On 01/28/2014 03:14 PM, Kay Sievers wrote: > > What would be the interface for additional functionality like > sealing/unsealing that thing, that no operation can destruct its > content as long as there is more than a single owner? That would be a > new syscall or fcntl() with specific shmemfd options? > > We also need to solve the problem that the inode does not show up in > /proc/$PID/fd/, so that nothing can create a new file for it which we > don't catch with the "single owner" logic. Or we could determine the > "single owner" state from the inode itself? > If the "single owner" is determined by the file structure (e.g. via a fcntl as opposed to a ioctl), then presumably we would simply deny an attempt to open the inode and create a new file structure for it. On Linux, /proc/$PID/fd is an open as opposed to a dup (as much as I personally don't like those semantics, they are well set in stone at this point) so it satisfies your requirements. -hpa -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>