nvme: simplify resets
Don't delete the controller from dev_list before queuing a reset, instead
just check for it being reset in the polling kthread. This allows to remove
the dev_list_lock in various places, and in addition we can simply rely on
checking the queue_work return value to see if we could reset a controller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index e683bd1..febcef5 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -77,7 +77,6 @@
struct nvme_queue;
struct nvme_iod;
-static int __nvme_reset(struct nvme_dev *dev);
static int nvme_reset(struct nvme_dev *dev);
static void nvme_process_cq(struct nvme_queue *nvmeq);
static void nvme_unmap_data(struct nvme_dev *dev, struct nvme_iod *iod);
@@ -1093,13 +1092,11 @@
* the admin queue.
*/
if (!nvmeq->qid || cmd_rq->aborted) {
- spin_lock_irq(&dev_list_lock);
- if (!__nvme_reset(dev)) {
+ if (queue_work(nvme_workq, &dev->reset_work)) {
dev_warn(dev->dev,
"I/O %d QID %d timeout, reset controller\n",
req->tag, nvmeq->qid);
}
- spin_unlock_irq(&dev_list_lock);
return BLK_EH_RESET_TIMER;
}
@@ -1496,9 +1493,15 @@
int i;
u32 csts = readl(dev->bar + NVME_REG_CSTS);
+ /*
+ * Skip controllers currently under reset.
+ */
+ if (work_pending(&dev->reset_work) || work_busy(&dev->reset_work))
+ continue;
+
if ((dev->subsystem && (csts & NVME_CSTS_NSSRO)) ||
csts & NVME_CSTS_CFS) {
- if (!__nvme_reset(dev)) {
+ if (queue_work(nvme_workq, &dev->reset_work)) {
dev_warn(dev->dev,
"Failed status: %x, reset controller\n",
readl(dev->bar + NVME_REG_CSTS));
@@ -2228,33 +2231,17 @@
schedule_work(&dev->probe_work);
}
-static int __nvme_reset(struct nvme_dev *dev)
-{
- if (work_pending(&dev->reset_work))
- return -EBUSY;
- list_del_init(&dev->node);
- queue_work(nvme_workq, &dev->reset_work);
- return 0;
-}
-
static int nvme_reset(struct nvme_dev *dev)
{
- int ret;
-
if (!dev->ctrl.admin_q || blk_queue_dying(dev->ctrl.admin_q))
return -ENODEV;
- spin_lock(&dev_list_lock);
- ret = __nvme_reset(dev);
- spin_unlock(&dev_list_lock);
+ if (!queue_work(nvme_workq, &dev->reset_work))
+ return -EBUSY;
- if (!ret) {
- flush_work(&dev->reset_work);
- flush_work(&dev->probe_work);
- return 0;
- }
-
- return ret;
+ flush_work(&dev->reset_work);
+ flush_work(&dev->probe_work);
+ return 0;
}
static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)