On Wed, Aug 27, 2014 at 12:34:44AM +0000, Ma, Jianpeng wrote: > For aio+directio: > After io_submit, the content in request-queue of block-device. > In blkdev_fsync(), it will cal blkdev_issue_flush. This operation make all request to disk. > > Or am I missing something? You can't rely on implementation details of how far aio operations are processed before io_submit returns. It'd be entirely valid to implement aio by only copying the iocb structures from user space and handing them off to kernel threads before returning from io_submit(). In that case the kernel wouldn't even know what file descriptors the aios reference when fsync is called. So what you describe might be true today (I doubt it, but I'm not going to look), but an application that relied on those assumptions runs a good chance of breaking in the future. - z -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
