Tue, Aug 14, 2012 at 10:32:53PM CEST, bhutchings@xxxxxxxxxxxxxx wrote: >On Tue, 2012-08-14 at 16:19 -0400, Andy Gospodarek wrote: >> On Tue, Aug 14, 2012 at 05:05:33PM +0200, Jiri Pirko wrote: >> > Hi all. >> > >> > Recent discussion around >> > "[net-next] bonding: don't allow the master to become its slave" >> > forced me to think about upper<->lower device connections. >> > >> > This patchset adds a possibility to record upper device linkage. >> > All upper<->lower devices are converted to use this mechanism right after. >> > That leads to dev->master removal because this info becomes redundant since >> > "unique links" have the same value. >> > >> > After all changes, there is no longer possible to do: >> > "bond->someotherdevice->samebond" >> > >> > Also I think that drivers like cxgb3, qlcnic, qeth would benefit by this >> > in future by being able to get more appropriate info about l3 addresses. >> > >> > v1->v2: >> > - s/unique/master/ better naming + stays closer to the history >> > - fixed vlan err goto >> > - original patch 15 (WARN_ON change) is squashed into the first patch >> > - fixed netdev_unique_upper_dev_get_rcu() case of upper==NULL >> I just started to review v1 when v2 came out, but luckily the changes >> were not too significant that I need to start all over. >> >> The first note is that I didn't like the use of the term 'upper' -- it >> seems like 'stacked' might be a better alternative as these are stacked >> devices. > >When linking any two devices in a stack, one will be upper and the other >lower. The lower device might itself be stacked on top of a further >device, so 'stacked' is not a useful distinguishing adjective in >variable names. It might be a useful term in the commit messages and >kernel-doc, though. > >> One thing to note is that I don't see any clear changelog that states >> the current goals for this. You have stated in several places that it >> will no longer be possible to create bonds of bonds, but there are >> probably a few more things it might be wise to intentionally outlaw. >> >> What about teams of teams? Or teams of bonds? Or bonds of teams? >> Bonds of vlans? >[...] > >It doesn't disallow bonds of bonds (unless I'm missing something). It >disallows loops that involve any or all of those types of stacked >devices. Exactly. It's every "upper driver" responsibility to check which device it allows to be added as lower. > >Ben. > >-- >Ben Hutchings, Staff Engineer, Solarflare >Not speaking for my employer; that's the marketing department's job. >They asked us to note that Solarflare product names are trademarked. >
