Hello, everyone, I have a problem when I use the loop device. I compiled and built the loop.o and losetup.o. Then I used the insmod loop.o to load the loop.o into the kernel. Up to now everything is OK. Then I used the following command to connect the loop0 with the floppy disk device. losetup -e xor /dev/loop0 /dev/fd0 It succeeded. Then I used "mke2fs /dev/loop0" and "mount /dev/loop0 /floppy" to format and mount the loop device. Then I copied some files to the loop device. But I found that the data on the floppy was never encrypted. After tracing the code I found that the loop.o always called the transfer_none() function. That means that it doesn't use the transfer_xor(). At last I found the exact reason. Both losetup and loop use the loop.h header file. In this header file there is a struct loop_info which contains 2 parameters, dev_t loop_device and dev_t loop_rdevice. I print the size of this structure and the size of the dev_t variable type both is losetup and loop. The following is the output. In losetup: The sizeof(struct loop_info) is 148. The sizeof(dev_t) is 8. In loop: The sizeof(struct loop_info) is 136. The sizeof(dev_t) is 2. You see that means that the definition of dev_t in losetup and loop is different. So I couldn't get the correct result. I know that losetup runs in user space while loop runs in kernel space. Is that the reason of this? After I omitted these two parameters in the loop_info structure, then everything is OK. What is the problem? Thanks in advance. Michael ______________________________________________________________________ Web-hosting solutions for home and business! http://website.yahoo.ca - Linux-crypto: cryptography in and on the Linux system Archive: http://mail.nl.linux.org/linux-crypto/
