erofs-freebsd-out-tree/tests/TC024-extended-inode-large.md

Test Case: Extended Inode File Above 4 GiB

Test ID: TC024-extended-inode-large

Objective

Verify a 64-bit extended i_size above 4 GiB without materializing a multi-GiB payload, using deterministic FLAT_PLAIN hole reads at distant offsets.

Fixture

Use images/extended-large-hole.erofs and expected/large-hole-zero-64k.bin. Structured evidence asserts a 64-byte inode, size 4294971393, layout 0, startblk=0xffffffffffff, valid CRC, and an all-zero content descriptor.

Procedure

After mounting, run three bounded reads:

stat -f 'size=%z blocks=%b mode=%p' "$mnt/huge-sparse.dat"
./read_probe pread "$mnt/huge-sparse.dat" 0 65536 /tmp/tc024-start
./read_probe pread "$mnt/huge-sparse.dat" 2147483648 65536 /tmp/tc024-middle
./read_probe pread "$mnt/huge-sparse.dat" 4294905857 65536 /tmp/tc024-end
cmp /tmp/repo22-g1/expected/large-hole-zero-64k.bin /tmp/tc024-start
cmp /tmp/repo22-g1/expected/large-hole-zero-64k.bin /tmp/tc024-middle
cmp /tmp/repo22-g1/expected/large-hole-zero-64k.bin /tmp/tc024-end
sha256 /tmp/tc024-start /tmp/tc024-middle /tmp/tc024-end

Remove outputs, unmount, and detach.

Expected Results

• Size is exactly 4294971393, not truncated to 32 bits.
• Start, middle, and final 64 KiB ranges match the deterministic zero source.
• Reads are bounded, no large allocation/panic occurs, and cleanup succeeds.