file-posix: Avoid aio_worker() for QEMU_AIO_READ/WRITE

aio_worker() doesn't add anything interesting, it's only a useless
indirection. Call the handler function directly instead.

As we know that this handler function is only called from coroutine
context and the coroutine stays around until the worker thread finishes,
we can keep RawPosixAIOData on the stack.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/file-posix.c

@@ -1300,8 +1300,9 @@ static ssize_t handle_aiocb_rw_linear(RawPosixAIOData *aiocb, char *buf)
     return offset;
 }
 
-static ssize_t handle_aiocb_rw(RawPosixAIOData *aiocb)
+static int handle_aiocb_rw(void *opaque)
 {
+    RawPosixAIOData *aiocb = opaque;
     ssize_t nbytes;
     char *buf;
 
@@ -1793,15 +1794,11 @@ static int aio_worker(void *arg)
     ssize_t ret = 0;
 
     switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
-    case QEMU_AIO_READ:
-        ret = handle_aiocb_rw(aiocb);
-        break;
-    case QEMU_AIO_WRITE:
-        ret = handle_aiocb_rw(aiocb);
-        break;
     case QEMU_AIO_IOCTL:
         ret = handle_aiocb_ioctl(aiocb);
         break;
+    case QEMU_AIO_READ:
+    case QEMU_AIO_WRITE:
     case QEMU_AIO_FLUSH:
     case QEMU_AIO_DISCARD:
     case QEMU_AIO_WRITE_ZEROES:
@@ -1865,6 +1862,7 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
                                    uint64_t bytes, QEMUIOVector *qiov, int type)
 {
     BDRVRawState *s = bs->opaque;
+    RawPosixAIOData acb;
 
     if (fd_open(bs) < 0)
         return -EIO;
@@ -1887,7 +1885,20 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
         }
     }
 
-    return paio_submit_co(bs, s->fd, offset, qiov, bytes, type);
+    acb = (RawPosixAIOData) {
+        .bs             = bs,
+        .aio_fildes     = s->fd,
+        .aio_type       = type,
+        .aio_offset     = offset,
+        .aio_nbytes     = bytes,
+        .io             = {
+            .iov            = qiov->iov,
+            .niov           = qiov->niov,
+        },
+    };
+
+    assert(qiov->size == bytes);
+    return raw_thread_pool_submit(bs, handle_aiocb_rw, &acb);
 }
 
 static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,