A block write the device refuses after the kernel has taken the node's
copy: the node was told "Storage refused" while the kernel's cache kept
the new data, to be read back and perhaps written later. The kernel now
puts its own copy back as it was. Tested with a device whose writes can
be made to fail; it failed first.
POST's runner: a case whose starting state could not be set says so, with
what the node said, where it showed nothing; and a case that ends with
QUIT fails, as it did when the cases were a capsule, where the runner had
taken it for a completed line. Both tests failed first.
The v4 boot says "Artemis: virtio-blk attached" only when the attach
worked.
make -C v4 test, sanitize and hosted-check pass; amd64, aarch64 and
riscv64 boot, POST 538 of 538, dict_hash 0x5f0a949a6fc8ef2b on all six:
logs/20261007-135741, -140004, -140329.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Ruled 2026-10-07. BLOCK, BUFFER, UPDATE, SAVE-BUFFERS and EMPTY-BUFFERS
are each one kernel request on port 0, by block number only. The node
has a window of four slots in its memory, as a v3 VM has; the kernel
copies blocks into it, keeps the record of which block is in which slot,
and decides when a block is written (v4/system/blocks.c). The node keeps
no record and gives the kernel no address, so a request cannot overwrite
the node's code. When a block is written stays FORTH-79's: UPDATE marks
it. When the chain of devices changes the slots are let go, as in v3.
The window is 512 cells more than the two buffers were; the dictionary
space ends that much lower, at 13824.
MESH.md 8.5 had said, from the review, that a v3 VM's BLOCK is the
kernel's buffer. It is not, and the section now says what was reported,
what v3 does, and what was ruled.
make -C v4 test, sanitize and hosted-check pass; amd64, aarch64 and
riscv64 boot, POST 538 of 538, the same hashes on all six:
logs/20261007-092835, -093112, -093456.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
