MAX_PATTERN_LEN
if (*off + to_write > MAX_PATTERN_LEN)
to_write = MAX_PATTERN_LEN - *off;
if (*off + to_read >= MAX_PATTERN_LEN)
to_read = MAX_PATTERN_LEN - *off;
patt_bufs[i].buf = kmalloc(MAX_PATTERN_LEN, GFP_KERNEL);
strscpy_pad(patt_bufs[i].buf, DEFAULT_PATTERN, MAX_PATTERN_LEN);