[PATCH 14/14] nvme: use blk_mq_[un]quiesce_tagset

Christoph Hellwig
2022-11-01T15:02:22Z

From: Chao Leng <lengchao@huawei.com>

All controller namespaces share the same tagset, so we can use this
interface which does the optimal operation for parallel quiesce based on
the tagset type(e.g. blocking tagsets and non-blocking tagsets).

nvme connect_q should not be quiesced when quiesce tagset, so set the
QUEUE_FLAG_SKIP_TAGSET_QUIESCE to skip it when init connect_q.

Currently we use NVME_NS_STOPPED to ensure pairing quiescing and
unquiescing. If use blk_mq_[un]quiesce_tagset, NVME_NS_STOPPED will be
invalided, so introduce NVME_CTRL_STOPPED to replace NVME_NS_STOPPED.
In addition, we never really quiesce a single namespace. It is a better
choice to move the flag from ns to ctrl.

Signed-off-by: Chao Leng <lengchao@huawei.com>
[hch: rebased on top of prep patches]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chao Leng <lengchao@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
drivers/nvme/host/core.c | 34 ++++++++--------------------------
drivers/nvme/host/nvme.h | 2 +-
2 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 66b0b6e110024..f94b05c585cbc 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4895,6 +4895,8 @@ int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
ret = PTR_ERR(ctrl->connect_q);
goto out_free_tag_set;
}
+ blk_queue_flag_set(QUEUE_FLAG_SKIP_TAGSET_QUIESCE,
+ ctrl->connect_q);
}

ctrl->tagset = set;
@@ -5096,20 +5098,6 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
}
EXPORT_SYMBOL_GPL(nvme_init_ctrl);

-static void nvme_start_ns_queue(struct nvme_ns *ns)
-{
- if (test_and_clear_bit(NVME_NS_STOPPED, &ns->flags))
- blk_mq_unquiesce_queue(ns->queue);
-}
-
-static void nvme_stop_ns_queue(struct nvme_ns *ns)
-{
- if (!test_and_set_bit(NVME_NS_STOPPED, &ns->flags))
- blk_mq_quiesce_queue(ns->queue);
- else
- blk_mq_wait_quiesce_done(ns->queue->tag_set);
-}
-
/* let I/O to all namespaces fail in preparation for surprise removal */
void nvme_mark_namespaces_dead(struct nvme_ctrl *ctrl)
{
@@ -5172,23 +5160,17 @@ EXPORT_SYMBOL_GPL(nvme_start_freeze);

void nvme_stop_queues(struct nvme_ctrl *ctrl)
{
- struct nvme_ns *ns;
-
- down_read(&ctrl->namespaces_rwsem);
- list_for_each_entry(ns, &ctrl->namespaces, list)
- nvme_stop_ns_queue(ns);
- up_read(&ctrl->namespaces_rwsem);
+ if (!test_and_set_bit(NVME_CTRL_STOPPED, &ctrl->flags))
+ blk_mq_quiesce_tagset(ctrl->tagset);
+ else
+ blk_mq_wait_quiesce_done(ctrl->tagset);
}
EXPORT_SYMBOL_GPL(nvme_stop_queues);

void nvme_start_queues(struct nvme_ctrl *ctrl)
{
- struct nvme_ns *ns;
-
- down_read(&ctrl->namespaces_rwsem);
- list_for_each_entry(ns, &ctrl->namespaces, list)
- nvme_start_ns_queue(ns);
- up_read(&ctrl->namespaces_rwsem);
+ if (test_and_clear_bit(NVME_CTRL_STOPPED, &ctrl->flags))
+ blk_mq_unquiesce_tagset(ctrl->tagset);
}
EXPORT_SYMBOL_GPL(nvme_start_queues);

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 1cd7168002438..f9df10653f3c5 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -237,6 +237,7 @@ enum nvme_ctrl_flags {
NVME_CTRL_FAILFAST_EXPIRED = 0,
NVME_CTRL_ADMIN_Q_STOPPED = 1,
NVME_CTRL_STARTED_ONCE = 2,
+ NVME_CTRL_STOPPED = 3,
};

struct nvme_ctrl {
@@ -486,7 +487,6 @@ struct nvme_ns {
#define NVME_NS_ANA_PENDING 2
#define NVME_NS_FORCE_RO 3
#define NVME_NS_READY 4
-#define NVME_NS_STOPPED 5

struct cdev cdev;
struct device cdev_device;
--
2.30.2