On Wed 2009-07-01 10:44:47, James Bottomley wrote: > On Wed, 2009-07-01 at 14:48 +0300, Boaz Harrosh wrote: > > On 07/01/2009 01:50 PM, tridge@xxxxxxxxx wrote: > > > Hi Pavel, > > > > > > We did of course consider that, and the changes to the patch to > > > implement collision avoidance are relatively simple. We didn't do it > > > as it would weaken the legal basis behind the patch. I'll leave it to > > > John Lanza (the LF patent attorney) to expand on that if you want more > > > information. > > > > > > > You completely lost me here. And I thought I did understand the patent > > and the fix. > > > > what is the difference between. > > > > short_name = rand(sid); > > and > > short_name = sid++; > > > > Now if you would do > > short_name = MD5(long_name); > > > > That I understand since short_name is some function of long_name > > but if I'm just inventing the short_name out of my hat. In what legal > > system does it matter what is my random function I use? > > We're sort of arguing moot technicalities here. If you look at the way > the filename is constructed, given the constraints of a leading space > and a NULL, the need for a NULL padded leading slash extension and the > need to put control characters in the remaining bytes, we've only got 30 > bits to play with, we're never going to avoid collisions in a space of > up to 31 bits. Technically, a random function is at least as good at > collision avoidance as any deterministic solution ... and it's a lot > easier to code. You could be deterministic and restrict maximum number of entries in directory? You could do random function but check if duplicate exists, and return -EPERM if it does? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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
