static int virtio_mem_sbm_unplug_sb_online()

in virtio_mem.c [1910:1946]

• 30 lines of code
• 5 McCabe index (conditional complexity)

static int virtio_mem_sbm_unplug_sb_online(struct virtio_mem *vm,
					   unsigned long mb_id, int sb_id,
					   int count)
{
	const unsigned long nr_pages = PFN_DOWN(vm->sbm.sb_size) * count;
	const int old_state = virtio_mem_sbm_get_mb_state(vm, mb_id);
	unsigned long start_pfn;
	int rc;

	start_pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) +
			     sb_id * vm->sbm.sb_size);

	rc = virtio_mem_fake_offline(start_pfn, nr_pages);
	if (rc)
		return rc;

	/* Try to unplug the allocated memory */
	rc = virtio_mem_sbm_unplug_sb(vm, mb_id, sb_id, count);
	if (rc) {
		/* Return the memory to the buddy. */
		virtio_mem_fake_online(start_pfn, nr_pages);
		return rc;
	}

	switch (old_state) {
	case VIRTIO_MEM_SBM_MB_KERNEL:
		virtio_mem_sbm_set_mb_state(vm, mb_id,
					    VIRTIO_MEM_SBM_MB_KERNEL_PARTIAL);
		break;
	case VIRTIO_MEM_SBM_MB_MOVABLE:
		virtio_mem_sbm_set_mb_state(vm, mb_id,
					    VIRTIO_MEM_SBM_MB_MOVABLE_PARTIAL);
		break;
	}

	return 0;
}