[PATCH V2 6/6] nvme-pci: discard wait timeout when delete cq/sq

From: Jianchao Wang
Date: Mon Feb 05 2018 - 04:21:38 EST


Currently, nvme_disable_io_queues could be wakeup by both request
completion and wait timeout path. This is unnecessary and could
introduce race between nvme_dev_disable and request timeout path.
When delete cq/sq command expires, the nvme_disable_io_queues will
also be wakeup and return to nvme_dev_disable, then handle the
outstanding requests. This will race with the request timeout path.

To fix it, just use wait_for_completion instead of the timeout one.
The request timeout path will wakeup it.

Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
---
drivers/nvme/host/pci.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 43033fc..f3262cc 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2050,7 +2050,6 @@ static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
static void nvme_disable_io_queues(struct nvme_dev *dev)
{
int pass, queues = dev->online_queues - 1;
- unsigned long timeout;
u8 opcode = nvme_admin_delete_sq;

for (pass = 0; pass < 2; pass++) {
@@ -2058,15 +2057,12 @@ static void nvme_disable_io_queues(struct nvme_dev *dev)

reinit_completion(&dev->ioq_wait);
retry:
- timeout = ADMIN_TIMEOUT;
for (; i > 0; i--, sent++)
if (nvme_delete_queue(&dev->queues[i], opcode))
break;

while (sent--) {
- timeout = wait_for_completion_io_timeout(&dev->ioq_wait, timeout);
- if (timeout == 0)
- return;
+ wait_for_completion(&dev->ioq_wait);
if (i)
goto retry;
}
--
2.7.4