static void __exit null_exit(void)
{
struct nullb *nullb;
unregister_blkdev(null_major, "nullb");
mutex_lock(&lock);
while (!list_empty(&nullb_list)) {
nullb = list_entry(nullb_list.next, struct nullb, list);
null_del_dev(nullb);
}
mutex_unlock(&lock);
}
static int __init null_init(void)
{
int ret = 0;
unsigned int i;
struct nullb *nullb;
if (bs > PAGE_SIZE) {
pr_warn("null_blk: invalid block size\n");
pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE);
bs = PAGE_SIZE;
}
if (use_lightnvm && bs != 4096) {
pr_warn("null_blk: LightNVM only supports 4k block size\n");
pr_warn("null_blk: defaults block size to 4k\n");
bs = 4096;
}
if (use_lightnvm && queue_mode != NULL_Q_MQ) {
pr_warn("null_blk: LightNVM only supported for blk-mq\n");
pr_warn("null_blk: defaults queue mode to blk-mq\n");
queue_mode = NULL_Q_MQ;
}
if (queue_mode == NULL_Q_MQ && use_per_node_hctx) {
if (submit_queues < nr_online_nodes) {
pr_warn("null_blk: submit_queues param is set to %u.",
nr_online_nodes);
submit_queues = nr_online_nodes;
}
} else if (submit_queues > nr_cpu_ids)
submit_queues = nr_cpu_ids;
else if (!submit_queues)
submit_queues = 1;
mutex_init(&lock);
null_major = register_blkdev(0, "nullb");
if (null_major < 0)
return null_major;
if (use_lightnvm) {
ppa_cache = kmem_cache_create("ppa_cache", 64 * sizeof(u64),
0, 0, NULL);
if (!ppa_cache) {
pr_err("null_blk: unable to create ppa cache\n");
ret = -ENOMEM;
goto err_ppa;
}
}
for (i = 0; i < nr_devices; i++) {
ret = null_add_dev();
if (ret)
goto err_dev;
}
pr_info("null: module loaded\n");
return 0;
err_dev:
while (!list_empty(&nullb_list)) {
nullb = list_entry(nullb_list.next, struct nullb, list);
null_del_dev(nullb);
}
kmem_cache_destroy(ppa_cache);
err_ppa:
unregister_blkdev(null_major, "nullb");
return ret;
}
