On Mon, 2008-09-01 at 10:43 +0100, David Woodhouse wrote: > > UBIFS stores 16-bit UUID in the superblock, and it is a good > > idea to return part of it in 'f_fsid' filed of kstatfs structure. > > I think you mean a 16-byte UUID, not 16-bit? Oh, right. > > > + memcpy(&buf->f_fsid, c->uuid, sizeof(__kernel_fsid_t)); > > For btrfs I xor the first 64 bits with the second 64 bits, and put > _that_ into f_fsid. You're just putting the first 64 bits in and > ignoring the second 64 bits. Neither is really _better_ than the other; > you just alter the circumstances in which you get collisions. But I > suppose we might as well be consistent about how we do it? Well, xor-ing should not make the random UUID more random, but for consistency purposes sure, I may use xor as well. > Alternatively, there's space in the struct statfs to export a couple > more uint32_ts, and thus the _whole_ of the uuid. Perhaps we should do > that? You mean f_spare? I do not think any application would use it so I doubt it is good idea to use it. -- Best regards, Artem Bityutskiy (Битюцкий Артём) -- 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
