linux-kernel - [PATCH] char: xillybus: replace usage of found with dedicated list iterator variable

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Message-Id: <20220324070939.59297-1-jakobkoschel@gmail.com>
Date:   Thu, 24 Mar 2022 08:09:39 +0100
From:   Jakob Koschel <jakobkoschel@...il.com>
To:     Eli Billauer <eli.billauer@...il.com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-kernel@...r.kernel.org, Mike Rapoport <rppt@...nel.org>,
        "Brian Johannesmeyer" <bjohannesmeyer@...il.com>,
        Cristiano Giuffrida <c.giuffrida@...nl>,
        "Bos, H.J." <h.j.bos@...nl>, Jakob Koschel <jakobkoschel@...il.com>
Subject: [PATCH] char: xillybus: replace usage of found with dedicated list iterator variable

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@...il.com>
---
 drivers/char/xillybus/xillybus_class.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/char/xillybus/xillybus_class.c b/drivers/char/xillybus/xillybus_class.c
index 5046486011c8..0f238648dcfe 100644
--- a/drivers/char/xillybus/xillybus_class.c
+++ b/drivers/char/xillybus/xillybus_class.c
@@ -174,18 +174,17 @@ void xillybus_cleanup_chrdev(void *private_data,
 			     struct device *dev)
 {
 	int minor;
-	struct xilly_unit *unit;
-	bool found = false;
+	struct xilly_unit *unit = NULL, *iter;
 
 	mutex_lock(&unit_mutex);
 
-	list_for_each_entry(unit, &unit_list, list_entry)
-		if (unit->private_data == private_data) {
-			found = true;
+	list_for_each_entry(iter, &unit_list, list_entry)
+		if (iter->private_data == private_data) {
+			unit = iter;
 			break;
 		}
 
-	if (!found) {
+	if (!unit) {
 		dev_err(dev, "Weird bug: Failed to find unit\n");
 		mutex_unlock(&unit_mutex);
 		return;
@@ -216,22 +215,21 @@ int xillybus_find_inode(struct inode *inode,
 {
 	int minor = iminor(inode);
 	int major = imajor(inode);
-	struct xilly_unit *unit;
-	bool found = false;
+	struct xilly_unit *unit = NULL, *iter;
 
 	mutex_lock(&unit_mutex);
 
-	list_for_each_entry(unit, &unit_list, list_entry)
-		if (unit->major == major &&
-		    minor >= unit->lowest_minor &&
-		    minor < (unit->lowest_minor + unit->num_nodes)) {
-			found = true;
+	list_for_each_entry(iter, &unit_list, list_entry)
+		if (iter->major == major &&
+		    minor >= iter->lowest_minor &&
+		    minor < (iter->lowest_minor + iter->num_nodes)) {
+			unit = iter;
 			break;
 		}
 
 	mutex_unlock(&unit_mutex);
 
-	if (!found)
+	if (!unit)
 		return -ENODEV;
 
 	*private_data = unit->private_data;

base-commit: f443e374ae131c168a065ea1748feac6b2e76613
-- 
2.25.1