Hi James
On 3/16/19 12:33 AM, James Smart wrote:
> On 3/15/2019 1:57 AM, Jianchao Wang wrote:
>> blk_mq_tagset_busy_iter is not safe that it could get stale request
>> in tags->rqs[]. Use blk_mq_queue_tag_busy_iter here. A new helper
>> interface nvme_iterate_inflight_rqs is introduced to iterate
>> all of the ns under a ctrl.
>>
>> Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
>> ---
>> drivers/nvme/host/core.c | 12 ++++++++++++
>> drivers/nvme/host/fc.c | 12 ++++++------
>> drivers/nvme/host/nvme.h | 2 ++
>> drivers/nvme/host/pci.c | 5 +++--
>> drivers/nvme/host/rdma.c | 6 +++---
>> drivers/nvme/host/tcp.c | 5 +++--
>> drivers/nvme/target/loop.c | 6 +++---
>> 7 files changed, 32 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index 6a9dd68..5760fad 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -3816,6 +3816,18 @@ void nvme_start_queues(struct nvme_ctrl *ctrl)
>> }
>> EXPORT_SYMBOL_GPL(nvme_start_queues);
>> +void nvme_iterate_inflight_rqs(struct nvme_ctrl *ctrl,
>> + busy_iter_fn *fn, void *data)
>> +{
>> + struct nvme_ns *ns;
>> +
>> + down_read(&ctrl->namespaces_rwsem);
>> + list_for_each_entry(ns, &ctrl->namespaces, list)
>> + blk_mq_queue_tag_busy_iter(ns->queue, fn, data, true);
>> + up_read(&ctrl->namespaces_rwsem);
>> +}
>> +EXPORT_SYMBOL_GPL(nvme_iterate_inflight_rqs);
>
> Hmm... so this aborts ios for namespaces. How about ios that aren't for a namespace but rather for the controller itself. For example, anything on the admin queue ? Rather critical for those ios be terminated as well.
>
The blk_mq_tagset_busy_iter which is currently used by nvme is iterating the in-flight ios for the controller.
But due to blk_mq_tagset_busy_iter is not safe which is talked in the patch 0/8,
so change it to blk_mq_queue_busy_tag_iter which is for a namespace/request_queue.
Thanks
Jianchao
