On 2010-06-26, at 03:35, Christoph Hellwig wrote: > We copy the flag values from glibc, and add a new ST_VALID flag to > denote that f_flags is implemented. Adding ST_VALID is only of marginal use, IMHO. If we are worried about this field being filled with garbage, then a single bit still has a 50% chance of being set. When there was a transition to binary flags in the mount(2) API, we had a full 16-bit magic value (0xC0ED0000, IIRC) in the high bits to verify the validity of the low 16-bit flags. Then, a couple years later, when all of the tools and kernels were handling the binary flags properly the 16-bit magic was removed and we could use the full 32-bit value. I would advocate at least an 8-bit magic value, if there is a concern about this field not always being 0-filled on older kernels, or not using any ST_VALID flag at all, if it was always zero-filled in the past. Cheers, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
