linux-kernel - [PATCH] Drivers: char: misc: 'misc_deregister()' changed the 'mutex

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Date:	Sat, 14 Sep 2013 18:02:11 +0300
From:	Elad Wexler <elad.wexler@...il.com>
To:	gregkh@...uxfoundation.org
Cc:	linux-kernel@...r.kernel.org, Elad Wexler <elad.wexler@...il.com>
Subject: [PATCH] Drivers: char: misc: 'misc_deregister()' changed the 'mutex_unlock' logic upon an error

From: Elad Wexler <elad.wexler@...il.com>

This change improves code readability & is less error-prone.
For example: case adding more error paths one should remember to call 'mutex_unlock'

Signed-off-by: Elad Wexler <elad.wexler@...il.com>
---
 drivers/char/misc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 190d442..dd91726 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -193,8 +193,8 @@ int misc_register(struct miscdevice * misc)
 	if (misc->minor == MISC_DYNAMIC_MINOR) {
 		int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS);
 		if (i >= DYNAMIC_MINORS) {
-			mutex_unlock(&misc_mtx);
-			return -EBUSY;
+			err =  -EBUSY;
+			goto out;
 		}
 		misc->minor = DYNAMIC_MINORS - i - 1;
 		set_bit(i, misc_minors);
@@ -203,8 +203,8 @@ int misc_register(struct miscdevice * misc)
 
 		list_for_each_entry(c, &misc_list, list) {
 			if (c->minor == misc->minor) {
-				mutex_unlock(&misc_mtx);
-				return -EBUSY;
+				err = -EBUSY;
+				goto out;
 			}
 		}
 	}
-- 
1.8.3.1

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