[PATCH 4.12 09/10] ext4: check return value of kstrtoull correctly in reserved_clusters_store

From: Greg Kroah-Hartman
Date: Thu Jul 13 2017 - 11:41:28 EST


4.12-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chao Yu <yuchao0@xxxxxxxxxx>

commit 1ea1516fbbab2b30bf98c534ecaacba579a35208 upstream.

kstrtoull returns 0 on success, however, in reserved_clusters_store we
will return -EINVAL if kstrtoull returns 0, it makes us fail to update
reserved_clusters value through sysfs.

Fixes: 76d33bca5581b1dd5c3157fa168db849a784ada4
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Miao Xie <miaoxie@xxxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/ext4/sysfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -100,7 +100,7 @@ static ssize_t reserved_clusters_store(s
int ret;

ret = kstrtoull(skip_spaces(buf), 0, &val);
- if (!ret || val >= clusters)
+ if (ret || val >= clusters)
return -EINVAL;

atomic64_set(&sbi->s_resv_clusters, val);