Comment 7 for bug 690606

Yes, btrfs require libcrc32c to help handle compression checksum of the filesystem, so the module is required to be loaded before actually mount it. There is a fact, that AMD CPUs won't have the chance to use crc32c_intel, I am curious about if everyone commented above is running AMD CPUs.

I didn't read the actual code in Ubuntu kernel tree, but I guess they have hard code to load the Intel specific crc32c_intel module first, then crc32c module for other architectures So the problem should be reproducible on any other platforms other than on Intel CPUs. If the kernel just load crc32c, Intel CPUs won't have the chance to load crc32c_intel because crc32c has a higher priority than crc32_intel.