From a90ac7b348770ff3d246fac575306783de381e51 Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Wed, 31 Jan 2024 09:51:12 +0100 Subject: 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: Daniel Wagner Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch --- drivers/nvme/target/fc.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) (limited to 'drivers') diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c index 671d096745a5..fd229f310c93 100644 --- a/drivers/nvme/target/fc.c +++ b/drivers/nvme/target/fc.c @@ -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; -- cgit v1.2.3