On Thu, Jul 3, 2025 at 4:01 AM Olivier Certner <[email protected]> wrote: > > > It is not the right usage of the MNT_ flags. They are for feature > > controlling, not for the feature reporting. > > That is not the case today (MNT_LOCAL, MNT_QUOTA, MNT_ROOTFS, MNT_USER, > etc.). I also would like this to become true at some point. > > > VOP_PATHCONF() is exactly for reporting some mnt features. > > No, it is to report features that depend on a path. It can be (ab)used to > report mount features (calling it on any file inside the mount), but that > obfuscates the fact that an information is per-mount, whereas > statfs()/statvfs() are exactly designed for per-mount information. Note that, for a NFSv4 client mount, support for hidden/system could change somewhere in the mounted server tree, since for NFSv4 the tree can consist of multiple file systems of different types. For example: If an ext2 fs was mounted under a ufs file system, the hidden/system support would go away when the mount point is crossed into the ext2 subtree.
So, I think pathconf is the best way to go (and avoids using up flag bits). rick > > > Also, this namespace should not be used frivolously, we already had to > > extend flags to 64bit, and again we are not too far from exhausting it. > > I don't disagree. That said, at some point, we'll have to dodge the bullet, > including separating control flags from report ones in the MNT_* namespace > (and provide compat' functionality), and probably extending control flags > with a second 64-bit field. > > I suspected from the start that that was the main reason behind you > recommending VOP_PATHCONF(). My point here is that it is a slightly > non-optimal design choice (as explained just above) that will stay and was > made out of a practical issue that anyway will have to be solved at some > point, and I find this a bit unfortunate. Solving the issue now is certainly > much more work, and in any case I didn't mean to object to not doing it now. > But if someone(tm) wants to do it now, that would be great (perhaps me, but > not sure yet). > > Regards. > > -- > Olivier Certner
