Re: [PATCH v2] target/file: add support of direct and async I/O

[Christoph Hellwig <hch@infradead.org>]

> 
> DIF (PI) emulation doesn't work when a target uses async I/O, because
> DIF metadata is saved in a separate file, and it is another non-trivial
> task how to synchronize writing in two files, so that a following read
> operation always returns a consisten metadata for a specified block.

As said, this isn't really in any way aio specific.

> +	int is_write = !(data_direction = DMA_FROM_DEVICE);

	bool is_write = data_direction != DMA_FROM_DEVICE;

> +	if (is_write && (cmd->se_cmd_flags & SCF_FUA))
> +		aio_cmd->iocb.ki_flags |= IOCB_DSYNC;
> +
> +	if (is_write)
> +		ret = call_write_iter(file, &aio_cmd->iocb, &iter);
> +	else
> +		ret = call_read_iter(file, &aio_cmd->iocb, &iter);
> +
> +	kfree(bvec);

While this looks good to me this is the same pattern just said doesn't
work in loop.  So it works here just fine?

Otherwise this looks fine to me:

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