[Qemu-devel] [PATCH 1/2] fix asynchronous ioctls

[Christoph Hellwig <hch@lst.de>]

posix_aio_read expect aio requests to return the number of bytes
requests to be successfull, so we need to fake this up for ioctls.

[NB: this function is formatted using tabs, so the new code is too.
 Or should I convert the whole function in my patch?]


Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: qemu/posix-aio-compat.c
===================================================================
--- qemu.orig/posix-aio-compat.c	2009-04-28 11:42:33.801074561 +0200
+++ qemu/posix-aio-compat.c	2009-04-28 11:44:18.392076590 +0200
@@ -90,7 +90,16 @@ static size_t handle_aiocb_ioctl(struct 
 	ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_ioctl_buf);
 	if (ret == -1)
 		return -errno;
-	return ret;
+
+	/*
+	 * This looks weird, but the aio code only consideres a request
+	 * successfull if it has written the number full number of bytes.
+	 *
+	 * Now we overload aio_nbytes as aio_ioctl_cmd for the ioctl command,
+	 * so in fact we return the ioctl command here to make posix_aio_read()
+	 * happy..
+	 */
+	return aiocb->aio_nbytes;
 }
 
 #ifdef HAVE_PREADV