Untangle code in bio.c

Untangle code in bio.c

[Pavel Machek]

Hi!

bio.c uses quite ugly code with goto's, completely
unneccessarily. Please apply,
								Pavel

--- clean-mm/fs/bio.c	2004-09-15 12:58:10.000000000 +0200
+++ linux-mm/fs/bio.c	2004-09-15 13:00:51.000000000 +0200
@@ -143,7 +143,7 @@
 
 	bio = mempool_alloc(bio_pool, gfp_mask);
 	if (unlikely(!bio))
-		goto out;
+		return NULL;
 
 	bio_init(bio);
 
@@ -157,13 +157,11 @@
 noiovec:
 		bio->bi_io_vec = bvl;
 		bio->bi_destructor = bio_destructor;
-out:
 		return bio;
 	}
 
 	mempool_free(bio, bio_pool);
-	bio = NULL;
-	goto out;
+	return NULL;
 }
 
 /**
-- 
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Re: Untangle code in bio.c

[Andrew Morton]

Pavel Machek <pavel@ucw.cz> wrote:
>
> Hi!
> 
> bio.c uses quite ugly code with goto's, completely
> unneccessarily. Please apply,

I wouldn't describe this as an improvement, really.  Multiple return
statements give me hysterics.

> 
> --- clean-mm/fs/bio.c	2004-09-15 12:58:10.000000000 +0200
> +++ linux-mm/fs/bio.c	2004-09-15 13:00:51.000000000 +0200
> @@ -143,7 +143,7 @@
>  
>  	bio = mempool_alloc(bio_pool, gfp_mask);
>  	if (unlikely(!bio))
> -		goto out;
> +		return NULL;
>  
>  	bio_init(bio);
>  
> @@ -157,13 +157,11 @@
>  noiovec:
>  		bio->bi_io_vec = bvl;
>  		bio->bi_destructor = bio_destructor;
> -out:
>  		return bio;
>  	}
>  
>  	mempool_free(bio, bio_pool);
> -	bio = NULL;
> -	goto out;
> +	return NULL;
>  }

How's this look?

struct bio *bio_alloc(int gfp_mask, int nr_iovecs)
{
	struct bio *bio = mempool_alloc(bio_pool, gfp_mask);

	if (likely(bio)) {
		struct bio_vec *bvl = NULL;

		bio_init(bio);
		if (likely(nr_iovecs)) {
			unsigned long idx;

			bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx);
			if (unlikely(!bvl)) {
				mempool_free(bio, bio_pool);
				bio = NULL;
				goto out;
			}
			bio->bi_flags |= idx << BIO_POOL_OFFSET;
		}
		bio->bi_io_vec = bvl;
		bio->bi_destructor = bio_destructor;
	}
out:
	return bio;
}

Re: Untangle code in bio.c

[Jens Axboe]

On Wed, Sep 15 2004, Andrew Morton wrote:
> Pavel Machek <pavel@ucw.cz> wrote:
> >
> > Hi!
> > 
> > bio.c uses quite ugly code with goto's, completely
> > unneccessarily. Please apply,
> 
> I wouldn't describe this as an improvement, really.  Multiple return
> statements give me hysterics.

Me neither...

> > --- clean-mm/fs/bio.c	2004-09-15 12:58:10.000000000 +0200
> > +++ linux-mm/fs/bio.c	2004-09-15 13:00:51.000000000 +0200
> > @@ -143,7 +143,7 @@
> >  
> >  	bio = mempool_alloc(bio_pool, gfp_mask);
> >  	if (unlikely(!bio))
> > -		goto out;
> > +		return NULL;
> >  
> >  	bio_init(bio);
> >  
> > @@ -157,13 +157,11 @@
> >  noiovec:
> >  		bio->bi_io_vec = bvl;
> >  		bio->bi_destructor = bio_destructor;
> > -out:
> >  		return bio;
> >  	}
> >  
> >  	mempool_free(bio, bio_pool);
> > -	bio = NULL;
> > -	goto out;
> > +	return NULL;
> >  }
> 
> How's this look?
> 
> struct bio *bio_alloc(int gfp_mask, int nr_iovecs)
> {
> 	struct bio *bio = mempool_alloc(bio_pool, gfp_mask);
> 
> 	if (likely(bio)) {
> 		struct bio_vec *bvl = NULL;
> 
> 		bio_init(bio);
> 		if (likely(nr_iovecs)) {
> 			unsigned long idx;
> 
> 			bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx);
> 			if (unlikely(!bvl)) {
> 				mempool_free(bio, bio_pool);
> 				bio = NULL;
> 				goto out;
> 			}
> 			bio->bi_flags |= idx << BIO_POOL_OFFSET;
> 		}
> 		bio->bi_io_vec = bvl;
> 		bio->bi_destructor = bio_destructor;
> 	}
> out:
> 	return bio;
> }

Same semantics and it looks good to me.

-- 
Jens Axboe