On 1/16/25 4:28 AM, Christian Brauner wrote: > On Wed, Jan 15, 2025 at 10:50:31AM -0600, Eric Sandeen wrote: >> I was finally getting back to some more mount API conversions, >> and was looking at pstore, which I thought would be straightforward. >> >> I noticed that mount options weren't being accepted, and I'm fairly >> sure that this is because there's some internal or hidden mount of >> pstore, and mount is actually a remount due to it using a single >> superblock. (looks like it was some sort of clone mount done under > > Yes, some legacy filesystems behave that way unforunately. Is it not the case that every current (or past) user of mount_single behave[sd] this way due to the internals of mount_single()? gadgetfs, configfs, debugfs, tracefs, efivars, openpromfs and more all currently call get_tree_single (and used to call mount_single, which did the reconfigure for them). Or am I missing something? ... > I would think we should make this the filesystems problem or add a > get_tree_single_reconfigure() helper that the few filesystems that need > this behavior can use. Thoughts? I wasn't seeing this as individual filesystems needing it, it looked to me like every filesystem that used to call mount_single() automatically got the behavior. So was looking at this from a consistency/regression POV. While it seems odd to me that mounting any "_single" sb filesystem would reconfigure all of its current mounts on a new mount, that's the way it used to work for everyone, as far as I can tell, so I was assuming that we'd need to keep the behavior. But if it's a question of just fixing it up per-filesystem, I don't mind going that route either. Thanks, -Eric
