An variable used before init

[geng sun <sun.gengeration.sun@gmail.com>]

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Hi linux-mm

I find one odd variable “new” in slub, it was used before init.  
Maybe the value in new was undefined. 
And I can not understand how it work.
Could you explain this code for me?
 Thanks.

Best regards.
static void __slab_free(struct kmem_cache *s, struct page *page,
            void *head, void *tail, int cnt,
            unsigned long addr)

{
    void *prior;
    int was_frozen;
    struct page new;
    unsigned long counters;
    struct kmem_cache_node *n = NULL;
    unsigned long flags;
    stat(s, FREE_SLOWPATH);
    if (kmem_cache_debug(s) &&
        !free_debug_processing(s, page, head, tail, cnt, addr))
        return;

    do {
        if (unlikely(n)) {
            spin_unlock_irqrestore(&n->list_lock, flags);
            n = NULL;
        }
        prior = page->freelist;
        counters = page->counters;
        set_freepointer(s, tail, prior);
        new.counters = counters;
        was_frozen = new.frozen;
        new.inuse -= cnt;
        if ((!new.inuse || !prior) && !was_frozen) {

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