[dm-devel] [PATCH v2 20/26] block: Add bio_for_each_segment_all()

[Tejun Heo]

Hello,

On Mon, Sep 10, 2012 at 05:22:31PM -0700, Kent Overstreet wrote:
> This is part of the immutable bvec prep work; bio_for_each_segment() is
> going to have a different implementation so these need to be split
> apart.
>
> This change is also to better document the intent of code that's using
> it - bio_for_each_segment_all() is only legal to use for code that owns
> the bio.

How about something like following?

 __bio_for_each_segment() iterates bvecs from the specified index
 instead of bio->bv_idx.  Currently, the only usage is to walk all the
 bvecs after the bio has been advanced by specifying 0 index.

 To help immutable bvec implementation, replace it with
 bio_for_each_segment_all() which also better documents the intent of
 code that's using it.  Note that bio_for_each_segment_all() should
 only be used by the code which owns the bio.

-- 
tejun