On Sat, Apr 27, 2019 at 09:55:23AM +1000, NeilBrown wrote: > On Fri, Apr 26 2019, J. Bruce Fields wrote: > > But it's true that from the start nfsd didn't really fit the model > > of a single (possibly writeable) attribute per file. > > Depends on what you mean by that. Original files where write-only and > where slightly complex attributes. Yes I thought it was just those too, but then I looked at the original commit it also included at least the "exports" file. > Writing performed an action, like > adding an entry to the export table (first you add a client, then add a > client+filesystem to export it). > > This idea for a file performing an action, rather than presenting an > attribute, is much the same as the "bind" and "unbind" files you can > find in sysfs. > > (see also https://lwn.net/Articles/378884/ for examples of sysfs files > that are not one-attribute-per-file) I'll give that a re-read, thanks. I did spend maybe a few minutes looking into basing nfsd code on kernfs and didn't think it was worth it. I could take a more serious look. --b.