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Commit 472105fc authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
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UPSTREAM: cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS 



a5e112e6424a ("cgroup: add cgroup_parse_float()") accidentally added
cgroup_parse_float() inside CONFIG_SYSFS block.  Move it outside so
that it doesn't cause failures on !CONFIG_SYSFS builds.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Fixes: a5e112e6424a ("cgroup: add cgroup_parse_float()")
(cherry picked from commit 38cf3a687f5827fcfc81cbc433ef5822693a49c1)
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
Change-Id: Icbd35d6b73b2f7d05a23ad84880c447a6035fa11
parent e0ceb101

kernel/cgroup/cgroup.c

+42 −42
Original line number Diff line number Diff line
@@ -6156,6 +6156,48 @@ struct cgroup *cgroup_get_from_fd(int fd) 
}

EXPORT_SYMBOL_GPL(cgroup_get_from_fd);



static u64 power_of_ten(int power)

{

	u64 v = 1;

	while (power--)

		v *= 10;

	return v;

}



/**

 * cgroup_parse_float - parse a floating number

 * @input: input string

 * @dec_shift: number of decimal digits to shift

 * @v: output

 *

 * Parse a decimal floating point number in @input and store the result in

 * @v with decimal point right shifted @dec_shift times.  For example, if

 * @input is "12.3456" and @dec_shift is 3, *@v will be set to 12345.

 * Returns 0 on success, -errno otherwise.

 *

 * There's nothing cgroup specific about this function except that it's

 * currently the only user.

 */

int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v)

{

	s64 whole, frac = 0;

	int fstart = 0, fend = 0, flen;



	if (!sscanf(input, "%lld.%n%lld%n", &whole, &fstart, &frac, &fend))

		return -EINVAL;

	if (frac < 0)

		return -EINVAL;



	flen = fend > fstart ? fend - fstart : 0;

	if (flen < dec_shift)

		frac *= power_of_ten(dec_shift - flen);

	else

		frac = DIV_ROUND_CLOSEST_ULL(frac, power_of_ten(flen - dec_shift));



	*v = whole * power_of_ten(dec_shift) + frac;

	return 0;

}



/*

 * sock->sk_cgrp_data handling.  For more info, see sock_cgroup_data

 * definition in cgroup-defs.h.
@@ -6332,46 +6374,4 @@ static int __init cgroup_sysfs_init(void) 
}

subsys_initcall(cgroup_sysfs_init);



static u64 power_of_ten(int power)

{

	u64 v = 1;

	while (power--)

		v *= 10;

	return v;

}



/**

 * cgroup_parse_float - parse a floating number

 * @input: input string

 * @dec_shift: number of decimal digits to shift

 * @v: output

 *

 * Parse a decimal floating point number in @input and store the result in

 * @v with decimal point right shifted @dec_shift times.  For example, if

 * @input is "12.3456" and @dec_shift is 3, *@v will be set to 12345.

 * Returns 0 on success, -errno otherwise.

 *

 * There's nothing cgroup specific about this function except that it's

 * currently the only user.

 */

int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v)

{

	s64 whole, frac = 0;

	int fstart = 0, fend = 0, flen;



	if (!sscanf(input, "%lld.%n%lld%n", &whole, &fstart, &frac, &fend))

		return -EINVAL;

	if (frac < 0)

		return -EINVAL;



	flen = fend > fstart ? fend - fstart : 0;

	if (flen < dec_shift)

		frac *= power_of_ten(dec_shift - flen);

	else

		frac = DIV_ROUND_CLOSEST_ULL(frac, power_of_ten(flen - dec_shift));



	*v = whole * power_of_ten(dec_shift) + frac;

	return 0;

}



#endif /* CONFIG_SYSFS */