drivers/char/misc.c:misc_register(): do not loop on misc_list unconditionally

If the minor number is assigned dynamically, there is no need to search
for misc->minor in misc_list, since misc->minor == MISC_DYNAMIC_MINOR.

[akpm@linux-foundation.org: reduce scope of local `c']
Signed-off-by: Dae S. Kim <dae@velatum.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 7 deletions

diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 522136d40843..190d4423653f 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -183,19 +183,12 @@ static const struct file_operations misc_fops = {
  
 int misc_register(struct miscdevice * misc)
 {
-        struct miscdevice *c;
         dev_t dev;
         int err = 0;
 
         INIT_LIST_HEAD(&misc->list);
 
         mutex_lock(&misc_mtx);
-        list_for_each_entry(c, &misc_list, list) {
-                if (c->minor == misc->minor) {
-                        mutex_unlock(&misc_mtx);
-                        return -EBUSY;
-                }
-        }
 
         if (misc->minor == MISC_DYNAMIC_MINOR) {
                 int i = find_first_zero_bit(misc_minors, DYNAMIC_MINORS);
@@ -205,6 +198,15 @@ int misc_register(struct miscdevice * misc)
                 }
                 misc->minor = DYNAMIC_MINORS - i - 1;
                 set_bit(i, misc_minors);
+        } else {
+                struct miscdevice *c;
+
+                list_for_each_entry(c, &misc_list, list) {
+                        if (c->minor == misc->minor) {
+                                mutex_unlock(&misc_mtx);
+                                return -EBUSY;
+                        }
+                }
         }
 
         dev = MKDEV(MISC_MAJOR, misc->minor);