On Fri, Aug 10, 2018 at 04:11:31PM +0100, David Howells wrote: > > Yes. Since you *absolutely* *insist* on this being fixed *right* *now* *or* > *else*, I'm working up a set of additional patches to give userspace the > option of whether they want no sharing; sharing, but only with exactly the > same parameters; or to ignore the parameter differences and just accept > sharing of what's already already mounted (ie. the current behaviour). But there's no way to support "no sharing", at least not in the general case. A file system can only be mounted once, and without file system support, there's no way for a file system to be mounted with the bsddf or minixdf mount simultaneously. Even *with* file system support, there's no way today for the VFS to keep track of whether a pathname resolution came through one mountpoint or another, so I can't do something like this: mount /dev/sdXX -o casefold /android-data mount /dev/sdXX -o nocasefold /android-data-2 Which is a pity, since if we could we could much more easily get rid of the horror which is Android's wrapfs... So if the file system has been mounted with one set of mount options, and you want to try to mount it with a conflicting set of mount options and you don't want it to silently ignore the mount options, the *only* thing we can today is to refuse the mount and return an error. I'm not sure Eric would really consider that an improvement for the container use case.... - Ted P.S. And as Al has pointed out, this would require special, per-file system support to determine whether the mount options are conflicting or not....
