On Fr, 03.04.20 13:38, Miklos Szeredi (miklos@xxxxxxxxxx) wrote: > On Fri, Apr 3, 2020 at 1:11 PM Lennart Poettering <mzxreary@xxxxxxxxxxx> wrote: > > > > On Fr, 03.04.20 09:44, Ian Kent (raven@xxxxxxxxxx) wrote: > > > > > > Currently the only way to find the mount id from a path is by parsing > > > > /proc/self/fdinfo/$fd. It is trivial, however, to extend statx(2) to > > > > return it directly from a path. Also the mount notification queue > > > > that David implemented contains the mount ID of the changed mount. > > > > I would love to have the mount ID exposed via statx(). > > Here's a patch. Oh, this is excellent. I love it, thanks! BTW, while we are at it: one more thing I'd love to see exposed by statx() is a simple flag whether the inode is a mount point. There's plenty code that implements a test like this all over the place, and it usually isn't very safe. There's one implementation in util-linux for example (in the /usr/bin/mountpoint binary), and another one in systemd. Would be awesome to just have a statx() return flag for that, that would make things *so* much easier and more robust. because in fact most code isn't very good that implements this, as much of it just compares st_dev of the specified file and its parent. Better code compares the mount ID, but as mentioned that's not as pretty as it could be so far... Lennart -- Lennart Poettering, Berlin
