Re: [V9fs-developer] [GIT PULL] 9p Patches for 2.6.23 merge window

["Latchesar Ionkov" <lucho@ionkov.net>]

The original patchset had three patches:

1. Renames all functions and macros
2. Moves the header files from fs/9p to include/net/9p and updates the
C files with the new header locations
3. Moves the C files from fs/9p to net/9p

Unfortunately the three patches were applied as a single one in Eric's
repository and made tracking of the changes harder. We will be more
careful next time.

Thanks for you comments,
    Lucho

On 7/16/07, Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
>
> On Sun, 15 Jul 2007, Latchesar Ionkov wrote:
> >
> > I thought that it is not a good idea to keep the v9fs_ prefix for code
> > that is in different places (fs/9p and net/9p). If keeping the old
> > prefix is more acceptable, I can create a new patch without the
> > "v9fs_"->"p9_" renames.
>
> It's fine, I don't care *that* much, and I already pulled. If it had been
> something more central, I'd have rejected it, but soemthing as specialized
> as the Plan9 fs, I just wanted to point out that this is now how we should
> do things.
>
> In other words: when doing renames it is generally *much* nicer to do a
> 100% rename (perhaps with just _trivial_ changes to make it compile - the
> include statements etc change, and maybe you want to change the name in
> the comment header too).
>
> Doing "move the code and change it at the same time" is considered bad
> form. Movement diffs are much harder to read anyway (a traditional diff
> will show it as a new-file + delete, of course), so the general rule is:
>
>  - move code around _without_ modifying it, so that code movement (whether
>    it's a whole file, or just a set of functions between files) doesn't
>    really introduce any real changes, and is easier to look through the
>    changes.
>
>  - do the actual changes to the code as a separate thing.
>
> This should be true in just about *any* development model, and it's
> especially true in Linux, where patches are the main way people
> communicate.
>
> And when using git, the whole "keep code movement separate from changes"
> has an even more fundamental reason: git can track code movement (again,
> whether moving a whole file or just a function between files), and doing a
> "git blame -C" will actually follow code movement between files. It does
> that by similarity analysis, but it does mean that if you both move the
> code *and* change it at the same time, git cannot see that "oh, that
> function came originally from that other file", and now you get worse
> annotations about where code actually originated.
>
> So next time, please don't move code and change it at the same time.
>
>                 Linus
>