Commit a90ac7b3 authored by Daniel Wagner's avatar Daniel Wagner Committed by Keith Busch
Browse files

nvmet-fc: use RCU list iterator for assoc_list 



The assoc_list is a RCU protected list, thus use the RCU flavor of list
functions.

Let's use this opportunity and refactor this code and move the lookup
into a helper and give it a descriptive name.

Signed-off-by: default avatarDaniel Wagner <dwagner@suse.de>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent fe506a74

drivers/nvme/target/fc.c

+22 −12
Original line number Diff line number Diff line
@@ -1114,14 +1114,27 @@ nvmet_fc_schedule_delete_assoc(struct nvmet_fc_tgt_assoc *assoc) 
	queue_work(nvmet_wq, &assoc->del_work);

}



static bool

nvmet_fc_assoc_exits(struct nvmet_fc_tgtport *tgtport, u64 association_id)

{

	struct nvmet_fc_tgt_assoc *a;



	list_for_each_entry_rcu(a, &tgtport->assoc_list, a_list) {

		if (association_id == a->association_id)

			return true;

	}



	return false;

}



static struct nvmet_fc_tgt_assoc *

nvmet_fc_alloc_target_assoc(struct nvmet_fc_tgtport *tgtport, void *hosthandle)

{

	struct nvmet_fc_tgt_assoc *assoc, *tmpassoc;

	struct nvmet_fc_tgt_assoc *assoc;

	unsigned long flags;

	bool done;

	u64 ran;

	int idx;

	bool needrandom = true;



	if (!tgtport->pe)

		return NULL;
@@ -1145,24 +1158,21 @@ nvmet_fc_alloc_target_assoc(struct nvmet_fc_tgtport *tgtport, void *hosthandle) 
	INIT_WORK(&assoc->del_work, nvmet_fc_delete_assoc_work);

	atomic_set(&assoc->terminating, 0);



	while (needrandom) {

	done = false;

	do {

		get_random_bytes(&ran, sizeof(ran) - BYTES_FOR_QID);

		ran = ran << BYTES_FOR_QID_SHIFT;



		spin_lock_irqsave(&tgtport->lock, flags);

		needrandom = false;

		list_for_each_entry(tmpassoc, &tgtport->assoc_list, a_list) {

			if (ran == tmpassoc->association_id) {

				needrandom = true;

				break;

			}

		}

		if (!needrandom) {

		rcu_read_lock();

		if (!nvmet_fc_assoc_exits(tgtport, ran)) {

			assoc->association_id = ran;

			list_add_tail_rcu(&assoc->a_list, &tgtport->assoc_list);

			done = true;

		}

		rcu_read_unlock();

		spin_unlock_irqrestore(&tgtport->lock, flags);

	}

	} while (!done);



	return assoc;