Re: [PATCH vfs 2/2] {block|char}_dev: remove inode->i_devices

[Boaz Harrosh <boaz@plexistor.com>]

On 11/20/2014 03:11 PM, Tejun Heo wrote:
> Hello, Boaz.
> 
<>
> W/ preloading, one way to do it is,
> 
> 	if (preload())
> 		handle -ENOMEM;
> 	lock;
> 	error = insert();
> 	if (error)
> 		handle error which can't be -ENOMEM;
> 	unlock;
> 	preload_end();
> 

I like this one, cause of the place I come from. Where
in a cluster you want the local fails as early as possible
before you start to commit remotely, and need to undo on
errors.

And I can see the real flow of things

> Another way is
> 
> 	preload();	// can't fail
> 	lock;
> 	error = insert();
> 	if (error)
> 		handle error;'
> 	unlock;
> 	preload_end();
> 
> Both ways have pros and cons.  The latter seems to lead to simpler
> code in general.  Not always, but the overall.
> 

I still like the over all simplicity of the above pattern to
this behind the seen complexity hidden away under the carpet.

But I guess that is just me. That is your call sir.

I do see your point though.

<>
> 
> And that's why the pattern usually leads to simpler code - it doesn't
> create a new failure point.
> 

Again a matter of taste. I like the extra ENOMEM failure point before
I started to commit to any state changes, lock grabbing and unrolling
in case of errors.

But I see your points as well. For what it is worth I have reviewed
your code and did not find any faults in it. It looks like sound
code.

Thanks
Boaz