[Qemu-devel] [PATCH 12/12] file-posix: Avoid aio_worker() for QEMU_AIO_IOCTL

From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH 12/12] file-posix: Avoid aio_worker() for QEMU_AIO_IOCTL
Date: Wed, 31 Oct 2018 22:56:22 +0100	[thread overview]
Message-ID: <20181031215622.27690-13-kwolf@redhat.com> (raw)
In-Reply-To: <20181031215622.27690-1-kwolf@redhat.com>

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.

This was the last user of aio_worker(), so the function goes away now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/file-posix.c | 55 +++++++++++++---------------------------------
 1 file changed, 15 insertions(+), 40 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 9439e8c054..9f305f3d49 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1131,8 +1131,9 @@ static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
 }
 #endif
 
-static ssize_t handle_aiocb_ioctl(RawPosixAIOData *aiocb)
+static int handle_aiocb_ioctl(void *opaque)
 {
+    RawPosixAIOData *aiocb = opaque;
     int ret;
 
     ret = ioctl(aiocb->aio_fildes, aiocb->ioctl.cmd, aiocb->ioctl.buf);
@@ -1767,34 +1768,6 @@ out:
     return result;
 }
 
-static int aio_worker(void *arg)
-{
-    RawPosixAIOData *aiocb = arg;
-    ssize_t ret = 0;
-
-    switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
-    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:
-    case QEMU_AIO_WRITE_ZEROES | QEMU_AIO_DISCARD:
-    case QEMU_AIO_COPY_RANGE:
-    case QEMU_AIO_TRUNCATE:
-        g_assert_not_reached();
-    default:
-        fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
-        ret = -EINVAL;
-        break;
-    }
-
-    g_free(aiocb);
-    return ret;
-}
-
 static int coroutine_fn raw_thread_pool_submit(BlockDriverState *bs,
                                                ThreadPoolFunc func, void *arg)
 {
@@ -3096,8 +3069,7 @@ static int coroutine_fn
 hdev_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
 {
     BDRVRawState *s = bs->opaque;
-    RawPosixAIOData *acb;
-    ThreadPool *pool;
+    RawPosixAIOData acb;
     int ret;
 
     ret = fd_open(bs);
@@ -3114,15 +3086,18 @@ hdev_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
         }
     }
 
-    acb = g_new(RawPosixAIOData, 1);
-    acb->bs = bs;
-    acb->aio_type = QEMU_AIO_IOCTL;
-    acb->aio_fildes = s->fd;
-    acb->aio_offset = 0;
-    acb->ioctl.buf = buf;
-    acb->ioctl.cmd = req;
-    pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
-    return thread_pool_submit_co(pool, aio_worker, acb);
+    acb = (RawPosixAIOData) {
+        .bs         = bs,
+        .aio_type   = QEMU_AIO_IOCTL,
+        .aio_fildes = s->fd,
+        .aio_offset = 0,
+        .ioctl      = {
+            .buf        = buf,
+            .cmd        = req,
+        },
+    };
+
+    return raw_thread_pool_submit(bs, handle_aiocb_ioctl, &acb);
 }
 #endif /* linux */
 
-- 
2.19.1
