jsp+ext2.0.2分页简单实现

struct binder_write_read {signed longwrite_size;/* bytes to write */signed longwrite_consumed;/* bytes consumed by driver */unsigned longwrite_buffer;signed longread_size;/* bytes to read */signed longread_consumed;/* bytes consumed by driver */unsigned longread_buffer;};static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg){int ret;struct binder_proc *proc = filp->private_data;struct binder_thread *thread;unsigned int size = _IOC_SIZE(cmd);void __user *ubuf = (void __user *)arg;ret = wait_event_interruptible(binder_user_error_wait,binder_stop_on_user_error < 2);if (ret)return ret;mutex_lock(&binder_lock);thread = binder_get_thread(proc);if (thread == NULL) {ret = -ENOMEM;goto err;}switch (cmd) {case BINDER_WRITE_READ: {struct binder_write_read bwr;if (size != sizeof(struct binder_write_read)) {ret = -EINVAL;goto err;}if (copy_from_user(&bwr, ubuf, sizeof(bwr))) {ret = -EFAULT;goto err;}if (bwr.write_size > 0) {ret = binder_thread_write(proc, thread, (void __user *)bwr.write_buffer, bwr.write_size, &bwr.write_consumed);if (ret < 0) {bwr.read_consumed = 0;if (copy_to_user(ubuf, &bwr, sizeof(bwr)))ret = -EFAULT;goto err;}}if (bwr.read_size > 0) {ret = binder_thread_read(proc, thread, (void __user *)bwr.read_buffer, bwr.read_size,&bwr.read_consumed, filp->f_flags & O_NONBLOCK);if (!list_empty(&proc->todo))wake_up_interruptible(&proc->wait);if (ret < 0) {if (copy_to_user(ubuf, &bwr, sizeof(bwr)))ret = -EFAULT;goto err;}}if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {ret = -EFAULT;goto err;}break;}}