Add tests for mount bind

test/src/apps/scripts/fs.sh

@@ -53,6 +53,39 @@ test_fdatasync() {
     rm -f /exfat/test_fdatasync.txt
 }
 
+test_mount_bind_file() {
+    local file_a="/file_a.txt"
+    local file_b="/file_b.txt"
+    local content_a="initial content for file A"
+    local content_b_new="new content written to file B"
+
+    echo "$content_a" > "$file_a"
+    touch "$file_b"
+
+    mount --bind "$file_a" "$file_b"
+
+    # Read from file_b and check if it matches file_a's content
+    if [ "$(cat "$file_b")" != "$content_a" ]; then
+        echo "Error: Read from bind-mounted file failed. Content mismatch."
+        umount "$file_b"
+        rm -f "$file_a" "$file_b"
+        return 1
+    fi
+
+    echo "$content_b_new" > "$file_b"
+
+    # Check if file_a's content is updated
+    if [ "$(cat "$file_a")" != "$content_b_new" ]; then
+        echo "Error: Write to bind-mounted file did not affect the source file."
+        umount "$file_b"
+        rm -f "$file_a" "$file_b"
+        return 1
+    fi
+
+    umount "$file_b"
+    rm -f "$file_a" "$file_b"
+}
+
 echo "Start ext2 fs test......"
 test_ext2 "/ext2" "test_file.txt"
 echo "All ext2 fs test passed."
@@ -61,6 +94,10 @@ echo "Start fdatasync test......"
 test_fdatasync
 echo "All fdatasync test passed."
 
+echo "Start mount bind file test......"
+test_mount_bind_file
+echo "All mount bind file test passed."
+
 pipe/pipe_err
 pipe/short_rw
 epoll/epoll_err