diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index c4c4309..e72c72a 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3044,9 +3044,8 @@
 	if (sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group = ext4_flex_group(sbi,
 							  ac->ac_b_ex.fe_group);
-		spin_lock(sb_bgl_lock(sbi, flex_group));
-		sbi->s_flex_groups[flex_group].free_blocks -= ac->ac_b_ex.fe_len;
-		spin_unlock(sb_bgl_lock(sbi, flex_group));
+		atomic_sub(ac->ac_b_ex.fe_len,
+			   &sbi->s_flex_groups[flex_group].free_blocks);
 	}
 
 	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
@@ -4884,9 +4883,7 @@
 
 	if (sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
-		spin_lock(sb_bgl_lock(sbi, flex_group));
-		sbi->s_flex_groups[flex_group].free_blocks += count;
-		spin_unlock(sb_bgl_lock(sbi, flex_group));
+		atomic_add(count, &sbi->s_flex_groups[flex_group].free_blocks);
 	}
 
 	ext4_mb_release_desc(&e4b);