[PATCH] w1: replace usage of found with dedicated list iterator variable

[PATCH] w1: replace usage of found with dedicated list iterator variable

[Jakob Koschel]

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 drivers/w1/w1.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index f2ae2e563dc5..1219476cce88 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -830,49 +830,47 @@ int w1_slave_detach(struct w1_slave *sl)
 
 struct w1_master *w1_search_master_id(u32 id)
 {
-	struct w1_master *dev;
-	int found = 0;
+	struct w1_master *dev = NULL, *iter;
 
 	mutex_lock(&w1_mlock);
-	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
-		if (dev->id == id) {
-			found = 1;
-			atomic_inc(&dev->refcnt);
+	list_for_each_entry(iter, &w1_masters, w1_master_entry) {
+		if (iter->id == id) {
+			dev = iter;
+			atomic_inc(&iter->refcnt);
 			break;
 		}
 	}
 	mutex_unlock(&w1_mlock);
 
-	return (found)?dev:NULL;
+	return dev;
 }
 
 struct w1_slave *w1_search_slave(struct w1_reg_num *id)
 {
 	struct w1_master *dev;
-	struct w1_slave *sl = NULL;
-	int found = 0;
+	struct w1_slave *sl = NULL, *iter;
 
 	mutex_lock(&w1_mlock);
 	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
 		mutex_lock(&dev->list_mutex);
-		list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
-			if (sl->reg_num.family == id->family &&
-					sl->reg_num.id == id->id &&
-					sl->reg_num.crc == id->crc) {
-				found = 1;
+		list_for_each_entry(iter, &dev->slist, w1_slave_entry) {
+			if (iter->reg_num.family == id->family &&
+					iter->reg_num.id == id->id &&
+					iter->reg_num.crc == id->crc) {
+				sl = iter;
 				atomic_inc(&dev->refcnt);
-				atomic_inc(&sl->refcnt);
+				atomic_inc(&iter->refcnt);
 				break;
 			}
 		}
 		mutex_unlock(&dev->list_mutex);
 
-		if (found)
+		if (sl)
 			break;
 	}
 	mutex_unlock(&w1_mlock);
 
-	return (found)?sl:NULL;
+	return sl;
 }
 
 void w1_reconnect_slaves(struct w1_family *f, int attach)

base-commit: f443e374ae131c168a065ea1748feac6b2e76613
-- 
2.25.1

Re: [PATCH] w1: replace usage of found with dedicated list iterator variable

[Krzysztof Kozlowski]

On 24/03/2022 08:32, Jakob Koschel wrote:
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
> 
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable instead of a
> found boolean [1].
> 
> This removes the need to use a found variable and simply checking if
> the variable was set, can determine if the break/goto was hit.
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
> ---
>  drivers/w1/w1.c | 32 +++++++++++++++-----------------
>  1 file changed, 15 insertions(+), 17 deletions(-)

Hi,

I am going through old w1 patches and wanted to apply this, but it pops
a checkpatch warning about indentation. Can you fix the warning and send
a new version?

Best regards,
Krzysztof