Merge "fs/buffer.c: Revoke LRU when trying to drop buffers"

	return 0;

}

static void __evict_bh_lru(void *arg)

{

	struct bh_lru *b = &get_cpu_var(bh_lrus);

	struct buffer_head *bh = arg;

	int i;

	for (i = 0; i < BH_LRU_SIZE; i++) {

		if (b->bhs[i] == bh) {

			brelse(b->bhs[i]);

			b->bhs[i] = NULL;

			goto out;

		}

	}

out:

	put_cpu_var(bh_lrus);

}

static bool bh_exists_in_lru(int cpu, void *arg)

{

	struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu);

	struct buffer_head *bh = arg;

	int i;

	for (i = 0; i < BH_LRU_SIZE; i++) {

		if (b->bhs[i] == bh)

			return true;

	}

	return false;

}

void invalidate_bh_lrus(void)

{

	on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1, GFP_KERNEL);

}

EXPORT_SYMBOL_GPL(invalidate_bh_lrus);

static void evict_bh_lrus(struct buffer_head *bh)

{

	on_each_cpu_cond(bh_exists_in_lru, __evict_bh_lru, bh, 1, GFP_ATOMIC);

}

void set_bh_page(struct buffer_head *bh,

		struct page *page, unsigned long offset)

{

	bh = head;

	do {

		if (buffer_busy(bh)) {

			/*

			 * Check if the busy failure was due to an

			 * outstanding LRU reference

			 */

			evict_bh_lrus(bh);

			if (buffer_busy(bh))

				goto failed;

		}

		bh = bh->b_this_page;

	} while (bh != head);