Re: Why "splice" doesn't splice between two non-pipes?

[NeilBrown <neilb@suse.de>]

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On Fri, 27 Jun 2014 20:34:42 +0400 Askar Safin <safinaskar@mail.ru> wrote:

> Why "splice" doesn't splice between two non-pipes? I think such splice would be very useful (not only file-to-socket). For example, for dd, cp, cp -r. Also, it seems, the kernel already supports splice between non-pipes (do_splice_direct function), this function is just not available to userspace. (The patch is just an idea, not tested. I don't know how to actually add this feature.)
> 
> ==
> Askar Safin
> 
> diff --git a/fs/splice.c b/fs/splice.c
> index d37431d..ffb95db 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -1394,7 +1394,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
>                 return ret;
>         }
>  
> -       return -EINVAL;
> +       return do_splice_direct(in, off_in, out, off_out, len, flags);
>  }
>  
>  /*

Consider using "sendfile" instead of "splice".

NeilBrown

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