[PATCH] ext4: fix -Wstringop-truncation warnings

[Kang Wenlin]

From: Wenlin Kang <wenlin.kang@xxxxxxxxxxxxx>

The strncpy() function may create a unterminated string,
use strscpy_pad() instead.

This fixes the following warning:

fs/ext4/super.c: In function '__save_error_info':
fs/ext4/super.c:349:2: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
  strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/super.c:353:3: warning: 'strncpy' specified bound 32 equals destination size [-Wstringop-truncation]
   strncpy(es->s_first_error_func, func,
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    sizeof(es->s_first_error_func));
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Wenlin Kang <wenlin.kang@xxxxxxxxxxxxx>
---
 fs/ext4/super.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c3b864588a0b..3ade6e1f7a4d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -446,7 +446,7 @@ static void __save_error_info(struct super_block *sb, int error,
 		return;
 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 	ext4_update_tstamp(es, s_last_error_time);
-	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
+	strscpy_pad(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 	es->s_last_error_line = cpu_to_le32(line);
 	es->s_last_error_ino = cpu_to_le32(ino);
 	es->s_last_error_block = cpu_to_le64(block);
@@ -507,7 +507,7 @@ static void __save_error_info(struct super_block *sb, int error,
 	if (!es->s_first_error_time) {
 		es->s_first_error_time = es->s_last_error_time;
 		es->s_first_error_time_hi = es->s_last_error_time_hi;
-		strncpy(es->s_first_error_func, func,
+		strscpy_pad(es->s_first_error_func, func,
 			sizeof(es->s_first_error_func));
 		es->s_first_error_line = cpu_to_le32(line);
 		es->s_first_error_ino = es->s_last_error_ino;
-- 
2.17.1