On Mon, Mar 11, 2024 at 07:01:27PM +0100, Jan Kara wrote: > On Mon 11-03-24 15:39:39, Miklos Szeredi wrote: > > On Mon, 11 Mar 2024 at 14:25, Christian Brauner <brauner@xxxxxxxxxx> wrote: > > > > > Yeah, so with that I do agree. But have you read my reply to the other > > > thread? I'd like to hear your thoughs on that. The problem is that > > > mount(8) currently does: > > > > > > fsconfig(3, FSCONFIG_SET_FLAG, "usrjquota", NULL, 0) = -1 EINVAL (Invalid argument) > > > > > > for both -o usrjquota and -o usrjquota= > > > > For "-o usrjquota" this seems right. > > > > For "-o usrjquota=" it doesn't. Flags should never have that "=", so > > this seems buggy in more than one ways. > > > > > So we need a clear contract with userspace or the in-kernel solution > > > proposed here. I see the following options: > > > > > > (1) Userspace must know that mount options such as "usrjquota" that can > > > have no value must be specified as "usrjquota=" when passed to > > > mount(8). This in turn means we need to tell Karel to update > > > mount(8) to recognize this and infer from "usrjquota=" that it must > > > be passed as FSCONFIG_SET_STRING. > > > > Yes, this is what I'm thinking. Of course this only works if there > > are no backward compatibility issues, if "-o usrjquota" worked in the > > past and some systems out there relied on this, then this is not > > sufficient. > > No, "-o usrjquota" never worked and I'm inclined to keep refusing this > variant as IMHO it is confusing. Tbh, I'm not too sure that having empty string options was a good idea even though it can be useful. I think it would've been better if we had used a specific phantom value to signify this. But yes, I just filed an issue on util-linux to get this fixed. I think we should also util-linux and Karel's up for handling this. > > > > In any case, we need to document what we want: > > > > > > https://github.com/brauner/man-pages-md/blob/main/fsconfig.md > > > > What's the plan with these? It would be good if "man fsconfig" would > > finally work. > > Yes, merging these into official manpages would be nice. I'll try to get around to it.
