backing-dev: use kstrto* in preference to simple_strtoul

Fix checkpatch warnings:

WARNING: consider using kstrto* in preference to simple_strtoul

for the below sys entry parsers:
/sys/block/<block device>/bdi/read_ahead_kb
/sys/block/<block device>/bdi/max_ratio
/sys/block/<block device>/bdi/min_ratio

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com>

1 files changed, 26 insertions, 24 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index b41823cc05e6..d3ca2b3ee176 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -158,16 +158,16 @@ static ssize_t read_ahead_kb_store(struct device *dev,
                                   const char *buf, size_t count)
 {
         struct backing_dev_info *bdi = dev_get_drvdata(dev);
-        char *end;
         unsigned long read_ahead_kb;
-        ssize_t ret = -EINVAL;
+        ssize_t ret;
 
-        read_ahead_kb = simple_strtoul(buf, &end, 10);
-        if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
-                bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
-                ret = count;
-        }
-        return ret;
+        ret = kstrtoul(buf, 10, &read_ahead_kb);
+        if (ret < 0)
+                return ret;
+
+        bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
+
+        return count;
 }
 
 #define K(pages) ((pages) << (PAGE_SHIFT - 10))
@@ -187,16 +187,17 @@ static ssize_t min_ratio_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t count)
 {
         struct backing_dev_info *bdi = dev_get_drvdata(dev);
-        char *end;
         unsigned int ratio;
-        ssize_t ret = -EINVAL;
+        ssize_t ret;
+
+        ret = kstrtouint(buf, 10, &ratio);
+        if (ret < 0)
+                return ret;
+
+        ret = bdi_set_min_ratio(bdi, ratio);
+        if (!ret)
+                ret = count;
 
-        ratio = simple_strtoul(buf, &end, 10);
-        if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
-                ret = bdi_set_min_ratio(bdi, ratio);
-                if (!ret)
-                        ret = count;
-        }
         return ret;
 }
 BDI_SHOW(min_ratio, bdi->min_ratio)
@@ -205,16 +206,17 @@ static ssize_t max_ratio_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t count)
 {
         struct backing_dev_info *bdi = dev_get_drvdata(dev);
-        char *end;
         unsigned int ratio;
-        ssize_t ret = -EINVAL;
+        ssize_t ret;
+
+        ret = kstrtouint(buf, 10, &ratio);
+        if (ret < 0)
+                return ret;
+
+        ret = bdi_set_max_ratio(bdi, ratio);
+        if (!ret)
+                ret = count;
 
-        ratio = simple_strtoul(buf, &end, 10);
-        if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
-                ret = bdi_set_max_ratio(bdi, ratio);
-                if (!ret)
-                        ret = count;
-        }
         return ret;
 }
 BDI_SHOW(max_ratio, bdi->max_ratio)