diff options
| -rw-r--r-- | drivers/mtd/ubi/build.c | 66 |
1 files changed, 55 insertions, 11 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index eb8f19f87c68..99ff57d3ac68 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -37,6 +37,7 @@ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/stringify.h> +#include <linux/namei.h> #include <linux/stat.h> #include <linux/miscdevice.h> #include <linux/log2.h> @@ -50,7 +51,8 @@ /** * struct mtd_dev_param - MTD device parameter description data structure. - * @name: MTD device name or number string + * @name: MTD character device node path, MTD device name, or MTD device number + * string * @vid_hdr_offs: VID header offset */ struct mtd_dev_param { @@ -1116,13 +1118,50 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway) } /** - * find_mtd_device - open an MTD device by its name or number. - * @mtd_dev: name or number of the device + * open_mtd_by_chdev - open an MTD device by its character device node path. + * @mtd_dev: MTD character device node path + * + * This helper function opens an MTD device by its character node device path. + * Returns MTD device description object in case of success and a negative + * error code in case of failure. + */ +static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev) +{ + int err, major, minor, mode; + struct path path; + + /* Probably this is an MTD character device node path */ + err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path); + if (err) + return ERR_PTR(err); + + /* MTD device number is defined by the major / minor numbers */ + major = imajor(path.dentry->d_inode); + minor = iminor(path.dentry->d_inode); + mode = path.dentry->d_inode->i_mode; + path_put(&path); + if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode)) + return ERR_PTR(-EINVAL); + + if (minor & 1) + /* + * Just do not think the "/dev/mtdrX" devices support is need, + * so do not support them to avoid doing extra work. + */ + return ERR_PTR(-EINVAL); + + return get_mtd_device(NULL, minor / 2); +} + +/** + * open_mtd_device - open MTD device by name, character device path, or number. + * @mtd_dev: name, character device node path, or MTD device device number * * This function tries to open and MTD device described by @mtd_dev string, - * which is first treated as an ASCII number, and if it is not true, it is - * treated as MTD device name. Returns MTD device description object in case of - * success and a negative error code in case of failure. + * which is first treated as ASCII MTD device number, and if it is not true, it + * is treated as MTD device name, and if that is also not true, it is treated + * as MTD character device node path. Returns MTD device description object in + * case of success and a negative error code in case of failure. */ static struct mtd_info * __init open_mtd_device(const char *mtd_dev) { @@ -1137,6 +1176,9 @@ static struct mtd_info * __init open_mtd_device(const char *mtd_dev) * MTD device name. */ mtd = get_mtd_device_nm(mtd_dev); + if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV) + /* Probably this is an MTD character device node path */ + mtd = open_mtd_by_chdev(mtd_dev); } else mtd = get_mtd_device(NULL, mtd_num); @@ -1352,13 +1394,15 @@ static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp) module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000); MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: " - "mtd=<name|num>[,<vid_hdr_offs>].\n" + "mtd=<name|num|path>[,<vid_hdr_offs>].\n" "Multiple \"mtd\" parameters may be specified.\n" - "MTD devices may be specified by their number or name.\n" + "MTD devices may be specified by their number, name, or " + "path to the MTD character device node.\n" "Optional \"vid_hdr_offs\" parameter specifies UBI VID " - "header position and data starting position to be used " - "by UBI.\n" - "Example: mtd=content,1984 mtd=4 - attach MTD device" + "header position to be used by UBI.\n" + "Example 1: mtd=/dev/mtd0 - attach MTD device " + "/dev/mtd0.\n" + "Example 2: mtd=content,1984 mtd=4 - attach MTD device " "with name \"content\" using VID header offset 1984, and " "MTD device number 4 with default VID header offset."); |
