On Thu, Jun 24, 2010 at 11:59:22PM +0200, Jan Kara wrote: > Umm, I don't get this. Looking at the ->end_io callback it has been > always called with i_alloc_sem held. It's only aio_complete() which will > be called with i_alloc_sem held after your changes. Or am I missing > something? No, that part of the commit message is flat out wrong. Not sure what I was thinking when I wrote it. > Moreover the async testing you do does not seem to be completely right. > dio->is_async is a flag that controls whether dio code waits for IO to be > completed or not. In particular it is not set for AIO that spans beyond > current i_size so it does not seem to be exactly what you need (at least > for ext4 it isn't). I think that is_sync_kiocb() is a test that should be > used to recognize AIO - and that has an advantage that you don't have to > pass the is_async flag around. No. is_sync_kiocb() means the ioctb was not intended as sync I/O from the start. But we can only call aio_complete when we returned -EIOCBQUEUED from ->aio_read/write. Take a look at the comment near the end of direct_io_worker(). AIO beyond i_size is not supported using blockdev_direct_IO yet. I think I can add it fairly easily for XFS, but that will require passing a new DIO_* flag to __blockdev_direct_IO which will make is_async true for writes beyond i_size. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
