diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index e8067b4..8edb577 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -22,7 +22,7 @@ jobs:
         uses: actions/checkout@v4
       - name: coding convention
         run: |
-            sudo apt-get install -q -y clang-format-12
+            sudo apt-get install -q -y clang-format
             .ci/check-newline.sh
             .ci/check-format.sh
         shell: bash
diff --git a/file.c b/file.c
index b6cfc6d..f6868c0 100644
--- a/file.c
+++ b/file.c
@@ -413,8 +413,8 @@ static ssize_t simplefs_write(struct file *file,
         size_t bytes_to_write =
             min_t(size_t, len, SIMPLEFS_BLOCK_SIZE - pos % SIMPLEFS_BLOCK_SIZE);
 
-        if (copy_from_user(bh_data->b_data + pos % SIMPLEFS_BLOCK_SIZE, buf,
-                           bytes_to_write)) {
+        if (copy_from_user(bh_data->b_data + pos % SIMPLEFS_BLOCK_SIZE,
+                           buf + bytes_write, bytes_to_write)) {
             brelse(bh_data);
             bytes_write = -EFAULT;
             break;
diff --git a/mkfs.c b/mkfs.c
index 01a6e0b..59dd967 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -26,7 +26,7 @@ _Static_assert(sizeof(struct superblock) == SIMPLEFS_BLOCK_SIZE);
  *
  * Return the result of n / d, rounded up to the nearest integer.
  */
-#define DIV_ROUND_UP(n, d) (((n) + (d) -1) / (d))
+#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 
 static struct superblock *write_superblock(int fd, struct stat *fstats)
 {
diff --git a/script/test.sh b/script/test.sh
index b1df6fc..6ba5ad0 100755
--- a/script/test.sh
+++ b/script/test.sh
@@ -123,6 +123,18 @@ test_op 'dd if=/dev/zero of=file bs=1M count=12 status=none'
 filesize=$(sudo ls -lR  | grep -e "$F_MOD 2".*file | awk '{print $5}')
 test $filesize -le $MAXFILESIZE || echo "Failed, file size over the limit"
 
+# Write the file size larger than BLOCK_SIZE
+# test serial to write
+test_op 'bash -c "printf \"%.0s123456789\" {1..1600} > file.txt"'
+count=$(awk '{count += gsub(/123456789/, "")} END {print count}' "file.txt")
+echo "test $count"
+test "$count" -eq 1600 || echo "Failed, file size not matching"
+# test block to write
+test_op 'cat file.txt > checkfile.txt'
+count=$(awk '{count += gsub(/123456789/, "")} END {print count}' "checkfile.txt")
+echo "test $count"
+test "$count" -eq 1600 || echo "Failed, file size not matching"
+
 # test remove symbolic link
 test_op 'ln -s file symlink_fake'
 test_op 'rm -f symlink_fake'