Thread the direct flag from the disk open options through VhdDisk into
the AlignedFile the workers run on, so a fixed VHD opened with direct=on
issues O_DIRECT I/O instead of buffered I/O. Alignment is probed once on
that AlignedFile and reused by the sync and io_uring workers.
Advertise host topology from VhdDisk::topology by probing the underlying
file. On a 4096 byte sector filesystem opened with O_DIRECT this reports
logical_block_size 4096 to the guest, so the guest never issues 512 byte
I/O that the host kernel would reject as misaligned. Falls back to the
default topology with a warning when the probe fails.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
The raw sync, io_uring and AIO workers now own an AlignedFile and use
it for the O_DIRECT alignment value and for the unaligned fallback.
Aligned operations keep the fast preadv and pwritev iovec path straight
to the kernel. When the offset or an iovec base or length is not a
multiple of the probed alignment, the worker gathers the iovecs into
one contiguous host buffer and runs a synchronous RMW through
AlignedFile, then scatters the result back into guest memory.
RawDisk constructs the AlignedFile from the disk file and the direct
flag and passes it into each worker, so alignment is probed once at
open time. The fixed VHD workers are threaded through the same
AlignedFile based constructors using a non-direct AlignedFile to
preserve current behavior.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
By redirecting VHDx I/O through the AlignedFile the required RMW
semantics can be achieved for writes less than the logical block size
whilt reusing the same logic used for other backend implementations.
Assisted-by: Claude:Opus-4.8
Signed-off-by: Rob Bradford <rbradford@meta.com>
Port tests over to QcowTempDisk and also over to QcowDisk rather than
QcowFile where necessary.
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Rob Bradford <rbradford@meta.com>
Move QCOW2 format implementation into a structured directory layout:
qcow/ -> formats/qcow/internal/ (filenames unchanged)
qcow_disk.rs -> formats/qcow/mod.rs (QcowDisk)
qcow_sync.rs -> formats/qcow/worker/sync.rs (QcowSync)
qcow_async.rs -> formats/qcow/worker/async_uring.rs (QcowAsync)
qcow_common.rs -> formats/qcow/common.rs
All internal cross references continue to resolve through
re-exports in lib.rs: formats::qcow::internal as qcow,
formats::qcow as qcow_disk, and
formats::qcow::common as qcow_common.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Move VHDX format implementation into a structured directory layout:
vhdx/mod.rs -> formats/vhdx/internal/mod.rs (Vhdx)
vhdx/vhdx_bat.rs -> formats/vhdx/internal/bat.rs
vhdx/vhdx_header.rs -> formats/vhdx/internal/header.rs
vhdx/vhdx_io.rs -> formats/vhdx/internal/io.rs
vhdx/vhdx_metadata.rs -> formats/vhdx/internal/metadata.rs
vhdx_sync.rs -> formats/vhdx/mod.rs (VhdxDisk)
Extract VhdxSync from vhdx_sync.rs into formats/vhdx/worker/sync.rs.
Drop the vhdx_ prefix from internal file names since the parent
directory already provides the namespace. Update all internal cross
references to use the new module paths. Re-export formats::vhdx as
vhdx_sync in lib.rs for backward compatibility.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Move VHD format implementation into a structured directory layout:
fixed_vhd.rs -> formats/vhd/internal/fixed.rs (FixedVhd)
fixed_vhd_disk.rs -> formats/vhd/mod.rs (VhdDisk)
vhd.rs -> formats/vhd/internal/footer.rs (VhdFooter)
fixed_vhd_sync.rs -> formats/vhd/worker/sync.rs (FixedVhdSync)
fixed_vhd_async.rs -> formats/vhd/worker/async_uring.rs (FixedVhdAsync)
Add #[allow(dead_code)] to VhdFooter struct and impl because the
module is now pub(crate) and the compiler can see that several
fields and getters are only exercised by unit tests. Re-export
formats::vhd as fixed_vhd_disk in lib.rs for backward
compatibility with external consumers.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Move raw format implementation into a structured directory layout:
raw_disk.rs -> formats/raw/mod.rs (RawDisk)
raw_sync.rs -> formats/raw/worker/sync.rs (RawSync)
raw_async.rs -> formats/raw/worker/async_uring.rs (RawAsync)
raw_async_aio.rs -> formats/raw/worker/async_aio.rs (RawAio)
raw_async_io_tests.rs -> formats/raw/worker/tests.rs
Update imports in fixed_vhd_sync.rs and fixed_vhd_async.rs to use
the new paths. Re-export formats::raw as raw_disk in lib.rs to
preserve the external API.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
FixedVhdDisk is the format level DiskFile wrapper for VHD images.
Rename it to VhdDisk to match the <Format>Disk convention used by
RawDisk, QcowDisk, and VhdxDisk. The Fixed prefix remains on the
workers (FixedVhdSync, FixedVhdAsync) since those are specific to
the fixed subformat.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Align with the <Format>Disk wrapper naming convention. VHDx
has a single on disk format so no variant suffix is needed.
The async backend will be added to VhdxDisk.
No functional change.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Update open_qcow2 to construct QcowDisk instead of choosing
between QcowDiskAsync and QcowDiskSync. The backend decision
is now made inside QcowDisk::create_async_io.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Update open_fixed_vhd to construct FixedVhdDisk instead of choosing
between FixedVhdDiskAsync and FixedVhdDiskSync. The io_uring decision
is now made inside FixedVhdDisk::create_async_io().
Remove FixedVhdDiskSync and FixedVhdDiskAsync DiskFile wrapper structs
from fixed_vhd_sync.rs and fixed_vhd_async.rs. Only the FixedVhdSync
and FixedVhdAsync AsyncIo worker structs remain in those files.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Update open_raw to construct RawDisk instead of choosing between
RawFileDisk, RawFileDiskSync and RawFileDiskAio. The backend decision
is now made inside RawDisk::create_async_io.
Remove the DiskFile wrapper structs from raw_sync.rs, raw_async.rs
and raw_async_aio.rs. Only the AsyncIo worker structs remain in those
files. Reduce their module visibility to pub(crate).
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that open_disk() falls back to synchronous backend when both
io_uring and AIO are disabled, and that the returned disk reports
the correct logical size.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Create a minimal QCOW2 temp file via QcowFile::new() and verify
that open_disk() detects it as ImageType::Qcow2.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that open_disk() detects a plain temporary file as RAW and
returns a working backend with synchronous fallback.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that open_disk() returns BlockErrorKind::Io when the disk
image file does not exist.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Introduce block::factory with open_disk() as the single entry point
for opening disk images. It handles file opening, format detection,
async I/O probing, and backend construction.
Per format helpers (open_fixed_vhd, open_raw, open_qcow2, open_vhdx)
prefer io_uring over AIO over synchronous fallback. Warnings only
fire when a backend was eligible but its runtime probe failed, not
when the user intentionally disabled it.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
