On Tue, Mar 3, 2020 at 10:26 AM Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > On Tue, Mar 3, 2020 at 10:13 AM David Howells <dhowells@xxxxxxxxxx> wrote: > > > > Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > > > > I'm doing a patch. Let's see how it fares in the face of all these > > > preconceptions. > > > > Don't forget the efficiency criterion. One reason for going with fsinfo(2) is > > that scanning /proc/mounts when there are a lot of mounts in the system is > > slow (not to mention the global lock that is held during the read). BTW, I do feel that there's room for improvement in userspace code as well. Even quite big mount table could be scanned for *changes* very efficiently. l.e. cache previous contents of /proc/self/mountinfo and compare with new contents, line-by-line. Only need to parse the changed/added/removed lines. Also it would be pretty easy to throttle the number of updates so systemd et al. wouldn't hog the system with unnecessary processing. Thanks, Miklos