Splice(): exports for module programmers

Splice(): exports for module programmers

[Chris Smowton]

Just a couple of quick questions if anyone can shed light regarding 
functions exported for modules relating to splice():

* Is there a particular reason why the useful helper __splice_from_pipe 
is exported, but not the locking equivalent splice_from_pipe or its 
equally useful helper splice_to_pipe?
* Similarly is there anything wrong with exporting the generic 
pipe-buffer operations (e.g. generic_pipe_buf_map) to save effort 
writing modules which implement splice_read and splice_write?

Are these unexported because they are unstable and not yet considered 
suitable for use, or simply because nobody's written a module that 
splice()s yet?

Chris

Re: Splice(): exports for module programmers

[Jens Axboe]

On Fri, Jan 11 2008, Chris Smowton wrote:
> Just a couple of quick questions if anyone can shed light regarding 
> functions exported for modules relating to splice():
> 
> * Is there a particular reason why the useful helper __splice_from_pipe 
> is exported, but not the locking equivalent splice_from_pipe or its 
> equally useful helper splice_to_pipe?
> * Similarly is there anything wrong with exporting the generic 
> pipe-buffer operations (e.g. generic_pipe_buf_map) to save effort 
> writing modules which implement splice_read and splice_write?
> 
> Are these unexported because they are unstable and not yet considered 
> suitable for use, or simply because nobody's written a module that 
> splice()s yet?

The latter, I generally don't export things until they are used.
__splice_from_pipe() wasn't exported until some file systems grew they
own splice implementations.

-- 
Jens Axboe