NVMe: Call nvme_free_queue directly

Rather than relying on call_rcu, this patch directly frees the
nvme_queue's memory after ensuring no readers exist. Some arch specific
dma_free_coherent implementations may not be called from a call_rcu's
soft interrupt context, hence the change.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reported-by: Matthew Minter <matthew_minter@xyratex.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Keith Busch 2014-07-07 09:14:42 -06:00 committed by Jens Axboe
parent 2484f40780
commit f435c2825b

View file

@ -95,7 +95,7 @@ struct async_cmd_info {
* commands and one for I/O commands).
*/
struct nvme_queue {
struct rcu_head r_head;
struct llist_node node;
struct device *q_dmadev;
struct nvme_dev *dev;
char irqname[24]; /* nvme4294967295-65535\0 */
@ -1192,10 +1192,8 @@ static void nvme_cancel_ios(struct nvme_queue *nvmeq, bool timeout)
}
}
static void nvme_free_queue(struct rcu_head *r)
static void nvme_free_queue(struct nvme_queue *nvmeq)
{
struct nvme_queue *nvmeq = container_of(r, struct nvme_queue, r_head);
spin_lock_irq(&nvmeq->q_lock);
while (bio_list_peek(&nvmeq->sq_cong)) {
struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
@ -1225,14 +1223,21 @@ static void nvme_free_queue(struct rcu_head *r)
static void nvme_free_queues(struct nvme_dev *dev, int lowest)
{
LLIST_HEAD(q_list);
struct nvme_queue *nvmeq, *next;
struct llist_node *entry;
int i;
for (i = dev->queue_count - 1; i >= lowest; i--) {
struct nvme_queue *nvmeq = raw_nvmeq(dev, i);
nvmeq = raw_nvmeq(dev, i);
rcu_assign_pointer(dev->queues[i], NULL);
call_rcu(&nvmeq->r_head, nvme_free_queue);
llist_add(&nvmeq->node, &q_list);
dev->queue_count--;
}
synchronize_rcu();
entry = llist_del_all(&q_list);
llist_for_each_entry_safe(nvmeq, next, entry, node)
nvme_free_queue(nvmeq);
}
/**
@ -2929,7 +2934,6 @@ static void nvme_remove(struct pci_dev *pdev)
nvme_dev_remove(dev);
nvme_dev_shutdown(dev);
nvme_free_queues(dev, 0);
rcu_barrier();
nvme_release_instance(dev);
nvme_release_prp_pools(dev);
kref_put(&dev->kref, nvme_free_dev);