Re: [PATCH] splice support #2

[Andy Lutomirski <luto@myrealbox.com>]

Jens Axboe wrote:
> On Fri, Mar 31 2006, Linus Torvalds wrote:
> 
>>
>>On Fri, 31 Mar 2006, Jens Axboe wrote:
>>
>>>>  ssize_t psplice(int fdin, int fdout, size_t len, off_t ofs, unsigned flags);
>>>
>>>I definitely see some valid reasons for adding a file offset instead of
>>>using ->f_pos, I'll leave that decision up to Linus though. Linus?
>>
>>I think a file offset is fine, the one thing holding me back was just the 
>>interface. One file offset per fd? Or just have the rule that the file 
>>offset is for the "non-pipe" device?
> 
> 
> Intuitively, I'd expect the offset to be tied to the non-pipe if I were
> to eg see this for the first time. So my vote would go for that.
> 

Eee!  That means that splice(file_fd, pipe_fd, 1000) and splice(pipe_fd, 
file_fd, 1000) have different semantics.  It also would seem to prevent 
ever implementing direct file-to-file splicing.

--Andy