Re: [Nbd] [PATCH 6/9] nbd: Restructure debugging prints

[Joe Perches <joe@...1529...>]

On Fri, 2015-02-13 at 10:58 +0100, Markus Pargmann wrote:
> On Thu, Feb 12, 2015 at 01:08:48PM -0800, Joe Perches wrote:
> > On Thu, 2015-02-12 at 21:57 +0100, Markus Pargmann wrote:
> > > dprintk has some name collisions with other frameworks and drivers. It
> > > is also not necessary to have these custom debug print filters. Dynamic
> > > debug offers the same amount of filtered debugging.
> > > 
> > > This patch replaces all dprintks with dev_dbg(). It also removes the
> > > ioctl dprintk which prints the ingoing ioctls which should be
> > > replaceable by strace or similar stuff.
> > 
> > Perhaps add
> > 
> > #define nbd_dbg(nbd, fmt, ...)					\
> > 	dev_dbg(disk_to_dev((nbd)->disk), "%s: " fmt,		\
> > 		nbd->disk->disk_name, ##__VA_ARGS__)
> 
> I am not really happy with those custom debug print macros. What do you
> think about an inline function 'nbd_to_dev' instead?

Wouldn't that change the output?
What would the output look like?

> > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> > []
> > > +static void nbd_end_request(struct nbd_device *nbd, struct request *req)
> > >  {
> > >  	int error = req->errors ? -EIO : 0;
> > >  	struct request_queue *q = req->q;
> > >  	unsigned long flags;
> > >  
> > > -	dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name,
> > > -			req, error ? "failed" : "done");
> > > +	dev_dbg(disk_to_dev(nbd->disk), "%s: request %p: %s\n",
> > > +		req->rq_disk->disk_name, req, error ? "failed" : "done");
> > 
> > so this becomes
> > 
> > 	nbd_dbg(nbd, "request %p: %s\n",
> > 		req, error ? "failed" : "done");
> 
> so this would be:
>  	nbd_dbg(nbd_to_dev(nbd), "request %p: %s\n",
>  		req, error ? "failed" : "done");

I don't see much value in that style,
but I don't manage the code either.