md: remove unnecessary 'buf' from get_bitmap_file.

'buf' is only used because d_path fills from the end of the
buffer instead of from the start.
We don't need a separate buf to handle that, we just need to use
memmove() to move the string to the start.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5438834..bddecc0 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5502,7 +5502,7 @@ static int get_array_info(struct mddev *mddev, void __user *arg)
 static int get_bitmap_file(struct mddev *mddev, void __user * arg)
 {
        mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
-       char *ptr, *buf = NULL;
+       char *ptr;
        int err = -ENOMEM;
 
        file = kmalloc(sizeof(*file), GFP_NOIO);
@@ -5516,23 +5516,19 @@ static int get_bitmap_file(struct mddev *mddev, void __user * arg)
                goto copy_out;
        }
 
-       buf = kmalloc(sizeof(file->pathname), GFP_KERNEL);
-       if (!buf)
-               goto out;
-
        ptr = d_path(&mddev->bitmap->storage.file->f_path,
-                    buf, sizeof(file->pathname));
+                    file->pathname, sizeof(file->pathname));
        if (IS_ERR(ptr))
                goto out;
 
-       strcpy(file->pathname, ptr);
+       memmove(file->pathname, ptr,
+               sizeof(file->pathname)-(ptr-file->pathname));
 
 copy_out:
        err = 0;
        if (copy_to_user(arg, file, sizeof(*file)))
                err = -EFAULT;
 out:
-       kfree(buf);
        kfree(file);
        return err;
 }