virtio fs tunnels fuse over a virtio channel. One issue is two sides might be speaking different endian-ness. To detects this, host side looks at the opcode value in the FUSE_INIT command. Works fine at the moment but might fail if a future version of fuse will use such an opcode for initialization. Let's reserve this opcode so we remember and don't do this. Same for CUSE_INIT.
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| @@ -425,6 +425,10 @@ enum fuse_opcode { · 424 unmodified lines | ||
| 425 | 425 | |
| 426 | 426 | /* CUSE specific operations */ |
| 427 | 427 | CUSE_INIT = 4096, |
| 428 | + | |
| 429 | + /* Reserved opcodes: helpful to detect structure endian-ness */ | |
| 430 | + CUSE_INIT_BSWAP_RESERVED = 1048576, /* CUSE_INIT << 8 */ | |
| 431 | + FUSE_INIT_BSWAP_RESERVED = 436207616, /* FUSE_INIT << 24 */ | |
| 428 | 432 | }; |
| 429 | 433 | |
| 430 | 434 | enum fuse_notify_code { |