Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:
 "Documentation updates and the addition of cgroup_parse_float() which
  will be used by new controllers including blk-iocost"

* 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  docs: cgroup-v1: convert docs to ReST and rename to *.rst
  cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS
  cgroup: add cgroup_parse_float()

2 files changed, 44 insertions, 1 deletions

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index cdbeff87fa99..aaba2a41562a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6240,6 +6240,48 @@ 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.
@@ -6402,4 +6444,5 @@ static int __init cgroup_sysfs_init(void)
 	return sysfs_create_group(kernel_kobj, &cgroup_sysfs_attr_group);
 }
 subsys_initcall(cgroup_sysfs_init);
+
 #endif /* CONFIG_SYSFS */
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index a1590e244f5f..b3b02b9c4405 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -729,7 +729,7 @@ static inline int nr_cpusets(void)
  * load balancing domains (sched domains) as specified by that partial
  * partition.
  *
- * See "What is sched_load_balance" in Documentation/cgroup-v1/cpusets.txt
+ * See "What is sched_load_balance" in Documentation/cgroup-v1/cpusets.rst
  * for a background explanation of this.
  *
  * Does not return errors, on the theory that the callers of this