskiy Cc: Richard Genoud , linux-mtd@lists.infradead.org, Shmulik Ladkani This patch provides the possibility to adjust the "maximum expected number of bad blocks per 1024 blocks" (max_beb_per1024) for each mtd device from UBI_IOCATT ioctl. The majority of NAND devices have their max_beb_per1024 equal to 20, but sometimes it's more. We already could adjust that via a kernel parameter, now we can also use UBI_IOCATT ioctl: struct ubi_attach_req { __s32 ubi_num; __s32 mtd_num; __s32 vid_hdr_offset; __u16 max_beb_per1024; __s8 padding[10]; }; Signed-off-by: Richard Genoud --- drivers/mtd/ubi/Kconfig | 3 ++- drivers/mtd/ubi/build.c | 2 ++ drivers/mtd/ubi/cdev.c | 2 +- include/mtd/ubi-user.h | 19 ++++++++++++++++++- 4 files changed, 23 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/ubi/Kconfig b/drivers/mtd/ubi/Kconfig index 37e070c..9406d26 100644 --- a/drivers/mtd/ubi/Kconfig +++ b/drivers/mtd/ubi/Kconfig @@ -51,7 +51,8 @@ config MTD_UBI_BEB_LIMIT MTD partitions of the same size, UBI will reserve 40 eraseblocks when attaching a partition. - This option can be overridden by the kernel parameter ubi.mtd. + This option can be overridden by the kernel parameter ubi.mtd and the + ioctl UBI_IOCATT. Leave the default value if unsure. diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 5b987cb..a690d86 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -865,6 +865,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, /* * Use the default value if max_beb_per1024 isn't provided. + * This way, we are keeping the same behaviour between the UBI_IOCATT + * ioctl and the module parameter. */ if (!max_beb_per1024) max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT; diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index 619f914..7885dc0 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -1011,7 +1011,7 @@ static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd, */ mutex_lock(&ubi_devices_mutex); err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset, - CONFIG_MTD_UBI_BEB_LIMIT); + req.max_beb_per1024); mutex_unlock(&ubi_devices_mutex); if (err < 0) put_mtd_device(mtd); diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index 8787349..2a763ae 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -222,6 +222,7 @@ enum { * @ubi_num: UBI device number to create * @mtd_num: MTD device number to attach * @vid_hdr_offset: VID header offset (use defaults if %0) + * @max_beb_per1024: Maximum expected bad eraseblocks per 1024 eraseblocks * @padding: reserved for future, not used, has to be zeroed * * This data structure is used to specify MTD device UBI has to attach and the @@ -245,12 +246,28 @@ enum { * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes * aligned, which is OK, as UBI is clever enough to realize this is 4th * sub-page of the first page and add needed padding. + * + * The @max_beb_per1024 is the maximum bad eraseblocks UBI expects on the ubi + * device per 1024 eraseblocks. + * This value is often given in an other form in the NAND datasheet (min NVB + * i.e. minimal number of valid blocks). The maximum expected bad eraseblocks + * per 1024 is then: + * 1024 * (1 - MinNVB / MaxNVB) + * Which gives 20 for most NAND devices. + * This limit is used in order to derive amount of eraseblock UBI reserves for + * handling new bad blocks. + * If the device has more bad eraseblocks than this limit, UBI does not reserve + * any physical eraseblocks for new bad eraseblocks, but attempts to use + * available eraseblocks (if any). + * The accepted range is 0-768. If 0 is given, the default kernel value will be + * used for compatibility. */ struct ubi_attach_req { __s32 ubi_num; __s32 mtd_num; __s32 vid_hdr_offset; - __s8 padding[12]; + __u16 max_beb_per1024; + __s8 padding[10]; }; /**