[PATCH] partitions: Prefer strlcpy() over snprintf()

[PATCH] partitions: Prefer strlcpy() over snprintf()

[Jean Delvare]

Subject: partitions: Prefer strlcpy() over snprintf()

strlcpy is faster than snprintf when you don't use the returned value.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Andries Brouwer <aeb@cwi.nl>
---
This patch was already sent on:
 * 2008-05-09

 fs/partitions/check.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-2.6.26-rc1.orig/fs/partitions/check.c	2008-05-09 17:35:37.000000000 +0200
+++ linux-2.6.26-rc1/fs/partitions/check.c	2008-05-09 17:39:13.000000000 +0200
@@ -123,7 +123,7 @@ static int (*check_part[])(struct parsed
 char *disk_name(struct gendisk *hd, int part, char *buf)
 {
 	if (!part)
-		snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
+		strlcpy(buf, hd->disk_name, BDEVNAME_SIZE);
 	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
 		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
 	else


-- 
Jean Delvare

Re: [PATCH] partitions: Prefer strlcpy() over snprintf()

[Andries E. Brouwer]

On Thu, Jul 10, 2008 at 01:30:04PM +0200, Jean Delvare wrote:
> Subject: partitions: Prefer strlcpy() over snprintf()
> 
> strlcpy is faster than snprintf when you don't use the returned value.

>  	if (!part)
> -		snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
> +		strlcpy(buf, hd->disk_name, BDEVNAME_SIZE);
>  	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
>  		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
>  	else

Yecch. There is a parallelism between the two cases
which makes the source nice and readable.
You want to destroy the parallelism for no gain.
Different functions, different parameter order. Ach.

Re: [PATCH] partitions: Prefer strlcpy() over snprintf()

[Jean Delvare]

Hi Andries,

On Thu, 10 Jul 2008 14:28:01 +0200, Andries E. Brouwer wrote:
> On Thu, Jul 10, 2008 at 01:30:04PM +0200, Jean Delvare wrote:
> > Subject: partitions: Prefer strlcpy() over snprintf()
> > 
> > strlcpy is faster than snprintf when you don't use the returned value.
> 
> >  	if (!part)
> > -		snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
> > +		strlcpy(buf, hd->disk_name, BDEVNAME_SIZE);
> >  	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
> >  		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
> >  	else
> 
> Yecch. There is a parallelism between the two cases
> which makes the source nice and readable.
> You want to destroy the parallelism for no gain.
> Different functions, different parameter order. Ach.

At the moment I hit "Send" I thought about that and suspected that
someone would object for that reason. And that makes sense, indeed.
Just scratch this patch, sorry for the noise.

-- 
Jean Delvare