block: Use blk_co_ioctl() for all BB level ioctls

All read/write functions already have a single coroutine-based function
on the BlockBackend level through which all requests go (no matter what
API style the external caller used) and which passes the requests down
to the block node level.

This patch exports a bdrv_co_ioctl() function and uses it to extend this
mode of operation to ioctls.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 33 insertions, 6 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index 39336de..c53ca30 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1141,23 +1141,50 @@ void blk_aio_cancel_async(BlockAIOCB *acb)
     bdrv_aio_cancel_async(acb);
 }
 
-int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
+int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
 {
     if (!blk_is_available(blk)) {
         return -ENOMEDIUM;
     }
 
-    return bdrv_ioctl(blk_bs(blk), req, buf);
+    return bdrv_co_ioctl(blk_bs(blk), req, buf);
+}
+
+static void blk_ioctl_entry(void *opaque)
+{
+    BlkRwCo *rwco = opaque;
+    rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset,
+                             rwco->qiov->iov[0].iov_base);
+}
+
+int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
+{
+    return blk_prw(blk, req, buf, 0, blk_ioctl_entry, 0);
+}
+
+static void blk_aio_ioctl_entry(void *opaque)
+{
+    BlkAioEmAIOCB *acb = opaque;
+    BlkRwCo *rwco = &acb->rwco;
+
+    rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset,
+                             rwco->qiov->iov[0].iov_base);
+    blk_aio_complete(acb);
 }
 
 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
                           BlockCompletionFunc *cb, void *opaque)
 {
-    if (!blk_is_available(blk)) {
-        return blk_abort_aio_request(blk, cb, opaque, -ENOMEDIUM);
-    }
+    QEMUIOVector qiov;
+    struct iovec iov;
+
+    iov = (struct iovec) {
+        .iov_base = buf,
+        .iov_len = 0,
+    };
+    qemu_iovec_init_external(&qiov, &iov, 1);
 
-    return bdrv_aio_ioctl(blk_bs(blk), req, buf, cb, opaque);
+    return blk_aio_prwv(blk, req, 0, &qiov, blk_aio_ioctl_entry, 0, cb, opaque);
 }
 
 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int count)