Add various helper functions to the block device LED trigger: * blkdev_mkdir() - create a sysfs directory (and don't swallow error codes) * blkdev_streq(), blkdev_skip_space() & blkdev_find_space() - for parsing writes to sysfs attributes * blkdev_read_mode() & blkdev_write_mode() - LED mode activity type helpers Signed-off-by: Ian Pilcher <arequipeno@gmail.com> --- drivers/leds/trigger/ledtrig-blkdev.c | 74 +++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c index 28ccbd7946ba..fcae7ce63b92 100644 --- a/drivers/leds/trigger/ledtrig-blkdev.c +++ b/drivers/leds/trigger/ledtrig-blkdev.c @@ -6,6 +6,7 @@ * Copyright 2021 Ian Pilcher <arequipeno@gmail.com> */ +#include <linux/ctype.h> #include <linux/leds.h> #include <linux/list.h> #include <linux/mutex.h> @@ -64,3 +65,76 @@ static unsigned int ledtrig_blkdev_count; /* How often to check for drive activity - in jiffies */ static unsigned int ledtrig_blkdev_interval; + + +/* + * + * Miscellaneous helper functions + * + */ + +/* Like kobject_create_and_add(), but doesn't swallow error codes */ +static struct kobject *blkdev_mkdir(const char *const name, + struct kobject *const parent) +{ + struct kobject *dir; + int ret; + + dir = kobject_create(); + if (dir == NULL) + return ERR_PTR(-ENOMEM); + + ret = kobject_add(dir, parent, "%s", name); + if (ret != 0) { + kobject_put(dir); + return ERR_PTR(ret); + } + + return dir; +} + +/* + * Compare a null-terminated C string with a non-null-terminated character + * sequence of a known length. Returns true if equal, false if not. + */ +static bool blkdev_streq(const char *const cstr, + const char *const cbuf, const size_t buf_len) +{ + return (strlen(cstr) == buf_len) && (memcmp(cstr, cbuf, buf_len) == 0); +} + +/* + * Returns a pointer to the first non-whitespace character in s + * (or a pointer to the terminating null). + */ +static const char *blkdev_skip_space(const char *s) +{ + while (*s != 0 && isspace(*s)) + ++s; + + return s; +} + +/* + * Returns a pointer to the first whitespace character in s (or a pointer to the + * terminating null), which is effectively a pointer to the position *after* the + * last character in the non-whitespace token at the beginning of s. (s is + * expected to be the result of a previous call to blkdev_skip_space()). + */ +static const char *blkdev_find_space(const char *s) +{ + while (*s != 0 && !isspace(*s)) + ++s; + + return s; +} + +static bool blkdev_read_mode(const enum ledtrig_blkdev_mode mode) +{ + return mode != LEDTRIG_BLKDEV_MODE_WO; +} + +static bool blkdev_write_mode(const enum ledtrig_blkdev_mode mode) +{ + return mode != LEDTRIG_BLKDEV_MODE_RO; +} -- 2.31.1