On Wed, Sep 13, 2023 at 9:25 AM Miklos Szeredi <mszeredi@xxxxxxxxxx> wrote: > > Add a way to query attributes of a single mount instead of having to parse > the complete /proc/$PID/mountinfo, which might be huge. > > Lookup the mount by the old (32bit) or new (64bit) mount ID. If a mount > needs to be queried based on path, then statx(2) can be used to first query > the mount ID belonging to the path. > > Design is based on a suggestion by Linus: > > "So I'd suggest something that is very much like "statfsat()", which gets > a buffer and a length, and returns an extended "struct statfs" *AND* > just a string description at the end." > > The interface closely mimics that of statx. > > Handle ASCII attributes by appending after the end of the structure (as per > above suggestion). Allow querying multiple string attributes with > individual offset/length for each. String are nul terminated (termination > isn't counted in length). > > Mount options are also delimited with nul characters. Unlike proc, special > characters are not quoted. > Thank you for writing this patch. I wish that this had existed the many times I've written parsers for mounts files in my life. What do you think about exposing the locked flags, a la what happens on propagation of mount across user namespaces?