AioDataIo and UringDataIo each carried their own eventfd, their own
completion queue, and the same enqueue and signal idiom. Route both
through the existing CompletionCommon and keep each backend's own in
flight map.
The aio drain enqueues fetched events with complete rather than a
silent push, so a drain can leave the eventfd signaled and cause one
extra harmless device wake. The eventfd is a counter, so the extra
signal is safe and the syscall batching stays the same.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Filesystems such as tmpfs do not support fallocate with
FALLOC_FL_ZERO_RANGE or FALLOC_FL_PUNCH_HOLE and return EOPNOTSUPP.
When a raw disk image lives on such a filesystem, virtio write zeroes
and discard requests fail with IOERR.
Use the WriteZeroesAt trait from vmm_sys_util through AlignedFile,
which already bundles fallocate with a positional write fallback.
For punch_hole, catch EOPNOTSUPP and fall back to the same trait.
The io_uring engine previously submitted fallocate directly through
the ring, where the async EOPNOTSUPP completion had no retry path.
Route it through the same sync helpers that the other engines
already use.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Closing an io_uring fd does not synchronously finish requests that
already reached the kernel. During block worker teardown this can let
an io-wq worker keep using retained guest-memory iovecs after reset.
Drain UringDataIo in Drop: retry any published SQEs and wait for CQEs
until no retained operation remains. If draining fails, leak retained
buffers. Drop QcowAsync's ring before its data fd so retrying
published SQEs still uses a valid descriptor.
To avoid a potential infinite loop when completions fail to be delivered
cap the number of iterations of the loop (2x the number of inflight
requests).
Assisted-by: Codex:GPT-5
Signed-off-by: Rob Bradford <rbradford@meta.com>
Import the std modules used in the crate instead of spelling the full
paths at every use site.
Signed-off-by: Henry Hrvoje Tonkovac <htonkovac@gmail.com>
Assisted-by: Claude:Opus-4.8
Move async_io.rs, fcntl.rs, and request.rs into block/src/io/. These
files are generic I/O infrastructure shared by all formats rather
than format specific code.
The io/ directory name clashes with std::io in lib.rs, so the module
is declared as io_impl via #[path] and the submodules are re-exported
at the crate root to keep existing import paths working.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
