Kay Sievers <kay.sievers@xxxxxxxx> writes: > On Wed, Mar 31, 2010 at 01:04, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: >> Kay Sievers <kay.sievers@xxxxxxxx> writes: > > Yeah, /sys/bus/, which is the only sane layout of the needlessly > different 3 versions of the same thing (bus, class, block). > > /sys/bus/<subsys> can just be a plain symlinks to the > /sys/subsystem/<subsys> directories. > > /sys/class/<subsys> *could* be a symlink to the > /sys/subsystem/<subsys>/devices/ directory, but we really don't want > to continue to stupidly mix subsystem-wide control files with device > lists anymore. The "devices" directory needs to be a strict list of > devices, not some collection of random stuff, that it is today. :) > > So we either leave all the conceptually broken class attributes behind > us, and put them at the /sys/subsystem/<subsys>/ level only, or we > need to create the /sys/class/<subsys>/* stuff all as symlinks like we > do today. I expect, we have to create /sys/class as we do today. Ideally we will keep new subsystem attributes from creeping into /sys/class/xxxx/ directories. > Another problem to solve is that sysfs does not allow us to symlink > regular files, only directories, so we can currently not create the > class-wide attributes as symlinks to the proper file in > /sys/subsystem/. That seems to be part of the everything is a kobject interface, and all kobjects are directories. I don't think supporting the symlinks will be particularly hard, although there are issues to consider with respect to making the symlinks come and go when the attributes do. >> >> I'm not entirely clear on what you are doing but it all sounds like it >> will fit within what I am doing. > > The goal is to unify the 3 needlessly different versions of "device > lists of the same subsystem". We have /sys/class, /sys/bus, > /sys/block, and all of them will be unified at /sys/subsystem/ leaving > the old names as compat links only. Unlike block and class, the > /sys/subsystem/<subsys> directory can be extended with custom > subdirectories and files, without mixing random files into device > lists. That makes sense. I took a quick look and /sys/block is already a compatibility define. So I don't expect any issues there. At a practical level there don't appear to be too many class attributes that will cause problems, but even a couple are enough to be a pain. > Yeah, it did not makes sense it the first place to mix devices lists > with global attributes. It's a real mess what people do in sysfs. I was very disappointed in sysfs the first time I saw someone add writable attributes. But sysfs is here now. Eric -- 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
