[PATCH] bcache: Remove nested function from sysfs

[PATCH] bcache: Remove nested function from sysfs

[Matthias Kaehlcke]

From: Behan Webster <behanw@converseincode.com>

Replace the use of nested functions where a normal function will
suffice.

Nested functions are not liked by upstream kernel developers in
general. Their use breaks the use of clang as a compiler, and
doesn't make the code any better.

This code now works for both gcc and clang.

From: Behan Webster <behanw@converseincode.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
 drivers/md/bcache/sysfs.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 104c57cd666c..440c3906f852 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -745,6 +745,11 @@ static struct attribute *bch_cache_set_internal_files[] = {
 };
 KTYPE(bch_cache_set_internal);
 
+static int __bch_cache_cmp(const void *l, const void *r)
+{
+	return *((uint16_t *) r) - *((uint16_t *) l);
+}
+
 SHOW(__bch_cache)
 {
 	struct cache *ca = container_of(kobj, struct cache, kobj);
@@ -769,9 +774,6 @@ SHOW(__bch_cache)
 					       CACHE_REPLACEMENT(&ca->sb));
 
 	if (attr == &sysfs_priority_stats) {
-		int cmp(const void *l, const void *r)
-		{	return *((uint16_t *) r) - *((uint16_t *) l); }
-
 		struct bucket *b;
 		size_t n = ca->sb.nbuckets, i;
 		size_t unused = 0, available = 0, dirty = 0, meta = 0;
@@ -800,7 +802,7 @@ SHOW(__bch_cache)
 			p[i] = ca->buckets[i].prio;
 		mutex_unlock(&ca->set->bucket_lock);
 
-		sort(p, n, sizeof(uint16_t), cmp, NULL);
+		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
 
 		while (n &&
 		       !cached[n - 1])
-- 
2.14.2.920.gcf0c67979c-goog

Re: [PATCH] bcache: Remove nested function from sysfs

[Coly Li]

On 2017/10/7 上午5:35, Matthias Kaehlcke wrote:
> From: Behan Webster <behanw@converseincode.com>
> 
> Replace the use of nested functions where a normal function will
> suffice.
> 
> Nested functions are not liked by upstream kernel developers in
> general. Their use breaks the use of clang as a compiler, and
> doesn't make the code any better.
> 
> This code now works for both gcc and clang.
> 
> From: Behan Webster <behanw@converseincode.com>
> Signed-off-by: Behan Webster <behanw@converseincode.com>
> Reviewed-by: Mark Charlebois <charlebm@gmail.com>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>

Hi Behan,

This patch was posted by Peter Foley in Nov 2016, I test it, and add it
to for-next directory. It should be in 4.15.

Thanks.

Coly

> ---
>  drivers/md/bcache/sysfs.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
> index 104c57cd666c..440c3906f852 100644
> --- a/drivers/md/bcache/sysfs.c
> +++ b/drivers/md/bcache/sysfs.c
> @@ -745,6 +745,11 @@ static struct attribute *bch_cache_set_internal_files[] = {
>  };
>  KTYPE(bch_cache_set_internal);
>  
> +static int __bch_cache_cmp(const void *l, const void *r)
> +{
> +	return *((uint16_t *) r) - *((uint16_t *) l);
> +}
> +
>  SHOW(__bch_cache)
>  {
>  	struct cache *ca = container_of(kobj, struct cache, kobj);
> @@ -769,9 +774,6 @@ SHOW(__bch_cache)
>  					       CACHE_REPLACEMENT(&ca->sb));
>  
>  	if (attr == &sysfs_priority_stats) {
> -		int cmp(const void *l, const void *r)
> -		{	return *((uint16_t *) r) - *((uint16_t *) l); }
> -
>  		struct bucket *b;
>  		size_t n = ca->sb.nbuckets, i;
>  		size_t unused = 0, available = 0, dirty = 0, meta = 0;
> @@ -800,7 +802,7 @@ SHOW(__bch_cache)
>  			p[i] = ca->buckets[i].prio;
>  		mutex_unlock(&ca->set->bucket_lock);
>  
> -		sort(p, n, sizeof(uint16_t), cmp, NULL);
> +		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
>  
>  		while (n &&
>  		       !cached[n - 1])
>