[PATCH] nvme_fc: replace ioabort msleep loop with completion

[jsmart2021 at gmail.com]

From: James Smart <jsmart2021 at gmail.com>

Per the recommendation by Sagi on:
http://lists.infradead.org/pipermail/linux-nvme/2017-April/009261.html

Wait for io aborts to complete wait converted from msleep look to
using a struct completion.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
 drivers/nvme/host/fc.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 16a658c..2690824 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -167,6 +167,7 @@ struct nvme_fc_ctrl {
 	struct kref		ref;
 	u32			flags;
 	u32			iocnt;
+	struct completion	ioaborts_done;
 
 	struct nvme_fc_fcp_op	aen_ops[NVME_FC_NR_AEN_COMMANDS];
 
@@ -1241,8 +1242,10 @@ __nvme_fc_fcpop_chk_teardowns(struct nvme_fc_ctrl *ctrl,
 
 	spin_lock_irqsave(&ctrl->lock, flags);
 	if (unlikely(op->flags & FCOP_FLAGS_TERMIO)) {
-		if (ctrl->flags & FCCTRL_TERMIO)
-			ctrl->iocnt--;
+		if (ctrl->flags & FCCTRL_TERMIO) {
+			if (!(--ctrl->iocnt))
+				complete(&ctrl->ioaborts_done);
+		}
 	}
 	if (op->flags & FCOP_FLAGS_RELEASED)
 		complete_rq = true;
@@ -2488,10 +2491,14 @@ nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
 
 	/* wait for all io that had to be aborted */
 	spin_lock_irqsave(&ctrl->lock, flags);
-	while (ctrl->iocnt) {
+	if (ctrl->iocnt) {
+		init_completion(&ctrl->ioaborts_done);
 		spin_unlock_irqrestore(&ctrl->lock, flags);
-		msleep(1000);
+
+		wait_for_completion(&ctrl->ioaborts_done);
+
 		spin_lock_irqsave(&ctrl->lock, flags);
+		WARN_ON(ctrl->iocnt);
 	}
 	ctrl->flags &= ~FCCTRL_TERMIO;
 	spin_unlock_irqrestore(&ctrl->lock, flags);
-- 
2.9.3