chardev: set variable ret to -EBUSY before checking minor range overlap

When allocating dynamic major, the minor range overlap check
in __register_chrdev_region() will not fail, so actually
there is no real case to passing non negative error code to
caller. However, set variable ret to -EBUSY before checking
minor range overlap will avoid false-positive warning from
code analyzing tool(like Smatch) and also make the code more
easy to understand.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chengguang Xu <cgxu519@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/char_dev.c b/fs/char_dev.c
index d18cad2..00dfe17 100644 (file)
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -98,7 +98,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
                           int minorct, const char *name)
 {
        struct char_device_struct *cd, *curr, *prev = NULL;
-       int ret = -EBUSY;
+       int ret;
        int i;
 
        if (major >= CHRDEV_MAJOR_MAX) {
@@ -129,6 +129,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
                major = ret;
        }
 
+       ret = -EBUSY;
        i = major_to_index(major);
        for (curr = chrdevs[i]; curr; prev = curr, curr = curr->next) {
                if (curr->major < major)