lib: add idr_remove_all

		 int (*fn)(int id, void *p, void *data), void *data);

void *idr_replace(struct idr *idp, void *ptr, int id);

void idr_remove(struct idr *idp, int id);

void idr_remove_all(struct idr *idp);

void idr_destroy(struct idr *idp);

void idr_init(struct idr *idp);

}

EXPORT_SYMBOL(idr_remove);

/**

 * idr_remove_all - remove all ids from the given idr tree

 * @idp: idr handle

 *

 * idr_destroy() only frees up unused, cached idp_layers, but this

 * function will remove all id mappings and leave all idp_layers

 * unused.

 *

 * A typical clean-up sequence for objects stored in an idr tree, will

 * use idr_for_each() to free all objects, if necessay, then

 * idr_remove_all() to remove all ids, and idr_destroy() to free

 * up the cached idr_layers.

 */

void idr_remove_all(struct idr *idp)

{

	int n, id, max, error = 0;

	struct idr_layer *p;

	struct idr_layer *pa[MAX_LEVEL];

	struct idr_layer **paa = &pa[0];

	n = idp->layers * IDR_BITS;

	p = idp->top;

	max = 1 << n;

	id = 0;

	while (id < max && !error) {

		while (n > IDR_BITS && p) {

			n -= IDR_BITS;

			*paa++ = p;

			p = p->ary[(id >> n) & IDR_MASK];

		}

		id += 1 << n;

		while (n < fls(id)) {

			if (p) {

				memset(p, 0, sizeof *p);

				free_layer(idp, p);

			}

			n += IDR_BITS;

			p = *--paa;

		}

	}

	idp->top = NULL;

	idp->layers = 0;

}

EXPORT_SYMBOL(idr_remove_all);

/**

 * idr_destroy - release all cached layers within an idr tree

 * idp: idr handle