Commit 72e02075 authored by NeilBrown's avatar NeilBrown
Browse files

md: factor out parsing of fixed-point numbers 



safe_delay_store can parse fixed point numbers (for fractions
of a second).  We will want to do that for another sysfs
file soon, so factor out the code.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent f6af949c

drivers/md/md.c

+42 −22
Original line number Diff line number Diff line
@@ -2763,6 +2763,47 @@ static void analyze_sbs(mddev_t * mddev) 
	}

}



/* Read a fixed-point number.

 * Numbers in sysfs attributes should be in "standard" units where

 * possible, so time should be in seconds.

 * However we internally use a a much smaller unit such as 

 * milliseconds or jiffies.

 * This function takes a decimal number with a possible fractional

 * component, and produces an integer which is the result of

 * multiplying that number by 10^'scale'.

 * all without any floating-point arithmetic.

 */

int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)

{

	unsigned long result = 0;

	long decimals = -1;

	while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {

		if (*cp == '.')

			decimals = 0;

		else if (decimals < scale) {

			unsigned int value;

			value = *cp - '0';

			result = result * 10 + value;

			if (decimals >= 0)

				decimals++;

		}

		cp++;

	}

	if (*cp == '\n')

		cp++;

	if (*cp)

		return -EINVAL;

	if (decimals < 0)

		decimals = 0;

	while (decimals < scale) {

		result *= 10;

		decimals ++;

	}

	*res = result;

	return 0;

}





static void md_safemode_timeout(unsigned long data);



static ssize_t
@@ -2774,31 +2815,10 @@ safe_delay_show(mddev_t *mddev, char *page) 
static ssize_t

safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)

{

	int scale=1;

	int dot=0;

	int i;

	unsigned long msec;

	char buf[30];



	/* remove a period, and count digits after it */

	if (len >= sizeof(buf))

		return -EINVAL;

	strlcpy(buf, cbuf, sizeof(buf));

	for (i=0; i<len; i++) {

		if (dot) {

			if (isdigit(buf[i])) {

				buf[i-1] = buf[i];

				scale *= 10;

			}

			buf[i] = 0;

		} else if (buf[i] == '.') {

			dot=1;

			buf[i] = 0;

		}

	}

	if (strict_strtoul(buf, 10, &msec) < 0)

	if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)

		return -EINVAL;

	msec = (msec * 1000) / scale;

	if (msec == 0)

		mddev->safemode_delay = 0;

	else {

drivers/md/md.h

+2 −1
Original line number Diff line number Diff line
@@ -463,6 +463,7 @@ extern void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev); 
extern void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors);

extern int md_check_no_bitmap(mddev_t *mddev);

extern int md_integrity_register(mddev_t *mddev);

void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);

extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);

extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);



#endif /* _MD_MD_H */