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>
This commit is contained in:
Christoph Hellwig 2015-11-26 12:10:29 +01:00 committed by Jens Axboe
parent 297465c873
commit 846cc05f95

View file

@ -77,7 +77,6 @@ struct nvme_dev;
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 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
* 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 @@ static int nvme_kthread(void *data)
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 @@ static void nvme_reset_work(struct work_struct *ws)
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)