Messages in this thread | | | Date | Thu, 22 Jan 2015 07:32:12 -0500 | From | Tejun Heo <> | Subject | Re: [RFC][PATCH 0/5] tracing: Add new file system tracefs |
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Hey, Steven.
On Wed, Jan 21, 2015 at 10:51:09PM -0500, Steven Rostedt wrote: > > Tejun would know best, he wrote it :) > > Oh good, as Bugs Bunny would say "where's the doc?" (or was that > "what's up doc"?)
I didn't write any while extracting it out of sysfs. Sorry about that. I should get to it.
> > What specifically are you looking for? I think there's at least two > > filesystems using it already, are they not good enough examples? > > Well, I see the two biggest users are sysfs and cgroups, where I never > understood how sysfs actually works, and cgroups, the filesystem is > very integrated with the usage of cgroups.
Yes, cgroup's usage is rather complicated. I wouldn't suggest it as a good example. sysfs's usage is a bit complicated too in part because of the namespace support.
> There doesn't seem to be any abi where one can relate to the vfs > system. > > I'd like to keep the interface like debugfs had for tracefs, because > all of tracing depends on it, and it would require a full rewrite to > convert it to something that doesn't have the vfs type of paradigm, in > which case, tracefs would not be done for another decade. > > That is, I need to create the following interface: > > tracefs_create_file()
kernfs_create_file()
> tracefs_create_dir()
kernfs_create_dir()
> tracefs_remove() > tracefs_remove_recursive()
kernfs_remove[_by_name]() - recursive by default
> and that's all I need for the filesystem. There doesn't seem to be any > documentation on kernfs about how to implement this. > > Yes, I can study the code, but I was hoping that there was some > kernfs.txt that described how to create a new fs with it. It just saves > time if there was a document than having to read the code and perhaps > use it in a way it wasn't supposed to be used.
Yeah yeah, I hear you. I'll write one up.
Thanks.
-- tejun
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