Am 18.03.2026 um 16:32 hat Hanna Czenczek geschrieben:
> Put all request parameters into the qemu_laiocb struct, which will allow
> re-submitting the tail of short reads/writes.
>
> Signed-off-by: Hanna Czenczek <[email protected]>
> ---
> block/linux-aio.c | 35 ++++++++++++++++++++++-------------
> 1 file changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/block/linux-aio.c b/block/linux-aio.c
> index 53c3e9af8a..1f25339dc9 100644
> --- a/block/linux-aio.c
> +++ b/block/linux-aio.c
> @@ -40,10 +40,15 @@ struct qemu_laiocb {
> Coroutine *co;
> LinuxAioState *ctx;
> struct iocb iocb;
> + int fd;
> ssize_t ret;
> + off_t offset;
> size_t nbytes;
> QEMUIOVector *qiov;
> - bool is_read;
> +
> + int type;
If you put fd and type next to each other, you'd avoid a hole in the
struct.
> + BdrvRequestFlags flags;
> + uint64_t dev_max_batch;
> QSIMPLEQ_ENTRY(qemu_laiocb) next;
> };
>
> @@ -87,7 +92,7 @@ static void qemu_laio_process_completion(struct qemu_laiocb
> *laiocb)
> ret = 0;
> } else if (ret >= 0) {
> /* Short reads mean EOF, pad with zeros. */
> - if (laiocb->is_read) {
> + if (laiocb->type == QEMU_AIO_READ) {
> qemu_iovec_memset(laiocb->qiov, ret, 0,
> laiocb->qiov->size - ret);
> } else {
> @@ -367,23 +372,23 @@ static void laio_deferred_fn(void *opaque)
> }
> }
>
> -static int laio_do_submit(int fd, struct qemu_laiocb *laiocb, off_t offset,
> - int type, BdrvRequestFlags flags,
> - uint64_t dev_max_batch)
> +static int laio_do_submit(struct qemu_laiocb *laiocb)
> {
> LinuxAioState *s = laiocb->ctx;
> struct iocb *iocbs = &laiocb->iocb;
> QEMUIOVector *qiov = laiocb->qiov;
> + int fd = laiocb->fd;
> + off_t offset = laiocb->offset;
>
> - switch (type) {
> + switch (laiocb->type) {
> case QEMU_AIO_WRITE:
> #ifdef HAVE_IO_PREP_PWRITEV2
> {
> - int laio_flags = (flags & BDRV_REQ_FUA) ? RWF_DSYNC : 0;
> + int laio_flags = (laiocb->flags & BDRV_REQ_FUA) ? RWF_DSYNC : 0;
> io_prep_pwritev2(iocbs, fd, qiov->iov, qiov->niov, offset,
> laio_flags);
> }
> #else
> - assert(flags == 0);
> + assert(laiocb->flags == 0);
> io_prep_pwritev(iocbs, fd, qiov->iov, qiov->niov, offset);
> #endif
> break;
> @@ -399,7 +404,7 @@ static int laio_do_submit(int fd, struct qemu_laiocb
> *laiocb, off_t offset,
> /* Currently Linux kernel does not support other operations */
> default:
> fprintf(stderr, "%s: invalid AIO request type 0x%x.\n",
> - __func__, type);
> + __func__, laiocb->type);
> return -EIO;
> }
> io_set_eventfd(&laiocb->iocb, event_notifier_get_fd(&s->e));
> @@ -407,7 +412,7 @@ static int laio_do_submit(int fd, struct qemu_laiocb
> *laiocb, off_t offset,
> QSIMPLEQ_INSERT_TAIL(&s->io_q.pending, laiocb, next);
> s->io_q.in_queue++;
> if (!s->io_q.blocked) {
> - if (s->io_q.in_queue >= laio_max_batch(s, dev_max_batch)) {
> + if (s->io_q.in_queue >= laio_max_batch(s, laiocb->dev_max_batch)) {
> ioq_submit(s);
> } else {
> defer_call(laio_deferred_fn, s);
> @@ -425,14 +430,18 @@ int coroutine_fn laio_co_submit(int fd, uint64_t
> offset, QEMUIOVector *qiov,
> AioContext *ctx = qemu_get_current_aio_context();
> struct qemu_laiocb laiocb = {
> .co = qemu_coroutine_self(),
> - .nbytes = qiov ? qiov->size : 0,
> + .fd = fd,
> + .offset = offset,
> + .nbytes = (qiov ? qiov->size : 0),
Adding parentheses around the expression seems both unrelated and
unnecessary.
> .ctx = aio_get_linux_aio(ctx),
> .ret = -EINPROGRESS,
> - .is_read = (type == QEMU_AIO_READ),
> .qiov = qiov,
> + .type = type,
> + .flags = flags,
> + .dev_max_batch = dev_max_batch,
> };
>
> - ret = laio_do_submit(fd, &laiocb, offset, type, flags, dev_max_batch);
> + ret = laio_do_submit(&laiocb);
> if (ret < 0) {
> return ret;
> }
Reviewed-by: Kevin Wolf <[email protected]>
