[$] Zero-copy for FUSE

In a combined storage and filesystem session at the 2025 Linux Storage,Filesystem, Memory Management, and BPF Summit (LSFMM+BPF), Keith Busch leda discussion about zero-copy operations for the Filesystemin Userspace (FUSE) subsystem. The session was proposedby his colleague, David Wei, who could not make it to the summit, so Buschfilled in, though he noted that "I do not really know FUSE sowell". The idea is to eliminate data copies in the data path to andfrom the FUSE server in user space.