Ian Klemm 2b61bda35a block: qcow: check compressed L2 entries before zero flag ...

QCOW2 compressed L2 entries encode their extent layout in bits that
overlap with the flags used by standard L2 entries. In particular,
bit 0 can be part of the compressed entry layout, so it must not be
interpreted as ZERO_FLAG until the entry has first been ruled out as
compressed.

Keep compressed deallocation ahead of zero-flag handling in both the
shared QcowMetadata path and the legacy QcowFile path. This ensures
WRITE_ZEROES deallocates compressed clusters instead of treating a
compressed entry with bit 0 set as an existing logical-zero marker.

Add regression coverage that forces bit 0 on a compressed L2 entry
and verifies WRITE_ZEROES still clears the entry through the
compressed-cluster path.

Assisted-by: Codex:GPT-5
Signed-off-by: Ian Klemm <hi@ianklemm.de>

2026-05-22 14:26:04 +00:00

..

src

block: qcow: check compressed L2 entries before zero flag

2026-05-22 14:26:04 +00:00

Cargo.toml

block: fix cargo test -p block

2026-05-09 14:10:25 +00:00