f2fs: wrap sb_rdonly with f2fs_readonly

Use f2fs_readonly to wrap sb_rdonly for cleanup, and spread it in
all places.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -2467,9 +2467,9 @@ static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
 	return ret;
 }
 
-static inline int f2fs_readonly(struct super_block *sb)
+static inline bool f2fs_readonly(struct super_block *sb)
 {
-	return sb->s_flags & SB_RDONLY;
+	return sb_rdonly(sb);
 }
 
 static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)

fs/f2fs/super.c

@@ -336,7 +336,7 @@ static int f2fs_check_quota_options(struct f2fs_sb_info *sbi)
 			"QUOTA feature is enabled, so ignore jquota_fmt");
 		sbi->s_jquota_fmt = 0;
 	}
-	if (f2fs_sb_has_quota_ino(sbi->sb) && sb_rdonly(sbi->sb)) {
+	if (f2fs_sb_has_quota_ino(sbi->sb) && f2fs_readonly(sbi->sb)) {
 		f2fs_msg(sbi->sb, KERN_INFO,
 			 "Filesystem with quota feature cannot be mounted RDWR "
 			 "without CONFIG_QUOTA");
@@ -2805,7 +2805,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	 * Turn on quotas which were not enabled for read-only mounts if
 	 * filesystem has quota feature, so that they are updated correctly.
 	 */
-	if (f2fs_sb_has_quota_ino(sb) && !sb_rdonly(sb)) {
+	if (f2fs_sb_has_quota_ino(sb) && !f2fs_readonly(sb)) {
 		err = f2fs_enable_quotas(sb);
 		if (err) {
 			f2fs_msg(sb, KERN_ERR,
@@ -2890,7 +2890,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 
 free_meta:
 #ifdef CONFIG_QUOTA
-	if (f2fs_sb_has_quota_ino(sb) && !sb_rdonly(sb))
+	if (f2fs_sb_has_quota_ino(sb) && !f2fs_readonly(sb))
 		f2fs_quota_off_umount(sbi->sb);
 #endif
 	f2fs_sync_inode_meta(sbi);