SPIFFS_write error(-10001): File system is full

Hi,
I have a esp32-device with a webpage on it. There is a html script (from the example) for uploading and saving files to flash and it works fine, but it is not very useful for production. I tried to create an spiffs image of web with mkspiffs and it said "SPIFFS_write error(-10001): File system is full". Instead of 0x220000 bytes it requires 0x260000. What might be a problem?..